Positive clinical impact of an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy in patients with advanced oral cavity squamous cell carcinoma

J Nucl Med. 2015 Jan;56(1):22-30. doi: 10.2967/jnumed.114.145300. Epub 2014 Dec 18.

Abstract

The aim of this single-center study was to investigate whether obtaining an additional PET/CT scan before adjuvant radiotherapy or concurrent chemoradiotherapy (CCRT) could meaningfully improve 2-y disease-free survival (DFS) and disease-specific survival (DSS) rates.

Methods: Six hundred seventy-four patients with oral cavity squamous cell carcinoma who received adjuvant therapy after radical surgery were included. Of these, 152 patients were initially scheduled to receive an additional preradiotherapy/CCRT PET/CT scan within 1 wk of starting adjuvant therapy. However, 16 patients were excluded because of either medical problems or refusal. Therefore, 136 patients underwent a preradiotherapy/CCRT PET/CT scan (PET group), and 522 did not (NO-PET group). All of the participants were followed up for at least 2 y or censored at the last follow-up. The impact of preradiotherapy/CCRT PET/CT imaging was examined using Kaplan-Meier curves and Cox proportional hazards models.

Results: Two-year DFS (80% vs. 70%, P = 0.033) and DSS (84% vs. 75%, P = 0.010) rates were significantly higher in the PET than in the NO-PET group. In the PET group, both DFS and DSS were higher in patients with negative findings than in those without (88% vs. 22% and 91% vs. 36%, respectively; both P < 0.001). A prognostic scoring system based on the presence of the 2 independent risk factors in the PET group (extracapsular spread and lymphatic invasion) predicted both DFS (P = 0.001 and P < 0.001, respectively) and DSS (P = 0.001 and P < 0.001, respectively). Nineteen patients (14%) had their treatment modified by preradiotherapy/CCRT PET/CT findings. Of these, 15 were treated with curative intent due to the presence of locoregional disease, and 4 received palliative care due to distant metastases. Seven of the 15 patients are currently alive without disease.

Conclusion: An additional preradiotherapy/CCRT PET/CT scan improves both DFS and DSS in patients with advanced oral cavity squamous cell carcinoma.

Keywords: FDG PET/CT; adjuvant therapy; oral squamous cell carcinoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Carcinoma, Squamous Cell / diagnosis*
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / therapy*
  • Chemoradiotherapy*
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Male
  • Mouth Neoplasms / diagnosis*
  • Mouth Neoplasms / pathology
  • Mouth Neoplasms / therapy*
  • Multimodal Imaging
  • Positron-Emission Tomography*
  • Prognosis
  • Radiotherapy, Adjuvant
  • Risk Factors
  • Tomography, X-Ray Computed
  • Treatment Outcome

Substances

  • Fluorodeoxyglucose F18