Comparison of impact of target delineation of computed tomography- and magnetic resonance imaging-guided brachytherapy on dose distribution in cervical cancer

Abstract

PurposeThe dose distributions obtained from three imaging approaches for target delineation in cervical cancer using high-dose-rate (HDR) brachytherapy were investigated.Material and methodsTen cervical cancer patients receiving four fractions of HDR brachytherapy were enrolled. Based on different imaging approaches, three brachytherapy plans were developed for each patient: with the high-risk clinical target volume (HRCTV) delineated on magnetic resonance (MRI) images for every fraction (approach A; MRI-only); on MRI for the first fraction and computed tomography (CT) images for the subsequent fractions (approach B; MRI1st/CT); and on CT images for all fractions (approach C; CT-only). The volume, height, width at point A, width at maximum level, and dosimetric parameters (D100, D98, D95, and D90 of the HRCTV; and D0.1cc, D1cc, and D2cc of all organs at risk, or organ at risk – OAR: bladder, rectum, sigmoid colon, and bowel) provided by each approach were compared.ResultsThe mean HRCTV volume, width, and height obtained from approach C (CT-only) were overestimated compared to those from approaches A (MRI-only) and B (MRI1st/CT). The doses to the HRCTV for approaches A and B were similar. However, the HRCTV doses for approach C were significantly lower than those for approaches A and B for all parameters (D95-D100). As to the OAR, the three approaches showed no differences.ConclusionsA combination of MRI and CT is a safe alternative approach for cervical cancer HDR brachytherapy. The technique provides comparable dosimetric outcomes to MRI-based planning, while being more cost-effective.

Comparison of accuracy and long‐term prognosis between computed tomography‐based and magnetic resonance imaging‐based brachytherapy for cervical cancer: A meta‐analysis

“…These studies compared the effects and dose parameters between MRI and CT in BT for cervical cancer patients. Among them, two studies compared MRI‐ and hybrid (MRI/CT) imaging‐based BT therapies, while two other studies compared the effects of CT vs MRI vs hybrid imaging‐based BT . Another nine studies were performed to compare CT‐ and MRI‐based BT in cervical cancer patients .…”

Comparison of computed tomography- and magnetic resonance imaging-based target delineation for cervical cancer brachytherapy

“…There are only a few institutions that own dedicated MRI for direct BT planning. However, the limitations of delineated targets on CT images were noted when compared to MRI-based ones [ 11 , 16 , 17 , 18 ]. Herein, our study assessed the accuracy of CT versus MRI, utilizing conformality indices, geometrical dimensions, and dose parameters.…”

Dosimetric comparison of graphical optimization and inverse planning simulated annealing for brachytherapy of cervical cancer

“…The inverse planning approach [6] can be defined as a method of brachytherapy treatment planning, where the clinical objectives and treatment parameters are set up and adjusted along the optimization process to achieve the desired dose distribution. CT or magnetic resonance imaging (MRI) images are used not only to define the anatomy for visual assessment and dose calculation, but also to optimize the dose distribution [7]. Therefore, they provide to a physician additional flexibility and control to shape the dose distribution.…”