Supportive Measures and Finer Practice Points in 177Lu-DOTATATE PRRT for NET: Aiming for Optimal Disease Management

Peptide Receptor Radionuclide Therapy in the Management of Neuroendocrine Tumors (Neoplasms): Fundamentals and Salient Clinical Practice Points for Medical Oncologists

This editorial commentary is an expert summary of “Peptide Receptor Radionuclide Therapy (PRRT),” encompassing the essential fundamentals and salient clinical practice points, deliberated and designed in a point-wise manner with theme-based subheadings. Emphasis has been laid on the topics of practical relevance to the referring oncologists with relevant finer points where necessary. A part of the presented overview has been generated from the authors' own practical experience of more than 3500 successful therapies delivered over the last 9 years at a large tertiary care PRRT setting by the joint efforts of Radiation Medicine Centre (RMC), Bhabha Atomic Research Centre (BARC), and Gastrointestinal services of Tata Memorial Hospital (TMH) at the TMH-RMC premises. While the technical indigenization is beyond the scope of this treatise, we must mention here that India had been one of the frontrunners in this treatment modality, and the PRRT services in this country were developed purely as an indigenous effort right from the production of the radionuclide (177-Lutetium) at the reactor and radiolabeling and production of the radiopharmaceutical (177Lu-DOTATATE) by the radiopharmaceutical scientists at the BARC and RMC; such an endeavor allowed this very specialized therapy to be delivered at a very affordable cost in our setting which could be viewed as a major societal contribution of the atomic energy research in this country.

Peptide Receptor Radionuclide Therapy of Neuroendocrine Tumors

Peptide receptor radionuclide therapy (PRRT), over the years, has evolved as an important modality in the therapeutic armamentarium of advanced, metastatic or inoperable, progressive Neuroendocrine Neoplasms (NENs). This review deliberates on the basic understanding and applied clinical aspects of PRRT in NENs, with special reference to (1) tumor biology and receptor characteristics, (2) molecular PET-CT imaging (in particular the invaluable role of dual-tracer PET with [68Ga]-DOTA-TATE/NOC and [18F]-FDG for exploring tumor biology in continuum and individualizing treatment decision making) and NEN theranostics, (3) relevant radiochemistry of different therapeutic radionuclides (both beta emitting 177Lu-DOTATATE and 90Y-DOTATATE and alpha emitting 225Ac-DOTATATE), and (4) related dosimetric considerations. Successful clinical management of the NENs would require multifactorial considerations, and all the aforementioned points pertaining to the disease process and available logistics are key considerations for state-of-the-art clinical practice and delivering personalized care in this group of patients. Emphasis has been placed on relatively intriguing areas such as (1) NET grade 3 of WHO 2017 classification (ie, Ki-67>20% but well-differentiation features), (2) "Neoadjuvant PRRT," (3) combining chemotherapy and PRRT, (4) 'Sandwich Chemo-PRRT', (5) duo-PRRT and tandem PRRT, (6) resistant functioning disease with nuances in clinical management and how one can advocate PRRT rationally in such clinical settings and individualize the management in a patient specific manner. Relevant clinical management issues related to some difficult case scenarios, which the Nuclear Medicine attending physician should be aware of to run an efficient clinical PRRT services, are described.