Dosimetric comparison of three‐dimensional conformal radiotherapy and intensity‐modulated radiotherapy for left‐sided chest wall and lymphatic irradiation

Abstract

IntroductionThe aim of this study was to compare five different techniques for chest wall (CW) and lymphatic irradiation in patients with left‐sided breast carcinoma.MethodsThree‐dimensional conformal radiotherapy (3DCRT), forward‐planned intensity‐modulated radiotherapy (FP‐IMRT), inverse‐planned IMRT (IP‐IMRT; 7‐ or 9‐field), and hybrid IP‐/FP‐IMRT were compared in 10 patients. Clinical target volume (CTV) included CW and internal mammary (IM), supraclavicular (SC), and axillary nodes. Planning target volumes (PTVs), CTVs, and organs at risks (OARs) doses were analyzed with dose–volume histograms (DVHs).ResultsNo differences could be observed among the techniques for doses received by 95% of the volume (D95%) of lymphatics. However, the FP‐IMRT resulted in a significantly lower D95% dose to the CW‐PTV compared to other techniques (P = 0.002). The 9‐field IP‐IMRT achieved the lowest volumes receiving higher doses (hotspots). Both IP‐IMRT techniques provided similar mean doses (Dmean) for the left lung which were smaller than the other techniques. There was no difference between the techniques for maximum dose (Dmax) of right breast. However, FP‐IMRT resulted in lower Dmean and volume of right breast receiving at least 5 Gy doses compared to other techniques.ConclusionThe dose homogeneity in CW‐CTV was better using IMRT techniques compared to 3DCRT. Especially 9‐field IP‐IMRT provided a more homogeneous dose distribution in IM and axillary CTVs. Moreover, the OARs volumes receiving low radiation doses were larger with IP‐IMRT technique, while volumes receiving high radiation doses were larger with FP‐IMRT technique. Hybrid IMRT plans were found to have the advantages of both FP‐ and IP‐IMRT techniques.

The use of Hybrid Techniques in Whole-Breast Radiotherapy: A Systematic Review

“…61,62 The hybrid RT results obtained indicate that the quality of treatment plans can be increased with the hybrid techniques used. 10,61–65 Hybrid techniques are mostly created with the combination of 2D/3D-CRT + IMRT 31,37–42,45–57 or 2D/3DCRT + VMAT 47,51,55,56 or IMRT + VMAT. 42–44…”

“…Using the hybrid technique, the advantages of the 2 RT techniques can be combined and promising results can be obtained. 61,62 The hybrid RT results obtained indicate that the quality of treatment plans can be increased with the hybrid techniques used. 10,[61][62][63][64][65] Hybrid techniques are mostly created with the combination of 2D/3D-CRT + IMRT 31,[37][38][39][40][41][42][45][46][47][48][49][50][51][52][53][54][55][56][57] or 2D/3DCRT + VMAT 47,51,55,56 or IMRT + VMAT.…”

“…61,62 The hybrid RT results obtained indicate that the quality of treatment plans can be increased with the hybrid techniques used. 10,[61][62][63][64][65] Hybrid techniques are mostly created with the combination of 2D/3D-CRT + IMRT 31,[37][38][39][40][41][42][45][46][47][48][49][50][51][52][53][54][55][56][57] or 2D/3DCRT + VMAT 47,51,55,56 or IMRT + VMAT. [42][43][44] Many studies show that the H-IMRT technique used in breast RT is dosimetrically superior.…”

Dosimetric Analysis of Fast Forward Breast Radiotherapy Using 3D-CRT with Deep Inspiration Breath Hold (DIBH)

“…Although modern CT-based planning techniques have reduced unnecessary cardiac exposure, studies with over 10 years of follow-up are still needed to assess the true incidence of late cardiac events [1]. Darby et al reported that each 1 Gy increase in mean heart dose is associated with a 7.4% increase in the rate of major coronary events, including myocardial infarction and cardiac death [6,12]. Similarly, Sardaro et al estimated a 4% increase in the risk of late cardiac disease per 1 Gy [6].…”

“…Darby et al reported that each 1 Gy increase in mean heart dose is associated with a 7.4% increase in the rate of major coronary events, including myocardial infarction and cardiac death [6,12]. Similarly, Sardaro et al estimated a 4% increase in the risk of late cardiac disease per 1 Gy [6].…”