Simultaneous integrated boost in breast conserving treatment of breast cancer: A dosimetric comparison of helical tomotherapy and three-dimensional conformal radiotherapy

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• 作者：Tarek Hijal ; Nathalie Fournier-Bidoz ; Pablo Castro-Pena ; Youlia M. Kirova ; Sophia Zefkili ; Marc A. Bollet ; Ré ; mi Dendale ; Franç ; ois Campana ; Alain Fourquet
• 关键词：Radiotherapy ; Breast cancer ; Simultaneous integrated boost ; Tumor bed ; Helical tomotherapy
• 刊名：Radiotherapy and Oncology
• 出版年：2010
• 出版时间：March 2010
• 年：2010
• 卷：94
• 期：3
• 页码：300-306
• 全文大小：757 K

文摘

Background and purpose

To evaluate the dosimetry of helical tomotherapy (HT) and three-dimensional conformal radiotherapy (3D-CRT) in breast cancer patients undergoing whole breast radiation with simultaneous integrated boost (SIB) of the tumor bed.

Material and methods

Thirteen patients with breast cancer treated by lumpectomy and requiring whole breast radiotherapy with tumor bed boost were planned using both HT and 3D-CRT using the field-in-field technique. The whole breast and tumor bed were prescribed 50.68 Gy and 64.4 Gy, respectively, in 28 fractions. Dosimetries for both techniques were compared.

Results

Coverage of the whole breast was adequate with both techniques (V_{95 %}  = 96.22 % vs. 96.25 % , with HT and 3D-CRT, respectively; p = 0.64). Adequate tumor bed coverage was also achieved, although it was significantly lower with HT (V_{95 %}  = 97.18 % vs. 99.72 % ; p < 0.001). Overdose of the breast volume outside the tumor bed was significantly lower with HT (V_54.23Gy = 12.47 % vs. 30.83 % ; p < 0.001). Ipsilateral lung V_20Gy (6.34 % vs. 10.17 % ; p < 0.001), V_5Gy (16.54 % vs. 18.53 % ; p < 0.05) and mean dose (4.05 Gy vs. 6.36 Gy; p < 0.001) were significantly lower with HT. In patients with left-sided tumors, heart V_30Gy (0.03 % vs. 1.14 % ; p < 0.05) and mean dose (1.35 Gy vs. 2.22 Gy; p < 0.01) were significantly lower with HT, but not V_5Gy. Contralateral breast V_5Gy (0.27 % vs. 0.00 % ; p < 0.01) and maximum dose were significantly increased with HT.

Conclusions

In breast cancer treated with SIB, both HT and 3D-CRT provided adequate target volume coverage and low heart doses. Tumor bed coverage was slightly lower with HT, but HT avoided unnecessary breast overdosage while improving ipsilateral lung dosimetry.