TEAM participation in the irradiation of IROC phantoms for cooperative group clinical trials.

The participation of radiation oncology team members in the irradiation of Imaging and Radiation Oncology Core (IROC) phantom for cooperative group clinical trials is essential to comply with the latest quality management philosophy. Medical dosimetrists are expected to develop treatment plans for the irradiation of IROC phantoms. For advanced treatment techniques, such as three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), and volumetric-modulated arc therapy (VMAT), the irradiation of the IROC phantoms serves as quality audit. If successful, the irradiation processes demonstrate that the institution has the knowledge of the protocol, and has the appropriate equipment to comply with the protocol requirements. This article describes three IROC phantoms used for credentialing external beam photon beam therapy, delivered using conventional medical linear accelerators, to the medical dosimetry community. Guidance and strategies for the development of treatment plans are discussed. Our institutional irradiation of the three IROC phantoms, delivered using the Truebeam medical linear accelerator, resulted in consistent dose accuracy to within ±1%. The participation of the team members may reduce the overall published failing rate stated to be about one-third of all participating institutions.

Dose planning management of patients undergoing salvage whole brain radiation therapy after radiosurgery.

Dose or treatment planning management is necessary for the re-irradiation of intracranial relapses after focal irradiation, radiosurgery, or stereotactic radiotherapy. The current clinical guidelines for metastatic brain tumors are the use of focal irradiation if the patient presents with 4 lesions or less. Salvage treatments with the use of whole brain radiation therapy (WBRT) can then be used to limit disease progression if there is an intracranial relapse. However, salvage WBRT poses a number of challenges in dose planning to limit disease progression and preserve neurocognitive function. This work presents the dose planning management that addresses a method of delineating previously treated volumes, dose level matching, and the dose delivery techniques for WBRT.