Ramani R, O'Brien P F, Davey P, Schwartz M L, Young C S, Lightstone A W, Mason D L
Division of Medical Physics, Toronto Sunny Brook Regional Cancer Centre, North York, Ontario, Canada.
Br J Radiol. 1995 Jul;68(811):731-5. doi: 10.1259/0007-1285-68-811-731.
Radiosurgery using the dynamic rotation technique with a single isocentre was introduced at the Toronto-Bayview Regional Cancer Centre (T-BRCC) in 1988. Since then, over 100 patients have been treated. It was soon recognized that 25-30% of patients were referred with either non-spherical lesions or multiple lesions located sufficiently close together that consideration had to be given to the overlapping dose distributions throughout the treated volume. To treat these more complex targets a multiple isocentre technique was developed which also took account of these effects and the resulting normalization problem. This technique was implemented in September 1992. Comparisons between calculated doses and actual doses delivered have been undertaken using a spherical phantom containing radiochromic film. Measured dose distributions agreed with the planned distributions to within +/- 1 mm. The effect of multiple isocentres on the penumbra of dose distributions has been examined. The methods adopted for the normalization of treatment plans and clinical examples illustrating the application of the multiple isocentre technique are presented.
1988年，多伦多-湾景地区癌症中心（T-BRCC）引入了使用单等中心动态旋转技术的放射外科手术。从那时起，已有100多名患者接受了治疗。很快人们就认识到，25%至30%的患者被转诊时患有非球形病变或多个彼此位置足够接近的病变，因此必须考虑整个治疗体积内重叠的剂量分布。为了治疗这些更复杂的靶点，开发了一种多等中心技术，该技术也考虑了这些影响以及由此产生的归一化问题。该技术于1992年9月实施。已使用含有放射变色胶片的球形体模对计算剂量和实际输送剂量进行了比较。测量的剂量分布与计划分布的偏差在±1毫米以内。已研究了多等中心对剂量分布半影的影响。介绍了用于治疗计划归一化的方法以及说明多等中心技术应用的临床实例。
