Somatostatin receptor scintigraphy in the staging of lymphomas

In this prospective study we evaluated the somatostatin receptor scintigraphy in the initial staging of 19 patients suffering from Hodgkin's (HD) and non-Hodgkin's lymphomas (NHL) and in the restaging of 16 patients. Scintigraphy was compared to the results of the methods applied for adequate staging of lymphoma patients in the large multicentre trials. Planar imaging and SPECT was performed after intravenous injection of 110 or 220 MBq of 111In-pentetreotide. The patient-based analysis yielded an overall sensitivity of 88%, contrasting lesion-based sensitivities of 57%, 35%, and 43% in HD, low-grade NHL and high-grade NHL, respectively. The best results were obtained in the head-and-neck region and the worst in the abdomen (sensitivities of 61% and 24%, respectively). Bone marrow infiltration was visible in 1/12 cases only. There was no significant difference between the outcomes of patients in the initial staging and restaging and no influence of the amount of injected radiopharmaceutical on the results. In terms of the Ann-Arbor classification, 10/35 patients were concordant whereas 22 were understaged and 3 overstaged scintigraphically. In conclusion, somatostatin receptor scintigraphy is not useful in the initial staging or restaging of malignant lymphomas, especially NHL, due to low lesion detection rates most probably because of low receptor densities. In addition, intraindividual heterogeneity of somatostatin receptor expression has to be considered.