# Quantitative in vivo dosimetry for radiotherapy using model-based X-ray-induced acoustic computed tomography

> **NIH NIH R50** · UNIVERSITY OF CALIFORNIA-IRVINE · 2024 · $80,229

## Abstract

Abstract
Accurate dose delivery at the tumor site is crucial for the success of radiotherapy (RT) for cancer treatment.
However, as yet there are no techniques in clinics with the ability to monitor RT. This project proposes X-ray-
induced acoustic (XA) computed tomography (XACT) to facilitate dose monitoring during RT. Pulsed X-ray
radiation, when absorbed by tissues, leads to thermoelastic expansion which generates acoustic waves. These
waves can be sensed by ultrasonic transducers around the irradiated tissue and fed to an XACT algorithm to
reconstruct the X-ray energy deposition (XED) maps. As an expert in computational biomedical imaging, Dr.
Pandey’s current challenge is to develop efficient XACT algorithms to enable real-time/near real-time
quantitative monitoring of the XED: the focus of the proposed project. Existing RT setups in clinics only need to
integrate a transducer array to adopt XACT-based radiation dosimetry without significantly affecting existing
RT practices. Dr. Pandey is key personnel in the ongoing projects funded by the NIH/NCI (R37 CA240806) and
the American Cancer Society (133697-RSG-19-110-01-CCE); Dr. Liangzhong Xiang is the Principal
Investigator. These projects aim to achieve in vivo dosimetry using XACT. Although XACT has seen
substantial utilization in dosimetry research, certain challenges hinder its clinical translation. The first one being
suboptimal signal-to-noise ratios (SNR) in XA signals and the main focus of Dr. Xiang’s R37 research is
towards developing advanced instrumentation to resolve this. Dr. Pandey’s research as well as this R50
proposal addresses the algorithmic challenges which include the limited view artifacts, absence of quantitative
dose information, and lack of the capability of correcting for acoustic heterogeneity in the reconstructed dose
maps. The key objectives of this proposal are coherent with the aims of the ongoing NCI and ACS projects.
Protons, owing to their unique energy deposition characteristics, are an attractive choice for RT. Much like X-
rays, clinical pulsed proton beams are also known to produce acoustic waves and Dr. Xiang’s group’s recent
preliminary studies (with Dr. Pandey’s contribution) have shown the capability of dose monitoring during proton
therapy which led to the NIH/NCI U01 Award (U01CA288351). Since XA and proton-induced acoustic waves
share the underlying physics, Dr. Pandey’s algorithms from the R50 award will also benefit the U01 grant. Dr.
Pandey’s doctoral and postdoctoral training in developing advanced model-based (MB) algorithms for acoustic
tomographic modalities and experience with XACT qualify him to achieve the proposed aims. MB
reconstructions are computationally intensive and hence, graphics processing units-based acceleration will be
implemented for achieving real-time/near real-time dose monitoring. The R50 award will provide protected time
for Dr. Pandey to express his research creativity to grow into a seasoned research scientist and help...

## Key facts

- **NIH application ID:** 10978946
- **Project number:** 1R50CA283816-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA-IRVINE
- **Principal Investigator:** Prabodh Kumar Pandey
- **Activity code:** R50 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $80,229
- **Award type:** 1
- **Project period:** 2024-09-03 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10978946

## Citation

> US National Institutes of Health, RePORTER application 10978946, Quantitative in vivo dosimetry for radiotherapy using model-based X-ray-induced acoustic computed tomography (1R50CA283816-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10978946. Licensed CC0.

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