KEY POINTS
- This single-centre retrospective study evaluated 251 non-metastatic cervical cancer patients treated from 2012–2022: 222 (88%) had a consistently anteverted uterus and 29 (12%) a consistently retroverted uterus during all brachytherapy fractions. Median follow-up was 44 months.
- All patients received 45–50.4 Gy in 25–28 fractions of pelvic ± para-aortic external-beam radiotherapy followed by 28 Gy in four fractions of ^192Ir HDR intracavitary brachytherapy. Concurrent chemotherapy was given to 96%, most commonly weekly cisplatin 40 mg/m².
- Target coverage was statistically lower with retroversion: median cumulative HR-CTV D90 was 89.8 versus 91.3 Gy EQD2 (p=0.001) and IR-CTV D98 65.9 versus 67.4 Gy (p=0.044). Importantly, median HR-CTV D90 in the retroverted group remained above the institutional 85-Gy target.
- Retroversion produced a less favorable posterior OAR geometry. Rectum D2cc increased from 76.3 to 79.7 Gy (p=0.001) and bowel D2cc from 66.4 to 73.7 Gy (p=0.023), while sigmoid D2cc was lower at 59.9 versus 63.4 Gy (p=0.005). Bladder D2cc did not differ significantly.
- These dosimetric differences did not translate into worse disease control: 5-year overall survival was 71% with anteversion versus 77% with retroversion (p=0.8), and local recurrence occurred in 10% versus 11% (p=0.89). Five-year disease-free survival was 66% versus 69% (p=0.83).
- Mild late gastrointestinal toxicity was more frequent with retroversion (17% vs 4%, p=0.019), but severe toxicity was not: grade 3–4 GI toxicity occurred in 3% versus 6%, and grade 3–4 GU toxicity in 0% versus 1%. Across the cohort, higher bowel D2cc was associated with grade 3–4 GI toxicity (p=0.037).
- Uterine position cannot be isolated cleanly from applicator geometry in this study: all retroverted patients received tandem-ovoid applicators, whereas 23% of anteverted patients received tandem-ring applicators, often with a rectal retractor. The institution also did not use interstitial or hybrid brachytherapy, and planning was CT-based rather than MRI-based.
CLINICAL TAKEAWAY
A retroverted uterus should alert the brachytherapy team to potentially higher rectal and bowel exposure and somewhat more difficult target coverage, but retroversion alone did not compromise local control or survival in this cohort. The dosimetric signal is useful for planning vigilance, although applicator selection and the absence of interstitial techniques substantially confound the comparison.