Visualization of non-Hodgkin's lymphoma by high dosed somatostatin receptor specific scintigraphy and extended single...

The study aimed to increase the sensitivity of somatostatin receptor (SR) specific scintigraphy for the detection of non-Hodgkin's lymphoma (NHL). Ten selected patients presenting with histologically proven NHL and with 50% to 100% bone marrow involvement were injected with 20 micrograms octreotide labeled with a mean of 254 MBq 111In. The results were recorded with a double head gamma camera by long-time SPET (60 sec per frame, 3 interval) of neck/thorax and abdomen/pelvis. To show bone marrow displacement by lymphoma cells, SPET of the same regions (15 sec per frame, 3 interval) was recorded 3 to 7 days later after i.v. administration of 0.5-1 mg monoclonal anti-granulocyte antibody (Mab 250/183) labeled with a mean of 454 MBq 99mTc. This modality showed a person related sensitivity of 70%, a lesion related sensitivity of 48% (29/60), 60% (22/37) above and 30% (7/23) below the diaphragm. The sensitivity in detecting bone marrow involvement was 10%. Only 80% bone marrow infiltration with lymphoma cells in nodular configuration was shown by In-111-octreotide scintigraphy correlating with cold lesions in the anti-granulocyte scan. There was no false positive result; the smallest lesion correctly identified by SR scintigraphy had with a diameter of 1 cm, the largest lesion missed measured 3.5 cm. In conclusion, doubling the doses of octreotide and radiolabel and extended SPET recording improved to some extent the patient related sensitivity and visualized nodular bone marrow involvement in 10% of patients. The lesion related sensitivity improved mainly above but not below the diaphragm.