Background: Concurrent chemoradiotherapy (CCRT) is the standard of care in locally advanced cervical carcinoma, but due to irradiation of pelvic bone marrow (BM), it is associated with dose-limiting haematological toxicity (HT). Advanced radiotherapy (RT) techniques such as bone marrow-sparing volumetric modulated arc therapy (BMS-VMAT) may reduce BM dose and hence decrease treatment-related toxicities.

Aims and objectives: To compare dosimetric parameters and HTs between BMS-VMAT and three-dimensional conformal radiotherapy (3DCRT) in cervical cancer patients undergoing CCRT.

Methods: This retrospective single-institutional study included 60 patients (30 each in BMS-VMAT and 3DCRT arms), who had received external beam radiotherapy with a dose of 50 gray (Gy) in 25 fractions with concurrent weekly cisplatin 40 mg/m². BM was contoured anatomically and dosimetric parameters BM D_mean, V10, V20, V30, V40 and D_max were analysed. HTs were recorded weekly using CTCAE v5.0 criteria. Statistical analysis was performed using independent t-test, Mann–Whitney U test and chi-square test, p-value ≤0.05 was considered significant.

Results: BMS-VMAT significantly reduced BM D_mean (26.73 versus 36.09 Gy, p < 0.001); D_max (51.96 versus 52.72 Gy, p = 0.004); V30 (36.25% versus 56.69%, p <0.001) and V40 (17.37% versus 44.39%, p < 0.001) in comparison to 3DCRT. V10 and V20 were not significantly different. Planning target volume coverage was comparable in both arms. Grade ≥2 anaemia (26% versus 53%, p = 0.035), leukopenia (16.7% versus 46.7%, p = 0.025) and neutropenia (16.7% versus 40%, p = 0.008) were significantly lower in the BMS-VMAT arm.

Conclusion: BMS-VMAT reduces clinically relevant dose parameters and HTs without compromising target coverage, supporting its role in cervical cancer radiotherapy.