Kurth Jens, Heuschkel Martin, Tonn Alexander, Schildt Anna, Hakenberg Oliver W, Krause Bernd J, Schwarzenböck Sarah M
Department of Nuclear Medicine, Rostock University Medical Centre, 18057 Rostock, Germany.
Core Facility Multimodal Small Animal Imaging, Rostock University Medical Centre, 18057 Rostock, Germany.
Cancers (Basel). 2021 Aug 1;13(15):3884. doi: 10.3390/cancers13153884.
(Background) Aim of this retrospective analysis was to investigate in mCRPC patients treated with [Lu]Lu-PSMA-617 whether the absorbed dose (AD) in organs at risk (OAR, i.e., kidneys and parotid glands) can be calculated using simplified methodologies with sufficient accuracy. For this calculation, results and kinetics of the first therapy cycle were used. (Methods) 46 patients treated with 2 to 6 cycles of [Lu]Lu-PSMA-617 were included. As reference (current clinical standard) full dosimetry of the OAR based on quantitative imaging (whole body scintigraphy and quantitative SPECT/CT at 2, 24, 48 and 72 h p.i.) for every cycle was used. Alternatively, two dosimetry schemes, simplified in terms of image acquisition and dose calculation, were established, both assuming nearly unchanged kinetics of the radiopharmaceutical for subsequent cycles. (Results) In general, for both OAR the simplified methods provided results that were consistent with the dosimetric reference method, both per cycle and in terms of cumulative AD. Best results were obtained when imaging was performed at 48 h p.i. in each of the subsequent cycles. However, both simplified methods tended to underestimate the cumulative AD. (Conclusion) Simplified dosimetry schemes are feasible to tailor multi-cycle [Lu]Lu-PSMA-targeted therapies.
（背景）本回顾性分析的目的是研究在接受[镥]镥-PSMA-617治疗的去势抵抗性前列腺癌（mCRPC）患者中，是否可以使用简化方法以足够的准确性计算危及器官（OAR，即肾脏和腮腺）的吸收剂量（AD）。对于此计算，使用了第一个治疗周期的结果和动力学数据。（方法）纳入了46例接受2至6个周期[镥]镥-PSMA-617治疗的患者。作为参考（当前临床标准），每个周期均基于定量成像（全身闪烁显像以及注射后2、24、48和72小时的定量SPECT/CT）对OAR进行全剂量测定。另外，建立了两种在图像采集和剂量计算方面简化的剂量测定方案，两者均假定后续周期中放射性药物的动力学几乎不变。（结果）总体而言，对于两种OAR，简化方法得出的结果在每个周期以及累积AD方面均与剂量测定参考方法一致。在后续每个周期注射后48小时进行成像时获得了最佳结果。然而，两种简化方法都倾向于低估累积AD。（结论）简化剂量测定方案对于定制多周期[镥]镥-PSMA靶向治疗是可行的。
