International journal of radiation oncology, biology, physics
-
Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Comparative Study Clinical TrialDose heterogeneity in the target volume and intensity-modulated radiotherapy to escalate the dose in the treatment of non-small-cell lung cancer.
To quantify the dose escalation achievable in the treatment of non-small-cell lung cancer (NSCLC) by allowing dose heterogeneity in the target volume or using intensity-modulated radiotherapy (IMRT), or both. ⋯ The dose in NSCLC treatments can be escalated by loosening the constraints on maximum dose in the target volume or using IMRT, or both. For large and concave tumors, an average dose escalation of 6% and 17% was possible when dose heterogeneity and IMRT were applied alone. When they were combined, the average dose increase was as high as 35%. Intensity-modulated RT delivered in a static mode can produce homogeneous dose distributions in the target and does not lead to an increase of lung volume receiving (very) low doses, even down to 5 Gy.
-
Int. J. Radiat. Oncol. Biol. Phys. · Jun 2005
Predictors of locoregional recurrence in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy, mastectomy, and radiotherapy.
To identify the clinical and pathologic factors predictive of locoregional recurrence (LRR) after neoadjuvant chemotherapy, mastectomy, and radiotherapy. ⋯ Although the long-term rate of LRR after neoadjuvant chemotherapy, mastectomy, and radiotherapy is low, we identified a number of factors that correlated independently with greater rates of LRR. Patients with three or more of these factors may benefit from research protocols investigating alternative treatment strategies.
-
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.
-
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.
-
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.