Efficacy of preoperative combined 18-fluorodeoxyglucose positron emission tomography and computed tomography for assessing primary rectal cancer response to neoadjuvant therapy

Genevieve B. Melton, William C. Lavely, Heather A. Jacene, Richard D. Schulick, Michael A. Choti, Richard L. Wahl, Susan L Gearhart

Research output: Contribution to journalArticle


Efficacy of F-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) for determining neoadjuvant therapy response in rectal cancer is not well established. We sought to evaluate serial FDG-PET/CT for assessing tumor down-staging, percentage residual tumor, and complete response or microscopic disease with rectal cancer neoadjuvant therapy. Patients with rectal cancer undergoing neoadjuvant therapy, definitive surgical resection, and FDG-PET/CT before and 4-6 weeks after neoadjuvant treatment were included. Tumors were evaluated pretreatment and on final pathology for size and stage. FDG-PET/CT parameters assessed were visual response score (VRS), standardized uptake value (SUV), PET-derived tumor volume (PETvol), CT-derived tumor volume (CTvol), and total lesion glycolysis (δTLG). Twenty-one rectal cancer patients over 3 years underwent neoadjuvant treatment, serial FDG-PET/CT, and resection. Complete response or microscopic disease (n∈=∈7, 33%) was associated with higher ΔCTvol (AUC∈=∈0.82, p∈=∈0.004) and ΔSUV (AUC∈=∈0. 79, p∈=∈0.01). Tumor down-staging (n∈=∈14, 67%) was associated with greater ΔPETvol (AUC∈=∈0.82, p∈

Original languageEnglish (US)
Pages (from-to)961-969
Number of pages9
JournalJournal of Gastrointestinal Surgery
Issue number8
StatePublished - Aug 2007



  • Neoadjuvant therapy
  • Rectal cancer

ASJC Scopus subject areas

  • Surgery

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