Advances of surgery and radiation therapy of glioblastoma and metastatic tumor

Abstract On the surgery for malignant gliomas, most cases are beyond the stage for desirable removal of tumors, because of the risk of damage to the normal function of surrounding brain tissue. The restriction of the surgical treatment has inevitably required postoperative radiation therapy. With a protocol aiming at removing tumors extensively and delivering high dose radiation to the tumor area, we treated 107 patients with cerebral glioblastoma. Wide removal of the tumor combined with intraoperative radiation therapy (IORT) was applied to expected resectable cases at the first surgery or at the second salvage surgery after conventional external radiation therapy. Thirty patients underwent extensive removal with IORT and demonstrated a 2-year survival rate of 60%. Fifty six patients were treated only by postoperative radiation therapy and a two-year survival rate was only 6.8%. The results apparently indicate that areas adjacent to the margin of almost complete removal should be irradiated with a sufficient dose to sterilize the remaining malignant remnants. As metastatic brain tumors without systemic metastasis seldom develop to multiple lesions, surgical removal followed by local radiation therapy would be ideal in order to prevent brain atrophy and dementia induced by whole brain irradiation. IORT would be also useful for its strong local effect to tumors and for shortening the hospital stay of patients.