Hypofractionated Radiation Fractionation in Breast Cancer Patients With Implant-Based Reconstruction

Patients with breast cancer frequently have requirement for breast reconstruction after mastectomy. For patients with limited autologous tissue availability, implant-based reconstruction remains an effective alternative. Due to the absence of high-level evidence, collaborative efforts between surgical and radiation oncology teams are advised to determine the optimal sequencing and techniques for integrating reconstruction surgery with radiotherapy. The ongoing Alliance A221505 and FABREC phase III randomized controlled trials are comparing the incidence of reconstructive complications following hypofractionated and conventional fractionation radiotherapy. FABREC trial recently showed the hypofractionated regimen did not significantly improve change in physical well-being（PWB), domain of the Functional Assessment of Cancer Therapy-Breast (FACT-B) quality-of-life assessment tool, compared with the conventional fractionation radiotherapy. This trial added to the increasing experience with HF PMRT in patients with implant-based reconstruction.

In 2019, the European Society for Radiotherapy and Oncology (ESTRO) provided guidelines for target delineation based on the position of the implant in breast reconstruction to minimize the irradiation of normal tissues. Existing studies on the risk of complications from irradiating expanders and implants have yielded inconsistent conclusions, with each approach having its own advantages and disadvantages.

Our study aims to compare the incidence of reconstructive complications between hypofractionated and conventional fractionation radiotherapy after implant-based reconstruction surgery to provide high-level evidence for medium-dose hypofractionated radiotherapy after immediate implant-based reconstructive surgery.

Inclusion criteria

• Pathological diagnosis of stage I-III breast cancer (non-T4), >18 years old; 2. Complete breast cancer resection (including skin-sparing and nipple-sparing total resection) 3. According to the guidelines of the Chinese Anticancer Society, postoperative adjuvant radiotherapy is required; 4. Undergo immediate reconstructive surgery (tissue dilator or permanent implant)

Exclusion criteria

• Auto-reconstruction surgery
• Clinical or pathological T4
• Both sides need radiotherapy
• Have a history of chest radiotherapy
• Pregnancy/lactation
• Participate in other drug clinical trials