The patients are registered into the registry in anonymized form at the time of diagnosis after signing informed consent and data are updated/collected at the end of first line treatment, at each relapse including therapy for relapse and then annual follow-up and at the time of death. The registration is submitted electronically via secure internet system. For each patient are available following forms: registration form, diagnostic form, treatment form, follow- up form, and other malignancy form. The content of diagnostic form consists of diagnosis according WHO classification including the copy of original histology description, date of diagnosis, clinical stage, B symptoms, nodal and extranodal involvement, laboratory findings and prognostic systems (IPI, aaIPI, MIPI, FLIPII and others). The prognostic system is calculated automatically. The diagnostic form is the same for the first diagnosis and for the relapses. The treatment form consists of detailed information on the treatment: chemotherapy regimens, therapy with monoclonal antibodies, radiotherapy, autologous or allogeneic transplant. Response assessment has been adjusted to the different version of Chesson criteria for malignant lymphoma. It is expected that comorbidity score and toxicities evaluation will be added into the therapeutic form too.

The follow-up form is requested to be updated annually, besides that in case of relapse or death. This form includes information about clinical status, date of relapse or death.

The exports made from NiHiL content all data from registry and survival data (overall survival, progression survival and disease free survival).

Data quality in the NiHiL has been checked by audits recently, which have been carried out in each centre twice a year.

The data is analyzed according to NHL subtypes with endpoints: lymphoma distribution, epidemiological data, prognostic characteristic, treatment characteristics, response rate, relapse rate, mortality, PFS, OS, DFS, Lymphoma specific survival, longterm toxicity.

The registry has been repeatedly supported by the grants of Ministry of Health. A substantial number of papers originated from the NiHiL have been published in last 15 years in both Czech and international journals. The main aim of the registry is to collect data for malignant lymphoma for better understanding of epidemiological and clinical data about this disease.