Seven-year follow-up demonstrating sustained survival following 125I seed brachytherapy in an elderly patient with lip squamous cell carcinoma and Alzheimer's disease: A case report.

Lip squamous cell carcinoma is a distinct subtype of oral malignancy. Surgical resection provides satisfactory local tumor control; however, it frequently compromises oral function, diminishes local sensation and disfigures facial contour-sequelae are disproportionately debilitating in elderly patients with multimorbidity. This study reported the case of an 80-year-old woman with Alzheimer's disease who presented with locally advanced lip squamous cell carcinoma (cT3N2bM0, stage IVA) and cervical lymph node metastases. Following multidisciplinary team evaluation, the patient was deemed unsuitable for curative surgical resection or definitive external-beam radiotherapy. Therefore, computed tomography (CT)-guided radioactive 125I seed implantation, assisted by a three-dimensional (3D) printed template, was performed for both the primary lip tumor and the metastatic cervical nodes, with a prescribed dose of 140 Gy. Postprocedural dosimetric verification confirmed adequate target volume coverage. The patient achieved a durable clinical complete response, with remarkable tumor regression, preserved speech and swallowing function, and remains alive with overall survival exceeding 7 years. This case demonstrates the long-term efficacy and safety of the aforementioned minimally invasive approach in an elderly patient with severe cognitive impairment-a population routinely excluded from prospective trials. No radiation-related toxicities, including xerostomia or osteoradionecrosis, were documented during follow-up. These findings indicate that CT-guided 125I seed brachytherapy with 3D-printed templates is a feasible, function-preserving and potentially curative treatment option for carefully selected elderly patients with advanced lip squamous cell carcinoma who are unable to tolerate conventional definitive therapy. These results further challenge the common view that interventional brachytherapy serves only as a palliative measure.