Treatment of Neuroendocrine Neoplasms with Radiolabeled Peptides—Where Are We Now

Abstract

Peptide receptor radionuclide therapy (PRRT) has been one of the most successful and exciting examples of theranostics in nuclear medicine in recent decades and is now firmly embedded in many treatment algorithms for unresectable or metastatic neuroendocrine neoplasms (NENs) worldwide. It is widely considered to be an effective treatment for well- or moderately differentiated neoplasms, which express high levels of somatostatin receptors that can be selectively targeted. This review article outlines the scientific basis of PRRT in treatment of NENs and describes its discovery dating back to the early 1990s. Early treatments utilizing Indium-111, a γ-emitter, showed promise in reduction in tumor size and improvement in biochemistry, but were also met with high radiation doses and myelotoxic and nephrotoxic effects. Subsequently, stable conjugation of DOTA-peptides with β-emitting radionuclides, such as Yttrium-90 and Lutetium-177, served as a breakthrough for PRRT and studies highlighted their potential in eliciting progression-free survival and quality of life benefits. This article will also elaborate on the key trials which paved the way for its approval and will discuss therapeutic considerations, such as patient selection and administration technique, to optimize its use.

Neuroendocrine metastasis to the thyroid from unknown primary and extrathyroidal disease response to peptide receptor radionuclide therapy

“…Furthermore, the sequence, timing, and combination of PRRT with other treatment options remain an area of investigation [17] . Nuclear medicine imaging is crucial for staging and assessment of SR expression in patients with NETs.…”

Small Bowel Neuroendocrine Neoplasms—A Review

“…94,95 At the same time, the tumors with FDG and SSTR uptake may respond to combined chemotherapy and PRRT. 96 The efficacy of PRRT can be increased by combining it with chemotherapeutic radiosensitizers, called peptide receptor chemoradionuclide therapy, resulting in increased radiation and extensive tumor destruction. For this purpose, chemotherapeutic agents such as 5-fluorouracil, fluoropyrimidine, temozolomide, or capecitabine are used.…”

“…A tumor with high NETPET (FDG positive and SSTR negative) shall be treated with systemic chemotherapy as it is highly unlikely to respond to PRRT 94,95 . At the same time, the tumors with FDG and SSTR uptake may respond to combined chemotherapy and PRRT 96 …”