To determine whether growth rate differs for patients treated with mTOR inhibitor for SEGA or AML or no treatment.

Tuberous Sclerosis Complex (TSC) is characterized by epilepsy, renal angiomyolipoma (AML), subependymal giant cell astrocytoma (SEGA), and other cognitive, dermatologic, pulmonary, and cardiac manifestations. mTOR inhibitors are prescribed to reduce the size of AMLs or SEGA and reduce seizure frequency. Thus, the indication for initiating mTOR therapy differs for each patient.

Patients seen in the Atrium Health Wake Forest Baptist Adult Tuberous Sclerosis clinic were retrospectively evaluated. Patients were eligible if they were adults (age >18 years), had at least 1 renal AML, and had at least two instances of imaging (CT or MRI) to evaluate renal AMLs. Data was collected on patient demographics, current/prior mTOR use, renal involvement, and AML size. AML size was defined as the largest diameter of the dominant lesion. Change in median diameter of the dominant lesions of each treatment was calculated.

44 patients were reviewed (mean age = 35.6±13.8, 61% female); 22 met eligibility. AML growth differed for patients prescribed mTOR inhibitor to treat SEGA (n=3, mean treatment 25.5 months, 0.5 mm/year decrease on the right, 1.2 mm/year decrease on the left) compared to AML (n=5, mean treatment = 16.25 months, 0.96 mm/year decrease on the right, 3.5 mm/year decrease on the left). Patients who had never used an mTOR inhibitor displayed a 1.7 mm/year increase in AML size in the right kidney and 1.9 mm/year increase in AML size in the left kidney.

In this cohort of adult TSC patients with AMLs, patients who did not receive mTOR therapy experienced annual growth in AML size. Those having ever taken an mTOR inhibitor experienced annual decrease in AML size. The median decrease in size differed between patients who initiated treatment for SEGA vs. AMLs.