Residual mass in aggressive lymphoma--does size, measured by computed tomography, influence clinical outcome?

Residual masses are frequently found in patients with aggressive lymphomas, following therapy. A study was undertaken to determine whether initial tumour size, changes during treatment, or size of the residual mass could provide prognostic information. Computed tomography (CT) examinations were carried out before, midway and after completion of chemotherapy in 37 patients with aggressive lymphoma with residual mass after treatment. The tumours were measured for both the greatest diameter sizes and area. The size of the residual mass correlated with the tumour size at diagnosis. Neither a large tumour size before treatment nor a large residual mass after treatment correlated with an increase in rate of relapse. The initial tumour reduction (measured after completion of half of the planned chemotherapy) was less pronounced in relapsing patients compared to relapse-free patients. Using a cut-off level of 70% tumour reduction (measured after completion of half of the planned chemotherapy), 66% of patients with a tumour reduction of < 70% relapsed, compared with 22% (p < 0.05) in those with more marked tumour regression.