# Product Development of Intensity Modulation for Bolus Electron Conformal Therapy

> **NIH NIH R44** · DECIMAL, INC. · 2020 · $1,059,095

## Abstract

Project Summary/Abstract
Objective: This project aims to elevate electron beam therapy (EBT) technology, which provides effective
radiation treatment for superficial cancers (depth<6 cm), to that of other external beam radiotherapies (XRT),
e.g. x-rays and protons, by bringing electron intensity modulation into the clinic. Challenge: Approximately
10% of radiotherapy patients (173,000 in USA annually) receive EBT for a portion of their treatment, and as
many as 10% of these (17,300 annually) might benefit from bolus electron conformal therapy (BECT), which
conforms the distal 90% dose surface to the cancerous planning target volume (PTV), protecting adjacent
healthy tissue. Currently, radiation oncologists are limited in using BECT because PTV dose spread can be as
great as 30% due to irregular bolus surface. This can be reduced to 10% by spatially modulating incident
electron beam intensity. Heretofore, electron intensity modulation delivery technology has been unavailable.
Innovation: Using our research collaborator’s recently invented electron intensity modulator design, Phase I
demonstrated proof-of-principle for a PRIME (Passive Radiotherapy Intensity Modulator for Electrons), a
low cost technology for which .decimal developed a fabrication method. PRIME consists of a matrix of small-
diameter, cylindrical tungsten island blocks imbedded in a low-density foam in the beam-defining,
collimating aperture. Varying diameters of island blocks placed on a hexagonal grid achieves desired intensity
modulation. However, because current treatment planning systems (TPS) cannot manage PRIMEs, an
electron TPS needs to be developed as well. Research Design: Phase II specific aims include (1) refining the
pencil beam redefinition algorithm used for dose calculation under island blocks, (2) creating and evaluating
an electron specific TPS, COMET-Plan (Computer Optimized & Modulated Electron Therapy Planning),
which plans intensity modulated bolus electron conformal therapy (IM-BECT) and conventional EBT,
managing treatment aids such as skin collimators and eye shields, (3) developing factory and clinical PRIME
quality assurance methods, (4) performing a multi-institutional treatment planning study to determine the
degree to which IM-BECT improves BECT dose plans, and (5) validating IM-BECT planning and delivery by
comparing doses measured in anthropomorphic phantoms with planned (calculated) doses. Health Benefit:
PRIME devices and COMET-Plan software will allow a new technique, IM-BECT, which provides uniform
dose conforming to the PTV, resulting in (1) equally high chance of cancer control, (2) equally or better low
chance of acute normal tissue complications, and (3) decreased chance of secondary cancers. For some
patients, this will provide a better dose distribution than other XRT modalities, such as volumetric arc therapy
or helical tomotherapy, improving their cancer treatment. Commercialization: As the world’s leading
company producing patient-spe...

## Key facts

- **NIH application ID:** 10024062
- **Project number:** 5R44CA199838-03
- **Recipient organization:** DECIMAL, INC.
- **Principal Investigator:** Kevin James Erhart
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $1,059,095
- **Award type:** 5
- **Project period:** 2016-09-13 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10024062

## Citation

> US National Institutes of Health, RePORTER application 10024062, Product Development of Intensity Modulation for Bolus Electron Conformal Therapy (5R44CA199838-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10024062. Licensed CC0.

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