Comparison of intensity-modulated radiosurgery with gamma knife radiosurgery for challenging skull base lesions.

Purpose: To quantitatively compare intensity-modulated radiosurgery (IMRS) using 3-mm mini-multileaf collimation with gamma knife radiosurgery (GKRS) plans for irregularly shaped skull base lesions in direct proximity to organs at risk (OAR).

Methods And Materials: Ten challenging skull base lesions originally treated with GKRS were selected for comparison with IMRS using inverse treatment planning and 3-mm mini-multileaf collimation operating in step-and-shoot delivery mode. The lesions ranged in volume from 1.

The effect of beam energy and number of fields on photon-based IMRT for deep-seated targets.

Purpose: To examine the influence of energy and number of beams on nontarget dose when using intensity-modulated radiation therapy (IMRT) to treat deep-seated targets.

Methods And Materials: Ten patients with prostate cancer (36-226 cc) treated locally to 75.6 Gy were studied.