Diagnostic and Therapeutic Impact of 18F-FDG PET/CT in Head and Neck Cancers: Insights from a Newly Established Tertiary Oncology Care Centre in North India

ABSTRACT Introduction: Head and neck cancers (HNCs) represent a significant oncologic burden in India. The integration of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) into clinical workflows offers potential advantages in staging and treatment planning. However, real-world data from newly established tertiary oncology centres in North India are sparse. The objective of this article is to evaluate the diagnostic and therapeutic impact of 18F-FDG PET/CT in head and neck cancer patients treated at a new tertiary care oncology centre in North India. Methodology: This retrospective study analysed data from 627 patients with histologically confirmed HNC who underwent 18F-FDG PET/CT between August 2023 and May 2025. Clinical, imaging, and treatment records were reviewed to assess changes in staging and therapeutic decisions based on PET/CT findings. Results: 18F-FDG PET/CT led to a change in overall TNM staging in 20.4% of patients, with the greatest impact observed in regional nodal assessment. Metabolically active cervical lymph nodes not evident or considered equivocal on anatomical imaging resulted in nodal upstaging in a significant proportion of cases. Previously unrecognized distant metastases were detected in 7.3% of patients. In patients presenting with metastatic cervical lymphadenopathy and no detectable primary tumor on conventional work-up, PET/CT helped localize the primary site in approximately one-third of cases. From a therapeutic perspective, PET/CT findings resulted in a change in management in 18.6% of patients. These changes included modification of radiotherapy target volumes, alterations in surgical planning, adjustment of treatment intensity, and a shift from curative to palliative intent in patients with newly identified distant metastatic disease. Conclusion: In a newly established tertiary oncology centre, 18F-FDG PET/CT significantly influenced staging and treatment strategy in head and neck cancer patients. These findings support its integration into routine management protocols for HNC in similar settings. Keywords: 18F-FDG PET/CT, head and neck cancer, retrospective study, diagnostic impact, therapeutic impact, India