Early toxicity in patients treated with postoperative proton therapy for locally advanced breast cancer.

Journal Article (Journal Article)

PURPOSE: To report dosimetry and early toxicity data in breast cancer patients treated with postoperative proton radiation therapy. METHODS AND MATERIALS: From March 2013 to April 2014, 30 patients with nonmetastatic breast cancer and no history of prior radiation were treated with proton therapy at a single proton center. Patient characteristics and dosimetry were obtained through chart review. Patients were seen weekly while on treatment, at 1 month after radiation therapy completion, and at 3- to 6-month intervals thereafter. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Frequencies of toxicities were tabulated. RESULTS: Median dose delivered was 50.4 Gy (relative biological equivalent [RBE]) in 5 weeks. Target volumes included the breast/chest wall and regional lymph nodes including the internal mammary lymph nodes (in 93%). No patients required a treatment break. Among patients with >3 months of follow-up (n=28), grade 2 dermatitis occurred in 20 patients (71.4%), with 8 (28.6%) experiencing moist desquamation. Grade 2 esophagitis occurred in 8 patients (28.6%). Grade 3 reconstructive complications occurred in 1 patient. The median planning target volume V95 was 96.43% (range, 79.39%-99.60%). The median mean heart dose was 0.88 Gy (RBE) [range, 0.01-3.20 Gy (RBE)] for all patients, and 1.00 Gy (RBE) among patients with left-sided tumors. The median V20 of the ipsilateral lung was 16.50% (range, 6.1%-30.3%). The median contralateral lung V5 was 0.34% (range, 0%-5.30%). The median maximal point dose to the esophagus was 45.65 Gy (RBE) [range, 0-65.4 Gy (RBE)]. The median contralateral breast mean dose was 0.29 Gy (RBE) [range, 0.03-3.50 Gy (RBE)]. CONCLUSIONS: Postoperative proton therapy is well tolerated, with acceptable rates of skin toxicity. Proton therapy favorably spares normal tissue without compromising target coverage. Further follow-up is necessary to assess for clinical outcomes and cardiopulmonary toxicities.

Full Text

Duke Authors

Cited Authors

  • Cuaron, JJ; Chon, B; Tsai, H; Goenka, A; DeBlois, D; Ho, A; Powell, S; Hug, E; Cahlon, O

Published Date

  • June 1, 2015

Published In

Volume / Issue

  • 92 / 2

Start / End Page

  • 284 - 291

PubMed ID

  • 25754632

Pubmed Central ID

  • PMC4972493

Electronic International Standard Serial Number (EISSN)

  • 1879-355X

Digital Object Identifier (DOI)

  • 10.1016/j.ijrobp.2015.01.005

Language

  • eng

Conference Location

  • United States