Assessment of Rapamycin Response in LAM Patients Using [11C]Acetate PET Imaging

Lymphangioleiomyomatosis (LAM) is a rare disease affecting women, causing a growth of abnormal cells in the lungs and other organs. These cells have mutations in the TSC1 or TSC2 genes, leading to overactivation of a protein called mTORC1, which stimulates cell growth and metabolism. This results in lung damage, collapsed lungs, and fluid buildup around the lungs. LAM can also cause non-cancerous tumors in the kidneys and lymph vessels. Rapamycin, a drug approved by the FDA, is used to treat LAM and related kidney tumors. However, when treatment stops, the disease may start progressing again. This study aims to find a sensitive and specific way to measure how well the treatment is working and if the disease is progressing, using a type of imaging called [11C]Acetate positron emission tomography (PET) imaging. During the study, participants with LAM will undergo [11C]Acetate PET imaging. This non-invasive scan measures the metabolic activity of LAM lesions. The main goal is to assess how well the [11C]Acetate is taken up by the kidney tumors, using a measurement called Standardized Uptake Value (SUV). This will help determine if [11C]Acetate PET imaging can be used as an effective tool to monitor the response to Rapamycin treatment in LAM patients.