Chronology of cancer radiotherapy
Chronology of cancer radiotherapy.
This article refers to the chronology of cancer radiotherapy. Cancer is a major public health problem in the world and is responsible for 25% of all deaths. The predominant cause of death of heart disease in older people is no longer the main cause of death. Cancer treatment is gaining a growing interest in emerging countries.
The contribution of radiotherapy for fighting cancer.
Radiation cancer radiotherapy appeared in medicine at the end of the 19th century. At that time, three Nobel Prizes are given for discoveries related to ionizing radiation. In December 1895 the German mechanic and physicist Wilhelm Rontgen discovered the x-rays. In June 1896, natural radioactivity discovered.
What is natural radiotherapy?
It is the property that has certain elements emitting rays or particles from the material. French Antoine Henri Becquerel made this discovery.
A pair of scientists Marie Sklodowska Curie and the French physicist Pierre Curie isolated the radioactive elements radio and polonium. These three fundamental discoveries paved the way for the two basic techniques of cancer radiotherapy.
- Source-Surface-Distance SSD. In this form of treatment, the source and the radiated surface used remotely. Later on, it was called external beam radiotherapy.
- SSD. Brachytherapy based on a short SSD initially obtained by radio and later on X-rays 50kV.
The first patients.
Chronology of cancer radiotherapy and the first patients. Treated with radiation in 1896, nearly 6 months after the discovery of Rontgen. These patients had gastric cancer and basal cell carcinoma and originated from France, America, and Sweden. The harmful effects of radiation occurred very soon. They were taken seriously to optimize the therapeutic ratio, as well as to search for radiation protection methods.
For the use of cancer radiotherapy at the routine level, designed processed radium tubes, as well as Coolidge tubes. Until that time, the purpose of radiotherapy was to administer the dose of radiation to organs at risk. Thus, the radiation was used at 100% of the dose as close as possible to the problematic spot and virtually no radiation was given to the adjacent spot. A great achievement of that era was the ability to measure the dose of radiation using ionization chambers with the first accurate Rontgen dose unit in 1932. With energies between 50kV and 200kV, it was very difficult to administer adequate doses to deep-located tumors. This was mainly due to the inevitable coexisting toxic effect on the skin.
The treatment of cancer by external beam radiotherapy involved small and superficial tumors. For example, tumors of the skin, vocal cords, or lymphomas. Finally, brachytherapy restricted to accessible tumors such as mobile tongue, rectum and uterine cancers.
In the 1920s.
An oncological revolution occurred when it was possible for the first time to treat early-stage larynx without primary abnormal tracheostomy. There followed three fundamental laws, which were discovered, which are still the basis of the current practice. First in 1906, the different inherent radiosensitivity patterns between cells and tissues proven by French oncologist Jean Bergonie and French physician Louis Tribondeau. Secondly, in 1927, the French physician-biologist Claudius Regaud discovered the role of division to create a favorable differential effect between cancerous and healthy cells.
French pioneer radiotherapy and oncologist Henri Coutard proposed a 200 Rontgen splitting scheme per fraction five times a week. This transformed into the modern model shape of the 2 Gy fraction, which relatively recently well combined with the a / b model to describe the biological effect. In 1928 the ICRP International Radiation Protection Committee set up to address the question of radiation protection. In the same year, the Geiger Muller meter constructed for the detection and measurement of radioactivity.
Following the award of the Nobel Prize to Irene and Frederic Joliot Curie for the discovery of technical radioactivity, followed by Jones and Cunningham, Cobalt 60 adopted as an alternative source of high-energy gamma rays for radiotherapy. This was accomplished with a higher dose than that achievable with the radio element.
The first cobalt unit installed in Canada in 1948. In the next 10 years, more than a thousand units sold to hospitals around the world. These units widely used for 20-30 years. The photon energy beam enabled skin protection for the first time. It also made possible the delivery of large doses of radiation to localized tumors in depth. All this without exceeding the tolerance of organs at risk.
In 50’s – 60’s.
High-energy therapeutic machines, known as linear accelerators, were introduced. They produced high energy from deep penetrating beams, allowing for the first time the treatment of tumors located deep within the body and without the destruction of the skin and other normal tissues. The first accelerator stationed at Hammersmith Hospital in London in 1953.
Decades 1970 – 1980.
The computers started used to design the treatment. New imaging technologies, including MRI, emerged in the ’70s and PET, IMRT, and IGRT in the 80’s. IMRT uses radiation beams with different intensities to deliver different doses of radiation at the same time. This technology allows the administration of higher doses of radiation within the volume and lower doses to the adjacent healthy tissues. IGRT used in areas of the body that are prone to movement. Since tumors can actually migrate between therapies, the relevant technology allows the oncologist to visualize the tumor immediately before and after the duration of the treatment. Adjustments made to the patient’s location and the radiation directed more accurately, targeting the tumors.
Chronology of Cancer Radiotherapy Nowadays.
Thus, with technological achievements, oncologists are better targeting tumors. This has led to better therapeutic effects, fewer unwanted actions and greater salvage of human organs. Cancer radiotherapy is often the last stage in the fight against cancer.
The ancient known Greek physician Hippocrates said:
Diseases not cured with drugs treated with the medical scalpel and the surgery. Diseases not treated with surgery healed with fire, that is, burns. Finally, diseases not treated with fire, considered incurable.