Comparison of MRI and CT for target volume delineation and dose coverage for partial breast irradiation in patients with breast cancer
Song Yuchun1, Xie Xin1, Che Shunan2, Sun Guangyi1, Tang Yu1, Zhang Jianghu1, Wang Jianyang1, Fang Hui1, Chen Bo1, Song Yongwen1, Jin Jing1, Liu Yueping1, Qi Shunan1, Tang Yuan1, Lu Ningning1, Jing Hao1, Yang Yong1, Li Ning1, Li Jing2, Wang Shulian1, Li Yexiong1
1Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China; 2Department of Diagnostic Imaging, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China
Abstract：Objective To compare magnetic resonance imaging (MRI)-based and computed tomography (CT)-based target volume delineation and dose coverage in partial breast irradiation (PBI) for patients with breast cancer, aiming to explore the application value of MRI localization in PBI after breast-conserving surgery. Methods Twenty-nine patients with early breast cancer underwent simulating CT and MRI scans in a supine position. The cavity visualization score (CVS) of tumor bed (TB) was evaluated. The TB, clinical target volume (CTV), planning target volume (PTV) were delineated on CT and MRI images, and then statistically compared. Conformity indices (CI) between CT- and MRI-defined target volumes were calculated. PBI treatment plan of 40Gy in 10 fractions was designed based on PTV-CT, and the dose coverage for PTV-MRI was evaluated. Results The CVS on CT and MRI images was 2.97±1.40 vs. 3.10±1.40(P=0.408). The volumes of TB, CTV, PTV on MRI were significantly larger than those on CT,(24.48±16.60) cm3vs. (38.00±19.77) cm3,(126.76±56.81) cm3vs. (168.42±70.54) cm3,(216.63±81.99) cm3vs. (279.24±101.55) cm3, respectively,whereas the increasing percentage of CTV and PTV were significantly smaller than those of TB. The CI between CT-based and MRI-based TB, CTV, PTV were 0.43±0.13,0.66±0.11,0.70±0.09(P<0.001), respectively. The median percentage of PTV-MRI receiving 40Gy dose was 81.9%(62.3% to 92.4%),significantly lower than 95.6%(95.0%~97.5%) of PTV-CT. Conclusions The CVS between CT and MRI is not significantly different, but the MRI-based TB, CTV, PTV are significantly larger than CT-based values. The PTV-MRI is of underdose if PBI treatment plan is designed for PTV-CT. As a supplement of CT scan, MRI can enhance the accuracy of TB delineation after breast-onserving surgery.
Song Yuchun,Xie Xin,Che Shunan et al. Comparison of MRI and CT for target volume delineation and dose coverage for partial breast irradiation in patients with breast cancer[J]. Chinese Journal of Radiation Oncology, 2021, 30(3): 244-248.
[1] Blichert-Toft M,Nielsen M,During M,et al.Long-term results of breast conserving surgery vs.mastectomy for early stage Ⅰnvasive breast cancer:20-year follow-up of the Danish randomized DBCG-82TM protocol[J].Acta Oncol,2008,47(4):672-681.DOI:10.1080/02841860801971439. [2] Fisher B,Anderson S,Bryant J,et al.Twenty-year follow-up of a randomized trial comparing total mastectomy,lumpectomy,and lumpectomy plus irradiation for the treatment of invasive breast cancer[J].N Engl J Med,2002,347(16):1233-1241.DOI:10.1056/NEJMoa022152. [3] Early Breast Cancer Trialists′ Collaborative Group.Effects of radiotherapy and surgery in early breast cancer.An overview of the randomized trials[J].N Engl J Med,1995,333(22):1444-1455.DOI:10.1056/NEJM199511303332202. [4] Polgar C,Fodor J,Major T,et al.Breast-conserving therapy with partial or whole breast irradiation:ten-year results of the Budapest randomized trial[J].Radiother Oncol,2013,108(2):197-202.DOI:10.1016/j.radonc.2013.05.008. [5] Veronesi U,Orecchia R,Maisonneuve P,et al.Intraoperative radiotherapy versus external radiotherapy for early breast cancer (ELIOT):a randomised controlled equivalence trial[J].Lancet Oncol,2013,14(13):1269-1277.DOI:10.1016/s1470-2045(13)70497-2. [6] Livi L,Meattini I,Marrazzo L,et al.Accelerated partial breast irradiation using intensity-modulated radiotherapy versus whole breast irradiation:5-year survival analysis of a phase 3 randomised controlled trial[J].Eur J Cancer,2015,51(4):451-463.DOI:10.1016/j.ejca.2014.12.013. [7] Coles CE,Wilson CB,Cumming J,et al.Titanium clip placement to allow accurate tumour bed localisation following breast conserving surgery – Audit on behalf of the IMPORT trial management group[J].Eur J Surg Oncol,2009,35(6):578-582.DOI:10.1016/j.ejso.2008.09.005. [8] Madeley CR,Kessell MA,Madeley CJD,et al.Radiographer technique:does it contribute to the question of clip migration?[J].J Med Imag Radiat Oncol,2015,59(5):564-570.DOI:10.1111/1754-9485.12327. [9] Landis DM,Luo W,Song J,et al.Variability among breast radiation oncologists in delineation of the postsurgical lumpectomy cavity[J].Int J Radiat Oncol Biol Phys,2007,67(5):1299-1308.DOI:10.1016/j.ijrobp.2006.11.026. [10] Jacobson G,Zamba G,Betts V,et al.Image-based treatment planning of the post-lumpectomy breast utilizing CT and 3TMRI[J].Int J Breast Cancer,2011,75(3):246265.DOI:10.4061/2011/246265. [11] Smitt MC,Birdwell RL,Goffinet DR.Breast electron boost planning comparison of CT and US[J].Radiology,2001,219(1):203-206.DOI:10.1148/radiology.219.1.R01ap34203. [12] Kirby AM,Yarnold JR,Evans PM,et al.Tumor bed delineation for partial breast and breast boost radiotherapy planned in the prone position:what does MRI add to X-ray CT localization of titanium clips placed in the excision cavity wall?[J].Int J Radiat Oncol Biol Phys,2009,74(4):1276-1282.DOI:10.1016/j.ijrobp.2009.02.028. [13] Yang TJ,Tao R,Elkhuizen PH,et al.Tumor bed delineation for external beam accelerated partial breast irradiation:a systematic review[J].Radiother Oncol,2013,108(2):181-189.DOI:10.1016/j.radonc.2013.05.028. [14] Giezen M,Kouwenhoven E,Scholten AN,et al.MRI-versus CT-based volume delineation of lumpectomy cavity in supine position in breast-conserving therapy:an exploratory study[J].Int J Radiat Oncol Biol Phys,2012,82(4):1332-1340.DOI:10.1016/j.ijrobp.2011.05.008. [15] Huang W,Currey A,Chen X,et al.A comparison of lumpectomy cavity delineations between use of magnetic resonance imaging and computed tomography acquired with patient in prone position for radiation therapy planning of breast cancer[J].Int J Radiat Oncol Biol Phys,2016,94(4):832-840.DOI:10.1016/j.ijrobp.2015.12.014. [16] Berrang TS,Truong PT,Popescu C,et al.3D ultrasound can contribute to planning CT to define the target for partial breast radiotherapy[J].Int J Radiat Oncol Biol Phys,2009,73(2):375-383.DOI:10.1016/j.ijrobp.2008.04.041. [17] Cho O,Chun M,Oh YT,et al.Can initial diagnostic PET-CT aid to localize tumor bed in breast cancer radiotherapy feasibility study using deformable image registration[J].Radiat Oncol,2013,8(1):163.DOI:10.1186/1748-717X-8-163. [18] Ford EC,Lavely WC,Frassica DA,et al.Comparison of FDG-PET/CT and CT for delineation of lumpectomy cavity for partial breast irradiation[J].Int J Radiat Oncol Biol Phys,2008,71(2):595-602.DOI:10.1016/j.ijrobp.2008.02.004. [19] Kader HA,Truong PT,Pai R,et al.When is CT-based postoperative seroma most useful to plan partial breast radiotherapy? Evaluation of clinical factors affecting seroma volume and clarity[J].Int J Radiat Oncol Biol Phys,2008,72(4):1064-1069.DOI:10.1016/j.ijrobp.2008.02.049. [20] Mast M,Coerkamp E,Heijenbrok M,et al.Target volume delineation in breast conserving radiotherapy:are co-registered CT and MR images of added value[J].Radiat Oncol,2014,9(1):65.DOI:10.1186/1748-717X-9-65. [21] Dundas K,Pogson EM,Batumalai V,et al.The impact of imaging modality (CT vs. MRI) and patient position (supine vs. prone) on tangential whole breast radiation therapy planning[J].Pract Radiat Oncol,2018,8(3):e87-e97.DOI:10.1016/j.prro.2017.07.007.
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