Radioisotopes in Medicine

The Understanding the Atom Series

Nuclear energy is playing a vital role in the life of every man, woman, and child in the United States today. In the years ahead it will affect increasingly all the peoples of the earth. It is essential that all Americans gain an understanding of this vital force if they are to discharge thoughtfully their responsibilities as citizens and if they are to realize fully the myriad benefits that nuclear energy offers them.

The United States Atomic Energy Commission provides this booklet to help you achieve such understanding.

Edward J. Brunenkant, Director Division of Technical Information

UNITED STATES ATOMIC ENERGY COMMISSION

Dr. Glenn T. Seaborg, Chairman

James T. Ramey

Wilfrid E. Johnson

Dr. Theos J. Thompson

Dr. Clarence E. Larson

Radioisotopes in Medicine

by Earl W. Phelan

CONTENTS

INTRODUCTION 1

History 1

What Is Radiation? 5

What Is Radioactivity? 5

What Are Radioisotopes? 6

How Are Radioisotopes Used? 7

What Do We Mean by Tracer Atoms? 9

DIAGNOSIS 11

Pinpointing Disease 11

Arsenic-74 14

Chromium-51 15

Cobalt-60 16

Iodine-131 18

Iron-59 23

Phosphorus-32 24

Sodium-24 25

Technetium-99^m 26

Thulium-170 and Gamma Radiography 27

Tritium 28

Activation Analysis 30

Summary 30

THERAPY 31

A Successful Case 31

General Principles 32

Iodine-131 and Iodine-132 32

Boron-10 33

Phosphorus-32 35

Gold-198 37

Beads, Needles, and Applicators 38

Teletherapy 41

CONCLUSIONS 43

APPENDIX 44

SUGGESTED REFERENCES 47

United States Atomic Energy Commission
Division of Technical Information
Library of Congress Catalog Card Number: 66-62749
1966

THE COVER

This multi-detector positron scanner is used to locate tumors. A radioisotope-labeled substance is injected into the body and subsequently concentrates in the tumor tissue. The radioisotope emits positrons that immediately decay and produce two gamma rays that travel in opposite directions. These rays are detected simultaneously on a pair of opposing detection crystals and a line is established along which the tumor is located. This method is one of many ways doctors use radioisotopes to combat disease. In this, as in many other procedures described in this booklet, the patient remains comfortable at all times.