Primary Outcome Measures
- The diagnostic performance (sensitivity, specificity, positive predicative value, negative predicative value, and overall diagnostic accuracy – all parameters in %). in of FAPI PET compared to routine imaging modalities, including FDG PET/CT, in suspected PM lesions.
Secondary Outcome Measures
- Calculate the proportion of patients where the location of the intended pleural biopsy is altered due to FAPI PET/CT replacing FDG PET/CT.
- Compare the cancer stage (IASCL 9th edition TNM-classification) as determined by FAPI PET/CT compared to conventional imaging (including FDG PET/CT) at primary staging.
- Calculate the proportion of patients with suspected PM lesion with a change in treatment following the -hypothetical – addition of FAPI PET/CT at primary staging.
- Investigate the FAPI PET uptake parameters in suspicious PM lesions (primary tumor), regional lymph nodes, and distant metastases, and in benign lesions. Correlate FAPI uptake parameters in different PM sutypes.
- Calculate changes in FAPI PET uptake parameters – from before to after 2-3 series of anticancer treatment. Changes will be presented as ratios and in %
- Correlate the FAPI PET SUV to FAP targeting immunohistochemistry of biological material.
- Seek supplementary information in medical records, biochemistry, pathology, or other imaging modalities for a final diagnosis/condition in cases of unexpected FAPI PET/CT findings.
- Report Incidence Treatment-Emergent Adverse Events
- A 10 year follow up of included patients will be conducted to determine overall survival (OS) in days from diagnosis, correlated to FAPI PET/CT results.
- A 10 year follow up of included patients will be conducted to determine Recurrence Free Survival (RFS) and Progression Free Survival (PFS) in days from diagnosis, correlated to FAPI PET/CT results.
- Compare conventional CT-based response assessment (mRECIST/iRECIST) to PET based response assessment (PERCIST, and other FDG and FAPI PET derived data) to the clinical outcome, i.e., OS, RFS/PFS.
- Conduct an interobserver study of FAPI PET/CTs. Cohens Kappa d will be calculated.
Inclusion Criteria
- Patients with pleural lesions suspicious of pleural mesothelioma and referred to pleural biopsy.
- Undergone/undergoing FDG PET/CT as part of the diagnostic workup of a suspicious PM lesion.
- Considered physically and mentally able to participate in the research project.
- Understands the study subject information and able to consent to project participation.
- 18-years or older
Exclusion Criteria
- Patients with an imminent need for surgery or in an emergency
- Known concurrent other malignancy with active treatment within the last 1 year; non-melanoma skin cancer and cervical cancer in situ are exempt.
- Pregnant or breastfeeding women.
- Fertile women (women of childbearing potential) who could – theoretically – be pregnant (i.e., unknown pregnancy status).
Fertile women will be tested for pregnancy (by urine humane choriogonadotropin (HCG) or serum HCG) within 48h before FAPI PET/CTs, both at primary staging and restaging. Study subjects can participate in the study if the pregnancy test is negative (i.e., not pregnant).
- Subjects unable to undergo PET/CT: e.g., weighing more than 180 kg (weight limit scanner), unable to fit within the imaging gantry, inability to remain still for the duration of the examination, or with known severe claustrophobia unresponsive to oral anxiolytics or severe fear of needles.
- Subjects with any medical condition or other circumstances that, in the opinion of the Investigator, would significantly decrease the reliability of data, achievement of study objectives or completing the study.
- History of allergic reactions / hypersensitivity attributed to [18F]FDG or FAPI-tracers.
