Image-aided estimate of tumor burden in Hodgkin's disease: evidence of its primary prognostic importance.

ABSTRACT

PURPOSE: To explore a more direct method for evaluating tumor burden (TB) in Hodgkin's disease (HD) and to verify its prognostic importance. PATIENTS AND METHODS: The volume of TB at diagnosis was directly and retrospectively measured in 121 HD patients through images of the lesions recorded by computed tomographic (CT) scan of the thorax, abdomen, and pelvis for all deep sites of involvement and many superficial ones, and by ultrasonography (US) for the remaining superficial lesions. RESULTS: The TB, which was obtained from the sum of the volumes of all the lesions measured on CT scans and US and normalized to body-surface area (relative TB [rTB]), showed a median value of 102.6 cm(3)/m(2) (range, 2.2 to 582.8). At multivariate analysis for prognostic value, rTB was the parameter that statistically correlated best with time to treatment failure (P = 2.2 x 10(-6)), followed by erythrocyte sedimentation rate (ESR) (P =.0003), and serum fibrinogen (P =.0112). The prognostic discrimination allowed by rTB alone proved to be clearly superior to that obtained with the score of the International Prognostic Factor Project. The rTB was found to be correlated with many clinical staging parameters (bulky disease, number of involved lymph node regions, serum lactate dehydrogenase, ESR, hemoglobin, Karnofsky index), but its predictability from these variables was low (R(2) =.668). CONCLUSION: Relative TB is emerging as a strong prognostic factor in HD, more powerful than and largely independent of those hitherto known and used. Further studies are needed to confirm these results and exploit their clinical value, particularly the relationship among rTB, drug doses, and response.