A rare adverse event (AE) in a group of radioiodine-refractory differentiated thyroid cancer (RAI-R DTC) patients in therapy with lenvatinib.

Background: LM occur in 45% of patient with advanced MTC. In some cases LM cannot be treated with local therapy especially if a multifocal extension is present. Aim of the study: To investigate the biochemical (calcitonin and CEA) and structural response of the LM of MTC to TARE. Rational and Methods: TARE is a transarterial brachytherapy in which microspheres loaded with β-emitting yttrium-90 are selectively delivered into the hepatic arteries that supply blood to LM with radiation-induced tumor necrosis. Patients: We treated 8 patients (6 males and 2 females) with an average age of 55 years (range 31-75 aa) and progressive multiple LM of MTC with preserved liver function. Patients were treated from April 2017 to December 2018. They performed periodic evaluations at 1, 4 and 12 months after TARE and every 6 months thereafter. Two patients were also treated with vandetanib. The pre-TARE mean total hepatic tumor volume was 102.6 ml ± 183 DS (median 31.5 ml; range: 12-551 ml). The radiological response was evaluated with the RECIST 1.1. Results: One month after TARE, a clinically relevant although not statistically significant (p:022), reduction of the Ct and CEA values was observed in all patients. We also measured the total hepatic tumor at the best response post-TARE of six patients: the mean volume+ was 3.1 ml ± 2.0 DS (median 3.6 ml; range: 0-5.8 ml). Five out of 8 (62.5%) patients completed a 12 months follow-up: 2/5 (40%) showed an apparent CR, 1/5 (20%) a PR and 2/5 (40%) a SD, The only patient with a 18 months follow-up has still a SD. Conclusions: Our study showed a good response of LM from MTC to TARE. Furthermore, the absence of complications and the good tolerability of this treatment makes TARE a valid therapeutic strategy when LM are multiple and progressive.