18F-Fludeoxyglucose PET/CT in SCLC: Analysis of the CONVERT Randomized Controlled Trial

Prakash Manoharan, Ahmed Salem, Hitesh Mistry, Michael Gornall, Susan Harden, Peter Julyan, Imogen Locke, Jonathan McAleese, Rhona McMenemin, Nazia Mohammed, Michael Snee, Sarah Woods, Thomas Westwood, Corinne Faivre-Finn

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12 Citations (Scopus)

Abstract

Introduction: We used phase-3 CONVERT trial data to investigate the impact of fludeoxyglucose F 18 (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in SCLC. Methods: CONVERT randomized patients with limited-stage SCLC to twice-daily (45 Gy in 30 fractions) or once-daily (66 Gy in 33 fractions) chemoradiotherapy. Patients were divided into two groups in this unplanned analysis: those staged with conventional imaging (contrast-enhanced thorax and abdomen CT and brain imaging with or without bone scintigraphy) and those staged with 18F-FDG PET/CT in addition. Results: Data on a total of 540 patients were analyzed. Compared with patients who underwent conventional imaging (n = 231), patients also staged with 18F-FDG PET/CT (n = 309) had a smaller gross tumor volume (p = 0.003), were less likely to have an increased pretreatment serum lactate dehydrogenase level (p = 0.035), and received more chemotherapy (p = 0.026). There were no significant differences in overall (hazard ratio = 0.87, 95% confidence interval: 0.70–1.08, p = 0.192) and progression-free survival (hazard ratio = 0.87, 95% confidence interval: 0.71–1.07], p = 0.198) between patients staged with or without 18F-FDG PET/CT. In the conventional imaging group, we found no survival difference between patients staged with or without bone scintigraphy. Although there were no differences in delivered radiotherapy dose, 18F-FDG PET/CT–staged patients received lower normal tissue (lung, heart, and esophagus) radiation doses. Apart from a higher incidence of late esophagitis in patients staged with conventional imaging (for grade ≥1, 19% versus 11%; [p = 0.012]), the incidence of acute and late radiotherapy-related toxicities was not different between the two groups. Conclusion: In CONVERT, survival outcomes were not significantly different in patients staged with or without 18F-FDG PET/CT. However, this analysis cannot support the use or omission of 18F-FDG PET/CT owing to study limitations.

Original languageEnglish
Pages (from-to)1296-1305
Number of pages10
JournalJournal of Thoracic Oncology
Volume14
Issue number7
DOIs
Publication statusPublished - Jul 2019
Externally publishedYes

Keywords

  • F-FDG PET/CT
  • lung cancer
  • small-cell
  • staging
  • survival

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