Abstract 419P
Background
LAHNSCC post Radical CTRT 40-50% of patients recur locally within 5 years of treatment. Hence, we have tried to evaluate the role of dose escalation with dose painting IMRT using a Biological tumor volume. Local control at 3 months is the primary objective, with overall survival (OS) being the secondary objective.
Methods
Biopsy-proven LAHNSCC patients who were planned for Radical CTRT were considered for this study. The planning Radiotherapy Computed Tomogram (CT) was taken using Positron Emission Tomography (PET) with Fluoro-Deoxy-Glucose (FDG) as contrast. The volume of CT with SUV of more than 3 was considered for dose escalation. They were planned for 2.2 Gray per fraction, amounting to a total of 77 Gy in 35 fractions. The patients were followed up every week during Radiotherapy. The radiation reactions were monitored and graded according to Radiotherapy Oncology Group (RTOG) guidelines. The acute and late reactions were documented. The follow-up was according to institutional protocol. A PETCECT was repeated at 3 months after completion of CTRT.
Results
The study period was between January 2023 and March 2024. Twenty-eight patients were recruited for this study, all of whom completed the intended treatment protocol. The mean age was 59 years, with a male-to-female ratio of 2.5:1. Twelve patients had oropharyngeal malignancies, ten had hypopharyngeal malignancies, five had laryngeal, and one had oral cavity cancer. Twenty-two patients had stage IV A disease, and twenty-four patients showed a complete metabolic response on PET CECT conducted 3 months post-CTRT. Local control at 3 months was 85%, and at 1 year, it was 76%. Overall survival (OS) at 1 year was 96%. One patient developed a cardiovascular event. Seventeen percent of patients experienced grade 3 Acute RTOG reactions, which were managed conservatively.
Conclusions
Dose escalation using biological tumor volume is feasible and results in a superior outcome in terms of local control with a manageable level of grade 3 toxicities. This could be a future area of research to decrease local recurrences. However, a multicenter study with a larger number of patients and longer follow-up would be required to validate the same.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Ethics Committee of Kasturba Medical College.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.