PET/CT for HL Staging

Accurate baseline staging of Hodgkin lymphoma (HL) is crucial for prognostication and guides important treatment decisions. This remains true in the era of highly effective combined modality treatments and intensive multi-agent chemotherapy regimens that lead to cure in the vast majority of HL patients irrespective of disease stage [1, 2]. In the early 1970s the Committee on Hodgkin’s Disease Staging Classification convened in Ann Arbor, Michigan, and this resulted in the first staging classification for HL which was named after the city [3]. The Ann Arbor staging classification became the widely accepted classification for disease staging in HL and enabled comparison of studies by different investigators. The main clinical purpose of the Ann Arbor Classification was to accurately identify patients with limited-stage HL who could be treated with a curative intent with radiotherapy alone. Accurate staging was pursued through rigorous procedures, which included both a clinical and a pathological staging workup. Clinical stage was determined from physical examination, symptom assessment, lymphangiograms, and radiograms, some of which are still elements in modern HL staging. Pathological stage was derived from the results of invasive staging procedures including diagnostic laparotomy and iliac crest bone marrow biopsy (BMB). The risk of serious complications and discomfort related to invasive procedures were tolerated at that time as no good alternatives for evaluation of deep lymph node regions and organs were available. The introduction of computed tomography (CT) enabled noninvasive assessment of deep lymph node regions/organs and changed the staging of HL fundamentally. The committee convened to discuss the evaluation and staging of patients with Hodgkin’s disease met in the Cotswolds (UK) and the report generated by the committee recommended CT of the thorax and abdomen in the routine staging workup of HL. Invasive staging procedures with the exception of iliac crest bone marrow biopsy were no longer considered necessary (Cotswold modifications of the Ann Arbor Classification) [4].