Background: The target volume for post-mastectomy radiation therapy (PMRT) in breast cancer patients with reconstruction has been a subject of debate. This study aimed to assess the radiation dose distribution and treatment outcomes associated with different chest wall (CW) delineation according to ESTRO ACROP guideline for patients underwent implant-based reconstruction. Methods: We conducted a retrospective review of breast cancer patients who underwent mastectomy followed by two-stage implant-based breast reconstruction and adjuvant radiation therapy (RT) between 2007 and 2022. The expanders/implants were positioned retropectorally. The chest wall target volumes were categorized into two groups: the prepectoral group, which excluded the deep lymphatic plexus, and the whole expander group. Results: The study included 26 patients, 15 in prepectoral group and 11 in whole expander group. No significant differences were observed in normal organs exposure between the two groups. There was a trend toward a lower ipsilateral lung mean dose in the prepectoral group (10.2 vs. 11.1 Gy, p=0.06). Both groups exhibited limited instances of reconstruction failure and local recurrence. Conclusions: For patients undergoing two-stage expander-implant retropectoral breast reconstruction and PMRT, our data have provided comparable outcomes and normal organs exposure for those omitting the deep lymphatic plexus.

γδT have functions of innate and adaptive immunity, with the potential to induce durable responses while being well-tolerated, with limited adverse effects, making it attractive as a tool for immunotherapy. γδT faces challenges as a frontline tool in clinical oncology, with limited response rates due to difficulties in reaching tumor sites with consistent cytotoxic activity and strength. Modulated Electro-hyperthermia (mEHT) is a loco-regional treatment, whereby energy-transmission from an electromagnetic field selectively targets the plasma membrane of tumor cells, inducing apoptosis and activating immune cells. We hypothesized that mEHT could enhance therapeutic effects by drawing γδT to tumor cells, while also rendering tumor cells to be more susceptible to cytotoxic effects. In this study, NOD/SCID mice harboring subcutaneous human HepG2 tumors were treated with intravenous injections of γδT after mEHT treatment. This method increased infiltration of γδT into the tumor site, significantly inhibiting tumor growth as compared to monotherapy with either modality. These data suggest that γδT could mediate a potent anti-tumor effect when combined with mEHT, and provide a strong rationale for combining these modalities in clinical application for cancer treatment.