Oropharyngeal squamous cell carcinoma (SCC) is a common type of head and neck cancer often linked to tobacco, alcohol use, and, in youngers, HPV infection. Standard care for locally advanced SCC involves radiotherapy (RT) and cisplatin, (total doses of 66–70Gy in 30–35fractions). However, some patients with significant comorbidities cannot tolerate chemotherapy, requiring alternative approaches. We present a case of a 66-year-old male with p16-negative oropharyngeal SCC and bulky cervical nodal metastasis, ineligible for chemotherapy.

The patient was treated using adaptive volumetric modulated arc therapy (VMAT) with simultaneous integrated boost (SIB) and central gross tumor volume (GTV) dose escalation. This approach delivered up to 72Gy to the central GTV in 30 fractions; 66 Gy in 30 fractions to the high-risk area; 60Gy in 30 fractions to the intermediate-risk area; 54 Gy in 30 fractions to the low-risk area.

An epithelolysis (grade 3) led to a four-day treatment pause. A mid-treatment CT showed tumor shrinkage, reducing the nodal GTV volume from 107to 33cc, prompting adaptive planning to optimize dose distribution and reduce toxicity. The patient completed RT without further interruptions. At six months post-treatment, no recurrence or severe toxicities were detected and four years post-treatment, the patient remains in complete remission without significant late toxicity.

This case demonstrates the effectiveness of VMAT with SIB in delivering accelerated radiotherapy to a bulky nodal lesion in a patient with p16-negative oropharyngeal SCC unfit for chemotherapy; This allowed for tumor control while minimizing exposure to critical structure.