IMRT for the breast: a comparison of tangential planning techniques

Abstract

Three intensity-modulated tangential beam radiotherapy plan types for breast cancer treatment were evaluated based on PTV homogeneity index (HI) and equivalent uniform dose (EUD), heart V30 and EUD, whole lung V20 and EUD, and typical planning time compared to conventional 2D plans. 20 early-stage breast cancer patients were CT-scanned in the supine position, and tangential field extent, gantry and collimator angles were chosen. Four treatment plans were created for each patient: conventional, dynamically wedged plan based on the dose distribution on the central axial slice; forward planned IMRT; surface compensated plan created using an Eclipse tool and hybrid IMRT plan combining open and inverse-optimized fields. All three IMRT planning techniques represent significant improvement in PTV HI and EUD compared to conventional plans. Among the IMRT plans, the hybrid IMRT plan produced the best HI. IMRT lowered heart V30 and lung V20, but no significant differences in heart or lung EUD were detected between IMRT techniques. The IMRT technique with the shortest planning time was the compensated plan, followed by the hybrid IMRT. IMRT planning provides dosimetric benefits in breast cancer patients. The selection of the most appropriate IMRT technique must include careful consideration of the resources available.

In vivo surface dose measurement using GafChromic film dosimetry in breast cancer radiotherapy: comparison of 7-field IMRT, tangential IMRT and tangential 3D-CRT

“…In agreement with the literature, comparison of calculated plan parameters showed an advantage of TB-IMRT compared to 3D-CRT concerning the CI, heart dose in patients with left-sided breast cancer and ipsilateral lung dose [6,7,21]. As expected, due to the multiple beam angles used, 7 F-IMRT showed a higher low-dose volume to the heart, ipsilateral and contralateral lung compared to TB-IMRT [22].…”

“…Intensity modulated radiotherapy (IMRT) has the potential to improve dose homogeneity and conformity of a radiotherapy of the breast or chest wall thereby reducing side-effects [4-7]. Concerning skin toxicity, several studies have reported clinical benefit for IMRT of the breast [8-12].…”

Dosimetric comparison of three different external beam whole breast irradiation techniques

“…10 The development of accelerators with multi-leaf collimators (MLC) has facilitated the creation of newer techniques, such as field-in-field intensity-modulated RT (FiF-IMRT). 11,12 In this clinic, 3D-CRT is used as the routine planning technique for treating the intact breast. However, two major questions are raised.…”

Intensity-modulated radiation therapy for early-stage breast cancer: is it ready for prime time?

“…The literature reports that IMRT requires longer planning time and advanced planning skills 32. Smith et al32 found that CRT required a mean time of 15 minutes compared to 60–90 minutes required by FP FIF IMRT, while Al-Rahbi et al15 reported an average time of 20–30 minutes, 15–20 minutes, and 45–60 minutes for 3D CRT, FP FIF IMRT, and IP IMRT, respectively.…”

“…Smith et al32 found that CRT required a mean time of 15 minutes compared to 60–90 minutes required by FP FIF IMRT, while Al-Rahbi et al15 reported an average time of 20–30 minutes, 15–20 minutes, and 45–60 minutes for 3D CRT, FP FIF IMRT, and IP IMRT, respectively. It is interesting to note that the planning time for FP FIF IMRT is quartered in Al-Rahbi et al’s15 study.…”