177
Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) alone has lesser potential in the clinical setting of neuroendocrine tumor (NET) with large bulky disease and nonhomogeneous somatostatin receptors (SSTR) distribution, owing to lower energy (Eβmax 0.497 MeV) and a shorter particle penetration range (maximum 2–4 mm) of
177
Lu. In large bulky NETs,
90
Yttrium (
90
Y) has the theoretical advantages because of a longer beta particle penetration range (a maximum soft tissue penetration of 11 mm). Therefore, a combination of
177
Lu and
90
Y is a theoretically sound concept that can result in better response in metastatic NET with large-bulky lesion and non-homogeneous SSTR distribution. The aim of the study was to determine the feasibility of combining
90
Y-DOTATATE with
177
Lu-DOTATATE PRRT as sequential duo-PRRT in metastatic NET with (≥5 cm) including the post
90
Y-DOTATATE-PRRT imaging and also to determine early toxicity of the duo-PRRT approach. A total of 9 patients received combination of
177
Lu-DOTATATE with
90
Y-DOTATATE (indigenously prepared and approved) through sequential duo-PRRT approach. These 9 NET patients were included and analyzed in this study. All 9 patients had undergone post-PRRT
90
Y-DOTATATE imaging, including a whole-body planar bremsstrahlung imaging followed by regional single-photon emission computed tomography (SPECT)-computed tomography (CT) imaging and also a regional positron emission tomography–computed tomography imaging. Grading of
90
Y-DOTATATE and
177
Lu-DOTATATE uptake was done on post-PRRT imaging by both modalities. The size of the lesions ranged from 5.5 cm to 16 cm with average size of 10 cm before sequential duo-PRRT was decided. Sequential duo-PRRT was administered because of stable, unresponsive disease following
177
Lu-DOTATATE in 5 patients (55.6%), progressive disease after
177
Lu-DOTATATE in 2 patients (22.2%), and with neoadjuvant intent in 2 patients (22.2%). The total cumulative dose of
177
Lu-DOTATATE before duo-pRRT ranged from 11.84 GBq to 37 GBq per patient and average administered dose of 27.21 GBq per patient in this study. Out of 9 patients, 8 patients received single cycle of
90
Y-DOTATATE (ranging from 2.66 GBq to 3.4 GBq per patient with average administered dose of 3.12 GBq per patient). One patient received two cycles of
90
Y-DOTATATE (total dose of 6.2 GBq). Out of 9 patients, 8 patients showed excellent tracer concentration in lesions on post-PRRT
90
Y-DOTATATE imaging and the remaining 1 patient showed fairly adequate
90
Y-DOTATATE tracer uptake in lesion on visual anal...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.