PDF
ePub
Citation
Print
Abstract
Purpose:
To compare the dosimetrical and radiobiological parameters among various volumetric modulated arc therapy (VMAT) techniques using restricted and continuous arc beams for left-sided breast cancer.
Materials and Methods:
Ten patients with left-sided breast cancer without regional nodes were retrospectively selected and prescribed the dose of 42.6 Gy in 16 fractions on the planning target volume (PTV). For each patient, three plans were generated using the EclipseTM system (Varian Medical System, Palo Alto, CA) with one partial arc 1pVMAT, two partial arcs 2pVMAT, and two tangential arcs 2tVMAT. All plans were calculated through anisotropic analytic algorithm and photon optimizer with 6 MV photon beam of VitalBEAMTM. The same dose objectives for each plan were used to achieve a fair comparison during optimization.
Results:
For PTV, dosimetrical parameters such as Homogeneity index, conformity index, and conformal number were superior in 2pVMAT than those in both techniques. V95%, which indicates PTV coverage, was 91.86%, 96.60%, and 96.65% for 1pVMAT, 2pVMAT, and 2tVMAT, respectively. In most organs at risk (OARs), 2pVMAT significantly reduced the delivered doses compared with the other techniques, excluding the doses to contralateral lung. For the analysis of radiobiological parameters, a significant difference in normal tissue complication probability was observed in ipsilateral lung while no difference was observed in the other OARs.
REFERENCES
1.Fisher B., Anderson S., Bryant J, et al. Twenty-year followup of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. N Engl J Med. 2002. 347(16):1233–1241.
2.Veronesi U., Cascinelli N., Mariani L, et al. Twenty-year follow-up of a randomized study comparing breast-conserving surgery with radical mastectomy for early breast cancer. N Engl J Med. 2002. 347(16):1227–1232.
3.Munshi A., Pai RH., Phurailatpam R, et al. Do all patients of breast carcinoma need 3-dimensional CT-based planning? A dosimetric study comparing different breast sizes. Med Dosim. 2009. 34(2):140–144.
4.Pignol J., Olivotto I., Rakovitch E, et al. A multicenter randomized trial of breast intensity-modulated radiation therapy to reduce acute radiation dermatitis. J Clin Oncol. 2008. 26(13):2085–2092.
5.Bird B., Swain S. Cardiac toxicity in breast cancer survivors: review of potential cardiac problems. Clin Cancer Res. 2008. 14(1):14–24.
6.Lohr F., El-Haddad M., Dobler B, et al. Potential effect of robust and simple IMRT approach for left-sided breast cancer on cardiac mortality. Int J Radiat Oncol Biol Phys. 2009. 74(1):73–80.
7.Schubert LK, et al. Dosimetric comparison of left-sided whole breast irradiation with 3DCRT, forward-planned IMRT, inverse-planned IMRT, helical tomotherapy, and topotherapy. Radiother Oncol. 2010. 100(2):241–246.
8.Nilsson G., Holmberg L., Garmo H., Duvernoy O., Sjögren I., Lagerqvist B, et al. Distribution of coronary artery stenosis after radiation for breast cancer. J Clin Oncol. 2012. 30(4):380–386.
9.Darby SC., Ewertz M., McGale P., Bennet AM., Blom-Goldman U., Brønnum D, et al. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med. 2013. 368(11):987–998.
10.Hurkmans CW., Cho BCJ., Damen E., Zijp L., Mijnheer BJ. Reduction of cardiac and lung complication probabilities after breast irradiation using conformal radiotherapy with or without intensity modulation. Radiother Oncol. 2002. 62(2):163–171.
11.Hong L., Hunt M., Chui C., Spirou S., Forster K., Lee H, et al. Intensity modulated tangential beam irradiation of the intact breast. Int J Radiat Oncol Biol Phys. 1999. 44(5):1155–1164.
12.Xu XL., Wu H., Han SK. Dosimetry study of intensity modulated radiation therapy for left side breast cancer. Chinese Journal of Radiation Oncology. 2006. 15(3):192–195.
13.Virén Tuomas, et al. Tangential volumetric modulated arc therapy technique for left-sided breast cancer radiotherapy. Radiol Oncol. 2015. 10(1):79.
14.Jin Guang-Hua, et al. A comparative dosimetric study for treating left-sided breast cancer for small breast size using five different radiotherapy techniques: conventional tangential field, filed-in-filed, tangential-IMRT, multi-beam IMRT and VMAT. Radiol Oncol. 2013. 8(1):89.
15.Qiu Jian-Jian, et al. Dosimetric comparison of 3D conformal, IMRT, and V-MAT techniques for accelerated partial-breast irradiation (APBI). Med Dosim. 2014. 39(2):152–158.
16.Badakhshi H., Kaul D., Nadobny J., Wille B., Sehouli J., Budach V. Image-guided volumetric modulated arc therapy for breast cancer: a feasibility study and plan comparison with three-dimensional conformal and intensity-modulated radiotherapy. Br J Radiol. 2013. 86(1032):20130515.
17.Munshi Anusheel, et al. Short tangential arcs in VMAT based breast and chest wall radiotherapy lead to conformity of the breast dose with lesser cardiac and lung doses: a prospective study of breast conservation and mastectomy patients. Australas Phys Eng Sci Med. 2017. 40(3):729–736.
18.Fogliata Antonella, et al. Dosimetric trade-offs in breast treatment with VMAT technique. Br J Radiol. 2016. 90(1070):20160701.
19.Whelan. Timothy J, et al. Long-term results of hypofractionated radiation therapy for breast cancer. N Engl J Med. 2010. 362(6):513–520.
20.Gay HA., Niemierko A. A free program for calculating EUD-based NTCP and TCP in external beam radiotherapy. Phys Med. 2007. 23:115–125.
21.Liu Haiyun, et al. Evaluation of 3D-CRT, IMRT and VMAT radiotherapy plans for left breast cancer based on clinical dosimetric study. Comput Med Imaging Graph. 2016. 54:1–5.
22.Vicini F.., Freedman G. M.., White J. R.A phase III trial of accelerated whole breast irradiation with hypofraction-ation plus concurrent boost versus standard whole breast irradiation plus sequential boost for early-stage breast cancer. RTOG 1005. 2012.
23.Xi Dan, et al. Advantages of a technique using two 50 degree arcs in simultaneous integrated boost radiotherapy for left-sidebreast cancer. Sci Rep. 2017. 7(1):14748.
Table 1.
The optimization objectives used for inverse IMRT VMAT planning.
| Structure | Objectives |
|---|---|
| PTV | V44.6Gy<1%, V42.5Gy>95%, V40.4Gy>100% |
| Heart | V10Gy<20% and V20Gy<10%, Dmean<5 Gy |
| Left lung | V10Gy<40%, V20Gy<30% and V30Gy<20% |
| Contralateral lung | V10Gy<10% |
Table 2.
Dosimetrical parameters to PTV obtained by three VMAT techniques (mean±standard deviation).
Table 3.
Dosimetrical and statistical analysis for the organs at risk according to three VMAT techniques (mean±standard deviation).
XML Download