Childhood Hodgkin Lymphoma Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Diagnosis and Staging
Staging and evaluation of disease status is undertaken at diagnosis and performed again early in the course of chemotherapy and at the end of chemotherapy.
The diagnostic and staging evaluation is a critical determinant in the selection of treatment. Initial evaluation of the child with Hodgkin lymphoma includes the following:[1,2]
The following three specific constitutional symptoms (B symptoms) correlate with prognosis and are considered in assignment of stage:
Additional Hodgkin-associated constitutional symptoms without prognostic significance include the following:
- Alcohol-induced nodal pain.
- All node-bearing areas, including the Waldeyer ring, should be assessed by careful physical examination.
- Enlarged nodes should be measured to establish a baseline for evaluation of therapy response.
- Hematological and chemical blood parameters show nonspecific changes that may correlate with disease extent.
- Abnormalities of peripheral blood counts may include neutrophilic leukocytosis, lymphopenia, eosinophilia, and monocytosis.
- Acute-phase reactants such as the erythrocyte sedimentation rate and C-reactive protein, if abnormal at diagnosis, may be useful in follow-up evaluation.
Anatomic information from CT is complemented by PET functional imaging, which is sensitive in determining initial sites of involvement, particularly sites too small to be considered abnormal by CT criteria.
Definition of bulky disease
The posteroanterior chest radiograph remains important since the criterion for bulky mediastinal lymphadenopathy used in North American protocols is defined by the ratio of the diameter of the mediastinal lymph node mass to the maximal diameter of the rib cage on an upright chest radiograph; a ratio of 33% or higher is considered bulky. This definition is no longer used in some European protocols because it does not influence risk classification.
The criteria for bulky peripheral (nonmediastinal) lymphadenopathy have varied per cooperative group study protocols from aggregate nodal masses exceeding 4 to 6 cm. This disease characteristic has not been consistently used among all groups for risk stratification.
Criteria for lymphomatous involvement by CT
Defining strict CT size criteria for the establishment of lymphomatous nodal involvement is complicated by a number of factors, such as overlap between benign reactive hyperplasia and malignant lymphadenopathy and obliquity of node orientation to the scan plane. Additional difficulties more specific to children include greater variability of normal nodal size with body region and age and the frequent occurrence of reactive hyperplasia.
General concepts to consider in regard to defining lymphomatous involvement by CT include the following:
- Contiguous nodal clustering or matting is highly suggestive of lymphomatous involvement.
- Any focal mass lesion large enough to characterize in a visceral organ is considered lymphomatous involvement unless the imaging characteristics indicate an alternative etiology.
- North American protocols have used a consistent size criteria: A measurable lesion by CT is defined as one that can be accurately measured in two orthogonal dimensions, which typically requires a lesion at least 1 cm in diameter for extranodal sites; lymph nodes are considered abnormal if the long axis is 1.5 cm or greater or between 1.1 cm and 1.5 cm with a short axis of at least 1.0 cm.
- Criteria for nodal involvement may vary by cooperative group or protocol. For example, in the Society for Paediatric Oncology and Haematology (Gesellschaft für Pädiatrische Onkologie und Hämatologie [GPOH]) completed study (GPOH-HD-2002), nodal involvement was defined if the node was greater than 2 cm in largest diameter. The node was not involved if it was less than 1 cm and was considered questionably involved if it was between 1 cm and 2 cm. Involvement decision was then based on all further clinical evidence available.