Limited positron emission tomography-computed tomography for restaging of lymphoma: A strategy for reducing radiation exposure among patients with early-stage curable lymphoma

Repeated imaging with positron emission tomography-computed tomography (PET-CT) is associated with cumulative exposure to substantial doses of radiation. Furthermore, PET-CT is an expensive and limited resource in many institutions. We conducted a retrospective analysis to evaluate whether limited PET-CT focused on the initially involved field of view (FOV) at diagnosis, corresponding to an above- or below-the-diaphragm scan, is sufficient for follow-up of patients with Hodgkin (HL) and aggressive non-Hodgkin lymphoma (NHL). One hundred thirty-one examinations of 44 patients with early-stage (I-II) HL (n = 27) and aggressive NHL (n = 17) who had PET-CT performed as part of their initial staging and at follow-up were analyzed. Regardless of the extent of response to treatment, there was no single case in which the disease progressed outside of the initially involved FOV (0/44, 95% CI 0-0.08). This was true even in cases of disease progression, including in the setting of relapse. Our findings suggest that limited PET-CT analysis of the initially involved FOV in patients with early-stage curable lymphoma may be satisfactory for response assessment.