Use of 177Lu-dotatate in the treatment of iodine refractory thyroid carcinomas

Towards an era of precise diagnosis and treatment: Role of novel molecular modification-based imaging and therapy for dedifferentiated thyroid cancer

Dedifferentiated thyroid cancer is the major cause of mortality in thyroid cancer and is difficult to treat. Hence, the essential molecular mechanisms involved in dedifferentiation should be thoroughly investigated. Several studies have explored the biomolecular modifications of dedifferentiated thyroid cancer such as DNA methylation, protein phosphorylation, acetylation, ubiquitination, and glycosylation and the new targets for radiological imaging and therapy in recent years. Novel radionuclide tracers and drugs have shown attractive potential in the early diagnosis and treatment of dedifferentiated thyroid cancer. We summarized the updated molecular mechanisms of dedifferentiation combined with early detection by molecular modification-based imaging to provide more accurate diagnosis and novel therapeutics in the management of dedifferentiated thyroid cancer.

Efficacy and safety of peptide receptor radionuclide therapy in advanced radioiodine-refractory differentiated thyroid cancer and metastatic medullary thyroid cancer: a systematic review

Background

It has been shown that a subgroup of patients with differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC) would progress to advanced stages of thyroid cancer. Therefore, the present study was done to systematically review available evidence in order to investigate efficacy and safety of peptide receptor radionuclide therapy (PRRT) in the patients with advanced radioiodine refractory differentiated thyroid cancer (RR-DTC) and metastatic MTC.

Methods

For this purpose, relevant studies investigated safety and efficacy of PRRT in the patients with advanced RR-DTC and metastatic MTC were identified by searching Medline (Pubmed, Ovid, and Ebsco), Scopus, Embase, Web of Science, and Cochrane Library databases (from database inception to March 24, 2021). The review was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. Searching was done independently by two investigators. Two researchers independently extracted the data and any disagreement was adjudicated by consensus. Quality of the studies was assessed using the tool of case reports/series in systematic reviews.

Results

Among 2284 related papers, 41 papers met the inclusion criteria. A total of 157 patients with RR-DTC were treated with PPRT. Biochemical and objective responses (partial and complete) were observed in 25.3 and 10.5% of patients, respectively. Among 220 patients with metastatic MTC, biochemical and objective responses were observed in 37.2 and 10.6% of the patients, respectively.

Forty-six deaths were reported in 95 patients with advanced RR-DTC. In addition, 63 deaths were observed in 144 patients with metastatic MTC. Major side effects were reported in 124 patients treated with ⁹⁰Y -based agent. In the patients treated with 177Lu-DOTA-TATE and 111In-Octreotide, mild and transient hematologic or renal complications were reported.

Conclusion

Findings of the study revealed that in the absence of the established treatment for the patients with RR-DTC and metastatic MTC, PRRT could be effective with few adverse events.

Trial registration

PROSPERO registration number: CRD42019125245.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08257-x.

Occupational and ambient radiation exposures from Lu-177 DOTATATE during targeted therapy

Lutetium-177 (DOTATATE) (¹⁷⁷Lu; T_1/2 6.7 days), a labelled β^- and Auger-electron emitter, is widely used in treatment of neuroendocrine tumours. During performance of the procedure, staff and other patients can potentially receive significant doses in interception of the gamma emissions [113 keV (6.4%) and 208 keV (11%)] that are associated with the particle decays. While radiation protection and safety assessment are required in seeking to ensure practices comply with international guidelines, only limited published studies are available. The objectives of present study are to evaluate patient and occupational exposures, measuring ambient doses and estimating the radiation risk. The results, obtained from studies carried out in Riyadh over an 11 month period, at King Faisal Specialist Hospital and Research Center, concerned a total of 33 ¹⁷⁷Lu therapy patients. Patient exposures were estimated using a calibrated Victoreen 451P survey meter (Fluke Biomedical), for separations of 30 cm, 100 cm and 300 cm, also behind a bed shield that was used during hospitalization of the therapy patients. Occupational and ambient doses were also measured through use of calibrated thermoluminescent dosimeters and an automatic TLD reader (Harshaw 6600). The mean and range of administered activity (in MBq)) was 7115.2 ± 917.2 (4329-7955). The ambient dose at corridors outside of therapy isolation rooms was 1.2 mSv over the 11 month period, that at the nursing station was below the limit of detection and annual occupational doses were below the annual dose limit of 20 mSv. Special concern needs to be paid to comforters (carers) and family members during the early stage of radioisotope administration.