Multi-Center Experience of Proton Beam Therapy in the Treatment of H&N Cancer

1. Multi-Center Experience of Proton Beam Therapy in the Treatment of H&N Cancer Chicago, October 24, 2017

2. Disclosures • Katarina Petras, MD • None • Michelle Gentile, MD, PhD • None • John Chang, MD • None

3. Background • Proton therapy is becoming a more widely available & applied treatment modality in H&N cancer • The physical properties of protons make them aptly suited in the treatment of H&N cancer given improved conformality and superior dose distribution, potentially improving the therapeutic ratio • As the incidence of cancers with expected excellent prognosis increases (ie: HPV+ OPX tumors), these patients are most at risk for late treatment-related toxicities • Further investigation is needed into the safety and efficacy of proton therapy in H&N cancer

4. Study Design • Prospectively collected clinical data from 8 different proton centers around the U.S. • Northwestern, ProCure OKC, ProCure NJ, Willis-Knighton • SCCA Proton Center, Scripps, Mayo AZ, Maryland Proton Center • Proton Collaborative Group Registry • Patients were treated for H&N cancer of adult histology in either the initial or retreatment setting • RT delivered starting in 2010 – 2017

5. Study Design • Started with a large data set of 512 patients (4/8 centers) • After exclusions, 230 patients included in current analysis • Most common exclusions (for current analysis) were: • Data uncertainty (site, stage, dose) • Histology (lymphoma, sarcoma, skin primary, or benign) • IMRT only • Palliative intent • No follow-up data (required a minimum of 1 follow-up visit)

6. Initial Course RT Patient Demographics

7. OPX patients (n=32): HPV+ (25), HPV- (3), unknown (4)

8. 33% of proton only patients treated with PBS

9. Initial RT Course Acute & Late Grade 3+ Toxicities

10. ReRT Patient Demographics

11. OPX patients (n=26): HPV+ (10), HPV- (6), unknown (10)

12. 30% of proton only patients treated with PBS

13. ReRT Acute & Late Grade 3+ Toxicities

14. Analysis

15. Initial Course RT -All patients & plan types Median follow-up 12 months (range 1-60)

16. Initial Course RT -Proton vs. Hybrid Plans Median total dose: proton 66 Gy(RBE) and hybrid 70 Gy(RBE) Median proton boost dose: 20 Gy(RBE)

17. ReRT Course-All patients and plan types Median follow-up 7 months (range 1-45)

18. ReRT Comparison 1Emory and Indiana University 2MSK, ProCure NJ, Montefiore Medical Center, Northwestern 3MD Anderson, Mayo AZ, University of Cincinnati *only 15% of patients with enough follow-up to grade late toxicity

19. Oropharynx (Initial Course)-All plan types 75% proton only 25% hybrid plans

20. Oropharynx (Initial Course RT) HPV+ n=25 HPV- n=3

21. Study Limitations • Heterogeneous patient population • Limited long-term follow-up • Clinical outcomes • Late toxicity • Different median dose between proton only and hybrid plans • Logistical challenges of proton beam therapy?

22. Conclusions • Proton therapy provides good local control for initial course RT patients with H&N cancer (limited follow-up) • It appears to be a safe and effective treatment modality in previously irradiated patients • Our analysis showed minimal late grade 3 toxicity and no late grade 4 toxicity • Future directions: • Complete QA of large data set from multiple centers • Verify as much high-grade late toxicity as possible

23. THANK YOU! • Dr. Michelle Gentile & Dr. John Chang • Irene Helenowski, PhD • All participating patients & their families • All contributing proton centers & staff • Dr. Carlos Vargas (PCG Study Chair) • Dr. Gary Larson (OKC) • Dr. William Hartsell (CHI) • Dr. Henry Tsai (NJ) • Dr. George Laramore (UW) • Dr. Carl Rossi (Scripps) • Dr. Lane Rosen (Willis-Knighton) • Dr. ShahedBadiyan (Maryland)

24. QUESTIONS? Sólheimajökull Glacier, Iceland