Preop Single-Dose Radiation Shows Promise in Breast Cancer

TOPLINE: 

A high dose of preoperative single-fraction stereotactic partial breast irradiation (S-PBI) may be associated with a major response, including pathological complete response in patients with early-stage breast cancer.

METHODOLOGY:

• A phase 2 clinical trial enrolled 49 postmenopausal patients (age, > 50 years) with early-stage breast cancer who received preoperative S-PBI followed by breast-conserving surgery between January 2022 and November 2023.
• Treatment was delivered as single-fraction radiosurgery (30-36 Gy) using GammaPod technology.
• Pathological response was classified as pathological complete response (pCR; absence of any residual invasive tumour), near complete response (nCR; presence of < 10% residual tumour), partial pathological response (pPR; presence of 10-50% or ≥ 50% residual tumour), or stable disease (no change in tumour size).
• Major response was defined as the sum of pCR and nCR.

TAKEAWAY:

• Overall, 37% of patients who received P-SBI achieved a major response, including pathological complete response in 18% of cases.
• Patients who received increased radiation doses (36 Gy) were more likely to experience a major response than those who received decreased doses (59% vs 25%; P = .019).
• Preoperative radiotherapy led to a substantial reduction in the Ki-67 value, decreasing from a median of 9.5% to 3.5% (P < .05).

IN PRACTICE:

“In conclusion, we have demonstrated that a high dose of S-PBI may be correlated with a major response, including pCR, in early-stage breast cancer using the GammaPod system,” the authors wrote.

SOURCE:

The study was led by Chiara Reverberi, MD, Department of Radiation Oncology, ASUFC Santa Maria della Misericordia, Udine, Italy. It was published online on February 21, 2025, in the International Journal of Radiation Oncology, Biology, Physics.

LIMITATIONS:

The study was limited by a small sample size. The analysis did not account for important confounding factors.

DISCLOSURES:

The study did not receive any specific funding. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.