Somatostatin receptor scintigraphy in the initial staging of low-grade non-Hodgkin's lymphomas

In this prospective study, somatostatin receptor (SS-R) scintigraphy was co mpared with conventional staging procedures for the initial staging of pati ents with low-grade non-Hodgkin's lymphoma (NHL). Methods: Fifty consecutiv e untreated patients with low-grade NHL underwent SS-R scintigraphy as part of their initial staging. Planar images were obtained 24 and 48 h after in travenous injection of 220 MBq In-111-pentetreotide. SPECT images of the up per abdomen were obtained from all patients. SS-R scans were evaluated blin dly without knowledge of the results of the conventional staging methods. S S-R scintigraphy findings were compared with the results of physical and ra diologic examinations. Results: SS-R scintigraphy findings were positive in 42 of 50 patients (84%). In 10 patients (20%), the SS-R scan revealed new lesions that had not been revealed by conventional staging procedures. Thes e 10 patients were all upgraded to a higher stage. Consequently, the treatm ent plan would have been altered in 5 patients (10%). However, in 19 patien ts (38%), lesions apparent after conventional staging methods were missed b y SS-R scintigraphy. The sensitivity of SS-R scintigraphy varied from 62% f or supradiaphragmatic lesions to 44% for infradiaphragmatic lesions. The sp ecificity of SS-R scintigraphy was high (98%-100%). In comparison with CT s canning and sonography, SS-R scintigraphy is inferior for the visualization of NHL lesions in the thorax and abdomen. Conclusion: Although SS-R scinti graphy findings are positive in a large proportion of patients with low-gra de NHL, in most patients only part of the lesions can be visualized. Becaus e of the limited sensitivity, we recommend SS-R scintigraphy for initial st aging of patients with low-grade NHL only in selected conditions and not fo r the general work-up.