# Evaluation of image-guided, conformal, high-dose intraoperative radiation therapy (Precision Breast IORT) for early stage breast cancer

> **NIH NIH R01** · UNIVERSITY OF VIRGINIA · 2020 · $376,980

## Abstract

Our proposal aims to improve the efficacy of intraoperative radiation therapy (IORT) for the treatment of early
stage breast cancer, to investigate the immune effects of breast radiation therapy, and to evaluate the
comparative effectiveness and costs of an advanced form of breast IORT. IORT is an emerging alternative to
whole breast irradiation (WBI), but its current embodiment has several deficiencies including the lack of imaging
for target delineation and planning, and poor dosimetry due to the use of low-energy photons. We have leveraged
advanced CT-guided, high dose-rate brachytherapy techniques to develop Precision Breast IORT (PB-IORT),
a novel method that improves upon conventional breast IORT (CB-IORT) through customized, three-dimensional
treatment planning and delivery for higher dose, accurate, individualized IORT that better targets the breast
tissue. Our phase I safety and feasibility trial established that PB-IORT can safely deliver 12.5 Gy (roughly twice
the dose of CB-IORT) to the at-risk breast tissue. We will evaluate the efficacy of PB-IORT in a multi-center
Phase II trial that will assess important clinical and immunologic outcomes and will provide data to enable
comparative effectiveness studies, addressing the following specific aims: Aim 1: To determine the efficacy of
PB-IORT on 5-year local breast cancer recurrence rates. Because PB-IORT delivers a more accurate and higher
dose than CB-IORT, we hypothesize that PB-IORT will result in lower rates of local tumor recurrence than CB-
IORT, and similar rates compared to WBI. We will also characterize the cosmetic and quality of life outcomes
and mammographic changes after PB-IORT. Aim 2: To evaluate the effects of PB-IORT on the immune system.
We will use blood samples from patients treated with PB-IORT and a comparison cohort of WBI-treated to
provide fundamental insights into the impact of RT volume and fractionation on immune-suppressive effects of
breast RT, determining whether IORT can avoid the immune-suppressive effects of WBI. Aim 3: To evaluate
the comparative effectiveness of PB-IORT compared to treatment alternatives. We will apply Markov modeling
methods to compare PB-IORT to all other options for breast RT. We will consider how variations in patient
preference and recurrence risk impact outcomes and how reimbursement rates would impact cost effectiveness.
We will evaluate the costs of PB-IORT using time-driven activity-based costing to inform value-based
reimbursement decisions, providing policy-relevant evidence important for dissemination. Our two-institution
team provides a foundation for expansion of PB-IORT to facilities without an integrated image-guided
brachytherapy suite. As a technically optimized form of IORT, PB-IORT may may ultimately improve patient
outcomes and satisfy patient demand by providing an optimized, more effective form of IORT that will reduce
recurrences compared to CB-IORT, and will better preserve immune function compared to WBI whil...

## Key facts

- **NIH application ID:** 9991835
- **Project number:** 5R01CA214594-03
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** Shayna Lefrak Showalter
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $376,980
- **Award type:** 5
- **Project period:** 2018-09-20 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9991835

## Citation

> US National Institutes of Health, RePORTER application 9991835, Evaluation of image-guided, conformal, high-dose intraoperative radiation therapy (Precision Breast IORT) for early stage breast cancer (5R01CA214594-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9991835. Licensed CC0.

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