Accelerated partial breast irradiation in early stage breast cancer

Radiation Pneumonitis After Partial Breast Irradiation

This case presentation describes development of symptomatic radiation pneumonitis in a healthy woman who underwent partial breast irradiation with deep inspiration breath hold for early stage breast cancer meeting all published dose constraints. Risk factors for, diagnosis and management of radiation pneumonitis are discussed in detail. Radiation pneumonitis is rare, ranging from <1% to 1.5% (when regional nodal irradiation is included). Partial breast irradiation spares breast tissue, but may not spare lung tissue better than whole breast irradiation, depending upon treatment technique such as prone positioning. Dose constraints for normal and target structures from published trials are reviewed, however data specifically relating to pneumonitis in partial breast trials are limited.

Partial-accelerated irradiation with stereotactic radiotherapy at a dose of 30 Gy in 5 fractions in early breast cancer

PURPOSE

To evaluate feasibility of accelerated partial breast irradiation (APBI) using stereotactic radiotherapy (SBRT) Thirty Gy delivered in 5 fractions for patients with early breast cancer.

METHODS

Between January 1st, 2018, and December 31s, 2022, we conducted 117 treatments for patients with early-stage breast cancer. All patients underwent conservative surgery followed by APBI using stereotactic external beam radiotherapy. We analyzed local, regional, distant control, overall survival, toxicity, and cosmetic outcomes.

RESULTS

The average age was 62 years. 21.3% ductal and 78.7% invasive carcinomas. Regarding the PTV volume, the median was 198.8 cc (38-794 cc). Treatments were completed in all cases. The median follow-up period was of 21 months (1-62 months). Regarding acute toxicity, no Grade 3-4 toxicities were recorded. One patient experienced Grade 2 neuropathic pain. One patient developed subacute fibrosis and two patients developed telangiectasia as subacute and chronic toxicity. Cosmetic results were "good" or "very good" in 96.3% of cases. None of the patients relapsed at any level (local, regional, or distant) and overall survival during follow.up was 100%.

CONCLUSION

APBI with SBRT 30 Gy in 5 fractions in early-stage breast cancer is a feasible technique, very-well tolerated and has excellent oncologic and cosmetic outcome during our follow-up period.

Lung-heart toxicity in a randomized clinical trial of hypofractionated image guided radiation therapy for breast cancer

Background

TomoBreast hypothesized that hypofractionated 15 fractions/3 weeks image-guided radiation therapy (H-IGRT) can reduce lung-heart toxicity, as compared with normofractionated 25-33 fractions/5-7 weeks conventional radiation therapy (CRT).

Methods

In a single center 123 women with stage I-II operated breast cancer were randomized to receive CRT (N=64) or H-IGRT (N=59). The primary endpoint used a composite four-items measure of the time to 10% alteration in any of patient-reported outcomes, physician clinical evaluation, echocardiography or lung function tests, analyzed by intention-to-treat.

Results

At 12 years median follow-up, overall and disease-free survivals between randomized arms were comparable, while survival time free from alteration significantly improved with H-IGRT which showed a gain of restricted mean survival time of 1.46 years over CRT, P=0.041.

Discussion

The finding establishes TomoBreast as a proof-of-concept that hypofractionated image-guided radiation-therapy can improve the sparing of lung-heart function in breast cancer adjuvant therapy without loss in disease-free survival. Hypofractionation is advantageous, conditional on using an advanced radiation technique. Multicenter validation may be warranted.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT00459628. Registered 12 April 2007.