Brachytherapy for isolated tongue metastasis of renal clear cell carcinoma

Tongue metastasis of renal cell carcinoma (RCC) is rare. Treatment is hindered by the proximity of anatomic structures involved in swallowing, speech and mastication. It is, moreover, radioresistant.

We report a case of inaugural isolated tongue metastasis, where biopsy redirected diagnosis to RCC. To avoid potentially mutilating excision in a metastatic disease of poor prognosis, treatment was local, consisting in interstitial brachytherapy, enabling a high dose (65Gy) to be delivered. Despite initially complete response, recurrence at 10.5months required salvage surgery.

Brachytherapy allowed a higher dose to be delivered than with external beam radiation therapy, previously reported for similar cases. This dose, which can usually be expected to ensure local control in 90% of squamous cell carcinomas of the tongue, obtained 10months' response, insufficient to avoid salvage surgery.