Publications by authors named "Yıldız Guney"

26 Publications

  • Page 1 of 1

Improved disease-free survival with adjuvant radiotherapy in early-stage endometrial cancer: 10-year outcome analysis.

J Contemp Brachytherapy 2020 Dec 16;12(6):572-578. Epub 2020 Dec 16.

Department of Radiation Oncology, Ankara Memorial Hospital, Ankara, Turkey.

Purpose: The purpose of this study was to evaluate long-term treatment outcomes and prognostic factors affecting survival of patients with early-stage endometrial carcinoma.

Material And Methods: Data of 311 patients with FIGO stage I-II endometrial cancer, curatively treated at two different tertiary centers between June 2001 and December 2016 were retrospectively reviewed. The patients had primary surgery, 74 (24%) received no further treatment, 4 (1%) obtained chemotherapy only, 234 (75%) received radiotherapy, and 24 (7%) received both.

Results: Median follow-up time was 102 (range, 3-205) months. During this period, 68 (21.9%) patients died. 5-year and 10-year disease-free survival (DFS) were 76% and 74.3%, respectively. In multivariate analysis, lower uterine segment invasion positivity and no adjuvant radiotherapy were determined as independent unfavorable prognostic factors for DFS. The 5-year and 10-year disease-specific survival (DSS) were 86.8% and 82.2%, respectively. For DSS, high-grade, lymphovascular space invasion positivity, stage II, ≥ 65 age, and no adjuvant radiotherapy were found to be independent unfavorable prognostic markers.

Conclusions: The findings of our cohort have confirmed the importance of adjuvant radiotherapy on long-term early-stage endometrial carcinoma outcome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5114/jcb.2020.101690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787210PMC
December 2020

Prognostic factors in medically inoperable early stage lung cancer patients treated with stereotactic ablative radiation therapy (SABR): Turkish Radiation Oncology Society Multicentric Study.

Clin Respir J 2020 Nov 17;14(11):1050-1059. Epub 2020 Aug 17.

Faculty of Medicine, Radiation Oncology Department, Ankara University, Ankara, Turkey.

Objective: We identified factors influencing outcomes in patients with medically inoperable early stage lung cancer (MIESLC) treated with stereotactic ablative radiation therapy (SABR) at 14 centers in Turkey.

Materials And Methods: We retrospectively analyzed 431 patients with stage I-II MIESLC treated with SABR from 2009 through 2017. Age; sex; performance score; imaging technique; tumor histology and size; disease stage radiation dose, fraction and biologically effective dose with an α/β ratio of 10 (BED ); tumor location and treatment center were evaluated for associations with overall survival (OS), local control (LC) and toxicity.

Results: Median follow-up time was 27 months (range 1-115); median SABR dose was 54 Gy (range 30-70) given in a median three fractions (range 1-10); median BED was 151 Gy (range 48-180). Tumors were peripheral in 285 patients (66.1%), central in 69 (16%) and <1 cm from mediastinal structures in 77 (17.9%). Response was evaluated with PET/CT in most cases at a median 3 months after SABR. Response rates were: 48% complete, 36.7% partial, 7.9% stable and 7.4% progression. LC rates were 97.1% at 1 year, 92.6% at 2 years and 91.2% at 3 years; corresponding OS rates were 92.6%, 80.6% and 72.7%. On multivariate analysis, BED > 100 Gy (P = .011), adenocarcinoma (P = .025) and complete response on first evaluation (P = .007) predicted favorable LC. BED > 120 Gy (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.1-3.2, P = .019) and tumor size (<2 cm HR 1.9, 95% CI 1.3-3, P = .003) predicted favorable OS. No grade 4-5 acute side effects were observed; late effects were grade ≤3 pneumonitis (18 [4.2%]), chest wall pain (11 [2.5%]) and rib fracture (1 [0.2%]).

Conclusion: SABR produced encouraging results, with satisfactory LC and OS and minimal toxicity. BED > 120 Gy was needed for better LC and OS for large, non-adenocarcinoma tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/crj.13240DOI Listing
November 2020

Intraoperative radiotherapy with electrons as partial breast irradiation in limited stage breast cancer: Early term clinical and cosmetic outcomes.

J Cancer Res Ther 2019 Jul-Sep;15(5):994-998

Department of Surgery, Ankara Oncology Hospital, Ankara, Turkey.

Purpose: We aimed to report the experience of intraoperative electron radiation therapy (IOERT) with Mobetron (Intraop Medical Incorporated, Santa Clara, CA, USA) as a partial breast irradiation (PBI) for patients with early-stage breast cancer and explanation of IOERT application and present early clinical and cosmetic result.

Materials And Methods: Between November 2012 and February 2014, in Ankara Oncology Hospital, Radiation Oncology Clinic, was performed IOERT as a PBI with a single dose of 21 Gy for 21selected patients. Median tumor size was 1.5 cm (range, 0.6-2.8 cm). Median treatment duration was 2.04 min (range, 1.26-2.44 min). According to final pathology, two patients were found to have close margin and mastectomy was applied. Three cases (two were N1 mic and one case had perineural invasion and tumor size was >2 cm) received whole breast irradiation.

Results: Median follow-up time was 3 years (range, 26-42 months). One patient died because of nonbreast cancer reason, all of the other patients (except one) alive without disease. There was no Grade 3 or 4 toxicities related to the IOERT. Good or excellent cosmesis was revealed 79% (15/19) and 95% (18/19), by physician and patient, respectively.

Conclusion: IOERT, for patients with early-stage breast cancer as a part of breast-conserving treatment, offer patients better cosmetic results with less skin toxicity and increases comfort of patients by shortening duration of treatment time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/jcrt.JCRT_191_17DOI Listing
July 2020

Multicenter experience of adult medulloblastoma: A study of Anatolian Society of Medical Oncology (ASMO).

J BUON 2016 Mar-Apr;21(2):456-60

Department of Medical Oncology, Ankara Oncology Training and Research Hospital,Ankara, Turkey.

Purpose: Medulloblastoma (MB) is rarely seen in adults. For adjuvant therapy in adults the same therapy protocols used in pediatric cases are used. The present study retrospectively evaluated the data of MB patients who were treated in different Oncology Centers in Turkey.

Methods: The data of 60 adult patients with MB from 8 Oncology Centers diagnosed between 2005 and 2012 were retrospectively analyzed.

Results: The median patient age was 28.8 years (range 16-54). The administered chemotherapy included procarbazine+lomustin+vincristine (group A, N=31) and cyclophosphamide/ifosfamide+vincristine+cisplatin (group B, N=13). Median chemotherapy courses were 4 (range 1-8). Median progression free survival (PFS) was 76 months and median overall survival (OS) has not been reached in both groups. In young female patients and in those who received adjuvant chemotherapy, median PFS and OS were longer but without statistical significance. Mean PFS and OS were 65.9 months and 101.2 months in group A and 113.6 months and 141.6 months in group B, respectively.

Conclusion: Improved survival results were obtained in women, in patients aged below 25 years, in those who underwent gross total excision (GTE) and in those who received adjuvant therapy with cyclophosphamide/ifosphamide.
View Article and Find Full Text PDF

Download full-text PDF

Source
July 2016

Whole Brain Radiotherapy Combined with Stereotactic Radiosurgery versus Stereotactic Radiosurgery Alone for Brain Metastases.

Asian Pac J Cancer Prev 2015 ;16(17):7595-7

Radiation Oncology Department, Ankara Oncology Training and Research Hospital, Ankara, Turkey E-mail :

Background: The aim of this study was to evaluate the effect of whole brain radiotherapy (WBRT) combined with streotactic radiosurgery versus stereotactic radiosurgery (SRS) alone for patients with brain metastases.

Materials And Methods: This was a retrospective study that evaluated the results of 46 patients treated for brain metastases at Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Radiation Oncology Department, between January 2012 and January 2015. Twenty-four patients were treated with WBRT+SRS while 22 patients were treated with only SRS.

Results: Time to local recurrence was 9.7 months in the WBRT+SRS arm and 8.3 months in SRS arm, the difference not being statistically significant (p= 0.7). Local recurrence rate was higher in the SRS alone arm but again without significance (p=0,06).

Conclusions: In selected patient group with limited number (one to four) of brain metastases SRS alone can be considered as a treatment option and WBRT may be omitted in the initial treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7314/apjcp.2015.16.17.7595DOI Listing
September 2016

Challenges and differences in external radiation therapy for retinoblastoma: from standard techniques to new developments.

Tumori 2017 Sep 28;103(5):438-442. Epub 2015 Aug 28.

Department of Radiation Oncology, Ankara University School of Medicine, Cebeci Hospital, Ankara - Turkey.

Aims: The purpose of this study is to calculate the treatment plans and to compare the dose distributions and dose-volume histograms (DVH) for 6 external radiotherapy techniques for the treatment of retinoblastoma as well as intensity-modulated radiotherapy (IMRT) and fractionated stereotactic radiotherapy (Cyberknife).

Methods: Treatment plans were developed using 6 techniques, including an en face electron technique (ET), an anterior and lateral wedge photon technique (LFT), a 3D conformal (6 fields) technique (CRT), an inverse plan IMRT, tomotherapy, and conventional focal stereotactic external beam radiotherapy with Cyberknife (SBRT). Dose volume analyses were carried out for each technique.

Results: All techniques except electron provided similar target coverage. When comparing conformal plan with IMRT and SBRT, there was no significant difference in planning target volume dose distribution. The mean volume of ipsilateral bony orbit received more than 20 Gy, a suggested threshold for bone growth inhibition. The V20 Gy was 73% for the ET, 57% for the LFT, 87% for the CRT, 65% for the IMRT, 66% for the tomotherapy, and 2.7% for the SBRT.

Conclusions: This work supports the potential use of IMRT and SBRT to spare normal tissues in these patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5301/tj.5000406DOI Listing
September 2017

Adjuvant radiotherapy for gastric carcinoma: 10 years follow-up of 244 cases from a single institution.

Asian Pac J Cancer Prev 2014 ;15(20):8871-6

Department of Radiation Oncology, Ankara Oncology Hospital, Ankara, Turkey E-mail :

Background: Postoperative chemoradiotherapy (CRT) of gastric carcinoma improves survival among high- risk patients. This study was undertaken to analyse long-term survival probability and the impact of certain covariates on the survival outcome in affected individuals.

Materials And Methods: Between January 2000 and December 2005, 244 patients with gastric cancer underwent adjuvant radiotherapy (RT) in our institution. Data were retrieved retrospectively from patient files and analysed with SPSS version 21.0.

Results: A total of 244 cases, with a male to female ratio of 2.2:1, were enrolled in the study. The median age of the patients was 52 years (range, 20-78 years). Surgical margin status was positive or close in 72 (33%) out of 220 patients. Postoperative adjuvant RT dose was 46 Gy. Median follow-up was 99 months (range, 79-132 months) and 23 months (range, 2-155 months) for surviving patients and all patients, respectively. Actuarial overall survival (OS) probability for 1-, 3-, 5- and 10-year was 79%, 37%, 24% and 16%, respectively. Actuarial progression free survival (PFS) probability was 69%, 34%, 23% and 16% in the same consecutive order. AJCC Stage I-II disease, subtotal gastrectomy and adjuvant CRT were significantly associated with improved OS and PFS in multivariate analyses. Surgical margin status or lymph node dissection type were not prognostic for survival.

Conclusions: Postoperative CRT should be considered for all patients with high risk of recurrence after gastrectomy. Beside well-known prognostic factors such as stage, lymph node status and concurrent chemotherapy, the type of gastrectomy was an important prognostic factor in our series. With our findings we add to the discussion on the definition of required surgical margin for subtotal gastrectomy. We consider that our observations in gastric cancer patients in our clinic can be useful in the future randomised trials to point the way to improved outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7314/apjcp.2014.15.20.8871DOI Listing
July 2015

Characteristics of childhood glial tumors, management approaches and life expectancy of the patients.

J BUON 2014 Jul-Sep;19(3):724-32

Kayseri Education and Research Hospital, Department of Radiation Oncology, Kayseri, Turkey.

Purpose: To evaluate the clinical characteristics, management approaches and life expectancy in pediatric patients with neuroepithelial glial tumors except ependymal tumors.

Methods: Between January 2003 and August 2008, 48 patients (30 boys, 18 girls; mean age: 10.9 ± 4.6 years) who were diagnosed with neuroepithelial glial tumors except ependymal tumors and underwent curative radiotherapy (RT) for inoperable, postoperative adjuvant or palliative for residual/recurrent disease at Dr. Abdurahman Yurtsalan Ankara Oncology Education and Research Hospital, Radiation Oncology Clinic, were retrospectively analyzed. Progression-free survival (PFS) and overall survival (OS) were evaluated in relation to sex, previous surgical procedure, pathological diagnosis, low/high grade and the histopathological grade of disease.

Results: The mean follow-up was 28.8 ± 4.8 months. The mean and median PFS were 36.2 months and 20 months, respectively, while mean and median OS were 40.3 months and 23 months, respectively. One-year PFS and OS were 65.8% and 71%, respectively, whereas 3-year PFS and OS were 36.3% and 42.3%, respectively. Univariate Cox regression model and Log-Rank test revealed no statistical significance. Prolonged PFS and OS were observed in boys compared to girls, those who underwent total/gross total resection compared to subtotal resection, those with low grade tumors compared to high-grade tumors, and those with histopathological grade I disease compared to grade IV disease (p>0.05). The PFS and OS times were shortened in patients who developed side effects at any time following surgery and RT, compared to those without any side effects (p>0.05).

Conclusion: Low-grade disease and total/gross total resection prolong PFS and OS in patients with childhood glial tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
November 2014

An investigation into the serum thioredoxin, superoxide dismutase, malondialdehyde, and advanced oxidation protein products in patients with breast cancer.

Ann Surg Oncol 2014 Dec 25;21(13):4139-43. Epub 2014 Jun 25.

Faculty of Medicine, Department of Medical Biochemistry, Gazi University, Ankara, Turkey.

Background: Reactive oxygen species (free radicals) play an important role in carcinogenesis. Extensive antioxidant defense mechanisms counteract free radicals in mammalian cells. Oxidative stress is a disturbance in the balance between the production of free radicals and antioxidant defenses. There is direct evidence that oxidative stress and lipid peroxidation (LPO) are linked to the etiology of breast cancer. The increasing global incidence of breast cancer emphasizes the need to understand the various mechanisms involved in breast tumorigenesis. The present study was undertaken to investigate the oxidative stress and antioxidant status in the blood samples of patients with breast cancer.

Methods: The present study was based on 23 women who were surgically treated at Gazi University, Faculty of Medicine, Department of General Surgery. The malondialdehyde (MDA) levels as an index of LPO along with the examination of superoxide dismutase (SOD) activities and advanced oxidation protein product (AOPP) and thioredoxin (Trx) levels were determined in the blood samples of 23 patients with breast cancer and 13 healthy controls.

Results: MDA, AOPP, and Trx levels and SOD activities were significantly higher in patients with breast cancer than the controls.

Conclusions: The results showed that oxidative stress may be related to breast cancer and especially some molecules, such as Trx and AOPP, may be useful biomarkers in breast cancer diagnosis and treatment. More detailed knowledge related to the pathophysiology of these molecules could provide valuable information on the origin and development of malignant tumors, such as breast cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1245/s10434-014-3859-3DOI Listing
December 2014

Reirradiation with robotic stereotactic body radiotherapy for recurrent nasopharyngeal carcinoma.

Asian Pac J Cancer Prev 2014 ;15(8):3561-6

Radiation Oncology, Ankara Oncology Hospital, Ankara, Turkey E-mail :

Background: Recurrent nasopharyngeal carcinoma (NPC) after previous radiotherapy is challenging. There is no standard approach for salvage treatment. Here we present toxicity and treatment results for recurrent NFC patients who underwent fractionated stereotactic radiotherapy (FSRT) as second line radiotherapy (RT).

Materials And Methods: Between April 2009 and July 2012, 24 patients, with a male to female ratio of 3:1, were treated with CykerKnife® FSRT for recurrent NFC in our institution. Seven out of 24 patients had metastatic recurrent disease. Median age was 53 years (range, 20-70 years). Initial RT dose was 70Gy. The time period between initial RT and FSRT was a median of 33.2 months. The median prescription dose for FSRT was 30Gy (range, 24-30 Gy) in a median of 5 fractions (range, 4-6).

Results: The median follow-up for all patients was 19.5 months (IQR: 12.2. -29.2 months). The locoregional control; progression free survival and overall survival (OS) rates for 1-, 2- and 3-year were 64%, 38%, 21%; 60%, 30%, 17% and 83%, 43%, 31%, respectively. Median OS for the entire cohort was 22 months (95% CI: 16.5-27.5). On multivariate analysis recurrent tumor stage was the only prognostic factor for OS (p=0.004). One patient exhibited grade III temporal lobe necrosis. One died because of grade IV mucositis and overlapping infection.

Conclusions: The treatment of recurrent NPC is controversial. Fractionated stereotactic radiotherapy is promising. However, the published trials are heterogeneous with respect to the selection criteria and treatment details. Prospective studies with long term follow-up data are warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7314/apjcp.2014.15.8.3561DOI Listing
January 2015

Comparison of early oncological results of diode laser surgery with radiotherapy for early glottic carcinoma.

Otolaryngol Head Neck Surg 2014 May 31;150(5):818-23. Epub 2014 Jan 31.

Ankara Oncology Education and Research Hospital, Clinic of Otolaryngology, Ankara, Turkey.

Objective: To evaluate the oncologic results of transoral endolaryngeal microscopic diode laser surgery (MDLS) and radiotherapy (RT) for T1 and T2 glottic carcinoma.

Study Design: Case series with planned chart review.

Setting: Ankara Oncology Education and Research Hospital.

Subjects And Methods: The study was conducted on a series of 140 cases of early glottic carcinoma (T1, T2) treated with MDLS or RT. The tumors were defined according to T stage and the involvement of the anterior commissure (AC).

Results: The 3-year locoregional control rate of MDLS and RT groups was 93.1% and 89.7%, respectively (P = .434). There was no difference in 3-year disease-free survival when comparing T1 and T2 tumors treated with MDLS and those treated with RT (P = .618 for T1, P = .084 for T2). There was no difference in disease-free survival when comparing AC- and AC+ tumors treated with MDLS and those treated with RT (P = .291 for AC- and P = .530 for AC+ tumors).

Conclusions: Microscopic diode laser surgery in early glottic cancer seems to be an oncologically safe procedure that has similar oncological results with RT. In T2 glottic tumors and AC involvement, the results with either treatment are less satisfactory.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/0194599814521775DOI Listing
May 2014

The results of 21-year experience of treating anal squamous cell carcinomas.

Ulus Cerrahi Derg 2014 1;30(1):14-7. Epub 2014 Mar 1.

Clinic of Radiation Oncology, Ankara Oncology Teaching and Training Hospital, Ankara, Turkey.

Objective: Anal squamous cell carcinomas are one of the rare cancer types. Due to the developments in the past 35 years, surgery is no longer the first treatment of choice. The aim of this study was to retrospectively examine the outcomes of 24 patients treated in a single center in the last 21 years in terms of applied treatment, local relapse, distant metastasis, post-treatment complications, and survival.

Material And Methods: Data obtained from 24 anal squamous cell carcinoma patients, who were treated in Ankara Oncology Research and Education Hospital between 1990 and 2010, were retrospectively evaluated.

Results: Of the 24 patients, 16 had anal canal squamous cell carcinoma and eight had perianal squamous cell carcinoma. All of the patients with anal canal squamous cell carcinoma (n=16) received chemoradiotherapy. Three of these patients who did not respond to treatment, underwent abdominoperineal resection. The patients with perianal squamous cell tumors were treated by local excision. During the follow -ups, seven patients experienced local relapse, and one patient had distant organ metastasis. Only one patient died. Five-year disease free survival rate was found as 66%.

Conclusion: Our findings suggest that the first alternative in the treatment of anal squamous cell tumors should be chemoradiotherapy; and surgery seems to be the appropriate approach for the non-responsive and relapsing cases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5152/UCD.2014.2399DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4379785PMC
May 2015

Optic nerve glioma treatment with fractionated stereotactic radiotherapy.

J Neurosurg Pediatr 2013 May 15;11(5):596-9. Epub 2013 Mar 15.

Clinic of Radiation Oncology, Dr. Abdurrahman Yurtarslan Ankara Oncology Education and Research Hospital, Demetevler, Ankara, Turkey.

In the current report, the authors present a case of optic nerve glioma treated with fractionated stereotactic radiotherapy (FSRT). An 11-year-old girl was referred to our clinic with increasing proptosis over a 1-year period. At that time orbital MRI revealed a 20 × 17-mm mass in the right retroorbital lipomatous tissue, and FSRT was delivered to the tumor using the CyberKnife. During the 1.5-year follow-up, ophthalmological examinations did not indicate any treatment-related severe toxicity, and posttreatment MRI demonstrated marked regression of the lesion to 13 × 10 mm. Given the scarcity of reports on this subject, the authors support more extended studies of the CyberKnife for the effective treatment of this relatively common childhood tumor.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2013.2.PEDS11435DOI Listing
May 2013

Gliosarcoma: a study of four cases.

Rare Tumors 2010 Jun 30;2(2):e37. Epub 2010 Jun 30.

Department of Radiation Oncology, Faculty of Medicine, Ankara University, Turkey.

Gliosarcomas (GS) are highly malignant and rare tumors of the central nervous system with a poor prognosis. We report here on four patients with GS, the median survival for whom was 9.25 months. Prognosis of GS remains poor, and a multidisciplinary approach (surgery, radiation therapy, and chemotherapy) seems to be associated with slightly more prolonged survival times.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4081/rt.2010.e37DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2994509PMC
June 2010

Role of Radionuclide Therapy as Adjuvant to Palliative External Beam Radiotherapy for Painful Multiple Skeletal Metastasis.

World J Oncol 2010 Aug 29;1(4):158-166. Epub 2010 Aug 29.

Ankara University School of Medicine Department of Nuclear Medicine, Turkey.

Background: The aim of this study was to evaluate the palliative efficacy of localized external radiotherapy (RT) combined with systemic radionuclide (RN) therapy in patients who had multiple painful osseous metastases of different primary origins.

Methods: Thirty-three patients initially local external radiotherapy was delivered to the most symptomatic region in all patients. Then they received either Re 186 HEDP or Sm 153 EDTMP. The performance status was assessed according to ECOG scale. Before treatment, at the end of the radiotherapy and after the four weeks of systemic radionuclide therapy, analgesic intake and pain status were recorded by the RTOG scoring system, and EORTC QLQ C30 (Version 3.0 Turkish) questionnaire was performed to evaluate the quality of life.

Results: Improved performances of 33.3% for post radiation therapy and 50% for post radionuclide therapy in the ECOG scale were observed. Statistically significant correlations were found between the primary origins and decreased pain and analgesic intake (p < 0.05), but no differences were observed on the self assessment quality of life questionnaire.

Conclusions: Both Re 186 HEDP, Sm 153 EDTMP are effective and safe in bone pain palliation as an adjuvant to local field radiation therapy of breast and prostate cancer patients, who also continued to receive chemotherapy and/or hormontherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4021/wjon235wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5649856PMC
August 2010

Lack of a time-dependent effect of melatonin on radiation-induced apoptosis in cultured rat lymphocytes.

Cell Biol Int 2007 Oct 27;31(10):1144-9. Epub 2007 Mar 27.

Baskent University Faculty of Medicine, Department of Medical Biology and Genetics, Ankara, Turkey.

Ionizing radiation is widely used for the treatment of solid tumors and it is thought to act by directly targeting tumor clonogens, also known as stem cells. Apoptosis is a genetically programmed mechanism of cell death often characterized by internucleosomal DNA cleavage. Although it has been previously shown that lymphocytes readily undergo apoptosis in patients receiving anticancer drugs or treatment with ionizing radiation, this is the first study to investigate the influence of radiotherapy and melatonin on apoptosis in rat lymphocytes at two different times of the day. Melatonin, a free radical scavenger, is an endogenous neurohormone predominantly synthesized in and secreted by the pineal gland. It has been shown that melatonin inhibits apoptosis in normal cells but it increases the rate of apoptosis in various cancer cells. Therefore, in the present study, the effect of melatonin on apoptosis in cultured lymphocytes was studied after total body irradiation (TBI) was given to rats in the morning (1 HALO) or evening (13 HALO) with morphological and DNA fragmentation analysis. Two-way analysis of variance (ANOVA) revealed that radiation increased the rate of apoptosis in rat lymphocytes after TBI, and melatonin treatment did not reduce the rate of apoptosis after TBI at either time point. We conclude that the lack of an effect of melatonin on the apoptosis rate in rat lymphocytes might be due to the dose-dependent effect of melatonin, the time course of apoptosis investigated, or the cell type in which apoptosis was examined.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cellbi.2007.03.030DOI Listing
October 2007

Cases of glioblastoma multiforme metastasizing to spinal cord.

Neurol India 2006 Dec;54(4):428-30

Department of Radiation Oncology, Ankara University Faculty of Medicine, Cebeci Hospital, Dikimevi Ankara, Turkey.

Cases of glioblastoma multiforme (GBM) metastasizing to the leptomeninx or the intramedullary spine are quite rare and prognoses are relatively poor. We present three cases of GBM with spinal metastasis, one of which also had leptomeningeal dissemination. Three patients with GBM were admitted to our clinic for postoperative radiotherapy after surgery. Leptomeningeal metastasis and dissemination were diagnosed with magnetic resonance imaging. Radiotherapy provided only temporary relief from pain with small improvement in neurological deficit but no survival advantage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/0028-3886.28122DOI Listing
December 2006

Ghrelin may reduce radiation-induced mucositis and anorexia in head-neck cancer.

Med Hypotheses 2007 9;68(3):538-40. Epub 2006 Oct 9.

Department of Radiation Oncology, Ankara University School of Medicine, Cebeci Hospital, Dikimevi, Ankara 06590, Turkey.

Body weight loss is common in cancer patients, and is often associated with poor prognosis, it greatly impairs quality of life (QOL). Radiation therapy (RT) is used in head and neck cancers (HNC) either as a primary treatment or as an adjuvant therapy to surgery. Patients with HNC are most susceptible to malnutrition especially due to anorexia, which is aggravated by RT. Multiple pro-inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1beta (IL-1beta), interferon (IFN)-gamma and tumor necrosis factor-alpha(TNF-alpha), have been all associated with the development of both anorexia and oral mucositis. Radiation-induced mucositis occurs in almost all patients, who are treated for HNC, it could also cause weight loss. Ghrelin is a novel 28-amino acid peptide, which up-regulates body weight through appetite control, increase food intake, down-regulate energy expenditure and induces adiposity. Furthermore, ghrelin inhibits pro-inflammatory cytokines such as IL-1alpha, IL-1beta, TNF-alpha which may cause oral mucositis and aneroxia, which are the results of weight loss. Thus weight loss during RT is an early indicator of nutritional decline, we propose that recombinant ghrelin used prophylactically could be useful as an appetite stimulant; and preventive of mucositis because of its anti-inflammatory effect, it might help patients maintain weight over the course of curative RT of the HNC and can improve specific aspects of QOL. This issue warrants further studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mehy.2006.08.022DOI Listing
April 2007

Carnosine may reduce lung injury caused by radiation therapy.

Med Hypotheses 2006 10;66(5):957-9. Epub 2006 Jan 10.

Ankara University School of Medicine, Department of Radiation Oncology, Cebeci Hospital, Dikimevi, Turkey.

Ionising radiation is known one of the most effective tools in the therapy of cancer but in many thoracic cancers, the total prescribed dose of radiation that can be safely administered to the target volume is limited by the risk of complications arising in the normal lung tissue. One of the major reasons for cellular injury after radiation is the formation of reactive oxygen species (ROS). Radiation pneumonitis is an acute phase side-effect which generally subsides after a few weeks and is followed by a chronic phase characterized by inflammation and fibrosis, that can develop months or years after irradiation. Carnosine is a dipeptide composed by the amino acids beta-histidine and l-alanine. The exact biological role of carnosine is not totally understood, but several studies have demonstrated that it possesses strong and specific antioxidant properties, protects against radiation damage,and promotes wound healing. The antioxidant mechanism of carnosine is attributed to its chelating effect against metal ions, superoxide dismutase (SOD)-like activity, ROS and free radicals scavenging ability . Either its antioxidant or anti-inflammatuar properties, we propose that carnosine ameliorates irradiation-induced lung injury. Thus, supplementing cancer patients to whom applied radiation therapy with carnosine, may provide an alleviation of the symptoms due to radiation-induced lung injury. This issue warrants further studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mehy.2005.11.023DOI Listing
May 2006

Electrocardiographic evidence of heart metastasis from a primary lung cancer.

Saudi Med J 2005 Jul;26(7):1139-40

Department of Radiation Oncology, School of Medicine, Ankara University, Ankara, Turkey.

View Article and Find Full Text PDF

Download full-text PDF

Source
July 2005

Lipid peroxidation and antioxidant activity in patients in labor with nonreassuring fetal status.

Eur J Obstet Gynecol Reprod Biol 2006 Jan 13;124(1):27-31. Epub 2005 Jun 13.

Department of Perinatology, SSK Ankara Maternity and Women's Health Teaching Hospital, Ankara, Turkey.

Objective: The aim of our study was to evaluate lipid peroxidation products and antioxidant enzyme activity in placental tissue and umbilical cord blood, as a marker for fetal hypoxia in patients in labor with nonreassuring fetal status.

Study Design: Umbilical cord arterial blood and placental tissue samples were collected from 24 patients with term pregnancies in labor and nonreassuring fetal heart rate (FHR) patterns (study) and 24 women with normal pregnancies in labor and normal FHR tracings (controls) for determination of malondialdehyde (MDA) as a marker for lipid peroxidation and superoxide dismutase (SOD) for the antioxidant activity. Measured values were compared statistically between two groups using independent samples t-test or Mann-Whitney U-test.

Results: The median 1min Apgar score was 8 (range 4-9) in the study group and 9 (range 8-10) in the control group, respectively (p < 0.001). There was no statistically significant difference between study and control groups in terms of mean 5 min Apgar scores (p > 0.05). Placental MDA levels in patients with nonreassuring fetal status were found to be significantly elevated compared to the control group (12.14 nmol/g tissue versus 9.75 nmol/g tissue; p < 0.01). The placental SOD activity in the study group was significantly higher (p < 0.01) compared to controls (3.57 U/mg protein versus 2.63 U/mg protein). The umbilical cord blood MDA levels in the study group were higher than in normal pregnancies (4.99 nmol/mL, 3.88 nmol/mL; p < 0.05). The activity of SOD in umbilical cord blood was significantly higher (p < 0.001) in patients with nonreassuring fetal status when compared with the control group (11.62 versus 6.95 U/mL).

Conclusion: Lipid peroxidation products and antioxidant functions were elevated in the umbilical cord blood and placenta of patients having nonreassuring FHR tracings during labor. These findings indicate that lipid peroxidation products in placenta and umbilical cord blood can be used as a possible marker for fetal hypoxia during labor and SOD levels may discriminate acute from chronic hypoxia. Further investigations are needed with large number of series to clarify the variations of lipid peroxidation and antioxidant activity due to acute or chronic fetal hypoxia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejogrb.2005.04.014DOI Listing
January 2006

Antithrombin III attenuates pulmonary tissue injury caused by mesenteric ischemia-reperfusion.

Am J Surg 2005 Feb;189(2):161-6

Department of General Surgery, Pamukkale University, Medical School, Denizli, Turkey.

Background: Mesenteric ischemia-reperfusion (I/R) is a well-known event causing both local and remote organ injuries, including the lungs. Recently, several studies indicated that activated leukocyte-endothelial cell interactions play an important role in the mechanisms of these injuries. As a natural inhibitor of serine proteases, antithrombin was shown previously to attenuate the tissue damage after local I/R in several organ systems. Here, we examined the effects of antithrombin on pulmonary injury after mesenteric I/R.

Methods: Wistar albino rats underwent median laparotomy and were randomized into 3 groups: (1) sham-operated control (n = 12), (2) 60 minutes of mesenteric ischemia and 3 hours of reperfusion (n = 12), and (3) antithrombin-pretreated (250 U/kg) group before the I/R (n = 12). At the end of reperfusion, animals were killed and neutrophil sequestration, myeloperoxidase (MPO) activity, and Evans blue dye extravasation in the lung parenchyma were assessed and compared.

Results: There was a statistically significant increase in the quantity of Evans blue dye concentration, leukocyte sequestration, and MPO activity in the I/R group when compared with the control group. The pretreatment of animals with antithrombin significantly decreased the pulmonary injury characterized by increased Evans blue dye extravasation, leukocyte sequestration, and MPO activity.

Conclusion: The data of the present study suggest that mesenteric ischemia and reperfusion induces pulmonary injury characterized by activated neutrophil sequestration and increased microvascular leakage in the lungs. A significant attenuation of intestinal I/R-related lung injury with the use of antithrombin concentrate warrants further studies to elucidate the potential role of this natural serine protease inhibitor in clinical settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.amjsurg.2004.11.003DOI Listing
February 2005

Antioxidant tolerance of kidney after irradiation.

Indian J Exp Biol 2003 Mar;41(3):267-9

Department of Biochemistry, Medical Faculty, Gazi University, Ankara, Turkey.

Different doses of irradiation were performed in which group 1 (non-irradiated), group 2 (8 Gy/single dose/whole body) and group 3 (15 Gy/single dose/whole body) were formed of guinea pigs. After 24 hr of radiation exposure the levels of lipid peroxidation product, malondialdehyde, (MDA), glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured in the whole kidney. The MDA content increased in animals irradiated with 8 and 15 Gy. And group 3 showed an increase the level of MDA. GSH contents of kidney in group 2 and 3 increased. The activity of SOD decreased markedly in group 3 when compared with control group. The activity of GSH-Px decreased significantly in group 2 and group 3 in comparison to controls. It may be concluded that a high dose of ionizing irradiation cause excessive oxidative stress in kidney.
View Article and Find Full Text PDF

Download full-text PDF

Source
March 2003

The effect of different dialysis membranes on oxidative stress and selenium status.

Clin Chim Acta 2004 Aug;346(2):153-60

Department of Medical Biochemistry, Duzce School of Medicine, Abant Izzet Baysal University, 81620 Konuralp-Duzce, Turkey.

Background: Oxidative stress is an important risk factor for the development and progression of several complications in hemodialysis patients. The aim of this study was to evaluate the effects of two different dialysis membranes on oxidative stress and selenium status.

Methods: Forty long-term dialysis patients and 20 age-matched healthy controls were enrolled into our study. Serum malondialdehyde (MDA) and selenium (Se) concentrations, and glutathione peroxidase (GSH-Px) activities were determined before and after hemodialysis (HD) using a hemophan (H) or a polysulfone (PS) membrane.

Results: MDA levels in the HD patients were significantly higher than those in the control group (p < 0.001). GSH-Px activity and selenium concentrations were significantly lower in HD patients compared to the control group (p < 0.001). MDA levels were significantly increased (p < 0.05); GSH-Px activity and selenium concentrations were significantly reduced (p < 0.001) in the PS membrane group compared to H membrane group after HD.

Conclusions: Comparing with H membrane, PS membrane caused more oxidative stress and lower levels of Se in HD patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cccn.2004.03.025DOI Listing
August 2004

Effects of two different high doses of irradiation on antioxidant system in the liver of guinea pigs.

Eksp Onkol 2004 Mar;26(1):71-4

Gazi University Medical Faculty Department of Biochemistry, Ankara, Turkey.

Aim: To examine the state of the oxidant-antioxidant system in the liver of guinea pig caused by high doses of ionizing radiation in the early period.

Methods: The research was carried out on guinea pigs irradiated with the doses of 8 Gy (group 2) or 15 Gy (group 3) (single dose/whole body) in comparison with control group (group 1). The levels of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH), the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the levels of selenium in the liver were measured.

Results: TBARS levels in the irradiated animals were markedly higher than those in controls. In group 3, GSH levels and GSH-Px activity were significantly increased while activity of SOD and CAT were significantly decreased compared to groups 1 and 2. Liver selenium levels were not influenced by irradiation.

Conclusion: The data have shown that gamma-irradiation at the doses of 8 Gy or 15 Gy results in significant increase in free radical formation while antioxidant enzymes were affected only at a dose of 15 Gy.
View Article and Find Full Text PDF

Download full-text PDF

Source
March 2004

Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses.

Am J Surg 2002 Aug;184(2):160-5

Department of General Surgery, Pamukkale University Medical School, PK-32, 20003, Denizli, Turkey.

Background: Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats.

Methods: Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, n = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, n = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, n = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared.

Results: On postoperative day 6 the mean bursting pressures were 149.6 +/- 4.8, 69.8 +/- 13.5, and 121.8 +/- 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 +/- 29.6, 263.1 +/- 10.0, and 376.0 +/- 33.8 microg/mg for groups I, II, III respectively (P = 0.005).

Conclusions: This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0002-9610(02)00908-xDOI Listing
August 2002