The Evolution of Radiation Therapy

UC San Diego School of Medicine

Wilhelm Roentgen• Wilhelm Roentgen discovered X-Rays in 1895

• He was performing experiments on electricity, when he noted that an energy ray was produced which passed through most objects, including his own body

• The field of Radiation Therapy - now known as Radiation Oncology - was born shortly after this discovery

• The first diagnostic x-ray was taken within 2 months of Roentgen’s discovery

Marie Sklodowska Curie

• While working at the Sorbonne in Paris, Marie and her husband Pierre Curie isolated the first known radioactive elements

• These elements were named Polonium and Radium

Emil Grubee• After noting the peeling of his hands

exposed to x-rays, medical student Emil Grubbe convinced one of his professors to allow him to irradiate a cancer patient

• The patient was suffering from advanced breast cancer

• Grubbe became the World’s first Radiation Oncologist

Claude Regaud

• After seeing the cancer patient benefit from Grubbe’s intervention, people began to understand the potential value of radiotherapy

• A professor at the Radium Institute in Paris, Glaude Regaud, recognized that treatment may be better tolerated and more effective if delivered slower and in smaller doses per day over several weeks

• This process is known as fractionation

Radiation Therapy Machines

• Early x-ray machines were unable to produce high energy, deeply penetrating beams making it difficult to treat deep-seated tumors.

Modern Linear Accelerator

• In the 1960s, linear accelerators where developed, which were capable of producing high energy, deeply penetrating beams

• This allowed for the first time treatment of tumors deep inside the body without excessive damage to the overlying skin and other normal tissues

Other Notable Discoveries• Malcolm Bagshaw - demonstrated the

curative potential or Radiation Therapy in prostate cancer

• Gilbert Fletcher - established optimal treatment regimens in a wide variety of tumor sites including head, neck and cervical cancer

• Samuel Hellman - instrumental in establishing breast conserving therapy through the use of lumpectomy plus radiation

Computer Tomography

• Allowed for the development of 3-dimensional conformal radiotherapy (3DCRT)

• 3DCRT significantly improved the quality and delivery of radiotherapy by reducing dose to surrounding normal tissues

Intensity Modulated Radiation Therapy

• IMRT conforms the prescription dose to the shape of the target in 3 dimensions, thereby reducing the volume of normal tissues receiving high doses and thus the risk of potential side effects

• Provides a means of safely excelling the prescription dose and even re-treating previously irradiated patients, potentially improving cure rates

Image-Guided Radiation Therapy

• Rapidly growing in popularity primarily due to the widespread adoption of new linear accelerators which function both as treatment and imaging machines.