Bradford Hoppe MD, MPH William Hartsell, MD Proton Therapy Patterns-of-Care and Early Outcomes for Hodgkin Lymphoma: Results from the Proton Collaborative Group Registry

Background Hodgkin lymphoma survivors are at the highest risk of late complications among cancer survivors CCSS-

Background Radiation oncology Reduce the radiation dose Reduce the radiation field size Utilize more conformal radiation techniques

3D-CRT IMRT Protons

3D-CRT IMRT Protons

3D-CRT IMRT Protons

Background Limited data exists utilizing conformal techniques IMRT- 3 studies (N=140 patients) Proton Therapy- 2 studies (N=20 patients)

Purpose Evaluate patients receiving proton therapy for Hodgkin lymphoma and describe the early results

Registry Evaluation Tracking Project: A Prospective Chart Review of Patients Treated with Radiation Therapy (REG001-09)

Methods Utilized the registry to identify patients treated with chemotherapy followed by consolidative proton therapy between June 2008 and March 2015. Identified 40 patients 50 patients treated for HL Excluded 8 relapse/refractory patients. Excluded 1 patient with composite NHL/HL. Excluded 1 patient with just a proton boost.

Results Patient characteristics Median age was 21 years old 36% were pediatric (<19 years old) 80% were under 30 years old 48% were female

Results Disease Characteristics 68% Stage I/II 32% Stage III/IV 93% Mediastinal involvement 65% Bulky disease 48% B symptoms Risk stratification 23% Early Favorable (IA/IIA) 45%- Early Unfavorable (I/II B or X) 33%- Advanced Stage (III, IV)

Results Treatment Characteristics Pediatric patients Adult patients ABVE-PC chemotherapy – 79% Median RT dose- 21 Gy (RBE) (21-25.5 Gy) Adult patients ABVD chemotherapy – 88% Median RT dose- 30.6 Gy (RBE) (21-36 Gy) All patients treated with ISRT field design

Results Median follow up 21 months (range 4-47) 2 year progression-free survival 85%

Pattern of Relapse 3 relapses 2 in-field in bulky mediastinum after 21 Gy 1 out-of-field in cervical neck after receiving 30 Gy to the mediastinum. Would have been outside a photon field

Toxicity No grade 3 toxicities

Conclusions Consolidative proton therapy following standard chemotherapy in HL is primarily used in young patients with bulky mediastinal disease Early relapse-free survival rates are similar to those reported with photons Longer follow up is needed to assess late toxicities.

Acknowledgement Brad Hoppe William Hartsell MD Henry Tsai MD Gary Larson MD George Laramore MD, PHD Carlos Vargas MD Yolanda Tseng MD Megan Dunn PhD Lisa McGee MD Oren Cahlon MD