# HYPERTHERMIA TREATMENT PLANNING

> **NIH NIH R01** · PURDUE UNIVERSITY · 1988 · $208,304

## Abstract

Uniform heating of tumor tissue to therapeutic temperatures without
damaging surrounding normal tissue is required for successful local heat
therapy of cancer.  We have previously shown that the mean temperature of
solid tumors during microwave therapy can be selectively elevated above
that of surrounding normal tissue with the adjunctive use of vasodilator
drugs.  We now propose a method of on-line treatment planning that will
allow the therapist to minimize the standard deviation of measured
intratumoral temperatures.  The method requires hardware incorporating
multiple (surface and/or interstitial) microwave applicators under control
of a small computer together with software incorporating a novel control
algorithm developed by the PI.  With this system the entire measured
temperature distribution may be continually reoptimized under closed loop
control.

The system infers relevant thermal parameters by analyzing responses of
multiple temperature sensors as each of the power applicators is briefly
turned off.  Applied power is measured from transient slope changes of the
temperature-time curves for each sensor.  Then all power is briefly turned
off, and effective perfusion is measured by thermal washout.  By
substituting these values into a system of linear equations derived from
the bio-heat transfer equation, the small computer can calculate the
optimal allocation of power among the various applicators ("knob settings")
to generate most uniform intratumoral temperature distribution with the
desired mean (or minimum) tumor temperature.

We propose to develop a prototype system and to determine its utility in
minimizing intratumoral temperature variations during microwave therapy.
Thereafter, we propose a clinical study of the prototype system vs. a
conventional multi-applicator system to test the hypothesis that a more
uniform intratumoral temperature distribution will lead both to a lower
incidence of complications caused by hot spots within the treatment field
and to a lower incidence of treatment failures caused by cold spots within
the tumor.

## Key facts

- **NIH application ID:** 3176184
- **Project number:** 5R01CA038144-03
- **Recipient organization:** PURDUE UNIVERSITY
- **SAM.gov UEI:** YRXVL4JYCEF5
- **Principal Investigator:** CHARLES F BABBS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $208,304
- **Award type:** 5
- **Project period:** 1986-08-01 → 1991-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3176184

## Citation

> US National Institutes of Health, RePORTER application 3176184, HYPERTHERMIA TREATMENT PLANNING (5R01CA038144-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3176184. Licensed CC0.

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