Implementation of image-guided brachytherapy (IGBT) for patients with uterine cervix cancer: a tumor volume kinetics approach

Abstract

PurposeTo evaluate tumor shrinking kinetics in order to implement image-guided brachytherapy (IGBT) for the treatment of patients with cervix cancer.Material and methodsThis study has prospectively evaluated tumor shrinking kinetics of thirteen patients with uterine cervix cancer treated with combined chemoradiation. Four high dose rate brachytherapy fractions were delivered during the course of pelvic external beam radiation therapy (EBRT). Magnetic resonance imaging (MRI) exams were acquired at diagnosis (D), first (B1), and third (B3) brachytherapy fractions. Target volumes (GTV and HR-CTV) were calculated by both the ellipsoid formula (VE) and MRI contouring (VC), which were defined by a consensus between at least two radiation oncologists and a pelvic expert radiologist.ResultsMost enrolled patients had squamous cell carcinoma and FIGO stage IIB disease, and initiated brachytherapy after the third week of pelvic external beam radiation. Gross tumor volume volume reduction from diagnostic MRI to B1 represented 61.9% and 75.2% of the initial volume, when measured by VE and VC, respectively. Only a modest volume reduction (15-20%) was observed from B1 to B3.ConclusionsThe most expressive tumor shrinking occurred in the first three weeks of oncological treatment and was in accordance with gynecological examination. These findings may help in IGBT implementation.

Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

“…It is worth pointing out that since the constraint was always met for the rectum and the sigmoid, the limiting value of EQD 2 was higher than the value in the previous fraction. The cumulative EQD 2 combining EBRT and brachytherapy for the bladder in this case was 85.4 Gy < 90 Gy, and for the rectum and sigmoid at 62.2 Gy < 75 Gy and 53 Gy < 75 Gy, respectively, thereby meeting all the OARs constraints recommended [14,15,16,19,27,28]. The increase in applicator angle in this case, however, was not found to increase D 2cc to the rectum and sigmoid.…”

Locally advanced squamous cell cervical cancer in a patient with septate uterus

“…Nevertheless, it was possible to achieve the suggested doses both in HR-CTV and OAR according to the GEC-ESTRO guidelines. In a recent study, it was shown that during the definitive radiotherapy for cervical cancer patients, the most expressive tumor shrinking occurs in the first three weeks of oncological treatment [ 20 ]. Platta et al started BRT application following 23 rd fraction of EPRT in order to complete the treatment within the recommended duration [ 21 ].…”

Reduction of applicator displacement in MR/CT-guided cervical cancer HDR brachytherapy by the use of patient hover transport system

“…Consequently, if such displacement occurs intra-fractionally, one should expect dose variation of similar magnitude as well as shown by some recent studies [ 15 , 16 ]. Some studies have looked into the geometric displacement, anatomic change, and other effect in each fraction of image-guided brachytherapy [ 17 , 18 , 19 , 20 , 21 ]. Monitoring of applicator motion relative to patient is therefore important in MR/CT-guided HDR brachytherapy.…”