Involved Node, Site, Field and Residual Volume Radiotherapy for Lymphoma: A Comparison of Organ at Risk Dosimetry and Second Malignancy Risks

Second cancer risk assessments after involved-site radiotherapy for mediastinal Hodgkin lymphoma

“…It is well known that the latent period for developing radiation‐induced solid tumors is 10 to 60 yr or more . Only a few dosimetric studies have provided data about the probability for carcinogenesis following ISRT in the mediastinum . The cancer risk assessments of these reports were based on the OED concept.…”

“…However, the LAR for esophageal cancer development of any study participant as estimated with the mechanistic approach differed by 65.5% or more from that calculated with the bell‐shaped model. Reported experience suggested that the OED of esophagus used for estimating the relevant carcinogenic effects can be defined by using the model parameters of stomach . Previous studies have already reported large deviations between the mechanistic and bell‐shaped models in the estimation of the radiotherapy‐induced stomach cancer risk …”

“…All plans consisted of two isocentric anteroposterior (AP) and posteroanterior (PA) fields with gantry angles of 0° and 180° giving a total dose of 30 Gy to the PTV. This irradiation technique has been extensively used for three‐dimensional conformal radiotherapy (3D CRT) for mediastinal HL . The XiO software was employed for the three‐dimensional treatment planning procedure (CMS Inc., St Louis, MO, USA).…”

“…The parameters employed for calculating the OED of esophagus, lung, and breast with the mechanistic model were derived from Murray et al, Schneider et al, and Schneider et al, respectively. Murray et al assumed that the α and R values for esophagus are the same with those given in a previous study for the stomach. The α / β ratio was considered to be equal to 3 for all organs examined in this study .…”

“…This irradiation technique has been extensively used for three-dimensional conformal radiotherapy (3D CRT) for mediastinal HL. [13][14][15] The XiO software was employed for the three-dimensional treatment planning procedure (CMS Inc., St Louis, MO, USA). The IFRT and ISRT plans were designed for use on a linear accelerator with multileaf collimators producing 6 MV photon beams (Primus, Siemens, Germany).…”