A Phase 1/2 interventional study of [11C]acetate in Lymphangioleiomyomatosis and Tuberous Sclerosis Complex, sponsored by Brigham and Women's Hospital. Active, not recruiting at 1 site in United States. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-21.
Sponsored by Brigham and Women's Hospital · Phase 1/2, Interventional, and Diagnostic
This study aims to assess [11C]acetate positron emission tomography (PET)/computed tomography (CT) as a biomarker for renal angiomyolipomas and pulmonary lymphangioleiomyomatosis (LAM) and an early biomarker of response to rapamycin in LAM patients.
[11C]Acetate is a radioactive form of acetate, a nutrient commonly processed in our body's cells to generate fat and energy. Preclinical studies support the hypothesis that TSC tumors enhance lipid synthesis compared to normal tissues, suggesting that quantification of [11C]acetate in these tumors by PET/CT may provide a metabolic biomarker of disease.
Participants in the study will undergo 1 or 2 PET/CT scans over 3 to 6 months at the Massachusetts General Hospital (Boston, MA). [11C]acetate is administered through an intravenous catheter. This small amount of radioactivity is short-lived and eliminated from the body within a few hours.
Lymphangioleiomyomatosis (LAM) is a rare, multisystem disease of women, consisting of a diffuse proliferation of smooth muscle actin-positive cells (LAM cells), which harbor inactivating mutations in either the TSC1 or TSC2 tumor suppressor gene. These inactivating mutations result in constitutive activation of mammalian/mechanistic TOR (target of rapamycin) complex 1 (mTORC1), which integrates growth factor and nutrient signaling to stimulate cell growth and metabolism. Pulmonary LAM is characterized by associated progressive cystic destruction of the lung parenchyma, recurrent pneumothorax, and chylous pleural effusions. Extrapulmonary proliferative lesions of LAM include renal angiomyolipomas and lymphangiomyomas. LAM can occur as a sporadic disorder where LAM cells harbor somatic inactivating mutations of the TSC1 or TSC2 gene, or in women with Tuberous Sclerosis Complex (TSC).
Rapamycin is an FKBP12-dependent allosteric inhibitor of mTORC1 approved by the FDA for the treatment of LAM and TSC-associated renal angiomyolipomas. Clinical trials of TSC and LAM have shown that 12 month-treatment with rapamycin induces response of renal angiomyolipomas and stabilization of pulmonary function. However, lung function decline and tumor growth resume when treatment is interrupted.
Sensitive and specific biomarkers of response to therapy and/or disease progression, including biomarkers of tumor metabolic activity, would facilitate clinical trials of novel therapeutic agents for LAM and enable optimization of current rapamycin-based regimens.
Our preclinical studies showed that lipogenic pathways can be detected in preclinical animal models of TSC and LAM using PET-based metabolic imaging.
The proposed study aims to quantitatively and non-invasively assess metabolic activity and response to rapamycin in LAM patients using [11C]acetate positron emission tomography (PET) imaging.
49 studies on the registry are indexed under Lymphangioleiomyomatosis; 11 are open to participants now.
This study's enrollment of 7 is below the median of 25 across 30 interventional studies indexed under Lymphangioleiomyomatosis.
Browse Lymphangioleiomyomatosis studies →Brigham and Women's Hospital is the lead sponsor of 1,267 studies on the registry; 228 are open to participants now.
Of its 116 completed or terminated interventional studies of FDA-regulated products, 65 (56%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Patients will undergo a single \[11c\]acetate PET scan OR Patients will undergo an \[11c\]acetate PET scan, initiate treatment with rapamycin or rapalogs and receive a second \[11c\]acetate PET scan 3 or 4 months after starting the treatment.
Drug: [11C]acetate
Positron Emission Tomography (PET)
Also known as: diagnostic test
Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions
Standardized uptake value (SUV) will be used to quantify uptake of \[11C\]acetate in kidney angiomyolipoma
Time frame: Single assessment (day of imaging)
Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions Following Treatment With mTORC1 Inhibitor
Standardized uptake value (SUV) will be used to quantify uptake of \[11C\]acetate in kidney angiomyolipoma following treatment with mTORC1 inhibitor
Time frame: Single assessment conducted while participants were on treatment with mTORC1 inhibitor (day of imaging)
Seven women with Lymphangioleiomyomatosis (LAM) and at least one renal angiomyolipoma greater than 1 cm diameter were recruited to participate in the imaging study. Patients were recruited between August 2021 and May 2024 and signed a consent form either in person or electronically.
| Milestone | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| Started | 7 |
| Completed | 6 |
| Not completed | 1 |
| Withdrew: One patient became ineligible after undergoing a renal procedure. | 1 |
Standardized uptake value (SUV) will be used to quantify uptake of \[11C\]acetate in kidney angiomyolipoma
| Standardized Uptake Value (SUV) | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions | 6.42 ± 3.34 |
Standardized uptake value (SUV) will be used to quantify uptake of \[11C\]acetate in kidney angiomyolipoma following treatment with mTORC1 inhibitor
| Standardized Uptake Value (SUV) | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions Following Treatment With mTORC1 Inhibitor | 2.80 ± 0.90 |
Collected over From imaging up to 10 days. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Undergoing [11C]Acetate PET/CT Imaging | 0/6 (0%) | 0/6 (0%) | 0/6 (0%) |
One patient became ineligible after undergoing a renal procedure.
| Age, Categorical(Participants) | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 6 |
| >=65 years | 1 |
| Sex: Female, Male(Participants) | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| Female | 7 |
| Male | 0 |
| Race (NIH/OMB)(Participants) | Undergoing [11C]Acetate PET/CT Imaging |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 1 |
| White | 6 |
| More than one race | 0 |
| Unknown or Not Reported | 0 |
PDFs hosted by the registry, ClinicalTrials.gov.
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drug tested here: Carbon-11 acetate
Brigham and Women's Hospital →