Abstract
Since the beginning of the nineties, stereotactic radiosurgery has been spreading rapidly in Japan, and in July 1995, the 4th Meeting of the Japanese Society of Stereotactic Radiosurgery (JSSR) was held in Sendai. Using this opportunity to present the latest thinking on radiosurgery, we prepared a questionnaire to elicit the current status of radiosurgery in Japan. This questionnaire, which asked whether radiosurgery is being used and contained other technical and clinical queries about radiosurgery, was sent to the members of the JSSR, the directors of neurosur-gery and radiology of all university hospitals, and the directors of category-A clinics of the Japan Neurosurgical Society. This questionnaire also solicited individual opinions about the indications for radiosurgery for model cases that presented different pathologies. A total of 114 clinics and 140 individuals responded to this questionnaire, and it was thus found that 20 radiosurgical linear accelerators (LINACs) , 14 gamma knives, and 2 charged-particle facilities are currently in use in Japan. Further, another 21 sites are preparing to use this equipment. Also, at the neurosurgeon's initiative, most gamma knife sites are treating more than 100 patients per year. In contrast, besed on the radiologist's initiative or in partnership with the neurosurgeon, most LINAC sites treat less than 50 patients per year. The value of radiosurgery for treating small surgically inaccessible arteriovenous malformations (AVMs) is well understood by many doctors, and to some extent, widening indicafion to surgically accessible AVM is accepted, as well. Radiosurgical treatment of acoustic tumors of less than 3 cm in diameter and of recurrent and bilateral tumors has become accepted as well. However, for treating surgiccaly removable meningiomas, many doctors, especially neurosurgeons, regard radiosurgery as a contraindication. Most doctors perfomming radiosur-gery believe that radiosurgery is the best treatment modility for metastatic tumors if the tumor is small, whereas many doctors who do not perform radiosurgery do not. Whether radiosurgery can be indicated for gliomas and cavernous angiomas requires greater exploration.
