Somatostatin Receptor Imaging in Non–131I-Avid Metastatic Differentiated Thyroid Carcinoma for Determining the Feasibility of Peptide Receptor Radionuclide Therapy With 177Lu-DOTATATE

Abstract

Avid expression of the SSTR on Ga-DOTATATE PET-CT/Tc-HYNIC-TOC scintigraphy in non-I-concentrating metastatic differentiated thyroid cancer is observed in a relatively low fraction of patients that could favor the feasibility of Lu-DOTATATE therapy. Although seen in a small fraction, taking into account that no treatment exists in this group, somatostatin receptor-targeted imaging can be an alternative diagnostic modality in the therapeutic decision making with peptide receptor radionuclide therapy and monitoring. The documentation of elevated serum chromogranin A level in 3 patients with intense tracer uptake could suggest a possible neuroendocrine differentiation in the affected tissues leading to the expression of chromogranin A along with SSTR-avid expression. This observation needs to be explored in future studies. No definite conclusions can be drawn on the therapeutic efficacy of the Lu-DOTATATE therapy in this group at present, and more prospective research is required in this area.

Lutetium-177 Therapeutic Radiopharmaceuticals: Linking Chemistry, Radiochemistry, and Practical Applications

“…A mild WBC toxicity was observed because of the radiosensitivity of lymphocytes. In another recent study, 283 the somatostatin receptor expression in noniodine-concentrating metastatic-differentiated thyroid carcinoma was evaluated by 68 Ga−DOTATATE PET-CT and 99m Tc−HYNIC-TOC scintigraphy in a group of 19 patients. The feasibility of 177 Lu− DOTATATE therapy with positive 68 Ga−DOTATATE PET-CT or 99m Tc−HYNIC-TOC scintigraphy was investigated in 2 patients.…”

“…The cross-fire effects available from 177 Lu can extend up to 20 cell diameters, and hence, it is expected that tumors with sufficient receptor density will benefit from 177 Lu treatment. Currently, 177 Lu–DOTATATE therapy has been reported to have been applied in about 3000 patients, and many more nuclear medicine centers are entering into clinical studies using this agent. ,− …”

Continued rapid growth in 68Ga applications: update 2013 to June 2014

“…The follow‐up of patients after curative NET resection using [ 68 Ga]Ga‐DOTA‐TATE/PET‐CT was found accurate . [ 68 Ga]Ga‐DOTA‐TOC and [ 68 Ga]Ga‐DOTA‐TATE were used for the treatment planning and monitoring the therapy response in patients affected, respectively, by meningiomas and thyroid carcinoma non‐iodine‐concentrating metastasis . Pre‐therapeutic tumour uptake of [ 68 Ga]Ga‐DOTA‐TOC and assumed uptake of [ 90 Y]‐DOTA‐TOC were strongly correlated with subsequent PRRT outcome in a retrospective study of 40 patients, thus proving the feasibility of treatment response prediction by [ 68 Ga]Ga‐DOTA‐TOC .…”

(Radio)Theranostic Patient Management in Oncology Exemplified by Neuroendocrine Neoplasms, Prostate Cancer, and Breast Cancer

“…The (semi)-quantitative assessment of the response, using [ 68 Ga]Ga-SST PET/CT, to the endoradiotherapy with 177 Lu-or 90 Y-based somatostatin analogues and re-staging of the disease have entered clinical practice. Patient selection, prognosis, prediction of absorbed dose for radiotherapy, and treatment response based on [ 68 Ga]Ga-SST PET/CT have been performed using various parameters such as maximum standardized uptake value (SUV max ), tumor-to-background SUV max ratio (TBR), tumor-to-liver SUV max ratio (TLR), tumor-to spleen SUV max ratio (TSR), functional volume (FV), K-Patlak and Ki [60,76,[82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97]. SUV max cut-off of 16.4 was proposed for patient stratification for endoradiotherapy [84].…”