title: Favourable outcomes of (177)Lu-octreotate peptide receptor chemoradionuclide therapy in patients with FDG-avid neuroendocrine tumours.
abstract: OBJECTIVE
  Increased glycolytic activity on FDG PET/CT defines a subgroup of patients with metastatic gastroenteropancreatic neuroendocrine tumour (NET) with a poor prognosis. A limited range of systemic treatment options exist for more aggressive NET. The role of peptide receptor chemoradionuclide therapy (PRCRT) in such patients is, however, unclear. This retrospective study assessed the outcomes of patients with FDG-avid NET treated with PRCRT.
  
  
  METHODS
  Clinical, biochemical and imaging response was assessed after completion of induction treatment of PRCRT with 5-fluorouracil in 52 patients selected for treatment on the basis of somatostatin-receptor imaging without spatially discordant FDG-avid disease. Of the cohort, 67% had received prior chemotherapy. Overall survival (OS) and progression-free survival (PFS) were also analysed.
  
  
  RESULTS
  PRCRT was well tolerated with negligible grade 3/4 toxicities. After a median follow-up period of 36 months, the median OS was not achieved with a median PFS of 48 months. At 3 months after completion of PRCRT 2% of patients showed a complete anatomical response, 28% a partial response, 68% stable disease, and only 2% progression. On FDG PET/CT, 27% achieved a complete metabolic response during the follow-up period. A biochemical response (>25% fall in chromogranin-A levels) was seen in 45%.
  
  
  CONCLUSIONS
  PRCRT is an effective treatment in patients with FDG-avid NET, even in patients who have failed conventional therapies. Given apparently higher response rates than with alternative therapeutic options and low toxicity, further research is needed to establish whether PRCRT should be used as a first-line treatment modality in this patient population.
authors.affiliation: Centre for Cancer Imaging, Peter MacCallum Cancer Center, St Andrews Place, 3002, Melbourne, Australia, kashyapk@americanoncology.com.
authors.forename: Raghava
authors.initials: R
authors.lastname: Kashyap
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hofman
authors.forename: Michael
authors.initials: M
authors.lastname: Michael
authors.forename: Grace
authors.initials: G
authors.lastname: Kong
authors.forename: Timothy
authors.initials: T
authors.lastname: Akhurst
authors.forename: Peter
authors.initials: P
authors.lastname: Eu
authors.forename: Diana
authors.initials: D
authors.lastname: Zannino
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Hicks
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D015282:Octreotide / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: C554548:177Lu-octreotate; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D015282:Octreotide