ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head.

OBJECTIVE

This study aimed to investigate the impact of bladder volume on dosimetric outcomes of organs at risk (OARs) in postoperative volumetric-modulated arc therapy (VMAT) for patients with cervical cancer.

METHODS

The study included 71 cervical cancer patients who received radical hysterectomy and postoperative VMAT between January 2020 and January 2023. Patients were divided into 3 groups according to average bladder volume observed in computed tomography simulation positioning images: Group A (<300 mL), Group B (300-500 mL), and Group C (≥500 mL). The study compared dosimetric parameters(V₃₀, V₄₀, V₄₅, and D2cc) for OARs like the bladder, rectum, small intestine, and sigmoid colon, as well as the incidence of radiation cystitis and proctitis among these groups.

RESULTS

The median follow-up of the cohort was 33 months, with a median patient age of 48 years. Group A demonstrated the highest V₄₀ and V₄₅ values for the bladder (p<0.05). Conversely, Group C displayed the highest values for the V₄₀ and V₄₅ of the rectum, as well as the V₄₅ and D2cc of the sigmoid colon (p<0.05). No statistically significant differences were observed in the incidence of acute radiation cystitis and radiation cystitis among the 3 groups. Significant difference was observed in the incidence rates of late radiation cystitis (p<0.05) and radiation proctitis (p<0.05) among the 3 groups. Group A exhibited the highest prevalence of late radiation cystitis, whereas Group C demonstrated the highest prevalence of late radiation proctitis.

CONCLUSION

Bladder volume significantly affects dosimetry of the bladder, rectum, and sigmoid colon in postoperative VMAT for cervical cancer patients. A recommended bladder volume of 300-500 mL helps reduce radiation-induced cystitis and proctitis.