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Sub-category:
Lymphoma, Adult
Category:
Hematologic Malignancies
Meeting:
2003 ASCO Annual Meeting
Abstract No:
2299
Citation:
Proc Am Soc Clin Oncol 22: 2003 (abstr 2299)
Author(s):
G. H. M. Jerusalem, V. Warland, Y. Beguin, R. Hustinx, M.-F. Fassotte, J. Foidart-Willems, G. Fillet; Centre Hospitalier Universitaire, Liege, Belgium
Abstract:
We have previously shown that PET has higher diagnostic and prognostic value than computed tomography in HD and NHL (Jerusalem et al, Blood, 1999; 94 : 429-33). The aim of this study was to obtain further information about the accuracy of PET in the end of treatment evaluation of patients suffering from lymphoma. One hundred and eight patients (39 HD, 69 NHL) were recruited prospectively between 5/94 and 10/01. Twenty-six patients relapsed (NHL : 23, HD : 3). End of treatment PET was positive in 16/108 (15%) patients. In 12 patients (NHL : 11, HD : 1), PET had correctly identified residual disease (high lesion-to-background ratio : 7 patients, low lesion-to-background ratio : 5 patients) confirmed either by biopsy or by unequivocal conventional imaging studies after a median of 1 (range 0-20) month. In the other 4 patients (NHL : 2, HD : 2), this was a false positive PET. The lesion-to-background ratio was low in 3 and high in 1 patient who actually had developed rectal cancer. The 2 of 16 patients with increased 18F-FDG uptake only outside of initial lymphoma involvement were both false positive (1 inflammatory lesion, 1 rectal cancer). Fourteen patients with a negative end of treatment PET relapsed 2-60 months (median : 13.5 months) later. Based on our data end of treatment PET had a sensitivity of 46% (12/26), a specificity of 95% (78/82), a positive predictive value (PPV) of 75% (12/16), a negative predictive value of 85% (78/92) and an overall accuracy of 83% (90/108). These patterns were not different between HD and NHL patients, except that because relapse was a rare event in HD, the impact of false positive PET on PPV value was much more important in HD (PPV : 33%) than in NHL (PPV : 85%). In conclusion, PET is very accurate in predicting short-term treatment failure. However, it cannot detect microscopic residual disease and thus its value is hampered by false negative results in patients relapsing later. On the other hand, a biopsy is always indicated before salvage therapy in order to exclude false positive PET results related to inflammatory lesions or to second primary tumors.
 Associated Presentation(s):
Other Abstracts in this Sub-Category:
Abstracts by G. H. M. Jerusalem:
Presentations by G. H. M. Jerusalem:
Educational Book Manuscripts by G. H. M. Jerusalem:
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