International journal of radiation oncology, biology, physics
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2008
Multicenter Study Clinical TrialMulti-institution prospective trial of reduced-dose craniospinal irradiation (23.4 Gy) followed by conformal posterior fossa (36 Gy) and primary site irradiation (55.8 Gy) and dose-intensive chemotherapy for average-risk medulloblastoma.
Limiting the neurocognitive sequelae of radiotherapy (RT) has been an objective in the treatment of medulloblastoma. Conformal RT to less than the entire posterior fossa (PF) after craniospinal irradiation might reduce neurocognitive sequelae and requires evaluation. ⋯ This prospective trial has demonstrated that irradiation of less than the entire PF after 23.4 Gy craniospinal irradiation for average-risk medulloblastoma results in disease control comparable to that after treatment of the entire PF.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2008
Universal survival curve and single fraction equivalent dose: useful tools in understanding potency of ablative radiotherapy.
Overprediction of the potency and toxicity of high-dose ablative radiotherapy such as stereotactic body radiotherapy (SBRT) by the linear quadratic (LQ) model led to many clinicians' hesitating to adopt this efficacious and well-tolerated therapeutic option. The aim of this study was to offer an alternative method of analyzing the effect of SBRT by constructing a universal survival curve (USC) that provides superior approximation of the experimentally measured survival curves in the ablative, high-dose range without losing the strengths of the LQ model around the shoulder. ⋯ The USC can be used to compare the dose fractionation schemes of both CFRT and SBRT. The USC provides an empirically and a clinically well-justified rationale for SBRT while preserving the strengths of the LQ model for CFRT.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 2008
Estimate of radiobiologic parameters from clinical data for biologically based treatment planning for liver irradiation.
The Radiation Therapy Oncology Group (RTOG) is initiating a few new hypofractionation regimens (RTOG 0438) to treat liver cancer patients. To evaluate the radiobiologic equivalence between different regimens requires reliable radiobiologic parameters. The purpose of this work is to estimate a plausible set of such parameters for liver tumors and to design new optimized dose fractionation schemes to increase patient survival. ⋯ A plausible set of radiobiologic parameters has been obtained based on clinical data. These parameters may be used for radiation treatment planning of liver tumors, in particular, for the design of new treatment regimens aimed at dose escalation.