TITLE:
Comparison of Simplified Intensity-Modulated Radiotherapy versus 3-Dimensional Conformal Radiotherapy in Locally Advanced Cervical Cancer: A Dosimetric Study
AUTHORS:
Mamady Keita, Chen Xi, Malick Bah, Abou Camara, Arbaba Balde, Bangaly Traore, Hong Liu
KEYWORDS:
Cervical Cancer, Simplified Intensity-Modulated Radiotherapy, 3D-CRT, Dosimetry
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.15 No.2,
February
25,
2025
ABSTRACT: Background: Early research describing the concept of intensity-modulated conformal radiotherapy (IMRT) was based on 7 to 9 beams to reach an adequate level of modulation. Nevertheless, its implementation demands significant resources. Our objective was to compare the compliance and homogeneity of target dose distribution between simplified IMRT and 3D-CRT in patients with cervical cancer and to assess the clinical value of simplified IMRT. Materials and Methods: From 2016 to 2017, 17 patients with stage IIB - IIIC cervical cancer were treated with external beam radiotherapy using simplified IMRT (12 cases) or 3DCRT (05 cases) and brachytherapy. Prior to radiotherapy, CT scans were conducted to delineate the target volume. The clinical target volume (CTV) included the uterus, primary tumor, supravaginal portion of the cervix, paracervical tissue, common iliac, internal and external iliac lymph nodes, obturator, and pre sacral lymph nodes, and the surrounding tissues. If the lower vagina was involved, the target volume included the whole vagina. The planning target volume (PTV) included the CTV with 1 cm anteriorly and 0.5 cm in all other directions. The PTV received 95% of 45 Gy (1.8 Gy/25 fraction). Dose-volume histogram, conformity index, homogeneity index, and treatment time per fraction were compared. Results: The 3D-CRT plan was more homogeneous than the simplified IMRT plan, while the simplified IMRT plan was more conformal. The volume of small bowels that received high-dose radiation significantly increased with simplified IMRT compared to 3D-CRT. Treatment time per fraction was 6 and 13 minutes for 3D-CRT and simplified IMRT, respectively. Conclusion: The simplified IMRT treatment plan is technically and dosimetrically acceptable and an alternative to the classic 3D-CRT plan for cervical cancer. It provides better dose distribution than 3D-CRT. However, the 3D-CRT treatment plan significantly reduced the overall treatment time per fraction.