Comparison of 3D-printed multichannel non-co-planar vaginal applicators and single-channel vaginal applicators for brachytherapy with positive or close surgical margins in cervical cancer.

ABSTRACT

OBJECTIVE: This study was conducted to compare the differences between 3D-printed multichannel non-co-planar vaginal applicators and single-channel vaginal applicators in cervical cancer patients with positive or close surgical margins. METHODS: Between January 2015 and June 2023, 104 cervical cancer patients who underwent radical surgery with positive or close surgical margins were enrolled to receive concurrent intensity-modulated chemoradiotherapy combined with 3D-printed multichannel non-co-planar vaginal applicators (3D-printed group, 41 patients) or single-channel vaginal applicators (single-channel group, 63 patients) guided brachytherapy. The dosimetric parameters, 5-year local control (LC), progression-free survival (PFS), overall survival (OS) of two groups were retrospectively analyzed. RESULTS: The high-risk clinical target volume (D90, D100) and high-dose volume fraction (V150) in 3D-printed group were significantly higher than those in single-channel group (p < 0.05), and the homogeneity index (HI) and conformal index (COIN) were equally better in 3D-printed group. In 3D-printed group, the D2cc, D1cc, and D0.1cc of the bladder and rectum were significantly lower than those of the single-channel group (p < 0.05). The 3D-printed group had significantly superior 5-year LC (70.0% vs. 51.3%, p = 0.041) and PFS (63.0% vs. 44.2%, p = 0.045), but OS were not significantly different between treatment groups (75.4% vs. 59.7%, p = 0.112). The incidence of radiation enteritis and cystitis was lower in the 3D-printed group than in the single-channel group, but no statistical difference was noted. CONCLUSIONS: The 3D-printed multichannel non-co-planar vaginal insertion applicators show the advantage of target dose, improve the LC and PFS in patients with positive or close surgical margins after cervical cancer surgery. Thus, the popularization of this method and its application may be of value.