Publications by authors named "Alan Stockdale"

10 Publications

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On-demand manufacturing of clinical-quality biopharmaceuticals.

Nat Biotechnol 2018 Oct 1. Epub 2018 Oct 1.

Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.

Conventional manufacturing of protein biopharmaceuticals in centralized, large-scale, single-product facilities is not well-suited to the agile production of drugs for small patient populations or individuals. Previous solutions for small-scale manufacturing are limited in both process reproducibility and product quality, owing to their complicated means of protein expression and purification. We describe an automated, benchtop, multiproduct manufacturing system, called Integrated Scalable Cyto-Technology (InSCyT), for the end-to-end production of hundreds to thousands of doses of clinical-quality protein biologics in about 3 d. Unlike previous systems, InSCyT includes fully integrated modules for sustained production, efficient purification without the use of affinity tags, and formulation to a final dosage form of recombinant biopharmaceuticals. We demonstrate that InSCyT can accelerate process development from sequence to purified drug in 12 weeks. We used integrated design to produce human growth hormone, interferon α-2b and granulocyte colony-stimulating factor with highly similar processes on this system and show that their purity and potency are comparable to those of marketed reference products.
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October 2018

A novel pilot study using spatial frequency domain imaging to assess oxygenation of perforator flaps during reconstructive breast surgery.

Ann Plast Surg 2013 Sep;71(3):308-15

Division of Plastic and Reconstructive Surgery, Department of Surgery, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.

Introduction: Although various methods exist for monitoring flaps during reconstructive surgery, surgeons primarily rely on assessment of clinical judgment. Early detection of vascular complications improves rate of flap salvage. Spatial frequency domain imaging (SFDI) is a promising new technology that provides oxygenation images over a large field of view. The goal of this clinical pilot study is to use SFDI in perforator flap breast reconstruction.

Methods: Three women undergoing unilateral breast reconstruction after mastectomy were enrolled for our study. The SFDI system was deployed in the operating room, and images acquired over the course of the operation. Time points included images of each hemiabdominal skin flap before elevation, the selected flap after perforator dissection, and after microsurgical transfer.

Results: Spatial frequency domain imaging was able to measure tissue oxyhemoglobin concentration (ctO2Hb), tissue deoxyhemoglobin concentration, and tissue oxygen saturation (stO2). Images were created for each metric to monitor flap status and the results quantified throughout the various time points of the procedure. For 2 of 3 patients, the chosen flap had a higher ctO2Hb and stO2. For 1 patient, the chosen flap had lower ctO2Hb and stO2. There were no perfusion deficits observed based on SFDI and clinical follow-up.

Conclusions: The results of our initial human pilot study suggest that SFDI has the potential to provide intraoperative oxygenation images in real-time during surgery. With the use of this technology, surgeons can obtain tissue oxygenation and hemoglobin concentration maps to assist in intraoperative planning; this can potentially prevent complications and improve clinical outcome.
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September 2013

Effective low-dose escalation of indocyanine green for near-infrared fluorescent sentinel lymph node mapping in melanoma.

Ann Surg Oncol 2013 Jul 26;20(7):2357-63. Epub 2013 Feb 26.

Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA.

Background: Regional lymph node metastasis is the strongest prognostic factor in patients with melanoma. Published reports that used lymphoscintigraphy with radioactive colloids and blue dye demonstrated accurate sentinel lymph node (SLN) identification in inguinal nodes and axillary nodes, but decreased accuracy in cervical, popliteal, epitrochlear, and parascapular nodes. Near-infrared imaging (NIR) may utilize indocyanine green (ICG) to improve SLN identification. The safety, feasibility and optimal dose of albumin-bound ICG (ICG:HSA) was assessed by NIR to improve SLN mapping in patients with melanoma.

Methods: Twenty-five consecutive patients with biopsy-proven melanoma underwent standard SLN mapping with preoperatively administered technetium-99 m nanocolloid (Tc-99 m). Intraoperative NIR fluorescence imaging was performed after injection of 1.0 ml of 100, 250 or 500 μM of ICG:HSA in four quadrants around the primary lesion.

Results: NIR fluorescent imaging demonstrated accuracy of 98 % when compared with radioactive colloid. A total of 65 lymph nodes were identified (65 with Tc-99 m, 64 with ICG:HSA). Overall, successful mapping that used either technique was 96 % as one patient failed to map with either modality. As the dose of ICG was increased, the signal-to-background ratio increased from a median of 3.1 to 8.4 to 10.9 over the range of 100, 250, and 500 μM, respectively.

Conclusions: SLN mapping with ICG:HSA is feasible and accurate in melanoma. ICG has the added advantage of a low cost and an intraoperative technique that does not alter the surgical field, thus allowing for easy identification of SLNs.
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July 2013

First-in-human pilot study of a spatial frequency domain oxygenation imaging system.

J Biomed Opt 2011 Aug;16(8):086015

Beth Israel Deaconess Medical Center, Division of Hematology∕Oncology, Department of Medicine, Boston, Massachusetts 02215, USA.

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.
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August 2011

Real-time simultaneous near-infrared fluorescence imaging of bile duct and arterial anatomy.

J Surg Res 2012 Jul 14;176(1):7-13. Epub 2011 Jul 14.

Department of Medicine, Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.

Background: We hypothesized that two independent wavelengths of near-infrared (NIR) fluorescent light could be used to identify bile ducts and hepatic arteries simultaneously, and intraoperatively.

Materials And Methods: Three different combinations of 700 and 800 nm fluorescent contrast agents specific for bile ducts and arteries were injected into N = 10 35-kg female Yorkshire pigs intravenously. Combination 1 (C-1) was methylene blue (MB) for arterial imaging and indocyanine green (ICG) for bile duct imaging. Combination 2 (C-2) was ICG for arterial imaging and MB for bile duct imaging. Combination 3 (C-3) was a newly developed, zwitterionic NIR fluorophore ZW800-1 for arterial imaging and MB for bile duct imaging. Open and minimally invasive surgeries were imaged using the fluorescence-assisted resection and exploration (FLARE) surgical imaging system and minimally invasive FLARE (m-FLARE) imaging systems, respectively.

Results: Although the desired bile duct and arterial anatomy could be imaged with contrast-to-background ratios (CBRs) ≥ 6 using all three combinations, each one differed significantly in terms of repetition and prolonged imaging. ICG injection resulted in high CBR of the liver and common bile duct (CBD) and prolonged imaging time (120 min) of the CBD (C-1). However, because ICG also resulted in high background of liver and CBD relative to arteries, ICG produced a lower arterial CBR (C-2) at some time points. C-3 provided the best overall performance, although C-2, which is clinically available, did enable effective laparoscopy.

Conclusions: We demonstrate that dual-channel NIR fluorescence imaging provides simultaneous, real-time, and high resolution identification of bile ducts and hepatic arteries during biliary tract surgery.
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July 2012

Near-infrared fluorescence imaging of thoracic duct anatomy and function in open surgery and video-assisted thoracic surgery.

J Thorac Cardiovasc Surg 2011 Jul 7;142(1):31-8.e1-2. Epub 2011 Apr 7.

Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Mass 02215, USA.

Objective: Chylothorax resulting from thoracic duct damage is often difficult to identify and repair. We hypothesized that near-infrared fluorescent light could provide sensitive, real-time, high-resolution intraoperative imaging of thoracic duct anatomy and function.

Methods: In 16 rats, 4 potential near-infrared fluorescent lymphatic tracers were compared in terms of signal strength and imaging time: indocyanine green, the carboxylic acid of IRDye 800CW (LI-COR, Lincoln, Neb), indocyanine green adsorbed to human serum albumin, and IRDye 800CW conjugated covalently to human serum albumin. Optimal agent was validated in 8 pigs approaching human size (n = 6 by open surgery with FLARE imaging system [Beth Israel Deaconess Medical Center, Boston, Mass] and n = 2 by video-assisted thoracoscopic surgery minimally invasive [m-FLARE] imaging system [Beth Israel Deaconess Medical Center]). Lymphatic tracer injection site, dose, and timing were optimized.

Results: For signal strength, sustained imaging time, and clinical translatability, the best lymphatic tracer was indocyanine green, which is already Food and Drug Administration approved for other indications. In pigs, a simple subcutaneous injection of indocyanine green into lower leg (≥ 36 μg/kg), provided thoracic duct imaging with onset of about 5 minutes after injection, sustained imaging for at least 60 minutes after injection, and signal-to-background ratio of at least 2. With this technology, normal thoracic duct flow, collateral flow, injury models, and repair models could all be observed under direct visualization.

Conclusions: Near-infrared fluorescent light could provide sensitive, sustained, real-time imaging of thoracic duct anatomy and function during both open and video-assisted thoracoscopic surgery in animal models.
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July 2011

Toward optimization of imaging system and lymphatic tracer for near-infrared fluorescent sentinel lymph node mapping in breast cancer.

Ann Surg Oncol 2011 Sep 1;18(9):2483-91. Epub 2011 Mar 1.

Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.

Background: Near-infrared (NIR) fluorescent sentinel lymph node (SLN) mapping in breast cancer requires optimized imaging systems and lymphatic tracers.

Materials And Methods: A small, portable version of the FLARE imaging system, termed Mini-FLARE, was developed for capturing color video and two semi-independent channels of NIR fluorescence (700 and 800 nm) in real time. Initial optimization of lymphatic tracer dose was performed using 35-kg Yorkshire pigs and a 6-patient pilot clinical trial. More refined optimization was performed in 24 consecutive breast cancer patients. All patients received the standard of care using (99m)Technetium-nanocolloid and patent blue. In addition, 1.6 ml of indocyanine green adsorbed to human serum albumin (ICG:HSA) was injected directly after patent blue at the same location. Patients were allocated to 1 of 8 escalating ICG:HSA concentration groups from 50 to 1000 μM.

Results: The Mini-FLARE system was positioned easily in the operating room and could be used up to 13 in. from the patient. Mini-FLARE enabled visualization of lymphatic channels and SLNs in all patients. A total of 35 SLNs (mean = 1.45, range 1-3) were detected: 35 radioactive (100%), 30 blue (86%), and 35 NIR fluorescent (100%). Contrast agent quenching at the injection site and dilution within lymphatic channels were major contributors to signal strength of the SLN. Optimal injection dose of ICG:HSA ranged between 400 and 800 μM. No adverse reactions were observed.

Conclusions: We describe the clinical translation of a new NIR fluorescence imaging system and define the optimal ICG:HSA dose range for SLN mapping in breast cancer.
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September 2011

The FLARE intraoperative near-infrared fluorescence imaging system: a first-in-human clinical trial in perforator flap breast reconstruction.

Plast Reconstr Surg 2010 Nov;126(5):1472-1481

Boston, Mass.; and Leiden, The Netherlands From the Division of Plastic and Reconstructive Surgery, Department of Surgery, the Divisions of General Medicine and Primary Care and Hematology/Oncology, Department of Medicine, and the Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, and the Department of Surgery, Leiden University Medical Center.

Background: The ability to determine flap perfusion in reconstructive surgery is still primarily based on clinical examination. In this study, the authors demonstrate the use of an intraoperative, near-infrared fluorescence imaging system for evaluation of perforator location and flap perfusion.

Methods: Indocyanine green was injected intravenously in six breast cancer patients undergoing a deep inferior epigastric perforator flap breast reconstruction after mastectomy. Three dose levels of indocyanine green were assessed using the fluorescence-assisted resection and exploration (FLARE) imaging system. This system uses light-emitting diodes for fluorescence excitation, which is different from current commercially available systems. In this pilot study, the operating surgeons were blinded to the imaging results.

Results: Use of the FLARE system was successful in all six study subjects, with no complications or sequelae. Among the three dose levels, 4 mg per injection resulted in the highest observed contrast-to-background ratio, signal-to-background ratio, and signal-to-noise ratio. However, because of small sample size, the authors did not have sufficient power to detect statistical significance for these pairwise comparisons at the multiple-comparison adjusted type I error of 0.017. Six milligrams per injection provided a similar contrast-to-background ratio but also a higher residual background signal.

Conclusion: Based on this pilot study, the authors conclude that near-infrared assessment of perforator flap breast reconstruction is feasible with a light-emitting diode-based system, and that a dose of 4 mg of indocyanine green per injection yields the best observed contrast-to-background ratio compared with a dose of 2 or 6 mg for assessment of flap perfusion.
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November 2010

Primary care physicians' use of family history for cancer risk assessment.

BMC Fam Pract 2010 Jun 3;11:45. Epub 2010 Jun 3.

Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont 05405, USA.

Background: Family history (FH) assessment is useful in identifying and managing patients at increased risk for cancer. This study assessed reported FH quality and associations with physician perceptions.

Methods: Primary care physicians practicing in two northeastern U.S. states were surveyed (n = 880; 70% response rate). Outcome measures of FH quality were extent of FH taken and ascertaining age at cancer diagnosis for affected family members. Predictors of quality measured in this survey included: perceived advantages and disadvantages of collecting FH information, knowledge of management options, access to supportive resources, and confidence in ability to interpret FH.

Results: Reported collection of information regarding second degree blood relatives and age of diagnosis among affected relatives was low. All hypothesized predictors were associated with measures of FH quality, but not all were consistent independent predictors. Perceived advantages of taking a family history, access to supportive resources, and confidence in ability to identify and manage higher risk patients were independent predictors of both FH quality measures. Perceived disadvantages of taking a family history was independently associated one measure of FH quality. Knowledge of management options was not independently associated with either quality measure.

Conclusions: Modifiable perception and resource factors were independently associated with quality of FH taking in a large and diverse sample of primary care physicians. Improving FH quality for identification of high risk individuals will require multi-faceted interventions.
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June 2010

Interviews with primary care physicians regarding taking and interpreting the cancer family history.

Fam Pract 2008 Oct 1;25(5):334-40. Epub 2008 Sep 1.

Hematology/Oncology Division, University of Vermont, Burlington, VT 05405, USA.

Background: The cancer family history can be used to stratify risk and guide management regarding screening and prevention of cancer.

Objective: The current study was designed to gain understanding of specific barriers to obtaining and using the cancer family history for the primary care physician.

Methods: Interviews were conducted with structured samples of specialists in family medicine, general internal medicine and gynaecology in three settings in two north-eastern states. A medical anthropologist conducted interviews based on a topical outline; transcripts were systematically analyzed by a research team to identify major themes expressed by participants.

Results: Among 40 urban, suburban and rural physicians interviewed, 40% were women and medical school graduation years ranged from 1963 to 2000. These physicians regarded cancer family history as important, but process and content were not standardized. Major barriers to more focused use of this information included limitations of patients' family history knowledge; time needed to clarify and interpret this information and the lack of clear and accessible guidelines to assist in collection, interpretation and management decisions for average, moderate and higher risk patients. Language and cultural barriers made it more difficult to collect family histories in some populations.

Conclusions: Barriers to effective application of cancer family history information included limitations of patients' family history information; lack of methods to systematically and efficiently focus on the most useful information and lack of accessible guidance for risk stratification and management. Results suggest a need for support addressing these concerns to better utilize several readily available cancer risk management opportunities.
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October 2008