KEY POINTS
- This retrospective single-centre study included 148 patients receiving intracavitary brachytherapy for cervical cancer between 2020 and 2025. A rectal retractor was used in 58 patients (39.2%).
- Most patients had locally advanced disease and received approximately 47.7 Gy EBRT, followed by brachytherapy in three fractions in 94.6%. Mean cumulative HR-CTV D90 was approximately 86 Gy EQD2.
- Retractor use reduced cumulative rectal exposure: median rectal D2cc fell from 65.7 to 60.8 Gy EQD2 (p=.002). Looking at brachytherapy alone, rectal D2cc decreased from 19.4 to 12.5 Gy EQD2 (p<.001).
- This rectal sparing came with a clear bladder-dose trade-off. Cumulative bladder D2cc increased from 75.6 to 80.1 Gy EQD2 (p<.001), and brachytherapy-only bladder D2cc increased from 27.6 to 30.6 Gy EQD2 (p=.001).
- Target coverage was preserved: cumulative HR-CTV D90 was 86.4 Gy without versus 86.7 Gy with the retractor, with no significant difference in HR-CTV D90, D98 or prescribed dose.
- Grade ≥2 vaginal toxicity was substantially less frequent with the retractor: 32.8% versus 56.7% (p=.004). After adjustment for age, stage, baseline vaginal involvement and surgical status, retractor use remained associated with lower odds of grade ≥2 vaginal toxicity (OR 0.29; 95% CI 0.13–0.63).
- Grade ≥2 rectal toxicity (8.6% vs 13.3%) and urinary toxicity (6.9% vs 16.7%) did not differ significantly. Interpretation is complicated by strong selection according to applicator type: retractors were used in most ring and tandem-ovoid cases but in none of the cylinder cases.
CLINICAL TAKEAWAY
Rectal retractors can meaningfully reduce rectal D2cc without sacrificing cervical target coverage, but the accompanying rise in bladder dose should be actively reviewed during optimization. The lower vaginal-toxicity signal is intriguing but cannot be considered causal because retractor placement was nonrandomized and closely linked to applicator selection.