The Efficacy, Toxicity, and Survival of Salvage PRRT with Indigenous ¹⁷⁷Lu-Dotatate in Metastatic Advanced Neuroendocrine Tumors with Progressive Disease after Initial Course of Therapy

• Areas of Interest: PRRT

Background: The study aimed at assessing the outcome of salvage PRRT using ¹⁷⁷Lu-DOTATATE in metastatic NET patients who progressed after 1 year of disease stabilization, following the initial course of PRRT.

Methods: A total of 26 out of 468 patients, who were treated with initial full course of PRRT and progressed after 1 year of disease stabilization, were analyzed. These patients received ¹⁷⁷Lu-DOTATATE salvage PRRT (mean dose = 170mci [6.29Gbq]) and assessed for the long-term outcome. Response was assessed under clinical, biochemical, and imaging (morphological and molecular) parameters with simultaneous assessment of toxicity.

Results: Disease control rate (= SD + PR + CR) of 68.1, 77.3, 63.8, and 63.8%, on clinical symptomatic, biochemical, molecular, and morphological imaging response, respectively, were observed after salvage PRRT. The median PFS after salvage PRRT was 17 months. Estimated OS-iPRRT rate was 68% at 108 months and OS-sPRRT rate was 82% at 18 months. Median OS was not reached. The highest level of toxicity was grade 2 (as reversible anemia, thrombocytopenia, and nephrotoxicity in 3 [13.5%], 1 [4.5%], and 2 patients [9%], respectively) with no grade 3/4 nephrotoxicity, hepatotoxicity, or AML/MDS after I-PRRT and S-PRRT at median follow-up of 72 and 15 months, respectively.

Conclusion: Considering the limited therapeutic options available for progressive NET retreatment with salvage PRRT may be considered as a relatively safe therapeutic option in view of well tolerability.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
10 May 2022