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Cameron Wright

Publications and source records attributed to Cameron Wright.

7 recordsLinked to original sources
PubMed2006

Concurrent cisplatin, 5-FU, paclitaxel, and radiation therapy in patients with locally advanced esophageal cancer.

PURPOSE: Phase I-II data regarding neoadjuvant cisplatin, 5-fluorouracil (5-FU), paclitaxel, and radiation (PFT-R) from our institution demonstrated encouraging pathologic complete response (pCR) rates. This article updates our experience with PFT-R, and compares these results to our experience with cisplatin, 5-FU, and radiation therapy (PF-R) in locally advanced esophageal cancer. PATIENTS AND METHODS: We searched the Massachusetts General Hospital cancer registry for esophageal cancer patients treated with radiation therapy and chemotherapy between 1994-2002. Records of patients treated with curative, neoadjuvant therapy were examined for chemotherapeutic regimen. Outcomes of patients treated with PF-R or PFT-R were assessed for response to therapy, toxicity, and survival. RESULTS: A total of 177 patients were treated with neoadjuvant therapy with curative intent; 164 (93%) received PF-R (n=81) or PFT-R (n=83). Median overall survival was 24 months. After a median follow-up of 54 months for surviving patients, 3-year overall survival was 40% with no significant difference between PF-R (39%) and PFT-R (42%). CONCLUSIONS: Our findings failed to demonstrate an improvement in pCR or survival with PFT-R vs. PF-R. These results do not support this regimen of concurrent neoadjuvant PFT-R in esophageal cancer, and suggest that further investigations into alternative regimens and novel agents are warranted.

Adenocarcinoma↗
PubMed2004

Twice-daily radiotherapy as concurrent boost technique during two chemotherapy cycles in neoadjuvant chemoradiotherapy for resectable esophageal carcinoma: mature results of phase II study.

PURPOSE: To determine the toxicities of neoadjuvant chemoradiotherapy using a three-drug regimen (cisplatin, 5-fluorouracil, and paclitaxel) and a conventional radiotherapy (RT) schedule combined with a concurrent boost technique during chemotherapy cycles, and to determine the rate of tumor response, overall survival, and impact of pathologic tumor response on survival. METHODS AND MATERIALS: The eligibility criteria included resectable adenocarcinoma or squamous cell carcinoma (T2-T3N0-N1M0), performance score < or =2, and no significant comorbidities for trimodality therapy. Chemotherapy consisted of two cycles of cisplatin, 5-fluorouracil, and paclitaxel. A concurrent boost technique was used in RT for 2 levels of radiation doses: 58.5 Gy in 34 fractions within 5 weeks to the gross tumor volume and 45 Gy in 25 fractions within 5 weeks to the clinical target volume by administering a boost dose of 13.5 Gy in 9 fractions, 1.5 Gy/fraction, as a second daily fraction for 9 days on Days 1-5 and 29-32 of the chemotherapy cycles. RESULTS: We enrolled 46 patients in the study. The paclitaxel dose was started at 75 mg/m(2) (n = 7) and escalated to 125 mg/m(2) (n = 5), at which point, dose-limiting toxicities occurred. Thereafter, paclitaxel at 100 mg/m(2) was used for an additional 34 patients. Toxicities included Grade 4 neutropenia (22%), febrile neutropenia requiring hospital admission (20%), Grade 3 (48%) and Grade 4 (7%) acute esophagitis, and paclitaxel-associated anaphylaxis (4%). Of the 46 patients, 3 (6.5%) died of treatment-related complications, 1 of pneumonia during induction therapy and 2 of postoperative complications (5% of the 40 patients who underwent resection). The histopathologic tumor response was a pathologic complete response (pT0N0) in 18 (45%) of 40 patients who underwent resection and 18 (39%) of all 46 registered patients. Minimal residual disease (pT1N0) at the primary site was present in 5 (11%) and residual disease in 23 (50%) of all 46 patients. The minimal follow-up for all long-term survivors (n = 16) was 5.5 years. The median survival time was 34 months, and the overall survival rate was 57%, 50%, and 37% at 2, 3, and 5 years, respectively. The 5-year overall survival (56% vs. 24%, p = 0.0214) and disease-free survival (48% vs. 6%) were significantly better statistically for patients with a pathologic complete response and minimal residual disease than for those with residual disease. All long-term survivors beyond 5.5 years without recurrence accrued from patient cohorts with a pathologic complete response or minimal residual disease. CONCLUSION: An incorporation of twice-daily RT as a concurrent boost to the conventional daily RT schedule during chemotherapy cycles is feasible and warrants additional study for radiation dose intensification. Such research would be prudent for both improved long-term survival and organ preservation in esophageal carcinoma.

Adenocarcinoma↗
PubMed2004

Edge encoding mechanisms in Musca domestica.

Musca domestica, the common house fly, has a simple yet powerful and accessible vision system. Cajal indicated in 1885 the vision system is the same as in the human retina [1]. We have modeled the intracellular connections of the vision system and have applied high resolution images to the model. Even though the animal does not have what we would consider a high resolution imaging system, it is still capable of high resolution and we are using the same processing principles to extract high resolution information from the visual input. In this paper we will discuss how we are using a purely local process from a single cartridge within the vision system to encode edge information: magnitude, orientation, displacement, and tilt. We also investigate a cooperative approach to link cartridges that have common numerical features in their field of view to share their information for potential edge connection and feature extraction.

Animals↗
PubMed2003

Vaccination with irradiated autologous tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor augments antitumor immunity in some patients with metastatic non-small-cell lung carcinoma.

PURPOSE: We demonstrated that vaccination with irradiated tumor cells engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates potent, specific, and long-lasting antitumor immunity in multiple murine models and patients with metastatic melanoma. To test whether this vaccination strategy enhances antitumor immunity in patients with metastatic non-small-cell lung cancer (NSCLC), we conducted a phase I clinical trial. PATIENTS AND METHODS: Resected metastases were processed to single-cell suspension, infected with a replication-defective adenoviral vector encoding GM-CSF, irradiated, and cryopreserved. Individual vaccines consisted of 1 x 10(6), 4 x 10(6), or 1 x 10(7) cells, depending on overall yield, and were administered intradermally and subcutaneously at weekly and biweekly intervals. RESULTS: Vaccines were successfully manufactured for 34 (97%) of 35 patients. The average GM-CSF secretion was 513 ng/10(6) cells/24 h. Toxicities were restricted to grade 1 to 2 local skin reactions. Nine patients were withdrawn early because of rapid disease progression. Vaccination elicited dendritic cell, macrophage, granulocyte, and lymphocyte infiltrates in 18 of 25 assessable patients. Immunization stimulated the development of delayed-type hypersensitivity reactions to irradiated, dissociated, autologous, nontransfected tumor cells in 18 of 22 patients. Metastatic lesions resected after vaccination showed T lymphocyte and plasma cell infiltrates with tumor necrosis in three of six patients. Two patients surgically rendered as having no evidence of disease at enrollment remain free of disease at 43 and 42 months. Five patients showed stable disease durations of 33, 19, 12, 10, and 3 months. One mixed response was observed. CONCLUSION: Vaccination with irradiated autologous NSCLC cells engineered to secrete GM-CSF enhances antitumor immunity in some patients with metastatic NSCLC.

Adult↗
PubMed2002

Dose-response relationship between probability of pathologic tumor control and glucose metabolic rate measured with FDG PET after preoperative chemoradiotherapy in locally advanced non-small-cell lung cancer.

PURPOSE: To determine the dose-response relationship between the probability of tumor control on the basis of pathologic tumor response (pTCP) and the residual metabolic rate of glucose (MRglc) in response to preoperative chemoradiotherapy in locally advanced non-small-cell lung cancer and to define the level of residual MRglc that corresponds to pTCP 50% and pTCP > or = 95%. METHODS AND MATERIALS: Quantitative dynamic 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography was performed to measure regional MRglc at the primary lesion before and 2 weeks after preoperative chemoradiotherapy in an initial group of 13 patients with locally advanced NSCLC. A simplified kinetic method was developed subsequently from the initial dynamic study and used in the subsequent 16 patients. The preoperative radiotherapy programs consisted of (1) a split course of 42 Gy in 28 fractions within a period of 28 days using a twice-daily treatment schedule for Stage IIIA(N2) NSCLC (n = 18) and (2) standard once-daily radiation schedule of 45-63 Gy in 25-35 fractions during a 5-7-week period (n = 11). The preoperative chemotherapy regimens included two cycles of cisplatin, vinblastine, and 5-fluorouracil (n = 24), cisplatin and etoposide (n = 2), and cisplatin, Taxol, and 5-fluorouracil (n = 3). Patients free of tumor progression after preoperative chemoradiotherapy underwent surgery. The degree of residual MRglc measured 2 weeks after preoperative chemoradiotherapy and 2 weeks before surgery was correlated with the pathologic tumor response. The relationship between MRglc and pTCP was modeled using logistic regression. RESULTS: Of 32 patients entered into the study, 29 (16 men and 13 women; 30 lesions) were evaluated for the correlation between residual MRglc and pathologic tumor response. Three patients did not participate in the second study because of a steady decline in general condition. The median age was 60 years (range 42-78). One of the 29 patients had two separate lesions, and MRglc was measured in each separately. The tumor histologic types included squamous cell carcinoma (n = 9), adenocarcinoma (n = 13), large cell carcinoma (n = 6), and poorly differentiated carcinoma (n = 2). The extent of the primary and nodal disease was as follows: Stage IIB (T3N0M0), Pancoast tumor (n = 2); Stage IIIA, T2-T3N2M0 (n = 18); Stage IIIB: T1-T3N3M0 (n = 5) and T4N0M0 (n = 2); a second lesion, T1 (n = 1); and localized stump recurrence (n = 2). A pathologically complete response was obtained in 14 (47%) of the 30 lesions. The remaining 16 lesions had residual cancer. The mean baseline value of the maximal MRglc was 0.333 +/- 0.087 micromol/min/g (n = 16), and it was reduced to 0.0957 +/- 0.059 micromol/min/g 2 weeks after chemoradiotherapy (p = 0.011). The correlation between residual MRglc and pTCP was made using an increment value of 0.02 micromol/min/g between the maximal and minimal values of MRglc. A pathologically complete response was obtained in 6 of 6 patients with residual MRglc of < or = 0.050 micromol/min/g, 3 of 4 with < or = 0.070, 4 of 7 with < or = 0.090, 0 of 4 with < or = 0.110, 1 of 3 with < or = 0.130, and 0 of 6 with > or = 0.130 micromol/min/g. The fitted logistic model showed that residual MRglc corresponding to pTCP 50% and pTCP > or = 95% was 0.076 and < or = 0.040 micromol/min/g, respectively. CONCLUSION: The correlation between the gradient of residual MRglc after chemoradiotherapy and pTCP is an inverse dose-response relationship. Residual MRglc of 0.076 and < or = 0.040 micromol/min/g, representing pTCP 50% and pTCP > or = 95%, respectively, may be useful surrogate markers for the tumor response to radiotherapy or chemoradiotherapy in lung cancer.

Adult↗
PubMed2002

Computer-assisted laser photocoagulation of the retina--a hybrid tracking approach.

A system for robotically assisted retinal surgery has been developed to rapidly and safely place lesions on the retina for photocoagulation therapy. This system provides real-time, motion stabilized lesion placement for typical irradiation times of 100 ms. The system consists of three main subsystems: a digital-based global tracking subsystem; a fast, analog local tracking subsystem; and a confocal reflectance subsystem to control lesion parameters dynamically. We have reported previously on these individual subsystems. This paper concentrates on the development of a second hybrid system prototype. Considerable progress has been made toward reducing the footprint of the optical system, simplifying the user interface, fully characterizing the analog tracking system, using measurable lesion reflectance parameters to develop a noninvasive method to infer lesion depth, and integrating the subsystems into a seamless hybrid system. These system improvements and progress toward a clinically significant system are covered in detail within this paper. The tracking algorithms and concepts developed for this project have considerable potential for application in many other areas of biomedical engineering.

Biomedical Engineering↗