Author of

• 12544

  +

  P3.08 - Poster Session 3 - Radiotherapy (ID 199)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12560

    +

    P3.08-016 - Clinical outcome of [18F] FDG-PET/CT versus conventional CT based planning for radiotherapy in locally advanced NSCLC patients: a propensity-score matching study (ID 2052)

    09:30 - 09:30  |  Author(s): W. Zhang
    • Abstract

    Background
    To evaluate the clinical outcome and toxicity after radiotherapy using [18F] FDG-PET/CT based target volume delineation instead of conventional CT for locally advanced non-small cell lung cancer (LA-NSCLC).

    Methods
    Between January 2007 and May 2011, 248 patients with stage IIIA or IIIB NSCLC were referred to our institution for radiotherapy. Among them, twelve patients were excluded, including four patients upstaged to stage IV after PET/CT and eight patients lost follow-up. The remaining 236 patients were investigated, including 67 patients received RT with PET/CT-based planning and 169 patients with CT-based planning. Propensity-score matching (PSM) method was utilized to obtain two matched groups (1:1) with similar baseline clinical characteristics. Kaplan-Meier method was conducted to calculate the overall survival (OS), progression-free survival (PFS), and locoregional control (LRC). Log-rank test was performed to compare the survival between two groups. Response to initial treatment was also compared, as well as acute radiation toxicity, especially the radiation-induced lung injury (RILI).

    Results
    Two matched groups with comparable baseline clinical characteristics were created using the PSM method, including 67 patients with PET/CT-based planning (PET/CT group) and 67 patients with CT-based planning (CT group). The covariates that we selected for the propensity score model were gender, age, Charlson comorbidity index, Karnofsky performance status, smoking history, FEV~1~ (%), VC (%), location of the primary tumor (central or peripheral), presence of atelectasis, histology type, T stage, N stage and TNM stage. Patients in the PET/CT group received a higher total radiation dose than those in the CT group (60.7 Gy vs. 59.0 Gy, P = 0.067). After initial treatment, 55 (82.1%) patients in the PET/CT group and 41 (62.1%) patients in the CT group achieved complete remission (CR) or partial remission (PR), respectively (P = 0.010). After a median follow-up of 24.7 months, a significant superior locoregional control was observed in the PET/CT group compared with the CT group (P = 0.036), with a 2-year LRC of 54.2% and 40.1%, respectively. Log-rank test showed no statistical difference in respect to OS (P =0.319) and PFS (P =0.582) between the two groups. However, patients in the PET/CT group tended to have a slightly longer median survival time (25.4 mo vs. 21.7 mo) and median progression-free survival time (12.7 mo vs. 10.7 mo). Patients in the PET/CT group were less likely to develop grade ≥ 2 RILI than those in the CT group (9.0% vs. 19.4%, P = 0.083). Other acute toxicities were all comparable between the two groups.

    Conclusion
    Using PET/CT instead of CT for target volume delineation in radiotherapy for LA-NSCLC was associated with a better LRC and lower incidence of grade≥2 RILI. A possible explanation was that the more accurate target delineation in PET/CT-based planning allowed for an escalated total dose delivered to a relatively small target volume.