International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Is a reduction in radiation lung volume and dose necessary with paclitaxel chemotherapy for node-positive breast cancer?
To evaluate and quantify the effect of irradiated lung volume, radiation dose, and paclitaxel chemotherapy on the development of radiation pneumonitis (RP) in breast cancer patients with positive lymph nodes. ⋯ The use of paclitaxel chemotherapy and RT in the primary treatment of node-positive breast cancer is likely to increase the incidence of RP. In patients treated with paclitaxel, reducing the percentage of lung irradiated by 24% should reduce the risk of RP to 1%, according to our calculations of lung tolerance. Future clinical trials using combination CHT that includes paclitaxel and RT should carefully evaluate the incidence and severity of RP and should also accurately monitor the extent of lung included within the RT volume to develop safe guidelines for the delivery of what is becoming standard therapy for node-positive breast cancer.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Long-term oncologic results of salvage radical prostatectomy for locally recurrent prostate cancer after radiotherapy.
Salvage radical prostatectomy (RP) may potentially cure patients who have isolated local prostate cancer recurrence after radiotherapy (RT). We report the long-term cancer control associated with salvage RP in a consecutive cohort of patients and identify the variables associated with disease progression and cancer survival. ⋯ Greater preoperative PSA levels are associated with disease progression and cancer-specific death. Long-term control of locally recurrent prostate cancer after definitive RT is possible when salvage RP is performed early in the course of recurrent disease.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Clinical TrialPhase I study of thoracic radiation dose escalation with concurrent chemotherapy for patients with limited small-cell lung cancer: Report of Radiation Therapy Oncology Group (RTOG) protocol 97-12.
The purpose of RTOG 97-12 was to determine the maximum tolerated dose (MTD) of thoracic radiation therapy (RT) with concurrent chemotherapy for patients with limited-stage small-cell lung cancer. ⋯ The MTD for this accelerated thoracic RT regimen with concurrent PE was 61.2 Gy over 5 weeks.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Benefit of using biologic parameters (EUD and NTCP) in IMRT optimization for treatment of intrahepatic tumors.
To investigate whether intensity-modulated radiotherapy (IMRT), optimized using the generalized equivalent uniform dose (gEUD) and normal tissue complication probability (NTCP) models, can increase the safe dose to intrahepatic tumors compared with three-dimensional conformal RT (3D-CRT). A secondary objective was to investigate the optimal beam arrangement for liver IMRT plans. ⋯ We have successfully used mathematical/biologic models directly as cost functions within the optimizing process to produce IMRT plans that maximize the gEUD while maintaining compliance with a well-defined protocol for the treatment of intrahepatic cancer. For both PTV-organ-at-risk overlap and nonoverlap situations, IMRT has the capacity to improve the maximal dose achievable across the PTV, expressed in terms of the gEUD. The use of multiple noncoplanar beams appears to confer an advantage over fewer beams in cases with PTV-organ-at-risk overlap. When liver toxicity is the dose-limiting factor, high gEUD values are obtained most frequently when the field arrangement is chosen to provide the shortest possible transhepatic path length.
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Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Prostate gland motion assessed with cine-magnetic resonance imaging (cine-MRI).
To quantify prostate motion during a radiation therapy treatment using cine-magnetic resonance imaging (cine-MRI) for time frames comparable to that expected in an image-guided radiation therapy treatment session (20-30 min). ⋯ Motion of the prostate and seminal vesicles during a time frame similar to a standard treatment session is reduced compared to that reported in interfraction studies. The most significant predictor for intrafraction prostate motion is the status of rectal filling. A prostate displacement of <3 mm (90%) can be expected for the 20 min after the moment of initial imaging for patients with an empty rectum. This is not the case for patients presenting with full rectum. The determination of appropriate intrafraction margins in radiation therapy to accommodate the time-dependent uncertainty in positional targeting is a topic of ongoing investigations for the on-line image guidance model.