Past, present, and future of radiotherapy for the benefit of patients

Abstract

Radiotherapy has been driven by constant technological advances since the discovery of X-rays in 1895. Radiotherapy aims to sculpt the optimal isodose on the tumour volume while sparing normal tissues. The benefits are threefold: patient cure, organ preservation and cost-efficiency. The efficacy and tolerance of radiotherapy were demonstrated by randomized trials in many different types of cancer (including breast, prostate and rectum) with a high level of scientific evidence. Such achievements, of major importance for the quality of life of patients, have been fostered during the past decade by linear accelerators with computer-assisted technology. More recently, these developments were augmented by proton and particle beam radiotherapy, usually combined with surgery and medical treatment in a multidisciplinary and personalized strategy against cancer. This article reviews the timeline of 100 years of radiotherapy with a focus on breakthroughs in the physics of radiotherapy and technology during the past two decades, and the associated clinical benefits.

Manejo del cáncer de cabeza y cuello: ¿Radioterapia a quién, cuándo y por qué?

“…Finalmente, a partir del año 2000, aparece la modulación de la intensidad del haz de radiación, dando paso a la RT con Intensidad Modulada (IMRT), técnica que permite obtener dosis precisas de acuerdo a la conformación del tejido tumoral, otorgando mayor protección a los tejidos sanos vecinos: glándulas salivales, oídos, ojos y cerebro. Esto explica, que actualmente esta técnica sea de elección para la radioterapia del cáncer de cabeza y cuello 5,21 .…”

“…Asociado a esto, se registra una Gray (Gy) que corresponde a la cantidad de energía depositada por unidad de masa. Sus posibles beneficios son permitir la cura del paciente, la preservación de la funcionalidad de los órganos, y su costo-efectividad, siempre que sea indicada adecuadamente y cumpla con los plazos temporales óptimos 5 .…”

Hadron accelerators for radiotherapy

“…Just a few months later x-rays were used by Freund and Schiff in Vienna to treat diseases of the skin [5][6][7][8], and in the following year Emil Grubbé -who ironically first trained as a homeopath -probably carried out the first treatment of cancer (of the breast) in Chicago [9]. These efforts were later aided by the realisation in 1896 by Herbert Jackson that electron focusing could improve the directionality of the x-rays [10]. Each of these early concepts has a counterpart in modern radiotherapy: one requires a suitable source of particles; a method by which they may be delivered accurately; and a manner in which the radiation dose delivered by the particles may be monitored.…”

Physical and Radiobiological Evaluation of Radiotherapy Treatment Plan

“…Modifications are then made after manual inspection of the dose distribution calculated after each iteration [2]. In IMRT, the dose calculation engine specified dose distribution over the target volume and surrounding normal structures.…”