Background
Everolimus is a potential alternative to embolization and nephrectomy for managing TSC-associated renal angiomyolipoma (AML). In 2016, NHS England approved its use through regional centres for renal AML ≥ 30mm showing interval growth. Evidence of lesion stabilisation or reduction after 6 months is mandated for continuation of long-term treatment.
Methods
From November 2016 to June 2021, all potentially eligible adult TSC patients with AML across Yorkshire and Humber were referred for assessment and monitoring. Eligible patients underwent baseline renal MRI assessment and a follow-up MRI scan after 6 months on everolimus. Dose titration was guided by trough levels and lesion responsiveness using a new 3D MRI volumetric protocol.
Results
Of 28 patients commencing treatment, 19 tolerated everolimus for >3 months. Overall, 11 patients (40%) discontinued treatment, mostly due to recurrent infections (42%) and allergic reactions (25%). 68% required dose adjustments from the initiating dose (10mg) due to sub-optimal trough levels (38%), minimal AML response (15%) or adverse events (47%). 3D volumetric assessment confirmed a reduction in AML volume of a pre-selected index lesion in all treatment-naive cases (n = 14) showing superiority over 2D measurements of lesion diameter.
Conclusion
In this cohort, everolimus promoted AML regression in all patients who tolerated the drug for > 6 months with stabilisation observed over 3 years. Trough levels enabled individual dose titration to maximise responsiveness and minimize side-effects. The use of 3D MRI assessment of lesion volume was superior to 2D measurements of lesion diameter in monitoring treatment response.