Early Clinical Results of Whole Breast Irradiation with Helical Tomotherapy or Fixed-field Intensity-modulated Radiation Therapy

  Objective  To observe the early therapeutic effects, toxicities and cosmetic results of whole breast radiotherapy with helical tomotherapy (HT) or fixed-field intensity-modulated radiotherapy (FF-IMRT) in patients with early-stage breast cancer after breast-conserving surgery.

  Methods  From September 2012 to March 2013, 24 patients with stage 0-ⅡB breast cancer after breast-conserving surgery were observed. HT and FF-IMRT were applied in 12 patients after breast-conserving surgery, respectively. The radiotherapy schedule was 46-50 Gy/23-25 fractions to the whole breast with a boost to the tumor bed to 60 Gy.Eleven patients (45.8%) received chemotherapy and 18 patients(75%)received endocrine therapy.The targets and the organs-at-risk were evaluated. Toxic and cosmetic results were observed.

  Results  Planning target volume(PTV)105% and PTV 110% were significantly less for HT than FF-IMRT (P=0.000, P=0.023). Homogeneity index (P=0.003) and conformity index(P=0.002) were better for HT than FF-IMRT. HT achieved significant decrease in 5 Gy (P=0.002), 20 Gy (P=0.001), and mean dose (P=0.000) for ipsilateral lung. Similar results were obtained for both lungs and heart(all P < 0.05). In the HT group, 10 patients developed grade 1 radiation dermatitis and 2 developed grade 2 radiation dermatitis; in the FF-IMRT group, 11 developed grade 1 radiation dermatitis and 1 developed grade 2 radiation dermatitis. No radiation pneumonitis was observed in all patients. Twelve patients in HT group and 11 patients in FF-IMRT group developed satisfactory cosmetic results (P > 0.05).

  Conclusions  Whole breast radiotherapy with HT or FF-IMRT for patients with early-stage breast cancer after breast-conserving surgery can achieve good therapeutic effectiveness, with satisfactory cosmetic results and acceptable toxicities, although the long-term clinical benefits need further observations.