International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2001
Multicenter Study Clinical TrialA phase I/II trial of three-dimensionally planned concurrent boost radiotherapy and protracted venous infusion of 5-FU chemotherapy for locally advanced rectal carcinoma.
Improving the response to preoperative therapy may increase the likelihood of successful resection of locally advanced rectal cancers. Historically, the pathologic complete response (pCR) rate has been < approximately 10% with preoperative radiation therapy alone and < approximately 20% with concurrent chemotherapy and radiation therapy. ⋯ 3D planned boost therapy is feasible. In addition to permitting the use of nonaxial beams for improved dose distributions, 3D planning provides tumor and normal tissue dose-volume information that is important in interpreting outcome. Every effort should be made to limit the treated small bowel to less than 150 cc. Tumor size is the most important predictor of response, with small lesions of PTV < 200 cc most likely to develop complete responses.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2001
Clinical TrialImprovement in dose escalation using the process of adaptive radiotherapy combined with three-dimensional conformal or intensity-modulated beams for prostate cancer.
Advances in technology allow the creation of complex treatment plans with tightly conforming doses. However, variations in positioning of the organ/patient with respect to treatment beams necessitate the use of an appreciable margin, potentially limiting dose escalation in many patients. To (1) reduce this margin and (2) test the hypothesis that the achievable level of dose escalation is patient dependent, a patient-specific, confidence-limited planning target volume (cl-PTV) was constructed using an adaptive radiotherapy (ART) process for prostate cancer treatment developed in-house. The potential dose escalation achievable with this ART process is quantified for both conformal radiotherapy (CRT) delivery and intensity-modulated radiotherapy (IMRT) delivery. ⋯ These results support our hypothesis that the achievable level of dose escalation using ART is patient dependent. By using the ART process to develop a cl-PTV, one can (1) optimize the dose level, (2) increase the applicability of IMRT, and (3) improve the quality of dose delivery. The ART process provides the foundation to identify a suitable option (CRT or IMRT) for the delivery of a safe treatment and dose escalation. It is now our standard of practice for prostate cancer treatment.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2001
Potency after permanent prostate brachytherapy for localized prostate cancer.
The evaluation of potency preservation after treatment of localized prostate cancer with transperineal permanent prostate brachytherapy (PPB) and the efficacy of sildenafil were studied. ⋯ The actuarial potency rates at 5 years for patients treated with PPB are lower than generally acknowledged, except for those patients treated with PPB as monotherapy. Patients who received sildenafil exhibited improved potency in a majority of cases.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2001
Comparative StudyA protocol for the reduction of systematic patient setup errors with minimal portal imaging workload.
To evaluate a new off-line patient setup correction protocol that minimizes the required number of portal images and perform a comparison with currently applied protocols. ⋯ The NAL protocol performed much more efficiently than the SAL protocol for both actually measured and simulated setup data. The resulting decrease in required portal images not only reduces workload, but also dose to healthy tissue, if dedicated large fields are required for portal imaging (double exposure).
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2001
Five-year biochemical outcome after prostate brachytherapy for hormone-naive men < or = 62 years of age.
To evaluate 5-year biochemical disease-free outcome for hormone naïve men 62 years of age or less who underwent transperineal ultrasound-guided permanent prostate brachytherapy. ⋯ With a median follow-up of 37 months, hormone naïve patients < or = 62 years of age have a high probability of 5-year biochemical disease-free survival following permanent prostate brachytherapy with an apparent plateau on the PSA curve.