Salvage therapy with (177)Lu-octreotate in patients with bronchial and gastroenteropancreatic neuroendocrine tumors.
Regular therapy with the radiolabeled somatostatin analog (177)Lu-octreotate (22.2-29.6 GBq) in patients with gastroenteropancreatic or bronchial neuroendocrine tumors results in tumor remission in 46% of patients, including minor response. We present the effects of additional therapy with (177)Lu-octreotate in patients in whom progressive disease developed after an initial benefit from regular therapy.


METHODS
Thirty-three patients with progressive disease after an initial radiologic or clinical response were treated with additional cycles of (177)Lu-octreotate. The intended cumulative dose of additional therapy was 14.8 GBq in 2 cycles. Responses were evaluated using Southwest Oncology Group criteria, including minor response (tumor size reduction of >or=25% and <50%).


RESULTS
Median time to progression (TTP) after regular therapy was 27 mo. In 4 patients, the intended cumulative dose was not achieved (2 had progressive disease, 2 had long-lasting thrombocytopenia). Hematologic toxicity grade 3 was observed in 4 patients, and grade 4, in 1. The median follow-up time was 16 mo (range, 1-40 mo). No kidney failure or myelodysplastic syndrome was observed. Renewed tumor regression was observed in 8 patients (2 partial remission, 6 minor response), and 8 patients had stable disease. Median TTP was 17 mo. Treatment outcome was less favorable in patients with a short TTP after regular cycles. Treatment effects in patients with pancreatic neuroendocrine tumors were similar to those in patients with other gastroenteropancreatic neuroendocrine tumors.


CONCLUSIONS
Most patients tolerated additional cycles with (177)Lu-octreotate well. None developed serious delayed adverse events. Additional cycles with (177)Lu-octreotate can have antitumor effects, but effects were less than for the regular cycles. This may be because of a worse clinical condition, more extensive tumor burden, or changed tumor characteristics. We conclude that this salvage therapy can be effective and is safe.
van Essen
Martijn
M
Department of Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands. m.vanessen@erasmusmc.nl
Krenning
Eric P
EP
Kam
Boen L R
BL
de Herder
Wouter W
WW
Feelders
Richard A
RA
Kwekkeboom
Dik J
DJ
D000328:Adult; D000368:Aged; D001984:Bronchial Neoplasms / Q000097:blood / Q000473:pathology / Q000628:therapy*; D053379:Chromogranin A / Q000097:blood; D018450:Disease Progression; D006801:Humans; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000097:blood / Q000473:pathology / Q000628:therapy*; D015282:Octreotide / Q000031:analogs & derivatives* / Q000378:metabolism / Q000627:therapeutic use; D009942:Organometallic Compounds / Q000378:metabolism / Q000627:therapeutic use*; D016879:Salvage Therapy; D016896:Treatment Outcome
D053379:Chromogranin A; D009942:Organometallic Compounds; C447941:lutetium Lu 177 dotatate; D015282:Octreotide