1. DEPT OF RADIATION ONCOLOGY Prognostic Value of Post-Radiotherapy FDG PET in Head and Neck Cancer after Intensity Modulated Radiation Treatment Heming Lu 1, MD; Min Yao 2, MD, PhD; John Buatti 3, MD; Minggen Lu 3, PhD; Henry Hoffman 3, MD; Gerry Funk 3, MD; Yusuf Menda 3, MD; Michael Graham 3, MD, PhD 1.People’s Hospital of Guangxi Zhuang Autonomous Region, China; 2. University of Texas Southwest Medical Center, Dallas, Texas; 3. University of Iowa School of Medicine, Iowa City, Iowa

2. DEPT OF RADIATION ONCOLOGY Objectives To determine the prognostic value of post-radiotherapy FDG-PET in head and neck squamous cell carcinoma (HNSCC) after IMRT.

3. DEPT OF RADIATION ONCOLOGY Materials and Method ■This is a retrospective study of HNSCC treated with IMRT at the University of Iowa from December 1999 to May 2005 ■Total 236 patients were treated. 188 of them had FDG PET study within 12 months after radiation. These patients consist of the population of this study.

4. DEPT OF RADIATION ONCOLOGY Patient Characteristics Tumor Site Nasopharynx 6 Oropharynx 78 Oral cavity 45 Larynx37 Hypopharynx10 Unknown 12 Population Male144 Female 44 Treatment Definitive128 Post-operative 60 AJCC Stage Stage I 2 Stage II 12 Stage III 37 Stage IV125 Unknown 12

5. DEPT OF RADIATION ONCOLOGY Timing for Obtaining FDG PET Range: 1.2 – 10.2 months Median:3.5 Months (15 weeks) Majority (64%) 12 – 20 weeks

6. DEPT OF RADIATION ONCOLOGY Follow-up Time ■Follow-up from the end of IMRT AllMedian: 32.6 months Range: 3.5 – 86.3 months Living Median: 36.2 months Range:19.4 – 86.3 months ■Follow-up from first FDG-PET study AllMedian: 29.2 months Range: 0.7 – 80 months Living Median: 33.1 months Range:13.9 – 80 months

7. DEPT OF RADIATION ONCOLOGY Results For all patients, the 3-year Survivals Local recurrence-free survival93% Regional recurrence-free survival 95.2% Locoregional recurrence-free survival 89.8% Distant metastasis-free survival79.1% Disease-free survival63.5% Overall survival 69.5%

8. DEPT OF RADIATION ONCOLOGY Fig. 1. Kaplan-Meier estimates of overall survival, disease-free survival, local recurrence- free survival, regional recurrence-free survival, local-regional recurrence-free survival, and distant metastasis-free survival of all patients.

9. DEPT OF RADIATION ONCOLOGY Fig. 2. Kaplan-Meier estimates of local recurrence-free survival according to the results of FDG PET at the primary sites

10. DEPT OF RADIATION ONCOLOGY Fig. 3. Kaplan-Meier estimates of regional recurrence-free survival according to the results of FDG PET at the cervical lymphatic regions.

11. DEPT OF RADIATION ONCOLOGY Fig. 4. Kaplan-Meier estimates of distant metastasis-free survival according to the results of FDG PET at the primary sites and cervical lymphatic regions..

12. DEPT OF RADIATION ONCOLOGY Fig. 5. Kaplan-Meier estimates of disease-free survival according to the results of FDG PET at the primary sites and cervical lymphatic regions.

13. DEPT OF RADIATION ONCOLOGY Fig. 6. Kaplan-Meier estimates of overall survival according to the results of FDG PET at the primary sites and cervical lymphatic regions.

14. DEPT OF RADIATION ONCOLOGY Conclusions ■FDG PET obtained after radiation treatment can provide significant prognostic value in head and neck squamous cell carcinoma after IMRT. ■ FDG PET is a useful tool to assess treatment response and predict treatment outcomes.