Clear Cell Renal Cell Carcinoma With Brain Metastases Treated With Complementary Ketogenic Metabolic Therapy: A Case Report

A 65-year-old woman was first diagnosed in 2011 with stage III clear cell renal cell carcinoma (pT3aNxM0) of the left kidney, managed successfully with radical nephrectomy. She remained disease-free for three years. In 2014, she developed a metachronous stage III papillary thyroid carcinoma (T1N1M0), treated with total thyroidectomy, nodal dissection, and adjuvant radioactive iodine therapy (100 mCi). In 2019, two pulmonary lesions were detected in the left upper lobe. Biopsy confirmed metastatic clear cell carcinoma. Due to intolerance to sunitinib, the patient was treated with pazopanib. By September 2022, she developed four intracranial metastatic lesions, predominantly in the right frontal lobe and bilateral mesial temporal lobes. A neurosurgeon performed a biopsy, confirming metastatic clear cell carcinoma. The patient underwent whole-brain radiotherapy over five sessions and began treatment with nivolumab. After receiving five cycles of immunotherapy, the patient experienced a seizure associated with edema around the dominant lesion and neurological decline. She was treated with anticonvulsants and a short steroid course, leading to functional recovery. We used this treatment for around 10 days and continued immunotherapy and anticonvulsant therapy. In January 2023, ketogenic metabolic therapy (KMT) was initiated using a 3:1 ratio ketogenic supplement (KetoVie). Ketone levels and neurological status were closely monitored. Upon confirmation of ketones in the urine or blood, therapy adjustments were made to optimize adherence. By July 2023, the patient no longer required assistance for medical appointments, discontinued anticonvulsant therapy, and retained full cognitive function. In January 2024, the patient maintained a partial response, and dietary supplementation was stopped. This case highlights the potential role of KMT as a safe and complementary approach in advanced clear cell renal cell carcinoma. KMT may enhance the efficacy of immunotherapy and radiotherapy, contributing to improved progression-free survival and neurological function without increasing toxicity.