Involved Nodal Irradiation vs Involved Field Irradiation After Cth in Ttt of Early Stages HDs

Hodgkin lymphoma (HL) is one of the most frequent lymphomas in the Western world, with an annual incidence of about 3 cases per 100,000 persons. This lymphoid malignancy involves peripheral lymph nodes and can also affect organs such as liver, lung, and bone marrow. About 40% of patients suffer from constitutional symptoms ("B-symptoms"). Based on differences in the histological picture and the phenotype of the tumor cells, HL is subclassified into nodular sclerosis, mixed cellularity, lymphocyte-rich, lymphocyte-depleted, and nodular lymphocyte-predominant HL (NLPHL) (1) Hodgkin lymphoma is estimated to account for about 10% of cases of newly diagnosed lymphoma in the United States (8,260 of 80,500), the remainder being Non-Hodgkin lymphoma. Of 21,210 estimated deaths yearly due to lymphoma, about 1,070 (or 5%) are from Hodgkin lymphoma. It accounts for about 0.5% of newly diagnosed cases of cancer in the United States and about 0.2% of all cancer deaths. However lymphoma is the most common cancer diagnosed in adolescents (aged 15 to 19 years) accounting for 21% of new diagnoses, almost two-thirds of which is Hodgkin lymphoma (2) In patients with Hodgkin lymphoma, a definitive diagnosis is critical and requires that the treating physician provide the pathologist with an adequate pathologic specimen. Fine-needle aspiration or core-needle biopsy specimens are commonly inadequate because they do not represent the architecture of the lymph node and therefore preclude an accurate diagnosis. Hodgkin lymphoma has the unique characteristic of malignant cells constituting only a minority of the intratumoral cell population, and therefore, a small biopsy specimen may not include sufficient malignant cells.(3)

To establish a definitive diagnosis, it is necessary to identify Reed-Sternberg cells within the biopsy specimen. These cells are commonly seen within a rich cellular environment composed of reactive lymphocytes, eosinophils, and histiocytes. Two distinct disease entities have been defined in Hodgkin lymphoma, the commonly diagnosed classical Hodgkin lymphoma and the uncommon nodular lymphocyte-predominant Hodgkin lymphoma.(4)

The past few decades have seen significant progress in the management of pt with HL, it is curable in at least 80% of patient. Early stage Hodgkin's lymphoma (HL) patients treated with a combination of chemotherapy and radiotherapy have an excellent clinical outcome, with overall survival of approximately 90% [5].

With modern techniques, including better CT scan imaging, FDG-PET/CT scans and more accurate radiation technology ,It is now possible to customize radiotherapy for each patient with accurate delivery of radiation to the initially involved volume while minimizing the radiation dose to normal tissues(6).

The advent of combined modality treatment had previously led to a Shift in practice from extended field radiotherapy techniques to involved Field radiotherapy (IFRT)(7-8).

Some recent studies have shown the safety of further reductions in field sites. With the concept of involved node radiotherapy (INRT) in order to reduce the risk of radiotherapy-induced toxicity. INRT is based on treating only initially involved lymph nodes and excluding adjacent uninvolved nodal areas(9-11)