- 作者：Saskia Harth ; Yasser Abo-Madyan ; Lei Zheng ; Kerstin Siebenlist ; Carsten Herskind ; Frederik Wenz ; Frank A. Giordano
- 关键词：Brain metastasis ; Hippocampal-sparing whole brain radiotherapy ; Whole brain radiotherapy ; Prophylactic cranial irradiation
- 刊名：Radiotherapy and Oncology
- 出版年：October, 2013
- 年：2013
- 卷：109
- 期：1
- 页码：152-158
- 全文大小：551 K
Purpose
To estimate the risk of undertreatment in hippocampal-sparing whole brain radiotherapy (HS-WBRT).Methods
Eight hundred and fifty six metastases were contoured together with the hippocampi in cranial MRIs of 100 patients. For each metastasis, the distance to the closest hippocampus was calculated. Treatment plans for 10 patients were calculated and linear dose profiles were established. For SCLC and NSCLC, dose-response curves were created based on data from studies on prophylactic cranial irradiation, allowing estimating the risk for intracranial failure.
Results
Only 0.4% of metastases were located inside a hippocampus in 3% of all patients. SCLC showed a relatively high rate of hippocampal metastasis (18.2% of all SCLC patients) and HS-WBRT in a commonly applied fractionation scheme would increase the risk for brain relapse by 鈭?% compared to conventional WBRT. NSCLC showed a lower rate of brain metastasis in the hippocampi (2.8%) and HS-WBRT would account for a slightly increased absolute risk of 0.2%.
Conclusions
Prophylactic or therapeutic HS-WBRT is expected to be associated with a low risk of undertreatment. For SCLC, it bears a minimally elevated risk of failure compared to standard WBRT. In NSCLC, HS-WBRT is most likely not associated with a clinically relevant increase in risk of failure.