Identifies the radiation modality administered during the first phase of radiation treatment delivered as part of the first course of treatment. This data item is required for CoC-accredited facilities as of 01/01/2018.

Radiation modality reflects whether a treatment was external beam, brachytherapy, a radioisotope as well as their major subtypes, or a combination of modalities. This data item should be used to indicate the radiation modality administered during the first phase of radiation.

Historically, the previously-named Regional Treatment Modality data item [1570] utilized codes that were not mutually exclusive. Rather, it included codes describing a mix of modalities, treatment planning techniques, and delivery techniques that are commonly utilized by radiation oncologists. However, every phase of radiation treatment will include a specific modality, planning technique, and delivery technique. The goal of the 2018 implementation of separate phase-specific data items for the recording of radiation modality and radiation treatment planning techniques is to clarify this information and implement mutually exclusive categories. A separate data item for delivery technique has not been implemented because this information is not consistently reported in end treatment summaries.

00	No radiation treatment
01	External beam, NOS
02	External beam, photons
03	External beam, protons
04	External beam, electrons
05	External beam, neutrons
06	External beam, carbon ions
07	Brachytherapy, NOS
08	Brachytherapy, intracavitary, LDR
09	Brachytherapy, intracavitary, HDR
10	Brachytherapy, interstitial, LDR
11	Brachytherapy, interstitial, HDR
12	Brachytherapy, electronic
13	Radioisotopes, NOS
14	Radioisotopes, radium-223
15	Radioisotopes, strontium-89
16	Radioisotopes, strontium-90
98	Radiation therapy administered but treatment modality is not specified or unknown
99	Unknown if radiation treatment administered