Technetium-99m depreotide imaging by single photon emission tomography/low resolution computed tomography in malignant lymphomas: comparison with gallium-67 citrate.

Abstract

OBJECTIVE:

Previous studies have demonstrated the feasibility of targeting lymphoma lesions with somatostatin receptor binding agents, mainly with In-111-pentetreotide. In the present work another somatostatin analog, Tc-99m depreotide, is investigated.

METHODS:

One-hundred and six patients, 47 with Hodgkin's (HL) and 59 with various types of non-Hodgkin's lymphoma (NHL), were imaged with both Tc-99m depreotide and Ga-67 citrate. Planar whole-body and single photon emission tomography/low resolution computerized tomography (SPECT/CT) images were obtained. A total of 142 examinations were undertaken at different phases of the disease. Depreotide and gallium findings were compared visually and semi-quantitatively, with reference to the results of conventional work-up and the patients' follow-up data.

RESULTS:

In most HL, intermediate- and low-grade B-cell, as well as in T-cell NHL, depreotide depicted more lesions than Ga-67 and/or exhibited higher tumor uptake. The opposite was true in aggressive B-cell NHL. However, there were notable exceptions in all lymphoma subtypes. During initial staging, 93.3% of affected lymph nodes above the diaphragm, 100% of inguinal nodes and all cases with splenic infiltration were detected by depreotide. On the basis of depreotide findings, 32% of patients with early-stage HL were upstaged. However, advanced HL and NHL cases were frequently downstaged, due to low sensitivity for abdominal lymph node (22.7%), liver (45.5%) and bone marrow involvement (36.4%). Post-therapy, depreotide detected 94.7% of cases with refractory disease or recurrence. Its overall specificity was moderate (57.1%). Rebound thymic hyperplasia, various inflammatory processes and sites of unspecific uptake were the commonest causes of false positive findings. The combination of depreotide and gallium enhanced sensitivity (100%), while various false positive results of either agent could be avoided.

CONCLUSION:

Except perhaps for early-stage HL, Tc-99m depreotide as a stand-alone imaging modality has limited value for the initial staging of lymphomas. Post-therapy, however, depreotide scintigraphy seems useful in the evaluation of certain anatomic areas, particularly in non-aggressive lymphoma types. The combination with Ga-67 potentially enhances sensitivity and specificity. If fluorodeoxyglucose positron emission tomography is not available or in case of certain indolent lymphoma types, Tc-99m depreotide may have a role as an adjunct to conventional imaging procedures.

• Authors: Dimitris J Apostolopoulos, Nikolaos I Papandrianos, Argiris Symeonidis, Tryfon Spyridonidis, Sotiria Alexiou, Petros Zampakis, Christos Savvopoulos, Pavlos J Vassilakos, Panagiota Matsouka
• Journal: Annals of nuclear medicine (Ann Nucl Med) Vol. 24 Issue 9 Pg. 639-47 (Nov 2010) ISSN: 1864-6433 [Electronic] Japan
• PMID: 20799079 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Citrates
• Organotechnetium Compounds
• Somatostatin
• technetium Tc 99m depreotide
• Gallium
• gallium citrate

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Biological Transport
• Citrates
• Female
• Gallium
• Humans
• Lymph Nodes (diagnostic imaging, metabolism)
• Lymphoma (diagnosis, metabolism, pathology, therapy)
• Male
• Middle Aged
• Neoplasm Staging
• Organotechnetium Compounds (pharmacokinetics)
• Recurrence
• Somatostatin (analogs & derivatives, pharmacokinetics)
• Tomography, Emission-Computed, Single-Photon (methods)
• Tomography, X-Ray Computed (methods)
• Young Adult