Comparative study of clinical efficacy, acute adverse effects and dosimetry of different radiotherapy modalities for locally advanced cervical cancer

Objective To observe and evaluate the clinical short-term efficacy, acute adverse effects and dosimetric difference and of volumetric rotational intensity-modulated radiotherapy (VMAT), intensity-modulated conformal radiotherapy (IMRT), and three-dimensional conformal radiotherapy (3DCRT) in advanced cervical cancer patients. Methods A total of 138 patients with locally advanced cervical cancer who were admitted to Huai'an Hospital Affiliated to Xuzhou Medical University from January 2018 to December 2022 were enrolled and their clinical data were retrospectively analyzed. According to the corresponding radiotherapy regimens, the patients were divided into three groups:a VMAT group (n=43), an IMRT group (n=64), and a 3DCRT group (n=31). The three groups were compared for clinical short-term outcomes, acute adverse reaction, and dosimetric differences. Results There was no statistical difference in response rate (RR) among the three groups. The VMAT group and the IMRT group showed remarkable decreases in the incidence of acute gastrointestinal injury, acute urinary tract injury and platelet decline, compared with the 3DCRT group (P<0.05), whereas the VMAT group presented decreases in the incidence of acute gastrointestinal injury and acute urinary tract injury, compared with the IMRT group (P<0.05). In contrast, VMAT was superior in reducing the incidence of adverse reactions compared with IMRT, and 3DCRT was relatively worse. Furthermore, both the VMAT group and the IMRT group showed remarkable improvement in the average dose of PTV, conformal index (CI), uniformity index (HI) and doses to organs at risk (OARs), compared with the 3DCRT group (P<0.05). There was no statistical difference in the average dose of PTV, CI, and HI between the VMAT group and the IMRT group. However, the VMAT group showed decreases in the does to the small intestine and bladder (P<0.05), decreases in the V30 of the rectum (P<0.05), but increases in the V40 and V50 of the rectum, compared with the IMRT group (P<0.05). The does to the bilateral femoral head in the VMAT group was lower than that to the IMRT group, without statistical difference. The monitor units (MUs) in the VMAT group and the IMRT group were significantly higher than that in the 3DCRT group, where the VMAT group showed significantly lower MU the IMRT group (P<0.05). Conclusions VMAT, IMRT and 3DCRT can be applied for the treatment of locally advanced cervical cancer, with satisfactory short-term outcomes. However, VMAT had advantages of protecting OARs in targeted area, reducing the incidence of acute reactions and improving therapeutic effect, which is worthy promoting in clinical practice.