Analysis of dosimetry and clinical outcome using intensity modulated radiation therapy for early breast cancer patients after breast conservative surgery / 中华放射医学与防护杂志

ABSTRACT

Objective To analyze the dosimetfic benefits, clinical effect and side-respond of whole breast using intensity modulated radiotherapy for early breast cancer after conservative surgery. Methods From Oct.2004 to Aug. 2005,103 patients received the whole breast intensity modulated radiation therapy (IMRT). A dosimetric comparison of IMRT with conventional radiotherapy (CR) was performed on each patient. The cosmetic results, clinical effect and side-respond were observed. Results The average volume proportion of 95% and 107% prescribed dose was 95.8% ± 4.90% and 84.0% ± 20.7% (t = 9.60, P < 0.01) with IMRT and CR in clinical target volume, respectively. The V20 (lung volume of aceepted> 20 Gy/all lung volume × 100%) of the ipsilateral lung were 15.70% ± 4.64% and 23. 11% ± 7.88% (t = - 13.3, P < 0.01). The V30of the heart were 4.44% ±3.93% and 15.55% ± 10.89%(t = - 11.3, P< 0.01) with IMRT and CR respectively for sixty-three left side breast cancer patients. The 1- and 2-year excellent rate of good cosmetic outcome was both 100%. The 1-, 2- and 3-year local control rate was 99% ,99% and 98% ,respectively. The 1-, 2- and 3-year disease-free survival rate was 99% ,99% and 96% ,respectively. The Grade 1 and 2 acute radiation skin reaction rate was 95.1% and 4.9%, respectively. Conclusion Compared with conventional radiotherapy, IMRT improves dose distribution of CTV and reduce the dose of normal tissue around CTV;but with better clinical effects and lower side-respond for early breast cancer patients after breast conservative surgery.