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Original Investigation
October 2015

Acute and Short-term Toxic Effects of Conventionally Fractionated vs Hypofractionated Whole-Breast IrradiationA Randomized Clinical Trial

Author Affiliations
  • 1Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston
  • 2Department of Radiation Oncology, The University of Tennessee Health Science Center, Memphis
  • 3Department of Radiation Oncology, University of Florida Health Cancer Center, Orlando Health, Orlando
  • 4Department of Radiation Oncology, Banner MD Anderson Cancer Center, Gilbert, Arizona
  • 5Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas
  • 6Houston Methodist Research Institute, The Methodist Hospital, Houston, Texas
  • 7Department of Plastic Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas
  • 8Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
  • 9Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
JAMA Oncol. 2015;1(7):931-941. doi:10.1001/jamaoncol.2015.2666

Importance  The most appropriate dose fractionation for whole-breast irradiation (WBI) remains uncertain.

Objective  To assess acute and 6-month toxic effects and quality of life (QOL) with conventionally fractionated WBI (CF-WBI) vs hypofractionated WBI (HF-WBI).

Design, Setting, and Participants  Unblinded randomized trial of CF-WBI (n = 149; 50.00 Gy/25 fractions + boost [10.00-14.00 Gy/5-7 fractions]) vs HF-WBI (n = 138; 42.56 Gy/16 fractions + boost [10.00-12.50 Gy/4-5 fractions]) following breast-conserving surgery administered in community-based and academic cancer centers to 287 women 40 years or older with stage 0 to II breast cancer for whom WBI without addition of a third field was recommended; 76% of study participants (n = 217) were overweight or obese. Patients were enrolled from February 2011 through February 2014 and observed for a minimum of 6 months.

Interventions  Administration of CF-WBI or HF-WBI.

Main Outcomes and Measures  Physician-reported acute and 6-month toxic effects using National Cancer Institute Common Toxicity Criteria, and patient-reported QOL using the Functional Assessment of Cancer Therapy for Patients with Breast Cancer (FACT-B). All analyses were intention to treat, with outcomes compared using the χ2 test, Cochran-Armitage test, and ordinal logistic regression.

Results  Of 287 participants, 149 were randomized to CF-WBI and 138 to HF-WBI. Treatment arms were well matched for baseline characteristics, including FACT-B total score (HF-WBI, 120.1 vs CF-WBI, 118.8; P = .46) and individual QOL items such as somewhat or more lack of energy (HF-WBI, 38% vs CF-WBI, 39%; P = .86) and somewhat or more trouble meeting family needs (HF-WBI, 10% vs CF-WBI, 14%; P = .54). Maximum physician-reported acute dermatitis (36% vs 69%; P < .001), pruritus (54% vs 81%; P < .001), breast pain (55% vs 74%; P = .001), hyperpigmentation (9% vs 20%; P = .002), and fatigue (9% vs 17%; P = .02) during irradiation were lower in patients randomized to HF-WBI. The rate of overall grade 2 or higher acute toxic effects was less with HF-WBI than with CF-WBI (47% vs 78%; P < .001). Six months after irradiation, physicians reported less fatigue in patients randomized to HF-WBI (0% vs 6%; P = .01), and patients randomized to HF-WBI reported less lack of energy (23% vs 39%; P < .001) and less trouble meeting family needs (3% vs 9%; P = .01). Multivariable regression confirmed the superiority of HF-WBI in terms of patient-reported lack of energy (odds ratio [OR], 0.39; 95% CI, 0.24-0.63) and trouble meeting family needs (OR, 0.34; 95% CI, 0.16-0.75).

Conclusions and Relevance  Treatment with HF-WBI appears to yield lower rates of acute toxic effects than CF-WBI as well as less fatigue and less trouble meeting family needs 6 months after completing radiation therapy. These findings should be communicated to patients as part of shared decision making.

Trial Registration  clinicaltrials.gov Identifier: NCT01266642