3D Conformal Radiotherapy Versus the Conventional Box Technique for Cervical Cancer: A Dosimetric Observational Study

Intensity-modulated radiotherapy (IMRT) and 3D-conformal radiotherapy (3D-CRT) have transformed radiation therapy in gynecologic cancers. However, access to advanced techniques in resource-limited settings is constrained. This study proposes a comparative dosimetric analysis using the cervical dosimetry mapping and planning (CERV-DOSIMAP) framework to evaluate the efficacy of 3D-CRT versus the conventional four-field box technique in locally advanced cervical cancer.

Radiotherapy planning was performed on 30 individuals with biopsy-confirmed International Federation of Gynaecology and Obstetrics (FIGO) stage IIB-IIIB cervical carcinoma using both conventional and 3D-CRT methods. Using CT-based organizing, volume goals (gross tumor volume (GTV), clinical target volume (CTV), and planning target volume (PTV)) and the organs at risk (OAR) were defined. Dose-volume histogram (DVH) data were analyzed. Key indices such as conformity index (CI), homogeneity index (HI), and dose coverage to PTV and OAR were statistically compared using paired t-tests.

The 3D-CRT demonstrated significantly higher conformity (CI: 0.92 ± 0.03; p=0.001) and better homogeneity (HI: 0.08 ± 0.01; p=0.002) compared to conventional plans (CI: 0.85 ± 0.04; HI: 0.13 ± 0.02; p=0.003). There was a meaningful reduction in bladder, rectum, and femoral head doses with 3D-CRT.

The CERV-DOSIMAP framework validates 3D-CRT as a superior alternative to conventional techniques in improving target dose conformity while minimizing exposure to critical pelvic structures.