La Rosa Alonso, Wieczorek D Jay J, Tolakanahalli Ranjini, Lee Yongsook C, Kutuk Tugce, Tom Martin C, Hall Matthew D, McDermott Michael W, Mehta Minesh P, Gutierrez Alonso N, Kotecha Rupesh
Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL 33176, USA.
Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA.
Cancers (Basel). 2023 Jan 27;15(3):780. doi: 10.3390/cancers15030780.
We evaluated the effect of lesion number and volume for brain metastasis treated with SRS using GammaKnife ICON™ (GK) and CyberKnife M6™ (CK). Four sets of lesion sizes (<5 mm, 5-10 mm, >10-15 mm, and >15 mm) were contoured and prescribed a dose of 20 Gy/1 fraction. The number of lesions was increased until a threshold mean brain dose of 8 Gy was reached; then individually optimized to achieve maximum conformity. Across GK plans, mean brain dose was linearly proportional to the number of lesions and total GTV for all sizes. The numbers of lesions needed to reach this threshold for GK were 177, 57, 29, and 10 for each size group, respectively; corresponding total GTVs were 3.62 cc, 20.37 cc, 30.25 cc, and 57.96 cc, respectively. For CK, the threshold numbers of lesions were 135, 35, 18, and 8, with corresponding total GTVs of 2.32 cc, 12.09 cc, 18.24 cc, and 41.52 cc respectively. Mean brain dose increased linearly with number of lesions and total GTV while V8 Gy, V10 Gy, and V12 Gy showed quadratic correlations to the number of lesions and total GTV. Modern dedicated intracranial SRS systems allow for treatment of numerous brain metastases especially for ≤10 mm; clinical evidence to support this practice is critical to expansion in the clinic.
我们评估了使用伽玛刀ICON™（GK）和射波刀M6™（CK）的立体定向放射治疗（SRS）对脑转移瘤的病灶数量和体积的影响。勾勒出四组病灶大小（<5毫米、5 - 10毫米、>10 - 15毫米和>15毫米），并给予20 Gy/1次分割的剂量。病灶数量不断增加，直到达到8 Gy的平均脑剂量阈值；然后进行个体化优化以实现最大适形度。在所有GK计划中，平均脑剂量与所有大小病灶的数量和总靶体积（GTV）呈线性比例关系。对于GK，每个大小组达到该阈值所需的病灶数量分别为177个、57个、29个和10个；相应的总GTV分别为3.62立方厘米、20.37立方厘米、30.25立方厘米和57.96立方厘米。对于CK，病灶的阈值数量分别为135个、35个、18个和8个，相应的总GTV分别为2.32立方厘米、12.09立方厘米、18.24立方厘米和41.52立方厘米。平均脑剂量随病灶数量和总GTV呈线性增加，而V8 Gy、V10 Gy和V12 Gy与病灶数量和总GTV呈二次相关。现代专用颅内SRS系统允许治疗大量脑转移瘤，尤其是对于≤10毫米的病灶；支持这种做法的临床证据对于在临床上的推广至关重要。
