Introduction: The aim of the present analysis is to evaluate the value of a biological treatment planning for patients with Hodgkin’s Lymphoma (HL). Because patients with HL have become longtime survivors the main goal of ongoing studies is to minimize treatment related late toxicity. Especially for patients with mediastinal involvement the use of IMRT should be considered carefully with regard to pulmonary toxicity. Methods: We included 27 patients with mediastinal involvement of HL. All patients received chemotherapy followed by 30.6 Gy Involved-Field RT. 20 patients were treated with APPA, 5 patients with a 5-field IMRT (5F-IMRT) and 3 patients with a 7-field IMRT (7F-IMRT). To compare the different techniques we calculated 3 treatment plans for every patient. We evaluated Dmean, V5, V10, V15, V20 and V30 of the lung, Dmax of the spinal cord and V50 of the body. To determine the probability of pneumonitis we used a biological evaluation of Eclipse© by Varian and compared them to values we calculated using the parameters of Quantec. We analyzed the follow-up CTs of all patients to test whether they had a radiogenic pneumonitis. Results: A total of 81 plans were calculated. The 7F-IMRT achieves the highest values with respect to Dmean, V5, V10, V15 and V20 of the lung. Regarding V30 APPA is inferior (14.9 Gy APPA vs 2.9 Gy 7F-IMRT median). With respect to Dmax of the spinal cord the 7F-IMRT is superior to 5F-IMRT and APPA (32.1 Gy APPA, 24.9 Gy 5F-IMRT and 19.9 Gy 7F-IMRT median). The 7F-IMRT achieves the highest NTCP-values: Left lung: (range 0.0-2.1%); 5F-IMRT (range 0.0-4.0%) and 7F-IMRT (range 0.0 – 5.1%). Right lung: APPA (range 0.0-2.1%); 5F-IMRT (range 0.0-2.9%) and 7F-IMRT (range 0.0-8.0%). The values calculated by using the Quantec-parameters were as follows: Left lung: APPA (range 1.4-12.2%); 5F-IMRT (range 1.6-15%) and 7F-IMRT (range 1.7 – 16.4%). Right lung: APPA (range 2.3-12.6%); 5F-IMRT (range 2.4-13.9%) and 7F-IMRT (range 2.3-18.2%). No patient had radiologic signs of pneumonitis by reviewing the follow up CTs. Conclusion: APPA is superior to IMRT with respect to the mean lung doses. This finding is underlined by the NTCP-values. If the local doses (e.g. V30) in the field of the PTV are observed, IMRT is superior. The calculated values show an increased risk by using the 7F-IMRT. The biological evaluation achieves remarkable results in both cases, that are usefull in the judgement of treatment plans.