Israel Medical Association Journal

Background: Adjuvant radiotherapy for breast cancer reduces local recurrence and improves survival. In patients with left sided breast cancer, anterior heart position or medial tumor location may cause inadequate breast coverage due to heart shielding. Respiration gating using the Real-time Position Management (RPM) system enables pushing the heart away from the tangential fields during inspiration, thus optimizing the treatment plan.

Objectives: To compare breathing inspiration gating (IG) techniques with free breathing (FB), focusing on breast coverage.

Methods: The study comprised 49 consecutive patients with left sided breast cancer who underwent lumpectomy and adjuvant radiation. RPM was chosen due to insufficient breast coverage caused by an anterior heart position or medial lumpectomy cavity. FB and IG computed tomography simulations were generated for each patient. Breast (PTVbreast) and lumpectomy cavity (CTVlump) were defined as the target areas. Optimized treatment plans were created for each scan. A dosimetric comparison was made for breast coverage and heart and lungs doses.

Results: PTVbreast V95% and mean dose (Dmean) were higher with IG vs. FB (82.36% vs. 78.88%, P = 0.002; 95.73% vs. 93.63%, P < 0.001, respectively). CTVlump V95% and Dmean were higher with IG (98.87% vs. 88.92%, P = 0.001; 99.14% vs. 96.73%, P = 0.003, respectively). The cardiac dose was lower with IG. The IG left lung Dmean was higher. No statistical difference was found for left lung V20.

Conclusions: In patients with suboptimal treatment plans due to anterior heart position or medial lumpectomy cavity, RPM IG enabled better breast/tumor bed coverage and reduced cardiac doses.

Background: Radiation-induced dermatitis is commonly seen during radiotherapy for breast cancer. Melatonin-based creams have shown a protective effect against ultraviolet-induced erythema and a radioprotective effect in rats.

Objectives: To evaluate the efficacy of melatonin-containing cream in minimizing acute radiation dermatitis. 

Methods: In this phase II, prospective, randomized, placebo-controlled double-blind study, patients who underwent breast-conserving surgery for stage 0-2 breast cancer were randomly allocated to melatonin emulsion (26 women) or placebo (21 women) for twice daily use during radiation treatment and 2 weeks following the end of radiotherapy. All women received 50 Gy whole breast radiation therapy with 2 Gy/fx using computed tomography-based 3D planning. Patients were examined and completed a detailed questionnaire weekly and 2 weeks following the end of treatment.

Results: The occurrence of grade 1/2 acute radiation dermatitis was significantly lower (59% vs. 90%, P = 0.038) in the melatonin group. Women older than 50 had significantly less dermatitis than younger patients (56% vs. 100%, P = 0.021). The maximal radiation dermatitis in the study group was grade 2 in 15% of the treated patients.

Conclusions: Patients treated with melatonin-containing emulsion experienced significantly reduced radiation dermatitis compared to patients receiving placebo.