2729 - Personalized Ultrafractionated Stereotactic Adaptive Radiotherapy for Palliative Head and Neck Cancer Treatment (PULS-Pal): Trial in Progress
Presenter(s)
R. K. Chin1, M. Santoso1, R. R. Savjani1, V. Reddy1, W. Chai-Ho2, M. A. Velez Velez3, D. J. Wong2, C. Palodichuk1, V. Basehart1, D. O'Connell1, M. Cao4, D. Telesca5, M. L. Steinberg1, and P. T. Courtney1; 1Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Dept of Medicine, Division of Hematology/Oncology, Los Angeles, CA, 3Department of Hematology-Oncology, University of California, Los Angeles, Los Angeles, CA, 4Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, 5Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA
Purpose/Objective(s): In patients with head and neck cancer who are ineligible for standard of care definitive treatments, locoregional palliative radiotherapy is often utilized, with the most common head and neck cancer palliative radiotherapy regimens being the RTOG-8502 regimen (“quad-shot”) and stereotactic body radiotherapy. While these existing regimens can provide adequate symptom improvement, they have limitations, particularly with respect to local tumor control. Local control is becoming more important in this setting as advances in systemic therapy are improving survival, and because local progression often worsens symptoms and possibly overall survival. We seek to evaluate a new head and neck cancer palliative radiotherapy regimen.
Materials/Methods: Personalized ultrafractionated stereotactic adaptive radiotherapy (PULSAR) is a novel radiotherapy regimen which utilizes advanced radiotherapy treatment technology and extended interfraction intervals to enable adaptive radiotherapy and possible synergy with immunotherapy. Additionally, automated, non-coplanar volumetric modulated arc therapy (VMAT) planning software allows for safe dose-escalation to head and neck tumors. We designed a single-institution, single-arm, phase II clinical trial to evaluate PULSAR in combination with automated, non-coplanar VMAT treatment planning software for palliative locoregional treatment in patients with newly diagnosed or recurrent, localized or metastatic head and neck cancer, including those who previously received 1 course of radiotherapy to the treatment area at least 6 months prior and with tumors up to 10cm, who are ineligible for or decline standard of care definitive treatments. Concurrent systemic therapy is permitted but not mandated. The trial aims to enroll 43 patients and includes a safety and feasibility lead-in portion of the first fifteen patients whereby the trial will continued if less than five patients experience a CTCAEv5.0 grade 3 or 4 and no patient experiences a grade 5 toxicity probably attributable to PULSAR during or within three months after its completion. Patients will receive an 11 Gy fraction of radiation once every 2 weeks for a total of 5 fractions and dose of 55 Gy, and adaptive radiotherapy planning is encouraged. The primary endpoint is 1-year local tumor control, and we hypothesize that this regimen will improve 1-year local tumor control to 85% compared with a historic control of 65%. Secondary endpoints include toxicity, symptomatic impact, disease-free and overall survival, and radiotherapy dosimetry and planning components. Outcomes data for the combination of PULSAR and systemic therapy, including immunotherapy, may be generated as well.
Results: The trial opened for enrollment on July 22nd, 2024, and thus far has enrolled 15 patients.
Conclusion: The PULS-Pal clinical trial will provide valuable, early safety and efficacy data of PULSAR in this clinical context and for the field of radiation oncology. Clinical Trial Number: NCT06572423.