由PSMA PET成像驱动的生物学引导放疗对转移性肾细胞癌的可行性。
Feasibility of biology-guided radiotherapy for metastatic renal cell carcinoma driven by PSMA PET imaging.
发表日期：2023 May
作者：
Mathieu Gaudreault, David Chang, Nicholas Hardcastle, Lachlan McIntosh, Price Jackson, Tomas Kron, Cristian Udovicich, Michael S Hofman, Shankar Siva
来源：
PHYSICAL THERAPY & REHABILITATION JOURNAL
摘要：
生物引导放疗（BgRT）是一种新型治疗方法，其通过检测生物追踪区（BTZ）中起源的正电子发射来启动剂量传递。前列腺特异性膜抗原（PSMA）正电子发射断层扫描（PET）是一种新型成像技术，可改善肾细胞癌（RCC）转移定向治疗的患者选择。本研究旨在确定BgRT治疗RCC的可行性。在2014年至2020年期间，我们回顾性考虑了在我们机构接受PSMA PET/CT扫描进行RCC分期的所有连续患者。在PET/CT扫描的CT部分上对病灶体积（GTV）进行了轮廓划分。从标准摄取值（SUV）的归一化标准摄取值（nSUV）中量化了肿瘤与背景的比值，定义为GTV内SUVmax与边缘扩展内SUVmean之比。如果（1）nSUV大于等于nSUV阈值，（2）如果BTZ除了肿瘤外不含任何PET亲和区域，则将肿瘤分类为适合BgRT的。在这组83例患者中，有47例患有转移性RCC并被纳入本研究。总共划定了136个肿瘤，每个患者1至22个肿瘤，大多数位于肺部（40%）。使用5mm / 10mm / 20mm边缘扩展和nSUV阈值= 3，66％/ 63％/ 41％的肿瘤适合于BgRT治疗。在判断为不适合BgRT的肿瘤中，来自另一个肿瘤、肾脏或肝脏的摄取通常位于BTZ内。在这组RCC患者中，超过60％的肿瘤适合于BgRT。然而，PET亲和的器官如肝脏或肾脏的接近可能会影响BgRT的传递。© 2023 The Author(s).
Biology-guided radiotherapy (BgRT) is a novel treatment where the detection of positron emission originating from a volume called the biological tracking zone (BTZ) initiates dose delivery. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is a novel imaging technique that may improve patient selection for metastasis-directed therapy in renal cell carcinoma (RCC). This study aims to determine the feasibility of BgRT treatment for RCC.All consecutive patients that underwent PSMA PET/CT scan for RCC staging at our institution between 2014 and 2020 were retrospectively considered for inclusion. GTVs were contoured on the CT component of the PET/CT scan. The tumor-to-background ratio was quantified from the normalized standardized uptake value (nSUV), defined as the ratio between SUVmax inside the GTV and SUVmean inside the margin expansion. Tumors were classified suitable for BgRT if (1) nSUV was greater or equal to an nSUV threshold and (2) if the BTZ was free of any PET-avid region other than the tumor.Out of this cohort of 83 patients, 47 had metastatic RCC and were included in this study. In total, 136 tumors were delineated, 1 to 22 tumors per patient, mostly in lung (40%). Using a margin expansion of 5 mm/10 mm/20 mm and nSUV threshold = 3, 66%/63%/41% of tumors were suitable for BgRT treatment. Uptake originating from another tumor, the kidney, or the liver was typically inside the BTZ in tumors judged unsuitable for BgRT.More than 60% of tumors were found to be suitable for BgRT in this cohort of patients with RCC. However, the proximity of PET-avid organs such as the liver or the kidney may affect BgRT delivery.© 2023 The Author(s).