Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

Abstract

PurposeA report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer.Material and methodsFifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m2) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV).ResultsThe mean cumulative doses – in terms of equivalent dose of 2 Gy (EQD2) – of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed.ConclusionThe combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles.

Comparative Evaluation of Two-dimensional Radiography and Three Dimensional Computed Tomography Based Dose-volume Parameters for High-dose-rate Intracavitary Brachytherapy of Cervical Cancer: A Prospective Study

“…These findings also strengthens earlier observations of maximum doses to both bladder and rectum higher than corresponding ICRU reference points and the significance of doses to OAR which can be estimated by three dimensional image based brachytherapy (Fellner et al, 2001;Kim et al, 2003). Combination of image based brachytherapy and intensity-modulated radiotherapy can also improve dose distribution in target volume and overdose to organs at risk (Tharavichitkul et al, 2013). Few studies have concluded that in centers where MRI based brachytherapy is not feasible due to logistics reasons, OAR and target may be contoured with CT which gives comparable results to MRI for dose volume estimation if clinical findings and baseline MRI findings are applied in contouring of CT images (Eskander et al, 2010;Krishnatry et al, 2012 observed MRI is being used by 20% for planning (Gueda et al, 2010).…”

University Cooperation Platform (UCP) between Christian-Albrechts-University Kiel (Germany) and Chiang Mai University (Thailand): implementation of image-guided gynecological brachytherapy

“…Again, the CT-trial inclusion and exclusion criteria were reused maintaining the study focus on large cervical tumors (FIGO IIB n = 12, IIIB n = 3), and the established brachytherapy constraints for HR-CTV and OARs (see first and second UCP major projects) were re-adopted. This study reconfirmed the prior findings of significant OARs dose reduction in bladder ( p < 0.001), rectum ( p = 0.001), and sigmoid ( p < 0.001), and maintained a high curative HR-CTV total dose (mean EQD2: 88 Gy) [ 27 ].…”

Outcomes with image-based interstitial brachytherapy for vaginal cancer

“…Patients with documented grade 3 toxicities received slightly higher cumulative doses to the clinical target volume. The observed difference in toxicity may be attributable to the benefit of volume-optimized dosimetric planning associated with image-based treatment and IMRT use, which have been shown to minimize radiation dose to organs at risk [25–27]. No grade 4 or 5 toxicity was observed.…”