IMRT sparing of normal tissues in locoregional treatment of breast cancer

Radiat Oncol. 2014 Jul 22;9:161. doi: 10.1186/1748-717X-9-161.

Abstract

Purpose: This clinical study was designed to prospectively evaluate the acute and moderately-late cardiac and lung toxicities of intensity modulated radiation therapy delivered by helical tomotherapy (IMRT-HT) for locoregional breast radiation treatment including the internal mammary nodes (IMN).

Material/methods: 30 patients with stage III breast cancers have been accrued in this study. All patients received adjuvant chemotherapy. Target volumes were defined as follows: the PTV included breast/chest wall, axillary level II, III, infra/supraclavicular, IM nodes CTVs plus 3 mm margins. The heart with subunits and the lungs were defined as critical organs. Dose to PTV was 50 Gy in 25 fractions. Acute toxicities were assessed every week and 2 weeks post treatment using the CTCAE v3.0.scale. The moderately-late toxicities were assessed clinically plus by cardiac myoview perfusion tests scheduled at baseline, 3 and 12-month follow-up, as well a CT chest at the 6 month follow-up. The data analysis is descriptive.

Results: All participants completed the 5-week course of radiation without interruption. Skin erythema was modest and mainly grade 1-2 between the 3rd and the 5th week of radiation treatment. Only 4/30 patients experienced grade 3 skin reactions, mostly seen 2 weeks post radiation. Only 5 patients demonstrated grade 1 or 2 dyspnea, but 3 of them already had symptoms pre-radiation treatment. With a median follow-up of 58 (24-76) months, there have been infrequent moderately-late side effects. Most were grade 1 and were sometimes present at the baseline assessment. Cardiac myoview tests done at baseline and 1-year follow-up for 15 out of 18 left sided breast cancers did not show any abnormalities related to radiation. The 6-month follow-up chest CT-scans done for 25 out of 30 patients showed minimal anterior lung fibrosis for 7 patients and were completely normal for the other 18. No locoregional recurrence has been recorded and the 5-year survival is 78% (95% CI: 70-97%).

Conclusion: IMRT-HT for locoregional breast radiation is very well tolerated with minimal acute or moderately-late side effects. Cardiac and respiratory tests did not show any strong evidence of significant treatment related abnormalities.

Trial registration: clinicaltrials.gov: http://NCT00508352.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Breast Neoplasms / radiotherapy*
  • Female
  • Heart / radiation effects*
  • Humans
  • Lung / radiation effects*
  • Middle Aged
  • Organs at Risk / radiation effects
  • Pilot Projects
  • Radiation Injuries / epidemiology*
  • Radiotherapy, Intensity-Modulated / adverse effects*

Associated data

  • ClinicalTrials.gov/NCT00508352