• Hidefumi Aoyama, Kyousuke Kamada, Hiroki Shirato, Fumiya Takeuchi, Shinya Kuriki, Yoshinobu Iwasaki, and Kazuo Miyasaka.
• Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan. hao@radi.med.hokudai.ac.jp
• Int. J. Radiat. Oncol. Biol. Phys. 2004 Mar 15; 58 (4): 1177-83.

PurposeTo minimize the risk of neurologic deficit after stereotactic irradiation, functional brain information was integrated into treatment planning.Methods And MaterialsTwenty-one magnetoencephalography and six magnetic resonance axonographic images were made in 20 patients to evaluate the sensorimotor cortex (n = 15 patients, including the corticospinal tract in 6), visual cortex (n = 4), and Wernicke's area (n = 2). One radiation oncologist was asked to formulate a treatment plan first without the functional images and then to modify the plan after seeing them. The pre- and postmodification values were compared for the volume of the functional area receiving > or =15 Gy and the volume of the planning target volume receiving > or =80% of the prescribed dose.ResultsOf the 21 plans, 15 (71%) were modified after seeing the functional images. After modification, the volume receiving > or =15 Gy was significantly reduced compared with the values before modification in those 15 sets of plans (p = 0.03). No statistically significant difference was found in the volume of the planning target volume receiving > or =80% of the prescribed dose (p = 0.99). During follow-up, radiation-induced necrosis at the corticospinal tract caused a minor motor deficit in 1 patient for whom magnetic resonance axonography was not available in the treatment planning. No radiation-induced functional deficit was observed in the other patients.ConclusionIntegration of magnetoencephalography and magnetic resonance axonography in treatment planning has the potential to reduce the risk of radiation-induced functional dysfunction without deterioration of the dose distribution in the target volume.

28 keywords...

hide…