Dosimetric study for cervix carcinoma treatment using intensity modulated radiation therapy (IMRT) compensation based on 3D intracavitary brachytherapy technique

Abstract

PurposeIntensity modulated radiation therapy (IMRT) compensation based on 3D high-dose-rate (HDR) intracavitary brachytherapy (ICBT) boost technique (ICBT + IMRT) has been used in our hospital for advanced cervix carcinoma patients. The purpose of this study was to compare the dosimetric results of the four different boost techniques (the conventional 2D HDR intracavitary brachytherapy [CICBT], 3D optimized HDR intracavitary brachytherapy [OICBT], and IMRT-alone with the applicator in situ).Material and methodsFor 30 patients with locally advanced cervical carcinoma, after the completion of external beam radiotherapy (EBRT) for whole pelvic irradiation 45 Gy/25 fractions, five fractions of ICBT + IMRT boost with 6 Gy/fractions for high risk clinical target volume (HRCTV), and 5 Gy/fractions for intermediate risk clinical target volume (IRCTV) were applied. Computed tomography (CT) and magnetic resonance imaging (MRI) scans were acquired using an in situ CT/MRI-compatible applicator. The gross tumor volume (GTV), the high/intermediate-risk clinical target volume (HRCTV/IRCTV), bladder, rectum, and sigmoid were contoured by CT scans.ResultsFor ICBT + IMRT plan, values of D90, D100 of HRCTV, D90, D100, and V100 of IRCTV significantly increased (p < 0.05) in comparison to OICBT and CICBT. The D2cc values for bladder, rectum, and sigmoid were significantly lower than that of CICBT and IMRT alone. In all patients, the mean rectum V60 Gy values generated from ICBT + IMRT and OICBT techniques were very similar but for bladder and sigmoid, the V60 Gy values generated from ICBT + IMRT were higher than that of OICBT. For the ICBT + IMRT plan, the standard deviations (SD) of D90 and D2cc were found to be lower than other three treatment plans.ConclusionsThe ICBT + IMRT technique not only provides good target coverage but also maintains low doses (D2cc) to the OAR. ICBT + IMRT is an optional technique to boost parametrial region or tumor of large size and irregular shape when intracavitary/interstitial brachytherapy cannot be used.

Individually customised parametrial boost for locally advanced cervical cancer: is 2D planned external beam radiotherapy useful?

“…17 Yin et al reported that an intensitymodulated radiation therapy (IMRT) PMB, in addition to ICRT, offered low organ-at-risk doses, and recommended its use in cases where ISBT was not feasible. 18 Cheng et al reported on the use of a simultaneous integrated boost to the parametrium using IMRT or VMAT. Either technique offered better dosimetry than the traditional midline block.…”

Comparison of dose volume parameters evaluated using three forward planning – optimization techniques in cervical cancer brachytherapy involving two applicators

“…When interdigitated, chemotherapy should be administered on an EBRT day and not on a brachytherapy day to avoid potential for increased complications [ 5 ]. Superior dosimetric coverage of parametrium has been reported after addition of intensity modulated radiotherapy (IMRT) [ 10 ] or interstitial brachytherapy (ISBT) [ 11 ] with intracavitary brachytherapy.…”

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.…”