Radiat Oncol
-
Prognosis for patients with brain metastasis remains poor. Whole brain radiation therapy is the conventional treatment option; it can improve neurological symptoms, prevent and improve tumor associated neurocognitive decline, and prevents death from neurologic causes. In addition to whole brain radiation therapy, stereotactic radiosurgery, neurosurgery and chemotherapy also are used in the management of brain metastases. ⋯ Neuropsychological testing and biomarkers are potential ways of measuring and better understanding CNS toxicity. These tools may help optimize current therapies and develop new treatments for these patients. This article will review the current management of brain metastases, summarize the data on the CNS effects associated with brain metastases and whole brain radiation therapy in these patients, discuss the use of neuropsychological tests as outcome measures in clinical trials evaluating treatments for brain metastases, and give an overview of the potential of biomarker development in brain metastases research.
-
High-dose radiotherapy is standard treatment for patients with brain cancer. However, in preclinical research external beam radiotherapy is limited to heterotopic murine models- high-dose radiotherapy to the murine head is fatal due to radiation toxicity. Therefore, we developed a stereotactic brachytherapy mouse model for high-dose focal irradiation of experimental intracerebral (orthotopic) brain tumors. ⋯ The intracerebral implantation of an iodine-125 brachytherapy seed through a stereotactic guide-screw in the skull of mice with implanted brain tumors resulted in a significantly prolonged survival, caused by high-dose irradiation of the brain tumor that is biologically comparable to high-dose fractionated radiotherapy- without fatal irradiation toxicity. This is an excellent mouse model for testing orthotopic brain tumor therapies in combination with radiation therapy.
-
To evaluate the effects of direct machine parameter optimization in the treatment planning of intensity-modulated radiation therapy (IMRT) for hypopharyngeal cancer as compared to subsequent leaf sequencing in Oncentra Masterplan v1.5. ⋯ The direct machine parameter optimization is a major improvement compared to the fluence modulation with subsequent leaf sequencing in Oncentra Masterplan v1.5. The resulting dose distribution complies better with the DVO and better plan quality is achieved for identical specification of DVO. An additional asset is the reduced number of MU as compared to IM.
-
Intensity-modulated radiation therapy (IMRT) affords unparalleled capacity to deliver conformal radiation doses to tumors in the central nervous system. However, to date, there are few reported outcomes from using IMRT, either alone or as a boost technique, for standard fractionation radiotherapy for glioblastoma multiforme (GBM). ⋯ While technically feasible, preliminary results suggest delivering standard radiation doses by IMRT did not improve survival outcomes in this series compared to historical controls. In light of this lack of a survival benefit and the costs associated with use of IMRT, future prospective trials are needed to evaluate non-survival endpoints such as quality of life and functional preservation. Short of such evidence, the use of IMRT for treatment of GBM needs to be carefully rationalized.
-
To correlate the metabolic changes with size changes for tumor response by concomitant PET-CT evaluation of lung cancers after radiotherapy. ⋯ Correlating and incorporating metabolic change by PET into size change by concomitant CT is more sensitive in assessing therapeutic response than CT alone.