Positron Emission Tomography (PET) represents a step forward in the definition of response to therapy in patients with Hodgkin Lymphoma (HL). In particular the use of PET for the early assessment of response has been described as the most important tool for predicting the risk of disease progression. As no data are available to support the use of early assessment of response for adapting and modifying subsequent treatment, the use of PET should be limited only to patients enrolled in clinical trials. Irrespective of recommendations PET scanning is included in the current management of patients with HL at baseline, mid treatment, end of treatment, and follow-up. So far no study has been performed to verify how PET is currently used in the clinical setting and to assess if and how results of PET scanning are used for supporting treatment and clinical decisions.

Inclusion Criteria:

1. Histologically confirmed classical Hodgkin lymphoma according to the current World Health Organisation Classification (nodular sclerosis, mixed cellularity, lymphocyte rich, lymphocyte depleted).
2. Clinical stage I-IV.
3. No previous chemotherapy, radiotherapy or other investigational drug for HL.

Exclusion Criteria:

1. None.

All cases of classical Hodgkin lymphoma diagnosed between 2006 and 2008 in the province of Modena, Reggio Emilia, Parma and Ferrara will be considered eligible for this study.