title: Clinical results of radionuclide therapy of neuroendocrine tumours with 90Y-DOTATATE and tandem 90Y/177Lu-DOTATATE: which is a better therapy option?
abstract: OBJECTIVE
  Peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues is a treatment option for patients with disseminated neuroendocrine tumours (NET). A combination treatment using the high-energy 90Y beta emitter for larger lesions and the lower energy 177Lu for smaller lesions has been postulated in the literature.The aim of the study was to evaluate combined 90Y/177Lu-DOTATATE therapy in comparison to 90Y-DOTATATE alone.
  
  
  METHODS
  Fifty patients with disseminated NET were included in the study prospectively and divided into two groups: group A (n=25) was treated with 90Y-DOTATATE, whereas group B (n=25) received the 1:1 90Y/177Lu-DOTATATE. The administered activity was based on 3.7 GBq/m2 body surface area in three to five cycles, with amino acid infusion for nephroprotection.
  
  
  RESULTS
  The median overall survival time in group A was 26.2 months while in group B median survival was not reached. Overall survival was significantly higher in group B (p=0.027). Median event-free survival time in group A was 21.4 months and in group B 29.4 months (p>0.1). At the 12-month follow-up, comparison of group A vs group B showed stable disease (SD) in 13 vs 16 patients, disease regression (RD) in 5 vs 3 patients and disease progression (PD) in 3 vs 4 patients; 4 and 2 patients died, respectively. The 24-month follow-up results were SD in nine vs ten patients, RD in one patient vs none and PD in four patients in both groups; three and four patients died, respectively. Side effects were rare and mild.
  
  
  CONCLUSIONS
  The results indicate that therapy with tandem radioisotopes (90Y/177Lu-DOTATATE) provides longer overall survival than with a single radioisotope (90Y-DOTATATE) and the safety of both methods is comparable.
authors.affiliation: Nuclear Medicine Department, Medical University of Warsaw, ul. Banacha 1 a, 02-097, Warsaw, Poland. jolanta.kunikowska@wum.edu.pl
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kunikowska
authors.forename: Leszek
authors.initials: L
authors.lastname: Królicki
authors.forename: Alicja
authors.initials: A
authors.lastname: Hubalewska-Dydejczyk
authors.forename: Renata
authors.initials: R
authors.lastname: Mikołajczak
authors.forename: Anna
authors.initials: A
authors.lastname: Sowa-Staszczak
authors.forename: Dariusz
authors.initials: D
authors.lastname: Pawlak
mesh_terms: D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008187:Lutetium / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging; D018358:Neuroendocrine Tumors / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D015282:Octreotide / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D009942:Organometallic Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011878:Radiotherapy / Q000379:methods*; D047368:Tumor Burden / Q000528:radiation effects
chemical_list: C539274:90Y-octreotate, DOTA(0)-Tyr(3)-Thr(8)-; D009942:Organometallic Compounds; D011868:Radioisotopes; D008187:Lutetium; D015282:Octreotide