HYpofractionated, Dose-redistributed RAdiotherapy With Protons and Photons in HNSCC — HYDRA  

Head and Neck Squamous Cell Carcinoma Clinical Trial

Official title: HYpofractionated, Dose-redistributed RAdiotherapy With Protons and Photons to Combat Radiation-induced Immunosuppression in Head and Neck Squamous Cell Carcinoma (HYDRA)

Status Recruiting

Clinical Trial Summary

Radiotherapy for advanced-stage head and neck squamous cell carcinoma (HNSCC) results in an unfavorable 5-year overall survival of 40%, and there is a strong biological rationale for improving outcome by combinatorial treatment with immunotherapy. However, also immunosuppressive effects of radiotherapy have been reported and recently a randomized phase-III trial failed to show any survival benefit following the combination of a PD-L1 inhibitor with chemoradiotherapy. The hypothesis is that the combination of these individually effective treatments failed because of radiation-induced lymphodepletion and that the key therefore lies in reforming conventional radiotherapy, which typically consists of large lymphotoxic radiation fields of 35 fractions. By integrating modern radiobiology and individually established innovative radiotherapy concepts, the patient's immune system could be maximally retained. This will be achieved by 1) increasing the radiation dose per fraction so that the total number of fractions can be reduced (HYpofractionation), 2) by redistributing the radiation dose towards a higher peak dose within the tumor center and a lowered elective-field dose (Dose-redistribution) and 3) by using RAdiotherapy with protons instead of photons (HYDRA).

The objectives of this study are to determine the safety of HYDRA with protons and photons by conducting two parallel phase-I trials. HYDRA's efficacy will be compared to standard of care (SOC). The immune effects of HYDRA-protons will be evaluated by longitudinal immune profiling and compared to HYDRA-photons and SOC (with protons and photons). There will be a specific focus on actionable immune targets and their temporal patterns that can be tested in future hypofractionated-immunotherapy combination trials. This trial therefore is an important step towards future personalized immuno-radiotherapy combinations with the ultimate goal to improve survival for patients with HNSCC.

Clinical Trial Description

The HYDRA dose prescriptions are, in 20 fractions (instead of the conventional 35 fractions):

• Inhomogeneous focal boost on the macroscopic gross tumor volume (GTVprimary tumor and GTVnodes) on FDG-PET: mean dose 59Gy, max dose 63Gy.

• The mean dose of 59Gy corresponds to an equal late normal tissue toxicity probability after conventionally fractionated radiotherapy of 70Gy in 35 fractions, considering an α/β=3 for normal tissue.

• Simultaneous integrated boost (SIB) on the clinical target volume (CTV-P1 = GTV+5mm):

55Gy

• Elective field / CTV-P2 (GTV+10mm): 40Gy

Patients who receive the HYDRA intervention treatment, as well as patients who receive standard of care may require the addition of a concurrent radiosensitizer based on clinicopathological features according to standard of care. Currently, the only two registered radiosensitizers are platinum-based chemotherapy (cisplatin/carboplatin) and cetuximab. These radiosensitizers should be administered according to standard care treatment protocols. ;

Related Conditions & MeSH terms

• Carcinoma
• Carcinoma, Squamous Cell
• Head and Neck Squamous Cell Carcinoma
• Hypofractionation
• Immune System Suppression
• Proton Therapy
• Radiotherapy
• Squamous Cell Carcinoma of Head and Neck

• NCT number: NCT05364411
• Study type: Interventional
• Source: Erasmus Medical Center
• Contact: Joris BW Elbers, MD, PhD
• Phone: 0031207041249
• Email: j.elbers@erasmusmc.nl
• Status: Recruiting
• Phase: N/A
• Start date: October 10, 2022
• Completion date: June 1, 2026