Staging of Hodgkin lymphoma is performed according to the Ann Arbor staging classification as detailed in Table 18.2 [8]. It is desirable to carefully document signs and symptoms at presentation as well as all sites of involvement at diagnosis in order to better follow up response to therapy. Furthermore, a proper staging is important in determining adequate risk category of the patient to help decide on the appropriate management. Table 18.3 lists all evaluations for presenting new patients. A thorough medical history focusing on unexplained fevers, drenching night sweats, or more than 10 % unintentional weight loss in the last 6 months will confirm the presence of B symptoms, an important prognostic factor and indicator of more advanced disease. In countries with prevalent malnutrition and endemic malaria, these symptoms may often be difficult to attribute to the lymphoma versus general health conditions, but given the often late presentation and bulk of the disease, it is best to err on the side of caution and attribute them to the lymphoma. Signs of superior vena cava syndrome (dyspnea, facial swelling, cough, orthopnea, and headache) or of tracheal and/or bronchial compression (cough, dyspnea, and orthopnea) should immediately alert the medical practitioner of a possible large mediastinal mass and prompt a chest radiograph for evaluation. Careful physical examination of all peripheral lymph node groups, documenting site and size, as well as evaluation for hepatosplenomegaly should be part of the initial staging work-up. While laboratory tests are desirable to determine adequate organ function prior to starting therapy, and can also contribute to inform on the prognosis, these are not required for risk classification and unavailability should not be an obstacle to therapy. In regard to diagnostic imaging, chest radiographs can inform about bulk of a chest mass (mediastinal to thoracic ratio greater than 33 %), as well as the presence of obvious pulmonary nodules. When CT or MRI is not available for a full anatomic localization of disease, an abdominal ultrasound can be used to evaluate infradiaphragmatic disease like liver and spleen involvement as well as inform about para-aortic and iliac nodal involvement. Currently, the gold standard as far as functional imaging is the ¹⁸Fluoro-deoxyglucose positron emission tomography (PET scan) which can reveal metabolic activity in involved nodal groups and extralymphatic organs, as well as indicate bone and bone marrow involvement. In the absence of this modality, a ⁹⁹Technetium bone scan can be performed in patients with suspected bony disease due to localized pain or elevated alkaline phosphatase; however, a localized skeletal radiograph of the involved bones showing destruction will also suffice. Bone marrow biopsies are painful and expensive, so that unless the information gained by this procedure will change the patient’s therapy, it shall be omitted [9].

Response assessment after the first two cycles of therapy should include the same modalities utilized at the time of diagnosis and should be performed according to the guidelines of the adopted treatment regimen. At the off-therapy evaluation all extranodal disease should have disappeared; most lymph nodes will have returned to a normal size (≤1 cm) and be soft and mobile. In case of nodular sclerosing HL, a large mediastinal mass may not have completely involuted at the end of therapy, given the nature of the pathology, but should be followed by regular chest radiographs to make sure it continues to regress over time. Frequent imaging is not required for follow-up; careful physical examination and evaluation will be more informative in raising concern of relapse [10].

As previously discussed in the staging section a correct risk classification is very important when selecting the right treatment approach. Every protocol or treatment guideline will have its own risk classification so that the medical practitioner choosing a treatment approach needs to carefully review the risk definitions prior to deciding on therapy (Tables 18.4 and 18.5). In most places the choice of regimen (Table 18.6) will be dictated by drug availability and the experience of the treating physician, as well as supportive care resources. As has recently and dramatically been shown, drug substitutions need to be carefully evaluated [11]. In Central America, AHOPCA (Central American Association of Pediatric Hematology-Oncology), a modified Stanford V regimen, was used for high risk patients in whom they substituted mechlorethamine by cyclophosphamide given that the former was not available. The disappointing result of only 55 % 3-year event-free survival was originally attributed to the bulky and advanced stages at presentation [12]; however, this may not be a sufficient explanation, as the same substitution carried out by the St Jude-Stanford-Dana-Farber consortium during a National shortage also led to poorer outcomes [11]. It is therefore best to choose a proven regimen that utilizes available drugs than to assume one can substitute an unavailable drug. The choice of whether or not to choose a regimen that includes radiotherapy will be determined by the available infrastructure, but also the experience and willingness of often adult radiation oncologists in treating children.