Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Int J Radiat Oncol Biol Phys. 2011 Nov 1;81(3):e15-20. doi: 10.1016/j.ijrobp.2010.11.081. Epub 2011 Apr 12.
We previously reported excellent local control for treating medulloblastoma with a limited boost to the tumor bed. In order to decrease ototoxicity, we subsequently implemented a tumor-bed boost using intensity-modulated radiation therapy (IMRT), the clinical results of which we report here.
A total of 33 patients with newly diagnosed medulloblastoma, 25 with standard risk, and 8 with high risk, were treated on an IMRT tumor-bed boost following craniospinal irradiation (CSI). Six standard-risk patients were treated with an institutional protocol with 18 Gy CSI in conjunction with intrathecal iodine-131-labeled monoclonal antibody. The majority of patients received concurrent vincristine and standard adjuvant chemotherapy. Pure-tone audiograms were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.
Median age was 9 years old (range, 4-46 years old). Median follow-up was 63 months. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) rates for standard-risk patients who received 23.4 or 36 Gy CSI (not including those who received 18 Gy CSI with radioimmunotherapy) were 81.4% and 88.4%, respectively, at 5 years; 5-year PFS and OS rates for high-risk patients were both 87.5%. There were no isolated posterior fossa failures outside of the boost volume. Posttreatment audiograms were available for 31 patients, of whom 6%, at a median follow-up of 19 months, had developed Grade 3 hearing loss.
An IMRT tumor-bed boost results in excellent local control while delivering a low mean dose to the cochlea, resulting in a low rate of ototoxicity.
我们之前报道过采用有限的肿瘤床增量照射治疗髓母细胞瘤可获得优异的局部控制效果。为了降低耳毒性，我们随后采用调强放疗（IMRT）进行肿瘤床增量照射，现将其临床结果报告如下。
共有 33 例新诊断的髓母细胞瘤患者，25 例为标准风险，8 例为高风险，在颅脊髓照射（CSI）后接受 IMRT 肿瘤床增量照射治疗。6 例标准风险患者按照机构方案治疗，接受 18 Gy CSI 联合鞘内注射碘-131 标记的单克隆抗体。大多数患者接受长春新碱联合标准辅助化疗。纯音听力图根据国家癌症研究所不良事件通用术语标准 3.0 分级。
中位年龄为 9 岁（范围，4-46 岁）。中位随访时间为 63 个月。接受 23.4 或 36 Gy CSI（不包括接受 18 Gy CSI 联合放射免疫治疗的患者）的标准风险患者的无进展生存（PFS）和总生存（OS）率的 Kaplan-Meier 估计值分别为 5 年时 81.4%和 88.4%；高风险患者的 5 年 PFS 和 OS 率均为 87.5%。在增量照射体积之外，没有孤立的后颅窝失败。31 例患者可获得治疗后听力图，其中 6%（中位随访 19 个月）发生 3 级听力损失。
IMRT 肿瘤床增量照射可获得优异的局部控制效果，同时使耳蜗接受的平均剂量较低，导致耳毒性发生率较低。
