International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Analysis of biopsy outcome after three-dimensional conformal radiation therapy of prostate cancer using dose-distribution variables and tumor control probability models.
To investigate tumor control following three-dimensional conformal radiation therapy (3D-CRT) of prostate cancer and to identify dose-distribution variables that correlate with local control assessed through posttreatment prostate biopsies. ⋯ Biopsy outcome after 3D-CRT of prostate cancer at MSKCC is not correlated with Dmin in the PTV and appears to be insensitive to cold spots in the dose distribution. This observation likely reflects the fact that much of the PTV, especially at the periphery, may not contain viable tumor cells and that the treatment margins were sufficiently large. Therefore, the predictive power of all variables which are sensitive to cold spots, like TCPs with Poisson models and EUD for low SF(2), is limited because the low dose region may not coincide with the tumor location. Instead, for MSKCC prostate cancer patients with their standardized CTV definition, substantial target motion and small dose inhomogeneities, Dmean (or any variable that downplays the effect of cold spots) is a very good predictor of biopsy outcome. While our findings may indicate a general problem in the application of current TCP models to clinical data, these conclusions should not be extrapolated to other disease sites without careful analysis.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Clinical TrialA phase II study of paclitaxel, carboplatin, and hyperfractionated radiation therapy for locally advanced inoperable non-small-cell lung cancer (a Vanderbilt Cancer Center Affiliate Network Study).
We conducted a prospective phase II study to determine the response rate, toxicity, and survival rate of concurrent weekly paclitaxel, carboplatin, and hyperfractionated radiation therapy (paclitaxel/carboplatin/HFX RT) followed by 2 cycles of paclitaxel and carboplatin for locally advanced unresectable non-small cell lung cancer (NSCLC). The weekly paclitaxel and carboplatin regimen was designed to optimize the radiosensitizing properties of paclitaxel during the concurrent phase of treatment. ⋯ Weekly paclitaxel, carboplatin, plus concurrent hyperfractionated RT is a well-tolerated outpatient regimen. The response rate from this regimen is encouraging and appears to be at least equivalent to the more toxic chemoradiation trials. These findings warrant further clinical evaluation of weekly paclitaxel/carboplatin/HFX RT in a phase III study.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
The role of whole brain radiotherapy and stereotactic radiosurgery on brain metastases from renal cell carcinoma.
We reviewed our experience with patients who have undergone stereotactic radiosurgery (SRS) for brain metastases secondary to renal cell carcinoma (RCC). Analysis was performed to determine the survival, local control, distant brain failure (DBF), and then to define which tumors may not require upfront whole-brain radiotherapy (WBRT). ⋯ Patients with brain metastases secondary to RCC treated by SRS alone have excellent local control. The decision of whether or not to add WBRT to SRS should depend on whether the patient has a high likelihood of developing DBF. Our study suggests that patients who present with multiple brain lesions may be more likely to benefit from the addition of WBRT because they appear to be more than twice as likely to develop DBF as compared to patients with a single lesion.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Randomized Controlled Trial Clinical TrialValidation of the RTOG recursive partitioning analysis (RPA) classification for brain metastases.
The Radiation Therapy Oncology Group (RTOG) previously developed three prognostic classes for brain metastases using recursive partitioning analysis (RPA) of a large database. These classes were based on Karnofsky performance status (KPS), primary tumor status, presence of extracranial system metastases, and age. An analysis of RTOG 91-04, a randomized study comparing two dose-fractionation schemes with a comparison to the established RTOG database, was considered important to validate the RPA classes. ⋯ This analysis indicates that the RPA classes are valid and reliable for historical comparisons. Both the RTOG and other clinical trial organizers should currently utilize this RPA classification as a stratification factor for clinical trials.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2000
Internal mammary node irradiation neither decreases distant metastases nor improves survival in stage I and II breast cancer.
To compare outcome for ipsilateral breast tumor recurrence (IBTR), or regional node recurrence, initial and subsequent distant metastases, and overall and cause-specific survival in women treated with conservative surgery and radiation based on whether or not radiation was targeted to the internal mammary nodes (IMN). ⋯ This retrospective series was unable to identify a significant benefit for IMN irradiation in terms of distant metastases or cause-specific survival for the entire patient population, and in particular, for patients with positive axillary nodes and medially located lesions. The results of the proposed or ongoing prospective randomized trials will further address this controversial issue.