Characterizing LAM With 11C-Choline PET/CT

Tuberous Sclerosis Complex (TSC) is an autosomal dominant disorder caused by inactivating mutations of the TSC1 or TSC2 gene, characterized by neurocognitive impairment and benign tumors of the brain, skin, heart, and kidneys. Lymphangioleiomyomatosis (LAM) is a diffuse proliferation of α-smooth muscle actin-positive cells associated with cystic destruction of the lung. LAM occurs almost exclusively in women, as a TSC manifestation or a sporadic disorder (TSC1/TSC2 somatic mutations). Biomarkers of whole-body tumor burden/activity and response to rapalogs or other therapies remain needed in TSC/LAM. It was reported that TSC2-deficient cells enhance phosphatidylcholine synthesis via the Kennedy pathway. 11C-Choline can reflect the metabolic process of choline in vivo by intravenous injection. The purpose of this study is the ability of 11C-Choline PET/CT to evaluate the baseline condition of LAM patients and the efficacy of rapamycin after treatment.

• 11C-Choline (Drug): 11C-Choline were injected into the patients before the PET/CT scans

Primary outcomes

• Standardized uptake value of 11C-Choline in LAM lesions [through study completion, an average of 2 year]: The semiquantitative analysis will be performed by the same person for all the cases, and the standardized uptake value (SUV) of the tracer in lymphatic lesion will be measured.

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

\- provide a written informed consent; Diagnostic CT or MRI suggesting a diagnosis of lymphangioleiomyomatosis.

Exclusion Criteria:

\- Females planning to bear a child recently or with childbearing potential; Known severe allergy or hypersensitivity to IV radiographic contrast； Inability to lie still for the entire imaging time.

• Fang Li, MD, Principal investigator, Peking Union Medical College Hospital