Prognostic value of FDG-PET SUV changes in cervical cancer following radiation therapy: a retrospective cohort study

TL;DR

This study found that changes in FDG-PET SUV values after radiation therapy for cervical cancer do not reliably predict cancer recurrence or survival.

Contribution

The study provides new evidence that post-treatment SUV changes are not predictive of outcomes in cervical cancer patients.

Findings

SUV changes in the cervix and lymph nodes were not significantly different between patients with and without recurrence.

Percent decrease in SUV was not predictive of local or overall recurrence.

Changes in SUV were not associated with overall or progression-free survival.

Abstract

This study sought to determine the relationship between cervical cancer recurrence and post-treatment change in standardized uptake value (SUV) of 18F-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in the cervix and lymph nodes.

This retrospective cohort study included patients who received curative intent radiation therapy for biopsy-proven stage I–IVA locally advanced cervical cancer at a single tertiary referral center from 2009 to 2021. The exposure was percent change in SUV from pre- to post-treatment FDG-PET scans at the cervix and lymph nodes. The primary outcome was recurrence rate, and secondary outcomes were overall and progression-free survival. Firth’s penalized logistic regression and Cox proportional hazards models were used to assess associations.

55 patients met eligibility criteria. Recurrence rate was 27% (15/55); of these, 33% had local recurrence (5/55) and 67% had distant recurrence (10/55). Median percent decrease of cervical SUV after treatment in those with and without recurrence was similar (71.4 vs 68.8, p = 0.89); this remained consistent when analyzing those with local recurrence only (70.5, p = 0.95). When the percent decrease in cervical SUV was examined in intervals (< 25%, 25–50%, 50–75%, > 75%), this was also not predictive of local (p = 0.91) or overall (p = 0.75) recurrence. Median percent decrease at the most avid and distant lymph node in those with and without recurrence was not significantly different (p > 0.05). Neither change in cervical nor lymph node SUV was associated with overall or progression-free survival.

Changes in SUV after treatment may not be a reliable stand-alone marker for predicting recurrence or survival in locally advanced cervical cancer after treatment with radiation therapy.

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