The unique features of GammaPod™ have enabled the team at ASUFC “Santa Maria della Misericordia” in Udine, led by Dr. Marco Trovò, in collaboration with the Medical Physics Department, headed by Dr. Eugenia Moretti, to explore the feasibility and safety of single-fraction stereotactic breast treatments in a pre-operative setting.
Pre-Operative Single Fraction Stereotactic Partial Breast Irradiation (S-PBI) for Early-Stage Breast Cancer Patients with GammaPod Technology: Pathological Findings and Ki-67 Evaluation is the title of the study set to appear in the upcoming issue of the prestigious Red Journal (International Journal of Radiation Oncology, Biology, Physics). This research lays the groundwork for a significant advancement in the treatment of early-stage breast cancer, highlighting the importance of technological innovation in oncology.
The study, conducted by the ASUFC “Santa Maria della Misericordia” team in Udine, aims to evaluate the safety and feasibility of pre-operative S-PBI radiotherapy using the GammaPod technology in early-stage breast cancer patients. The goal is to analyze tumor response to a single high-dose radiation treatment through pathological examination and immunohistochemical analysis of the surgically removed tissue.
Metods
This Phase II study involved 49 post-menopausal patients over the age of 50 with unifocal luminal-type tumors, all eligible for conservative surgery.
The treatment protocol included a single fraction dose of 30-36 Gy, delivered using the GammaPod system, followed by surgery within 8-28 weeks.
The pathological response was classified as follows:
- Complete Response (pCR): No residual tumor cells.
- Near Complete Response (nCR): Less than 10% of residual tumor cells.
- Partial Response (pPR): Residual tumor between 10-90%.
- Stable Disease: Over 90% of residual tumor cells.
- Major Response = pCR + nCR
Results
The results are extremely encouraging, as stated by Dr. Marco Trovò, Head of the Radiation Oncology Unit at ASUFC “Santa Maria della Misericordia” in Udine.
“The study demonstrates that high-dose stereotactic radiotherapy can be safely delivered to breast tumors when using dedicated technology. There is a correlation between radiation dose and tumor response, with a significant drop in the Ki-67 proliferation marker after radiosurgery, which may serve as a new surrogate for treatment response.”
Key findings include:
- Major Response in 37% of patients, with 18% achieving a complete response.
- Significant reduction in the Ki-67 proliferation marker:
- Pre-treatment: 9.5%
- Post- treatment: 2%
- Patients treated with 36 Gy had a higher pathological response rate (59%) compared to those treated with 30-33 Gy (25%).
- No significant increase in surgical complications.
“The study is actively enrolling patients, and soon a cohort treated with high-dose radiotherapy (36 Gy in a single fraction) and undergoing surgery six months later will be analyzed. This will allow researchers to assess a possible correlation between time to surgery and pathological response.
The next steps in research are twofold: 1. Further increasing the delivered dose to achieve higher rates of major pathological response; 2. If the positive trend persists, surgery could solely be considered in cases of disease progression.
There is still a long road ahead, but as the saying goes, “The secret of getting ahead is getting started.” (Attributed to Mark Twain)”
(Dr. Marco Trovò, Head of the Radiation Oncology Unit at ASUFC “Santa Maria della Misericordia” in Udine).
