Author of 1 Presentation
SS 2.7 - Positron emission tomography may be useful to stage patients with rectal cancer and lateral pelvic lymph nodes with a short axis of at least 5 mm
Abstract
Purpose
To verify the minimum size of lateral pelvic lymph nodes (LPLNs) that can be considered metastatic by positron emission tomography (PET) when integrated 18F-fluorodeoxyglucose (FDG)-PET/MRI is used to evaluate patients with rectal cancer at baseline staging.
Material and methods
IRB-approved retrospective analysis of prospectively collected data between Nov 2016 and Apr 2018 of 99 consecutive patients with rectal cancer at baseline staging (NCT02537340) was done. Inclusion criteria: >18 years with biopsy-proven rectal adenocarcinoma. Exclusion criteria: previous treatment, known neoplasia, PET/MRI contraindications, failure to consent and unavailable images. Images were reviewed in consensus by radiologist with 10years of experience in reading MRI and nuclear medicine physician with 3years of experience in reading PET. Assessment included a) MRI-identified LPLNs with malignant features (mixed signal intensity/border irregularity); b) the short axis (SA) of the largest LPLNs showing no malignant features in internal, external iliac or obturator compartments. Volume of interest (VOI) was drawn over the selected LPLNs to measure SUV; c) PET-identified LPLNs, considered metastatic when SUVmax was higher than 2.5. The SA of PET-positive nodes was recorded. The median node size was calculated.
Results
Fourteen patients (30 nodes) were positive on both PET and MRI components, five (5 nodes) were MRI-positive and PET-negative and two (2 nodes) were PET-positive and MRI negative. Median SUVmax uptake of PET-positive nodes was 4.9(2.6-17.6). Median size of PET-positive nodes was 10mm (5-18mm). Median size of MRI-positive nodes was 10mm (5-18mm). Twenty patients had no visible LPLN. Fifty-eight remaining patients had metabolic and morphological negative nodes with median size of 5.1mm (2-8mm).
Conclusion
The smallest PET-positive node had a short axis of 5mm.
Video-on-demand
Author of 1 Presentation
SS 2.7 - Positron emission tomography may be useful to stage patients with rectal cancer and lateral pelvic lymph nodes with a short axis of at least 5 mm (ID 366)
Abstract
Purpose
To verify the minimum size of lateral pelvic lymph nodes (LPLNs) that can be considered metastatic by positron emission tomography (PET) when integrated 18F-fluorodeoxyglucose (FDG)-PET/MRI is used to evaluate patients with rectal cancer at baseline staging.
Material and methods
IRB-approved retrospective analysis of prospectively collected data between Nov 2016 and Apr 2018 of 99 consecutive patients with rectal cancer at baseline staging (NCT02537340) was done. Inclusion criteria: >18 years with biopsy-proven rectal adenocarcinoma. Exclusion criteria: previous treatment, known neoplasia, PET/MRI contraindications, failure to consent and unavailable images. Images were reviewed in consensus by radiologist with 10years of experience in reading MRI and nuclear medicine physician with 3years of experience in reading PET. Assessment included a) MRI-identified LPLNs with malignant features (mixed signal intensity/border irregularity); b) the short axis (SA) of the largest LPLNs showing no malignant features in internal, external iliac or obturator compartments. Volume of interest (VOI) was drawn over the selected LPLNs to measure SUV; c) PET-identified LPLNs, considered metastatic when SUVmax was higher than 2.5. The SA of PET-positive nodes was recorded. The median node size was calculated.
Results
Fourteen patients (30 nodes) were positive on both PET and MRI components, five (5 nodes) were MRI-positive and PET-negative and two (2 nodes) were PET-positive and MRI negative. Median SUVmax uptake of PET-positive nodes was 4.9(2.6-17.6). Median size of PET-positive nodes was 10mm (5-18mm). Median size of MRI-positive nodes was 10mm (5-18mm). Twenty patients had no visible LPLN. Fifty-eight remaining patients had metabolic and morphological negative nodes with median size of 5.1mm (2-8mm).
Conclusion
The smallest PET-positive node had a short axis of 5mm.