Related Experiment Video
Updated: Jul 13, 2026

Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
The impact of protons on the incidence of second malignancies in radiotherapy
1Center for Radiological Research, Columbia University Medical Center, 630 West 168th Street, New York, NY 10032, USA. ejh1@columbia.edu
Abstract:
Protons represent a logical step forward as a modality for radiotherapy because it is possible to concentrate dose in the tumor region and minimize dose to normal tissue. The pencil beam emerging from a cyclotron or synchrotron needs to be expanded to a larger size to cover tumors of realistic size. Ideally, this should be accomplished by scanning the pencil beam using magnetic fields, but this is technically challenging. The simpler method is to use passive modulation, the downside of which is that neutrons are produced in the scattering foil, which results in a total body dose to the patient. Neutrons are highly effective at inducing second cancers and so, for the full potential of protons to be realized, spot scanning is essential.
Related Concept Videos
Types of Radioactivity
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
Biological Effects of Radiation
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Isotopes and Radioisotopes
An isotope containing more...
Cancer Prevention
Some...
Mismatch Repair
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
