Feasibility of [11C]Acetate-PET in LAM and TSC

January 5, 2026 updated by: Carmen Priolo, M.D., Ph.D., Brigham and Women's Hospital

Feasibility Study of [11C]Acetate Positron Emission Tomography (PET) as an Indicator of Early Response to Rapamycin in Lymphangioleiomyomatosis (LAM) Patients

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.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

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.

Study Type

Interventional

Enrollment (Actual)

7

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham and Women's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • diagnosis of LAM (or TSC-LAM)
  • age 18 or over
  • at least one renal angiomyolipoma (at least 1 cm in each diameter) confirmed by CT or MRI
  • no prior treatment with rapamycin/rapalogs OR candidate for initiating treatment with rapamycin/rapalogs OR under treatment with rapamycin/rapalogs for minimum 3 months and maximum of 1 year

Exclusion Criteria:

  • under treatment with rapamycin or rapalogs for < 3 months or > 1 year
  • participated in research studies involving radiation exposure (> 50 mSv/year) in the past 12 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients will undergo [11C]acetate PET/CT
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)
Other Names:
  • diagnostic test

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions
Time Frame: Single assessment (day of imaging)
Standardized uptake value (SUV) will be used to quantify uptake of [11C]acetate in kidney angiomyolipoma
Single assessment (day of imaging)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Quantitative Analysis of [11C]Acetate Uptake in LAM Lesions Following Treatment With mTORC1 Inhibitor
Time Frame: Single assessment conducted while participants were on treatment with mTORC1 inhibitor (day of imaging)
Standardized uptake value (SUV) will be used to quantify uptake of [11C]acetate in kidney angiomyolipoma following treatment with mTORC1 inhibitor
Single assessment conducted while participants were on treatment with mTORC1 inhibitor (day of imaging)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Brigham and Women's Hospital

Collaborators

Massachusetts General Hospital

Investigators

  • Principal Investigator: Carmen P Priolo, MD PhD, Brigham and Women's Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 30, 2021

Primary Completion (Actual)

June 4, 2024

Study Completion (Estimated)

June 30, 2026

Study Registration Dates

First Submitted

July 18, 2022

First Submitted That Met QC Criteria

July 18, 2022

First Posted (Actual)

July 20, 2022

Study Record Updates

Last Update Posted (Actual)

January 21, 2026

Last Update Submitted That Met QC Criteria

January 5, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2019p003557

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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