The Enumerated Value for Modality (0008,0060) shall determined by the IOD:
RTIMAGE if RT Image IOD,
RTDOSE if RT Dose IOD,
RTSTRUCT if RT Structure Set IOD,
RTPLAN if RT Plan IOD or RT Ion Plan IOD,
RTRECORD if RT Beams Treatment Record IOD, RT Ion Beams Treatment Record IOD, RT Brachy Treatment Record IOD, or RT Treatment Summary Record IOD.
Note: DICOM specifies that a given series shall contain objects of only one Modality, and shall be created by a single device (described in the General Equipment Module). However, in general there may be many series defined for a given modality/device pair. Note that a radiotherapy series is generally created over an extended time interval (unlike in radiology, where all images in an image series are generally created together).