Selecting Megavoltage Treatment Technologies in External Beam Radiotherapy

SELECTING MEGAVOLTAGE

TREATMENT TECHNOLOGIES

IN EXTERNAL BEAM RADIOTHERAPY

IAEA HUMAN HEALTH REPORTS No. 17

SELECTING MEGAVOLTAGE

TREATMENT TECHNOLOGIES

IN EXTERNAL BEAM RADIOTHERAPY

INTERNATIONAL ATOMIC ENERGY AGENCY

VIENNA, 2022

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Printed by the IAEA in Austria

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STI/PUB/1948

IAEA Library Cataloguing in Publication Data

Names: International Atomic Energy Agency.

Title: Selecting megavoltage treatment technologies in external beam radiotherapy / International Atomic Energy Agency.

Description: Vienna : International Atomic Energy Agency, 2022. | Series: IAEA human health reports, ISSN 2074–7667 ; no. 17 | Includes bibliographical references.

Identifiers: IAEAL 21-01424 | ISBN 978–92–0–116821–4 (paperback : alk. paper) | ISBN 978–92–0–116921–1 (pdf) | ISBN 978–92–0–117021–7 (epub)

Subjects: LCSH: Cancer — Radiotherapy. | Radiotherapy, High Energy. | Medical physics.

Classification: UDC 615.849 | STI/PUB/1948

FOREWORD

The global incidence of cancer is rising significantly, with low and middle income countries (LMICs) experiencing the highest increases. Radiotherapy is one of the three main modalities for the treatment of cancer, along with surgery and chemotherapy. The aim of radiotherapy is to control a malignant tumour by exposing it to a high dose of radiation, while at the same time limiting to acceptable levels the radiation dose received by normal tissue. In the light of the rising cancer incidence and the lack of sufficient treatment capabilities, the need for additional radiation treatment technologies is considerable. This is particularly the case in LMICs, where the shortage of radiotherapy capabilities is acute. In preparation for the expected increases in cancer incidence and in the corresponding number of patients in the coming decade, a large number of new high energy radiotherapy machines capable of delivering megavoltage beams will be required globally. However, the answer is not simply to buy a new linear accelerator (linac) or ⁶⁰Co teletherapy machine.

Radiotherapy can be delivered with different types of machine, such as external beam high energy radiation machines, kilovoltage machines and brachytherapy equipment. Variations in the incidence of different cancer types, the complexity and cost of treatment technologies, and differences in local social, economic and physical circumstances are all factors that influence technology acquisition, purchase and implementation.

The radiotherapy treatment process is itself complicated and involves much more than just radiotherapy machines. A cancer diagnosis requires, at a minimum, pathology and diagnostic imaging. Once radiotherapy is prescribed, imaging is needed to determine the location and extent of the disease. Without adequate numbers of professionally trained radiation oncologists, medical physicists and radiation therapists, treatment cannot proceed accurately or safely.

This publication addresses just one of the many factors, albeit an important one, associated with the planning of a new radiotherapy facility or the upgrade of an existing one. This concerns the selection of a high energy (megavoltage) radiotherapy machine. The two main high energy machine types are linacs and ⁶⁰Co machines.