Recommended procedure for dosimetry of patients undergoing therapy with radiopharmaceuticals that include 177Lu

Abstract

Currently the two radiopharmaceuticals approved by the AEMPS that include 177Lu are [177Lu]Lu-DOTA-TATE for the treatment of neuroendocrine tumors and [177Lu]Lu-PSMA-617 for the treatment of metastatic castration-resistant prostate cancer. The RD601/2019 states that for all medical exposure of patients for radiotherapeutic purposes, exposures of target volumes shall be individually planned and their delivery appropriately verified taking into account that doses to non-target volumes and tissues shall be as low as reasonably achievable and consistent with the intended radiotherapeutic purpose of the exposure. However, for both radiopharmaceuticals the treatment is performed by administering cycles of 7.4 GBq of the radiopharmaceutical — 4 cycles for [177Lu]Lu-DOTA-TATE and 6 cycles for [177Lu]Lu-PSMA-617. This implies that treatments cannot be planned, but can at least be verified by dosimetry. The purpose of the present document is to provide standardised procedures for the performance of such dosimetry in treatments with the aforementioned radiopharmaceuticals.