International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1998
Patterns of failure following treatment for medulloblastoma: is it necessary to treat the entire posterior fossa?
Craniospinal radiation (CSRT) followed by a boost to the entire posterior fossa (PF) is standard postoperative therapy for patients with medulloblastoma. A large proportion of recurrences after treatment are local, with approximately 50-70% of recurrences occurring in the PF. It is unclear, however, whether these failures are occurring in the original tumor bed or outside the tumor bed, but still within the PF. With improved diagnostic imaging, better definition of tumor volumes, and the use of three-dimensional conformal therapy (3D CRT), we may be able to restrict the boost volume to the tumor bed plus a margin without compromising local control. This retrospective study analyzes the patterns of failure within the PF in a series of patients treated with radiation therapy (RT). ⋯ Leptomeningeal failure is a common component of failure and occurs in the leptomeninges of the PF, as well as the spine. Isolated tumor bed failure is a rarely observed event and occurred in only 2 of 27 failures described here. Similarly, parenchymal (nonleptomeningeal) failures in the PF but outside of the tumor bed were rare: 4 patients recurred in this manner, only 1 of whom was an isolated event without other sites of recurrence. Our data suggest that, when the entire PF is treated, very few failures develop in isolation in the PF outside the tumor bed. Further studies will be necessary to determine if RT to the tu
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1998
A critical evaluation of the planning target volume for 3-D conformal radiotherapy of prostate cancer.
To determine an adequate planning target volume (PTV) margin for three-dimensional conformal radiotherapy (3D CRT) of prostate cancer, the uncertainties in the internal positions of the prostate and seminal vesicles (SV) and in the treatment setups were measured. ⋯ PTV margins of 10 to 16 mm are required to encompass all (99%) possible positions of the prostate or SV during 3D CRT. PTV margins of 7 to 11 mm will encompass the measured uncertainties with a 95% probability. PTV margins of 5 mm may not adequately cover the intended volume.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1998
Multicenter StudyIs there a role for a brachytherapy vaginal cuff boost in the adjuvant management of patients with uterine-confined endometrial cancer?
Many patients who have uterine-confined endometrial cancer with prognostic factors predictive of recurrence are treated with adjuvant pelvic radiation. The addition of a brachytherapy vaginal cuff boost is controversial. ⋯ There is no suggestion that the addition of a vaginal cuff brachytherapy boost to pelvic radiation is beneficial for pelvic control or disease-free survival for patients with Stage I or II endometrial cancer. Prospective randomized trials designed to study external irradiation alone versus external beam treatment plus vaginal brachytherapy are unlikely to show a positive result. Because EBRT provides excellent pelvic control, protocol development for uterine-confined corpus cancer should focus on identifying patients at risk for recurrence as well as other means of augmenting EBRT (e.g. addition of chemotherapy) in order to improve disease free survival in those subgroups.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1998
Long-term follow-up of axillary node-positive breast cancer patients receiving adjuvant tamoxifen alone: patterns of recurrence.
To determine the patterns, incidence and risk factors for local-regional recurrence in patients with Stage II and III breast cancer treated with adjuvant tamoxifen alone, without adjuvant radiation. ⋯ Postmenopausal women receiving adjuvant tamoxifen who have positive resection margins, > or = 4 positive axillary nodes and/or negative estrogen and progesterone receptors, are at higher risk of local and regional recurrence and should, therefore, receive local-regional radiation.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1998
Clinical TrialPhase I dose escalating trial of hyperfractionated pre-operative chemoradiation for locally advanced rectal cancer.
To determine the acute toxicity, post-operative complications, pathologic response and extent of downstaging to high dose pre-operative radiation using a hyperfractionated radiation boost and concurrent chemotherapy in a prospective Phase I trial. ⋯ This regimen of high dose pre-operative chemoradiation employing a hyperfractionated radiation boost is feasible and tolerable and results in significant downstaging in locally advanced rectal cancer. The vast majority of patients (96%) achieved negative margins, which appears to be a prerequisite for local control (p= 0.04). Older age (> or =61 years) was a significant predictor for improved DFS. This regimen (at dose Level III, 61.8 Gy) is currently being tested in a Phase II setting.