Souhami L, Olivier A, Podgorsak E B, Villemure J G, Pla M, Sadikot A F
Department of Radiation Oncology, McGill University, Montreal, Canada.
Cancer. 1991 Nov 15;68(10):2101-8. doi: 10.1002/1097-0142(19911115)68:10<2101::aid-cncr2820681003>3.0.co;2-c.
In stereotactic radio surgery, a single, large dose of radiation is delivered to a small, well-defined, stereotactically localized intracranial lesion. In contrast to conventional radiation therapy, in radio surgery no attempt is made to spare normal cells within the target volume by fractionating the tumor dose. In 1987, the authors began a program of fractionated stereotactic radiation therapy for selected tumors involving sensitive brain structures. Their objective was to improve the therapeutic index and study the feasibility of the fractionated technique. Fifteen patients were treated with a multifraction regimen typically consisting of six fractions of 700 cGy each, given on alternate days for 2 weeks (total tumor dose, 4200 cGy). All patients were treated with the dynamic stereotactic radio surgical technique. A head ring ("halo frame") was used for immobilization and setup during radiation treatments. At a median follow-up time of 27 months, the symptoms of the majority of the patients improved clinically; this improvement usually occurred within a few weeks after completion of the treatment. The radiologic response was much slower. Currently, only two patients have had complete radiologic disappearance of their lesions; the majority of the patients have only had a decrease in tumor size. The treatments were well tolerated by the patients and no acute complications were observed. One patient who had a vasogenic edema 11 months after treatment fully recovered after steroid therapy. Fractionated stereotactic radiation therapy is a feasible treatment technique and may prove to be useful for selected patients with intracranial tumors. Although the preliminary data are encouraging, this technique should still be considered experimental. A larger number of patients and a longer follow-up time are necessary to determine whether the results of this technique are actually better than those of conventional radiation therapy.
在立体定向放射外科治疗中，单次大剂量辐射被施加到一个小的、界限清楚的、经立体定向定位的颅内病变上。与传统放射治疗不同，在放射外科治疗中，不会试图通过分割肿瘤剂量来保护靶区内的正常细胞。1987年，作者开始了一项针对累及敏感脑结构的特定肿瘤的分次立体定向放射治疗计划。他们的目标是提高治疗指数并研究分次技术的可行性。15名患者接受了多分次方案治疗，通常包括每次700厘戈瑞，共6次，隔天给予，持续2周（肿瘤总剂量4200厘戈瑞）。所有患者均采用动态立体定向放射外科技术治疗。在放射治疗期间，使用头环（“晕环框架”）进行固定和摆位。在中位随访时间27个月时，大多数患者的症状在临床上有所改善；这种改善通常在治疗完成后的几周内出现。放射学反应则慢得多。目前，只有两名患者的病变在放射学上完全消失；大多数患者只是肿瘤大小有所减小。患者对治疗耐受性良好，未观察到急性并发症。一名患者在治疗11个月后出现血管源性水肿，经类固醇治疗后完全康复。分次立体定向放射治疗是一种可行的治疗技术，可能对选定的颅内肿瘤患者有用。尽管初步数据令人鼓舞，但该技术仍应被视为实验性的。需要更多的患者和更长的随访时间来确定该技术的结果是否实际上优于传统放射治疗。
