The sievert ( symbol: Sv) is a derived unit of ionizing radiation dose in the International System of Units ( SI) and is a measure of the health effect of low levels of ionizing radiation on the human body. The sievert is of importance in dosimetry and radiation protection, and is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement troduction. The purpose of these guidelines is to provide a consensus position on the modern approach to the delivery of radiation therapy ( RT) in the treatment of Hodgkin lymphoma ( HL) and to outline a new concept of involved site radiation therapy ( ISRT) in which reduced treatment volumes are planned for the effective control of involved sites of disease.
Background and Principles of Management. The heterogeneity of extranodal lymphomas ( ENLs), and the absence of prospective trial data or generally accepted management guidelines, have led to a variety of volume definitions, doses, and planning practices being implemented at different centers for the radiation treatment of ENLs.