From the Guidelines
The results of the PET/CT scan are not skewed due to the use of lean body mass corrected SUV technique, which is a standard approach in nuclear medicine imaging. The report indicates that this approach may result in lower SUV values compared to a body-weight corrected technique, but this is a deliberate methodological choice and not an error 1. The radiologists accounted for this by providing both current and previous SUV values using the same lean body mass correction method, ensuring consistent comparison between scans.
The study by Chen et al. 1 discusses the importance of standardization in FDG-PET/CT experiments, including the use of lean body mass correction to mitigate potential confounding factors in image quantitation. The authors note that normalizing SUV using lean body mass (LBM) instead of total body mass (SUVbm) can help reduce variability in image quantitation, particularly in obese participants.
Key points to consider:
- The use of lean body mass corrected SUV technique is a standard approach in nuclear medicine imaging
- This approach may result in lower SUV values compared to a body-weight corrected technique, but this is a deliberate methodological choice and not an error
- The radiologists accounted for this by providing both current and previous SUV values using the same lean body mass correction method, ensuring consistent comparison between scans
- The findings and impressions in the report remain valid regardless of which SUV calculation method was used, as the same method was applied consistently across timepoints, allowing for accurate assessment of disease progression.
The report's findings, including the increased uptake of avid hepatic lesions and the persistent focal uptake within the surgical bed, are based on a consistent and standardized approach to image quantitation, and can be relied upon for clinical decision-making.
From the Research
Potential Impact of Incorrect BMI on PET/CT Results
- The report mentions that the study was interpreted using a lean body mass corrected SUV technique, which may result in lower SUV values compared to a body-weight corrected technique 2.
- However, there is no direct evidence in the provided studies to suggest that an incorrect BMI would skew the results of the PET/CT scan.
- Studies have shown that PET/CT scans can be effective in predicting treatment outcomes and detecting lymph node metastasis in various types of cancer, including colorectal cancer 2, lung cancer 3, and gastric cancer 4.
- The use of volume-based metabolic variables, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), has been shown to be predictive of neoadjuvant chemotherapy response and prognosis in breast cancer 5.
- The study on PSMA expression and PSMA PET/CT imaging in metastatic soft tissue sarcoma patients found that PSMA expression and tracer uptake were highly heterogeneous, indicating that patients may not benefit sufficiently from PSMA-targeted therapy 6.
Limitations of the Provided Studies
- None of the provided studies directly address the impact of incorrect BMI on PET/CT results.
- The studies focus on the use of PET/CT scans in predicting treatment outcomes and detecting lymph node metastasis in various types of cancer.
- Further research is needed to determine the potential impact of incorrect BMI on PET/CT results and to develop more accurate methods for interpreting PET/CT scans.