Publications by authors named "Martin Kocher"

133 Publications

Radiomics for prediction of radiation-induced lung injury and oncologic outcome after robotic stereotactic body radiotherapy of lung cancer: results from two independent institutions.

Radiat Oncol 2021 Apr 16;16(1):74. Epub 2021 Apr 16.

Department of Stereotactic and Functional Neurosurgery, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany.

Objectives: To generate and validate state-of-the-art radiomics models for prediction of radiation-induced lung injury and oncologic outcome in non-small cell lung cancer (NSCLC) patients treated with robotic stereotactic body radiation therapy (SBRT).

Methods: Radiomics models were generated from the planning CT images of 110 patients with primary, inoperable stage I/IIa NSCLC who were treated with robotic SBRT using a risk-adapted fractionation scheme at the University Hospital Cologne (training cohort). In total, 199 uncorrelated radiomic features fulfilling the standards of the Image Biomarker Standardization Initiative (IBSI) were extracted from the outlined gross tumor volume (GTV). Regularized models (Coxnet and Gradient Boost) for the development of local lung fibrosis (LF), local tumor control (LC), disease-free survival (DFS) and overall survival (OS) were built from either clinical/ dosimetric variables, radiomics features or a combination thereof and validated in a comparable cohort of 71 patients treated by robotic SBRT at the Radiosurgery Center in Northern Germany (test cohort).

Results: Oncologic outcome did not differ significantly between the two cohorts (OS at 36 months 56% vs. 43%, p = 0.065; median DFS 25 months vs. 23 months, p = 0.43; LC at 36 months 90% vs. 93%, p = 0.197). Local lung fibrosis developed in 33% vs. 35% of the patients (p = 0.75), all events were observed within 36 months. In the training cohort, radiomics models were able to predict OS, DFS and LC (concordance index 0.77-0.99, p < 0.005), but failed to generalize to the test cohort. In opposite, models for the development of lung fibrosis could be generated from both clinical/dosimetric factors and radiomic features or combinations thereof, which were both predictive in the training set (concordance index 0.71- 0.79, p < 0.005) and in the test set (concordance index 0.59-0.66, p < 0.05). The best performing model included 4 clinical/dosimetric variables (GTV-D, PTV-D, Lung-D, age) and 7 radiomic features (concordance index 0.66, p < 0.03).

Conclusion: Despite the obvious difficulties in generalizing predictive models for oncologic outcome and toxicity, this analysis shows that carefully designed radiomics models for prediction of local lung fibrosis after SBRT of early stage lung cancer perform well across different institutions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13014-021-01805-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8052812PMC
April 2021

The Debatable Benefit of Gross-Total Resection of Brain Metastases in a Comprehensive Treatment Setting.

Cancers (Basel) 2021 Mar 21;13(6). Epub 2021 Mar 21.

Centre for Neurosurgery, Department of General Neurosurgery, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany.

The value of gross-total surgical resection remains debatable in patients with brain metastases (BMs) as most patients succumb to systemic disease progression. In this study, we evaluated the impact of the extent of resection of singular/solitary BM on in-brain recurrence (iBR), focusing on local recurrence (LR) and overall survival (OS) in an interdisciplinary adjuvant treatment setting. In this monocentric retrospective analysis, we included patients receiving surgery of one BM and subsequent adjuvant treatment. A radiologist and a neurosurgeon determined in consensus the extent of resection based on magnetic resonance imaging. The OS was calculated using Kaplan-Meier estimates; prognostic factors for LR and OS were analysed by Log rank test and Cox proportional hazards. We analyzed 197 patients. Gross-total resection was achieved in 123 (62.4%) patients. All patients were treated with adjuvant radiotherapy, and 130 (66.0%) received systemic treatment. Ninety-six (48.7%) patients showed iBR with an LR rate of 23.4%. LR was not significantly influenced by the extent of resection ( = 0.139) or any other parameter. The median OS after surgery was 18 (95%CI 12.5-23.5) months. In univariate analysis, the extent of resection did not influence OS ( = 0.6759), as opposed to adjuvant systemic treatment ( < 0.0001) and controlled systemic disease ( = 0.039). Systemic treatment and controlled disease status remained independent factors for OS ( < 0.0001 and = 0.009, respectively). In this study, the extent of resection of BMs neither influenced the LR nor the OS of patients receiving interdisciplinary adjuvant treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13061435DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004079PMC
March 2021

Cyberknife hypofractionated stereotactic radiosurgery (CK-hSRS) as salvage treatment for brain metastases.

J Cancer Res Clin Oncol 2021 Feb 26. Epub 2021 Feb 26.

Department of Stereotaxy and Functional Neurosurgery, Centre of Neurosurgery, Faculty of Medicine and University Hospital, University of Cologne, Cologne, 50937, Germany.

Purpose: The introduction of hypofractionated stereotactic radiosurgery (hSRS) extended the treatment modalities beyond the well-established single-fraction stereotactic radiosurgery and fractionated radiotherapy. Here, we report the efficacy and side effects of hSRS using Cyberknife (CK-hSRS) for the treatment of patients with critical brain metastases (BM) and a very poor prognosis. We discuss our experience in light of current literature.

Methods: All patients who underwent CK-hSRS over 3 years were retrospectively included. We applied a surface dose of 27 Gy in 3 fractions. Rates of local control (LC), systemic progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan-Meier method. Treatment-related complications were rated using the Common Terminology Criteria for Adverse Events (CTCAE).

Results: We analyzed 34 patients with 75 BM. 53% of the patients had a large tumor, tumor location was eloquent in 32%, and deep seated in 15%. 36% of tumors were recurrent after previous irradiation. The median Karnofsky Performance Status was 65%. The actuarial rates of LC at 3, 6, and 12 months were 98%, 98%, and 78.6%, respectively. Three, 6, and 12 months PFS was 38%, 32%, and 15%, and OS was 65%, 47%, and 28%, respectively. Median OS was significantly associated with higher KPS, which was the only significant factor for survival. Complications CTCAE grade 1-3 were observed in 12%.

Conclusion: Our radiation schedule showed a reasonable treatment effectiveness and tolerance. Representing an optimal salvage treatment for critical BM in patients with a very poor prognosis and clinical performance state, CK-hSRS may close the gap between surgery, stereotactic radiosurgery, conventional radiotherapy, and palliative care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00432-021-03564-zDOI Listing
February 2021

Evaluation of FET PET Radiomics Feature Repeatability in Glioma Patients.

Cancers (Basel) 2021 Feb 5;13(4). Epub 2021 Feb 5.

Research Center Juelich, Institute of Neuroscience and Medicine (INM-3, -4, -11), 52425 Juelich, Germany.

Amino acid PET using the tracer O-(2-[F]fluoroethyl)-L-tyrosine (FET) has attracted considerable interest in neurooncology. Furthermore, initial studies suggested the additional diagnostic value of FET PET radiomics in brain tumor patient management. However, the conclusiveness of radiomics models strongly depends on feature generalizability. We here evaluated the repeatability of feature-based FET PET radiomics. A test-retest analysis based on equivalent but statistically independent subsamples of FET PET images was performed in 50 newly diagnosed and histomolecularly characterized glioma patients. A total of 1,302 radiomics features were calculated from semi-automatically segmented tumor volumes-of-interest (VOIs). Furthermore, to investigate the influence of the spatial resolution of PET on repeatability, spherical VOIs of different sizes were positioned in the tumor and healthy brain tissue. Feature repeatability was assessed by calculating the intraclass correlation coefficient (ICC). To further investigate the influence of the isocitrate dehydrogenase (IDH) genotype on feature repeatability, a hierarchical cluster analysis was performed. For tumor VOIs, 73% of first-order features and 71% of features extracted from the gray level co-occurrence matrix showed high repeatability (ICC 95% confidence interval, 0.91-1.00). In the largest spherical tumor VOIs, 67% of features showed high repeatability, significantly decreasing towards smaller VOIs. The IDH genotype did not affect feature repeatability. Based on 297 repeatable features, two clusters were identified separating patients with IDH-wildtype glioma from those with an IDH mutation. Our results suggest that robust features can be obtained from routinely acquired FET PET scans, which are valuable for further standardization of radiomics analyses in neurooncology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13040647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915742PMC
February 2021

Contribution of PET imaging to radiotherapy planning and monitoring in glioma patients - a report of the PET/RANO group.

Neuro Oncol 2021 Feb 4. Epub 2021 Feb 4.

German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany.

The management of patients with glioma usually requires multimodality treatment including surgery, radiotherapy, and systemic therapy. Accurate neuroimaging plays a central role for radiotherapy planning and follow-up after radiotherapy completion. In order to maximize the radiation dose to the tumor and to minimize toxic effects on the surrounding brain parenchyma, reliable identification of tumor extent and target volume delineation is crucial. The use of PET for radiotherapy planning and monitoring in gliomas has gained considerable interest over the last several years, but Class I data are not yet available. Furthermore, PET has been used after radiotherapy for response assessment and to distinguish tumor progression from pseudoprogression or radiation necrosis. Here, the RANO working group provides a summary of the literature and recommendations for the use of PET imaging for radiotherapy of patients with glioma based on published studies, constituting levels 1-3 evidence according to the Oxford Centre for Evidence-based Medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuonc/noab013DOI Listing
February 2021

Feature-based PET/MRI radiomics in patients with brain tumors.

Neurooncol Adv 2020 Dec 23;2(Suppl 4):iv15-iv21. Epub 2021 Jan 23.

Institute of Neuroscience and Medicine (INM-3, -4, -11), Research Center Juelich, Juelich, Germany.

Radiomics allows the extraction of quantitative features from medical images such as CT, MRI, or PET, thereby providing additional, potentially relevant diagnostic information for clinical decision-making. Because the computation of these features is performed highly automated on medical images acquired during routine follow-up, radiomics offers this information at low cost. Further, the radiomics features can be used alone or combined with other clinical or histomolecular parameters to generate predictive or prognostic mathematical models. These models can then be applied for various important diagnostic indications in neuro-oncology, for example, to noninvasively predict relevant biomarkers in glioma patients, to differentiate between treatment-related changes and local brain tumor relapse, or to predict treatment response. In recent years, amino acid PET has become an important diagnostic tool in patients with brain tumors. Therefore, the number of studies in patients with brain tumors investigating the potential of PET radiomics or combined PET/MRI radiomics is steadily increasing. This review summarizes current research regarding feature-based PET as well as combined PET/MRI radiomics in neuro-oncology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/noajnl/vdaa118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7829472PMC
December 2020

Stereotactic radiosurgery for treating meningiomas eligible for complete resection.

Radiat Oncol 2021 Jan 28;16(1):22. Epub 2021 Jan 28.

Department of General Neurosurgery, Centre for Neurosurgery, Medical Faculty of the University of Cologne, Cologne, Germany.

Background: For meningiomas, complete resection is recommended as first-line treatment while stereotactic radiosurgery (SRS) is established for meningiomas of smaller size considered inoperable. If the patient´s medical condition or preference excludes surgery, SRS remains a treatment option. We evaluated the efficacy and safety of SRS in a cohort comprising these cases.

Methods: In this retrospective single-centre analysis we included patients receiving single fraction SRS either by modified LINAC or robotic guidance by Cyberknife for potentially resectable intracranial meningiomas. Treatment-related adverse events as well as local and regional control rates were determined from follow-up imaging and estimated by the Kaplan-Meier method.

Results: We analyzed 188 patients with 218 meningiomas. The median radiological, and clinical follow-up periods were 51.4 (6.2-289.6) and 55.8 (6.2-300.9) months. The median tumor volume was 4.2 ml (0.1-22), and the mean marginal radiation dose was 13.0 ± 3.1 Gy, with reference to the 80.0 ± 11.2% isodose level. Local recurrence was observed in one case (0.5%) after 239 months. The estimated 2-, 5-, 10- and 15-year regional recurrence rates were 1.5%, 3.0%, 6.6% and 6.6%, respectively. Early adverse events (≤ 6 months after SRS) occurred in 11.2% (CTCEA grade 1-2) and resolved during follow-up in 7.4% of patients, while late adverse events were documented in 14.4% (grade 1-2; one case grade 3). Adverse effects (early and late) were associated with the presence of symptoms or neurological deficits prior to SRS (p < 0.03) and correlated with the treatment volume (p < 0.02).

Conclusion: In this analysis SRS appears to be an effective treatment for patients with meningiomas eligible for complete resection and provides reliable long-term local tumor control with low rates of mild morbidity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13014-021-01748-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7841895PMC
January 2021

Brain Metastases in Elderly Patients-The Role of Surgery in the Context of Systemic Treatment.

Brain Sci 2021 Jan 18;11(1). Epub 2021 Jan 18.

Department of General Neurosurgery, University Hospital Cologne, Kerpener Straße 62, 50937 Cologne, Germany.

In patients with brain metastases (BM), advanced age is considered a negative prognostic factor. To address the potential reasons for that, we assessed 807 patients who had undergone BM resection; 315 patients aged at least 65 years (group A) were compared with 492 younger patients (group B). We analyzed the impact of the pre- and postoperative Karnofsky performance status (KPS), postoperative treatment structure and post-treatment survival. BM resection significantly improved KPS scores in both groups ( = 0.0001). Median survival after BM resection differed significantly between the groups (A: 5.81 . B: 8.12 months; = 0.0015). In both groups, patients who received postoperative systemic treatment showed significantly longer overall survival ( = 0.00001). However, elderly patients less frequently received systemic treatment ( = 0.0001) and the subgroup of elderly patients receiving such therapies had a significantly higher postsurgical KPS score ( = 0.0007). In all patients receiving systemic treatment, age was no longer a negative prognostic factor. Resection of BM improves the functional status of elderly patients, thus enhancing the likeliness to receive systemic treatment, which, in turn, leads to longer overall survival. In the context of such a treatment structure, age alone is no longer a prognostic factor for survival.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/brainsci11010123DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7831306PMC
January 2021

FET PET Radiomics for Differentiating Pseudoprogression from Early Tumor Progression in Glioma Patients Post-Chemoradiation.

Cancers (Basel) 2020 Dec 18;12(12). Epub 2020 Dec 18.

Institute of Neuroscience and Medicine (INM-3, -4, -11), Research Center Juelich, 52425 Juelich, Germany.

Currently, a reliable diagnostic test for differentiating pseudoprogression from early tumor progression is lacking. We explored the potential of O-(2-[F]fluoroethyl)-L-tyrosine (FET) positron emission tomography (PET) radiomics for this clinically important task. Thirty-four patients (isocitrate dehydrogenase (IDH)-wildtype glioblastoma, 94%) with progressive magnetic resonance imaging (MRI) changes according to the Response Assessment in Neuro-Oncology (RANO) criteria within the first 12 weeks after completing temozolomide chemoradiation underwent a dynamic FET PET scan. Static and dynamic FET PET parameters were calculated. For radiomics analysis, the number of datasets was increased to 102 using data augmentation. After randomly assigning patients to a training and test dataset, 944 features were calculated on unfiltered and filtered images. The number of features for model generation was limited to four to avoid data overfitting. Eighteen patients were diagnosed with early tumor progression, and 16 patients had pseudoprogression. The FET PET radiomics model correctly diagnosed pseudoprogression in all test cohort patients (sensitivity, 100%; negative predictive value, 100%). In contrast, the diagnostic performance of the best FET PET parameter (TBR) was lower (sensitivity, 81%; negative predictive value, 80%). The results suggest that FET PET radiomics helps diagnose patients with pseudoprogression with a high diagnostic performance. Given the clinical significance, further studies are warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers12123835DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766151PMC
December 2020

Stereotactic radiosurgery of benign brain tumors in elderly patients: evaluation of outcome and toxicity.

Radiat Oncol 2020 Dec 9;15(1):274. Epub 2020 Dec 9.

Department of Stereotaxy and Functional Neurosurgery, Centre of Neurosurgery, Medical Faculty and University Hospital Cologne, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.

Background: Stereotactic radiosurgery (SRS) is widely accepted as a therapeutic option for meningiomas (M) and vestibular schwannomas (VS). However, data on outcome and toxicity in the elderly population have rarely been reported in detail.

Methods: All patients aged ≥ 65 years with M or VS who underwent single fraction SRS were included. Patient data were analyzed in terms of clinical tumor control and incidence of early and late treatment related complications, which were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), RESULTS: We identified 245 patients with benign brain tumors (129 M and 116 VS, median tumor volume 2.9 ml, range 0.1-28). The median age was 71 years (range 65-86) and the mean follow-up times were 42 months (range 2-181). Tumors were irradiated with a median dose of 12.4 Gy. Actuarial clinical and radiological tumor control rates at 2, 5, and 10 years after SRS were 98%, 93%, and 88%, respectively. Recurrent tumors after previous treatment had a higher probability of post-radiosurgical progression (p < 0.001). Permanent toxicity (CTCAE I/II) were noted in 5.7%. No severe adverse events were observed during early and late follow up, although patients > 70 years had a slightly higher risk for toxicity (p = 0.027). The presence and extent of co-morbidities had no significant influence on local tumor control or toxicity.

Conclusion: SRS provides favorable tumor control with low risk for treatment-related severe complications. Thus, SRS should always be considered as treatment option for benign intracranial tumors (meningiomas, schwannomas), especially in the group of elderly patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13014-020-01714-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724716PMC
December 2020

miR-155 Contributes to Normal Keratinocyte Differentiation and Is Upregulated in the Epidermis of Psoriatic Skin Lesions.

Int J Mol Sci 2020 Dec 5;21(23). Epub 2020 Dec 5.

Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria.

The role of microRNAs (miRNAs) during keratinocyte (KC) differentiation and in skin diseases with epidermal phenotypes has attracted strong interest over the past few years. However, combined mRNA and miRNA expression analyses to elucidate the intricate mRNA-miRNA networks of KCs at different stages of differentiation have not been performed yet. In the present study, we investigated the dynamics of miRNA and mRNA expression during KC differentiation in vitro and in normal and psoriatic epidermis. While we identified comparable numbers of up- and downregulated mRNAs (49% and 51%, respectively), miRNAs were predominantly upregulated (76% vs 24%) during KC differentiation. Further bioinformatics analyses suggested an important inhibitory role for miR-155 in KC differentiation, as it was repressed during KC differentiation in normal skin but strongly upregulated in the epidermis of psoriatic skin lesions. Mimicking the inflammatory milieu of psoriatic skin in vitro, we could show that the pro-inflammatory cytokines IL17, IL1β and INFγ synergistically upregulated miR-155 expression in KCs. Forced over-expression of miR-155 in human in vitro skin models specifically reduced the expression of loricrin (LOR) in KCs, indicating that miR-155 interferes with the establishment of a normal epidermal barrier. Together, our data indicate that downregulation of miR-155 during KC differentiation is a crucial step for epidermal barrier formation. Furthermore, its strong upregulation in psoriatic lesions suggests a contributing role of miR-155 in the altered keratinocyte differentiation observed in psoriasis. Therefore, miR-155 represents as a potential target for treating psoriatic skin lesions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21239288DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7731132PMC
December 2020

Estimating the radiation dose to the fetus during prophylactic internal iliac occlusion in patients with abnormal placentation.

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2020 Nov 26. Epub 2020 Nov 26.

Department of Radiology, University Hospital Olomouc and Faculty of Medicine and Dentistry Palacky University Olomouc, Czech Republic.

Aims: To evaluate the estimated fetal radiation dose during prophylactic internal iliac arterial occlusion in patients with abnormal placenta and to estimate the risk of radiation induced cancer in child age.

Methods: Prophylactic occlusion of the internal iliac arteries during Caesarean section was performed in 42 patients with placenta praevia and/or placenta accreta spectrum. Fogarty embolectomy catheters were used for prophylactic occlusion of the internal iliac arteries. All procedures were performed in the hybrid operating room using Philips Allura Xper FD 20 X-ray system. Low dose X-ray fluoroscopy (7.5 frames per second) was used. The CODE (Conceptus dose estimation) Software was used to estimate the fetal dose and the risk of radiation induced carcinoma.

Results: Fluoroscopy times required for insertion of Fogarty catheters were 0.5-4.2 min (mean: 1.7 min, median: 1.5 min). The estimated radiation dose to the fetus was 0.26-3.36 mGy (mean: 1.49 mGy, median: 1.25 mGy). The risk of radiation induced cancer in child age was 0.01-0.04% (mean 0.02%, median 0.01%). One patient developed thrombosis of a common femoral artery.

Conclusion: Prophylactic occlusion of the internal iliac arteries is a simple and safe procedure with minimal risk of complications and with a very low estimated radiation dose to the fetus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5507/bp.2020.046DOI Listing
November 2020

Artificial intelligence and radiomics for radiation oncology.

Authors:
Martin Kocher

Strahlenther Onkol 2020 Oct;196(10):847

Department of Stereotaxy and Functional Neurosurgery, University Hospital of Cologne, Cologne, Germany.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00066-020-01676-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7498478PMC
October 2020

Treatment Monitoring of Immunotherapy and Targeted Therapy Using F-FET PET in Patients with Melanoma and Lung Cancer Brain Metastases: Initial Experiences.

J Nucl Med 2021 04 4;62(4):464-470. Epub 2020 Sep 4.

Center of Integrated Oncology, Universities of Aachen, Bonn, Cologne, and Duesseldorf, Germany.

We investigated the value of -(2-F-fluoroethyl)-l-tyrosine (F-FET) PET for treatment monitoring of immune checkpoint inhibition (ICI) or targeted therapy (TT) alone or in combination with radiotherapy in patients with brain metastasis (BM) since contrast-enhanced MRI often remains inconclusive. We retrospectively identified 40 patients with 107 BMs secondary to melanoma ( = 29 with 75 BMs) or non-small cell lung cancer ( = 11 with 32 BMs) treated with ICI or TT who had F-FET PET ( = 60 scans) for treatment monitoring from 2015 to 2019. Most patients ( = 37; 92.5%) had radiotherapy during the course of the disease. In 27 patients, F-FET PET was used to differentiate treatment-related changes from BM relapse after ICI or TT. In 13 patients, F-FET PET was performed for response assessment to ICI or TT using baseline and follow-up scans (median time between scans, 4.2 mo). In all lesions, static and dynamic F-FET PET parameters were obtained (i.e., mean tumor-to-brain ratios [TBR], time-to-peak values). Diagnostic accuracies of PET parameters were evaluated by receiver-operating-characteristic analyses using the clinical follow-up or neuropathologic findings as a reference. A TBR threshold of 1.95 differentiated BM relapse from treatment-related changes with an accuracy of 85% ( = 0.003). Metabolic responders to ICI or TT on F-FET PET had a significantly longer stable follow-up (threshold of TBR reduction relative to baseline, ≥10%; accuracy, 82%; = 0.004). Furthermore, at follow-up, time to peak in metabolic responders increased significantly ( = 0.019). F-FET PET may add valuable information for treatment monitoring in BM patients treated with ICI or TT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2967/jnumed.120.248278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8049362PMC
April 2021

Distal Aneurysms of Cerebellar Arteries-Case Series.

Brain Sci 2020 Aug 10;10(8). Epub 2020 Aug 10.

Radiology Clinic, University Hospital Olomouc, Nová Ulice, 779 00 Olomouc, Czech Republic.

(1) Background: Distal aneurysms of cerebellar arteries are very rare. The authors report their case series of distal aneurysms of the cerebellar arteries solved successfully by microsurgery or by endovascular treatment (Table 1) (2) Materials and Methods: Between January 2010 and March 2020, 346 aneurysms were treated in our institution. Eleven aneurysms in seven patients were located on distal cerebellar arteries and, in three patients, the aneurysms were combined with arteriovenous malformations. There were four women and three men, ranging from 50 to 72 years of age. Five patients presented with different grades of subarachnoid hemorrhage or intraventricular bleeding, and two patients were diagnosed because of headache. Aneurysm location was the posterior inferior cerebellar artery in six cases, the superior cerebellar artery in three cases, and the anterior inferior cerebellar artery in 2 cases. One patient had three aneurysms, and two patients had two aneurysms. (3) Results: Nine aneurysms were treated by microsurgery trapping or clipping and, in two patients, the associated arteriovenous malformation (AVM) was resected. Two aneurysms were treated by endovascular coiling, and one associated AVM was successfully embolized. Clinical follow-up was a mean of 11.5 months (range, 3-45 months). (4) Conclusion: The authors present their experience with the treatment of 11 peripheral aneurysms on distal branches of the cerebellar circulation in seven patients which were excluded from circulation by microsurgery or endovascular treatment. In three patients, the associated AVM was treated (two with microsurgery, one with embolization).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/brainsci10080538DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463481PMC
August 2020

Role of the default mode resting-state network for cognitive functioning in malignant glioma patients following multimodal treatment.

Neuroimage Clin 2020 26;27:102287. Epub 2020 May 26.

Institute of Neuroscience and Medicine (INM-1, -3, -4), Research Center Juelich, Wilhelm-Johnen-Str., 52428 Juelich, Germany; Department of Nuclear Medicine, University Hospital Aachen, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.

Background: Progressive cognitive decline following multimodal neurooncological treatment is a common observation in patients suffering from malignant glioma. Alterations of the default-mode network (DMN) represent a possible source of impaired neurocognitive functioning and were analyzed in these patients.

Methods: Eighty patients (median age, 51 years) with glioma (WHO grade IV glioblastoma, n = 57; WHO grade III anaplastic astrocytoma, n = 13; WHO grade III anaplastic oligodendroglioma, n = 10) and ECOG performance score 0-1 underwent resting-state functional MRI (rs-fMRI) and neuropsychological testing at a median interval of 13 months (range, 1-114 months) after initiation of therapy. For evaluation of structural and metabolic changes after treatment, anatomical MRI and amino acid PET using O-(2-[F]fluoroethyl)-L-tyrosine (FET) were simultaneously acquired to rs-fMRI on a hybrid MR/PET scanner. A cohort of 80 healthy subjects matched for gender, age, and educational status served as controls.

Results: The connectivity pattern within the DMN (12 nodes) of the glioma patients differed significantly from that of the healthy subjects but did not depend on age, tumor grade, time since treatment initiation, presence of residual/recurrent tumor, number of chemotherapy cycles received, or anticonvulsive medication. Small changes in the connectivity pattern were observed in patients who had more than one series of radiotherapy. In contrast, structural tissue changes located at or near the tumor site (including resection cavities, white matter lesions, edema, and tumor tissue) had a strong negative impact on the functional connectivity of the adjacent DMN nodes, resulting in a marked dependence of the connectivity pattern on tumor location. In the majority of neurocognitive domains, glioma patients performed significantly worse than healthy subjects. Correlation analysis revealed that reduced connectivity in the left temporal and parietal DMN nodes was associated with low performance in language processing and verbal working memory. Furthermore, connectivity of the left parietal DMN node also correlated with processing speed, executive function, and verbal as well as visual working memory. Overall DMN connectivity loss and cognitive decline were less pronounced in patients with higher education.

Conclusion: Personalized treatment strategies for malignant glioma patients should consider the left parietal and temporal DMN nodes as vulnerable regions concerning neurocognitive outcome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nicl.2020.102287DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7298724PMC
March 2021

Radiomics in neuro-oncology: Basics, workflow, and applications.

Methods 2021 04 6;188:112-121. Epub 2020 Jun 6.

Institute of Neuroscience and Medicine (INM-3, -4, -11), Research Center Juelich, Wilhelm-Johnen-Str., 52428 Juelich, Germany; Center of Integrated Oncology (CIO), Universities of Aachen, Bonn, Cologne and Duesseldorf, Kerpener Str. 62, 50937 Cologne, Germany; Department of Nuclear Medicine and Comprehensive Diagnostic Center Aachen (CDCA), RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany; JARA - BRAIN - Translational Medicine, Aachen, Germany.

Over the last years, the amount, variety, and complexity of neuroimaging data acquired in patients with brain tumors for routine clinical purposes and the resulting number of imaging parameters have substantially increased. Consequently, a timely and cost-effective evaluation of imaging data is hardly feasible without the support of methods from the field of artificial intelligence (AI). AI can facilitate and shorten various time-consuming steps in the image processing workflow, e.g., tumor segmentation, thereby optimizing productivity. Besides, the automated and computer-based analysis of imaging data may help to increase data comparability as it is independent of the experience level of the evaluating clinician. Importantly, AI offers the potential to extract new features from the routinely acquired neuroimages of brain tumor patients. In combination with patient data such as survival, molecular markers, or genomics, mathematical models can be generated that allow, for example, the prediction of treatment response or prognosis, as well as the noninvasive assessment of molecular markers. The subdiscipline of AI dealing with the computation, identification, and extraction of image features, as well as the generation of prognostic or predictive mathematical models, is termed radiomics. This review article summarizes the basics, the current workflow, and methods used in radiomics with a focus on feature-based radiomics in neuro-oncology and provides selected examples of its clinical application.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ymeth.2020.06.003DOI Listing
April 2021

Outcome and toxicity analysis of single dose stereotactic radiosurgery in vestibular schwannoma based on the Koos grading system.

Sci Rep 2020 06 9;10(1):9309. Epub 2020 Jun 9.

Department of Stereotaxy and functional Neurosurgery, Centre of Neurosurgery, University Hospital of Cologne, Cologne, Germany.

Stereotactic radiosurgery (SRS) has evolved as widely accepted treatment option for small-sized (Koos I up to II) vestibular schwannoma (VS). For larger tumors (prevalent Koos VI), microsurgery or combined treatment strategies are mostly recommended. However, in patients not suited for microsurgery, SRS might also be an alternative to balance tumor control, hearing preservation and adverse effects. The purpose of this analysis was to evaluate the efficacy and toxicity of SRS for VS with regard to different Koos grades. All patients with untreated VS who received SRS at our center were included. Outcome analysis included tumor control, preservation of serviceable hearing based on median pure tone averages (PTA), and procedure-related adverse events rated by the Common Terminology Criteria for Adverse Events (CTCAE; v4.03) classification. In total, 258 patients (median age 58 years, range 21-84) were identified with a mean follow-up of 52 months (range 3-228 months). Mean tumor volume was 1.8 ml (range 0.1-18.5). The mean marginal dose was 12.3 Gy ± 0.6 (range 11-13.5). The cohort was divided into two groups: A (Koos grades I and II, n = 186) and B (Koos grades III and IV, n = 72). The actuarial tumor control rate was 98% after 2 years and 90% after 5 and 10 years. Koos grading did not show a significant impact on tumor control (p = 0.632) or hearing preservation (p = 0.231). After SRS, 18 patients (7%) had new transient or permanent symptoms classified by the CTCAE. The actuarial rate of CTCAE-free survival was not related to Koos grading (p = 0.093). Based on this selected population of Koos grade III and IV VS without or with only mild symptoms from brainstem compression, SRS can be recommended as the primary therapy with the advantage of low morbidity and satisfactory tumor control. The overall hearing preservation rate and toxicity of SRS was influenced by age and cannot be predicted by tumor volume or Koos grading alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-66213-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7283483PMC
June 2020

Automated detection and delineation of hepatocellular carcinoma on multiphasic contrast-enhanced MRI using deep learning.

Abdom Radiol (NY) 2021 01 4;46(1):216-225. Epub 2020 Jun 4.

Department of Radiology and Biomedical Imaging, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA.

Purpose: Liver Imaging Reporting and Data System (LI-RADS) uses multiphasic contrast-enhanced imaging for hepatocellular carcinoma (HCC) diagnosis. The goal of this feasibility study was to establish a proof-of-principle concept towards automating the application of LI-RADS, using a deep learning algorithm trained to segment the liver and delineate HCCs on MRI automatically.

Methods: In this retrospective single-center study, multiphasic contrast-enhanced MRIs using T1-weighted breath-hold sequences acquired from 2010 to 2018 were used to train a deep convolutional neural network (DCNN) with a U-Net architecture. The U-Net was trained (using 70% of all data), validated (15%) and tested (15%) on 174 patients with 231 lesions. Manual 3D segmentations of the liver and HCC were ground truth. The dice similarity coefficient (DSC) was measured between manual and DCNN methods. Postprocessing using a random forest (RF) classifier employing radiomic features and thresholding (TR) of the mean neural activation was used to reduce the average false positive rate (AFPR).

Results: 73 and 75% of HCCs were detected on validation and test sets, respectively, using > 0.2 DSC criterion between individual lesions and their corresponding segmentations. Validation set AFPRs were 2.81, 0.77, 0.85 for U-Net, U-Net + RF, and U-Net + TR, respectively. Combining both RF and TR with the U-Net improved the AFPR to 0.62 and 0.75 for the validation and test sets, respectively. Mean DSC between automatically detected lesions using the DCNN + RF + TR and corresponding manual segmentations was 0.64/0.68 (validation/test), and 0.91/0.91 for liver segmentations.

Conclusion: Our DCNN approach can segment the liver and HCCs automatically. This could enable a more workflow efficient and clinically realistic implementation of LI-RADS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00261-020-02604-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7714704PMC
January 2021

Applications of radiomics and machine learning for radiotherapy of malignant brain tumors.

Strahlenther Onkol 2020 Oct 11;196(10):856-867. Epub 2020 May 11.

Institute of Neuroscience and Medicine (INM-3, -4), Research Center Juelich, Wilhelm-Johnen-Straße, 52428, Juelich, Germany.

Background: Magnetic resonance imaging (MRI) and amino acid positron-emission tomography (PET) of the brain contain a vast amount of structural and functional information that can be analyzed by machine learning algorithms and radiomics for the use of radiotherapy in patients with malignant brain tumors.

Methods: This study is based on comprehensive literature research on machine learning and radiomics analyses in neuroimaging and their potential application for radiotherapy in patients with malignant glioma or brain metastases.

Results: Feature-based radiomics and deep learning-based machine learning methods can be used to improve brain tumor diagnostics and automate various steps of radiotherapy planning. In glioma patients, important applications are the determination of WHO grade and molecular markers for integrated diagnosis in patients not eligible for biopsy or resection, automatic image segmentation for target volume planning, prediction of the location of tumor recurrence, and differentiation of pseudoprogression from actual tumor progression. In patients with brain metastases, radiomics is applied for additional detection of smaller brain metastases, accurate segmentation of multiple larger metastases, prediction of local response after radiosurgery, and differentiation of radiation injury from local brain metastasis relapse. Importantly, high diagnostic accuracies of 80-90% can be achieved by most approaches, despite a large variety in terms of applied imaging techniques and computational methods.

Conclusion: Clinical application of automated image analyses based on radiomics and artificial intelligence has a great potential for improving radiotherapy in patients with malignant brain tumors. However, a common problem associated with these techniques is the large variability and the lack of standardization of the methods applied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00066-020-01626-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7498494PMC
October 2020

Deep convolutional neural networks for automated segmentation of brain metastases trained on clinical data.

Radiat Oncol 2020 Apr 20;15(1):87. Epub 2020 Apr 20.

University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Stereotactic and Functional Neurosurgery, Cologne, Germany.

Introduction: Deep learning-based algorithms have demonstrated enormous performance in segmentation of medical images. We collected a dataset of multiparametric MRI and contour data acquired for use in radiosurgery, to evaluate the performance of deep convolutional neural networks (DCNN) in automatic segmentation of brain metastases (BM).

Methods: A conventional U-Net (cU-Net), a modified U-Net (moU-Net) and a U-Net trained only on BM smaller than 0.4 ml (sU-Net) were implemented. Performance was assessed on a separate test set employing sensitivity, specificity, average false positive rate (AFPR), the dice similarity coefficient (DSC), Bland-Altman analysis and the concordance correlation coefficient (CCC).

Results: A dataset of 509 patients (1223 BM) was split into a training set (469 pts) and a test set (40 pts). A combination of all trained networks was the most sensitive (0.82) while maintaining a specificity 0.83. The same model achieved a sensitivity of 0.97 and a specificity of 0.94 when considering only lesions larger than 0.06 ml (75% of all lesions). Type of primary cancer had no significant influence on the mean DSC per lesion (p = 0.60). Agreement between manually and automatically assessed tumor volumes as quantified by a CCC of 0.87 (95% CI, 0.77-0.93), was excellent.

Conclusion: Using a dataset which properly captured the variation in imaging appearance observed in clinical practice, we were able to conclude that DCNNs reach clinically relevant performance for most lesions. Clinical applicability is currently limited by the size of the target lesion. Further studies should address if small targets are accurately represented in the test data.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13014-020-01514-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7171921PMC
April 2020

Stereotactic Radiosurgery of Cavernous Sinus Meningiomas.

J Neurol Surg B Skull Base 2020 Apr 12;81(2):158-164. Epub 2019 Mar 12.

Department of Stereotaxy and Functional Neurosurgery, Centre of Neurosurgery, University Hospital Cologne, Cologne, Germany.

 Microsurgical resection of cavernous sinus meningiomas (CSM) is associated with a high rate of incomplete resection, recurrence, and the risk for permanent, severe cranial nerve deficits. Stereotactic radiosurgery (SRS) has evolved as alternative treatment for primary and recurrent CSM. Here, we report about the long-term clinical and radiological follow-up (FU) of a unique cohort of patients with CSM treated with LINAC or Cyberknife based SRS.  In this single-center retrospective analysis, we include all patients with CSM who underwent single fraction SRS between 1993 and 2016. Clinical and radiological tumor control were evaluated by the Kaplan-Meier method. Additionally, patient data were analyzed in terms of symptom control and incidence of side effects rated by the common terminology criteria for adverse events (CTCAE; v4.03).  116 patients (female/male = 91/25; median age, 54 years; range, 33-82 years) were included. Mean tumor volume was 5.7 ± 3.3 cm (range, 0.6-16.2 cm ), the median marginal dose was 12.6 Gy applied to isodose levels of 75%. Median clinical FU was 55 months (range, 3-226 months). Tumor control was 98% after 2 and 5 years and 90% after 10 years. Twelve patients (10.3%) had permanent or transient radiation related toxicity (CTCAE I-III). An improvement of symptoms was observed in 26.7% of the symptomatic patients (  = 20 of 75).  SRS for CSM provides excellent long-term tumor and symptom control without considerable permanent side effects. Thus, SRS should be considered when counseling patients suffering from CSM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0039-1683430DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7082171PMC
April 2020

PET/MRI Radiomics in Patients With Brain Metastases.

Front Neurol 2020 7;11. Epub 2020 Feb 7.

Institute of Neuroscience and Medicine (INM-3/-4/-11), Research Center Juelich, Jülich, Germany.

Although a variety of imaging modalities are used or currently being investigated for patients with brain tumors including brain metastases, clinical image interpretation to date uses only a fraction of the underlying complex, high-dimensional digital information from routinely acquired imaging data. The growing availability of high-performance computing allows the extraction of quantitative imaging features from medical images that are usually beyond human perception. Using machine learning techniques and advanced statistical methods, subsets of such imaging features are used to generate mathematical models that represent characteristic signatures related to the underlying tumor biology and might be helpful for the assessment of prognosis or treatment response, or the identification of molecular markers. The identification of appropriate, characteristic image features as well as the generation of predictive or prognostic mathematical models is summarized under the term radiomics. This review summarizes the current status of radiomics in patients with brain metastases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2020.00001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7020230PMC
February 2020

Is endovascular treatment of aorto-iliac aneurysms with simultaneous unilateral revascularization of internal iliac artery by branched iliac stentgraft sufficient?

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2020 Feb 25. Epub 2020 Feb 25.

Department of Diagnostic and Interventional Radiology, UKGM University Hospital Marburg, Philipps University, Marburg, Germany.

Aims: The coverage / occlusion of internal iliac artery (IIA) during endovascular treatment of aorto-iliac aneurysms (AIA) can be associated with risk of ischemic complications. To reduce these complications, unilateral or bilateral iliac branch device implantation (IBDI) has been reported. This study aims at evaluating the efficacy of simultaneous unilateral IBDI in the treatment of AIAs and comparing our results with literature.

Materials: and Methods. From March 2010 to December 2019, 27 patients (25 men, 2 women, range 54-84 years) were treated for aorto-iliac/isolated common iliac aneurysms with simultaneous unilateral revascularization of IIA and surgical / endovascular occlusion of contralateral IIA. 27 iliac-branched devices were implanted in 27 patients. The results including ischemic complications were evaluated and compared with literature.

Results: The technical success was 100% with no perioperative mortality and morbidity of 3.7%. Primary internal iliac branch patency at a median follow-up of 52 months (range 1-118 months) was 96.42%. Secondary endoleak was observed in 6 patients (Type 1a [1], Type 1b [1], Type II [4]) and inflammatory complication in 1 patient. The incidence of buttock claudication one year after the procedure was 11.1%. Except for buttock claudication no other ischemic complications occurred.

Conclusion: Unilateral flow preservation in the IIA territory using IBDI is associated with a lesser, but a certain risk of ischemic complications. Bilateral IBDI with bilateral flow preservation of IIAs increases the complexity, procedure -/ fluoroscopy times, contrast agent volume and cost, however, may further reduce these ischemic complications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5507/bp.2020.004DOI Listing
February 2020

Low Levels of Glycemia within the First 48 Hours after Mechanical Thrombectomy for Acute Ischemic Stroke May be Associated with Better Clinical Outcome.

J Stroke Cerebrovasc Dis 2020 Apr 24;29(4):104621. Epub 2020 Jan 24.

Comprehensive Stroke Center, Department of Neurology, Palacký University Medical School and Hospital, Olomouc, Czech Republic.

Introduction: Many different factors may have an impact on clinical outcome after mechanical thrombectomy (MT) for acute ischemic stroke (AIS). We aimed to investigate levels of serum glycemia (GLY) within the first 48 hours after MT.

Subjects And Methods: Consecutive AIS patients were enrolled in the retrospective bi-center study. Neurological deficit was assessed with National Institutes of Health Stroke Scale (NIHSS) and functional outcome after 3 months with modified Rankin scale with a score 0-2 for good outcome. Presence of symptomatic intracerebral hemorrhage was assessed according to the SITS- MOST criteria.

Results: In total, 868 patients (442 males, mean age 69.7 ± 12.2 years) with a median of admission NIHSS 17 points were enrolled in the study and 253 (29.1%) of them were diabetics. Recanalization was reached in 758 (87.3%) patients. Patients with good outcome (412, 47.5%) had lower median of GLY (6.5 versus 7.4 mmol/L, P < .0001) within the first 48 hours after MT. Similar results were found also in diabetics (8.1 versus 9.6 mmol/L, P < .0001) and in patients with achieved recanalization (6.5 versus 7.5 mmol/L, P < .0001). Multivariate regression analysis with adjustment for potential confounders showed median of GLY (P = .0001, odds ratio: 0.830, 95% confidence interval: 0.755-0.913) as a predictor of good outcome after MT.

Conclusion: Lower levels of GLY within the first 48 hours after MT may be associated with better functional outcome after 3 months.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2019.104621DOI Listing
April 2020

Low risk of contralateral lymph node recurrence in lateralized head and neck carcinoma after postoperative ipsilateral radiotherapy.

Strahlenther Onkol 2020 May 12;196(5):474-484. Epub 2019 Dec 12.

Department of Radiation Oncology, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne/Koeln, Germany.

Purpose: The role of postoperative irradiation to contralateral non-involved neck nodes in lateralized carcinoma of the head and neck is not clear. The contralateral neck failure rate in head and neck carcinoma treated postoperatively with ipsilateral neck irradiation only was evaluated.

Methods: Patients with carcinoma of the oral cavity, oropharynx, or hypopharynx without midline extension treated between 1990 and 2016 were analyzed. After tumor resection and neck dissection (ND), radiotherapy was given to the primary tumor site and ipsilateral neck. High-risk patients additionally received concurrent chemotherapy. Freedom from contralateral neck recurrence (FCNR), locoregional control rate (LRC), overall survival (OS), and disease-free survival (DFS) were evaluated.

Results: 197 patients (median age 60.7 years, 66.5% males, 52.8% oropharyngeal carcinomas) were analyzed. Complete resection (R0) was achieved in 85.8% of cases. Ipsilateral ND was performed in all patients and contralateral ND in 144 patients (73.1%). Concurrent chemotherapy was given to 59 patients (30.0%). After a median follow-up of 45.5 months, OS and DFS of all patients were 73.6% and 70.9% at 5 years, respectively. A total of 45 patients (22.8%) suffered from a locoregional recurrence, lymph node metastases of the contralateral neck developed in 12 patients (6.1%) only. There was no significant difference in contralateral nodal failure rate with or without performance of contralateral ND.

Conclusion: Regional failure of the contralateral neck was low after surgery and ipsilateral neck irradiation in head and neck carcinomas without midline extension, supporting evidence that contralateral neck radiotherapy can safely be omitted in selected cases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00066-019-01556-0DOI Listing
May 2020

Imaging challenges of immunotherapy and targeted therapy in patients with brain metastases: response, progression, and pseudoprogression.

Neuro Oncol 2020 01;22(1):17-30

Institute of Neuroscience and Medicine, Research Center Juelich, Juelich, Germany.

The advent of immunotherapy using immune checkpoint inhibitors (ICIs) and targeted therapy (TT) has dramatically improved the prognosis of various cancer types. However, following ICI therapy or TT-either alone (especially ICI) or in combination with radiotherapy-imaging findings on anatomical contrast-enhanced MRI can be unpredictable and highly variable, and are often difficult to interpret regarding treatment response and outcome. This review aims at summarizing the imaging challenges related to TT and ICI monotherapy as well as combined with radiotherapy in patients with brain metastases, and to give an overview on advanced imaging techniques which potentially overcome some of these imaging challenges. Currently, major evidence suggests that imaging parameters especially derived from amino acid PET, perfusion-/diffusion-weighted MRI, or MR spectroscopy may provide valuable additional information for the differentiation of treatment-induced changes from brain metastases recurrence and the evaluation of treatment response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuonc/noz147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6954406PMC
January 2020

Radiomic analysis of planning computed tomograms for predicting radiation-induced lung injury and outcome in lung cancer patients treated with robotic stereotactic body radiation therapy.

Strahlenther Onkol 2019 Sep 15;195(9):830-842. Epub 2019 Mar 15.

Department of Stereotactic and Functional Neurosurgery, University Hospital of Cologne, Kerpener Str. 62, 50937, Cologne, Germany.

Objectives: To predict radiation-induced lung injury and outcome in non-small cell lung cancer (NSCLC) patients treated with robotic stereotactic body radiation therapy (SBRT) from radiomic features of the primary tumor.

Methods: In all, 110 patients with primary stage I/IIa NSCLC were analyzed for local control (LC), disease-free survival (DFS), overall survival (OS) and development of local lung injury up to fibrosis (LF). First-order (histogram), second-order (GLCM, Gray Level Co-occurrence Matrix) and shape-related radiomic features were determined from the unprocessed or filtered planning CT images of the gross tumor volume (GTV), subjected to LASSO (Least Absolute Shrinkage and Selection Operator) regularization and used to construct continuous and dichotomous risk scores for each endpoint.

Results: Continuous scores comprising 1-5 histogram or GLCM features had a significant (p = 0.0001-0.032) impact on all endpoints that was preserved in a multifactorial Cox regression analysis comprising additional clinical and dosimetric factors. At 36 months, LC did not differ between the dichotomous risk groups (93% vs. 85%, HR 0.892, 95%CI 0.222-3.590), while DFS (45% vs. 17%, p < 0.05, HR 0.457, 95%CI 0.240-0.868) and OS (80% vs. 37%, p < 0.001, HR 0.190, 95%CI 0.065-0.556) were significantly lower in the high-risk groups. Also, the frequency of LF differed significantly between the two risk groups (63% vs. 20% at 24 months, p < 0.001, HR 0.158, 95%CI 0.054-0.458).

Conclusion: Radiomic analysis of the gross tumor volume may help to predict DFS and OS and the development of local lung fibrosis in early stage NSCLC patients treated with stereotactic radiotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00066-019-01452-7DOI Listing
September 2019

Impact of blood pressure levels within first 24 hours after mechanical thrombectomy on clinical outcome in acute ischemic stroke patients.

J Neurointerv Surg 2019 Aug 6;11(8):735-739. Epub 2019 Feb 6.

Department of Neurology, Univ Hosp Olomouc, Olomouc, Czech Republic.

Introduction: Despite early management and technical success of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), not all patients reach a good clinical outcome. Different factors may have an impact and we aimed to evaluate blood pressure (BP) levels in the first 24 hours after MT.

Methods: Consecutive AIS patients treated with MT were enrolled in the retrospective bi-center study. Neurological deficit was assessed with National Institutes of Health Stroke Scale (NIHSS) and functional outcome after 3 months with modified Rankin scale (mRS) with a score 0-2 for good outcome. The presence of symptomatic intracerebral hemorrhage (SICH) was assessed according to the SITS-MOST criteria.

Results: Of 703 treated patients, completed BP levels were collected in 690 patients (350 males, mean age 71±13 years) with median of admission NIHSS 17 points. Patients with mRS 0-2 had a lower median of systolic BP (SBP) compared with those with poor outcome (131 vs 140 mm Hg, P<0.0001). The rate of SICH did not differ between the patients with a median of SBP <140 mm Hg and ≥140 mm Hg. (5.1% vs 5.1%, P=0.980). Multivariate regression analysis with adjustment for potential confounders showed a median of distolic BP (P=0.024, OR: 0.977, 95% CI: 0.957 to 0.997) as a predictor of good functional outcome after MT, and a median of maximal SBP (P=0.038; OR: 0.990, 95% CI: 0.981 to 0.999) in the patients with achieved recanalization.

Conclusion: Lowering of BP within the first 24 hours after MT may have a positive impact on clinical outcome in treated patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/neurintsurg-2018-014548DOI Listing
August 2019

Comparison of Local Control of Brain Metastases With Stereotactic Radiosurgery vs Surgical Resection: A Secondary Analysis of a Randomized Clinical Trial.

JAMA Oncol 2019 02;5(2):243-247

Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania.

Importance: Brain metastases are a common source of morbidity for patients with cancer, and limited data exist to support the local therapeutic choice between surgical resection and stereotactic radiosurgery (SRS).

Objective: To evaluate local control of brain metastases among patients treated with SRS vs surgical resection within the European Organization for the Research and Treatment of Cancer (EORTC) 22952-26001 phase 3 trial.

Design, Setting, And Participants: This unplanned, exploratory analysis of the international, multi-institutional randomized clinical trial EORTC 22952-26001 (conducted from 1996-2007) was performed from February 9, 2017, through July 25, 2018. The EORTC 22952-26001 trial randomized patients with 1 to 3 brain metastases to whole-brain radiotherapy vs observation after complete surgical resection or before SRS. Patients in the present analysis were stratified but not randomized according to local modality (SRS or surgical resection) and treated per protocol with 1 to 2 brain metastases and tumors with a diameter of no greater than 4 cm.

Interventions: Surgical resection or SRS.

Main Outcomes And Measures: The primary end point was local recurrence of treated lesions. Cumulative incidence of local recurrence was calculated according to modality (surgical resection vs SRS) with competing risk regression to adjust for prognostic factors and competing risk of death.

Results: A total of 268 patients were included in the analysis (66.4% men; median age, 60.7 years [range, 26.9-81.1 years]); 154 (57.5%) underwent SRS and 114 (42.5%) underwent surgical resection. Median follow-up time was 39.9 months (range, 26.0-1982.0 months). Compared with the SRS group, patients undergoing surgical resection had larger metastases (median 28 mm [range, 10-40 mm] vs 20 mm [range, 4-40 mm]; P < .001), more frequently had 1 brain metastasis (112 [98.2%] vs 114 [74.0%]; P < .001), and differed in location (parietal, 21 [18.4%] vs 61 [39.6%]; posterior fossa, 30 [26.3%] vs 12 [7.8%]; P < .001). In adjusted models, local recurrence was similar between the SRS and surgical resection groups (hazard ratio [HR], 1.15; 95% CI, 0.72-1.83). However, when stratified by interval, patients with surgical resection had a much higher risk of early (0-3 months) local recurrence compared with those undergoing SRS (HR, 5.94; 95% CI, 1.72-20.45), but their risk decreased with time (HR for 3-6 months, 1.37 [95% CI, 0.64-2.90]; HR for 6-9 months, 0.75 [95% CI, 0.28-2.00]). At 9 months or longer, the surgical resection group had a lower risk of local recurrence (HR, 0.36; 95% CI, 0.14-0.93).

Conclusions And Relevance: In this exploratory analysis, local control of brain metastases was similar between SRS and surgical resection groups. Stereotactic radiosurgery was associated with improved early local control of treated lesions compared with surgical resection, although the relative benefit decreased with time.

Trial Registration: ClinicalTrials.gov Identifier: NCT00002899.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1001/jamaoncol.2018.4610DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6439566PMC
February 2019