The results of the present study indicate that when imaging bone metastases, prior treatment can alter the relationship between PET and CT findings. Most untreated bone metastases are PET positive and lytic on CT, while in previously treated patients most lesions are PET negative and blastic on CT. PET and CT therefore appear to be complementary in the assessment of bone metastases.

Introduction. The purpose of this study was to evaluate the feasibility of using 99mTc-TG SPECT in the detection and staging of malignant lymphoma.Materials and methods.Fifteen patients with newly diagnosed malignant lymphoma  underwent 99mTc-TG SPECT. Six patients had Hodgkin’s lymphoma and 9 patients had aggressive forms of non-Hodgkin’s lymphoma (NHL): diffuse large B-cell lymphoma (7  cases), B-cell follicular lymphoma (1 case), and lymphoma from B cells in the marginal zone  (1 case). Stage IIA was diagnosed in 5 patients, stage IIB in 1, stage IIIA in 1, stage IVA in 4 and stage IVB in 4 patients.Results.Pathological 99mTc-TG uptake in lymph nodes was observed in 14 (93 %) of the  15 patients. In one patient, the enlarged submandibular lymph node (16 mm in size)  detected by CT was not visualized by 99mTc-TG SPECT. This false-negative result was likely  to be associated with increased accumulation of 99mTc-TG in the oropharyngeal region.  There were difficulties in the visualization of paratracheal, para-aortic and paracardial lymph  nodes. These difficulties were associated with a high blood background activity, which  persisted even 4 hours after intravenous injection of 99mTc-TG. Software-based SPECT and  CT image fusion allowed visualization of these lymph nodes. The pathological 99mTc-TG  accumulation in axillary, supraclavicular, infraclavicular and cervical lymph nodes was  observed most often. Extranodal involvement was seen in 9 patients. 99mTc-TG SPECT identified extranodal hypermetabolic lesions in 7 (78 %) of these patients. In one  patient, hypermetabolic lesion in the lung detected by 99mTc-TG SPECT was not detected on CT image. CT identified bone marrow involvement in the pelvic and scapula in 1 patient. The  use of 99mTc-TG SPECT allowed the visualization of hypermetabolic bone tissue lesions  in this patient (Figure 4). In addition, in a patient with intact bone tissue on CT, 99mTc-TG SPECT detected hypermetabolic lesions in the iliac bone.Conclusion.99mTc-1-Thio-D-glucose demonstrated increased uptake in nodal and  extranodal sites of lymphoma. The results indicate that SPECT with 99mTc-1-Thio-D-glucose is a feasible and useful tool in the detection and staging malignant lymphoma.

Currently, 18F FDG-PET and 18F FDG-PET/CT are widely used for diagnosis and monitoring of lymphomas. The majority of aggressive lymphomas are characterized by high glycolytic activity, which enables the visualization by using 18F FDG-PET/CT. The use of PET/CT makes it possible to clarify the stage of the disease in 10–30 % of patients, with additional tumor sites typical for advanced stage of lymphomas, which in turn effects on treatment and disease prognosis. The 18F FDG-PET/CT has the advantage over other methods of radiation diagnosis in detecting bone marrow lesions in patients with lymphomas. It has been shown that 18F FDG-PET/CT performed at early stages of chemotherapy allows differentiating patients with favorable lymphoma, which is sufficient for standard therapy and high-risk patients who require more intensive treatment with high-dose regimens of chemotherapy. After completion of therapy over 60 % of patients with HL and 40 % with aggressive non-Hodgkin’s lymphomas, have residual masses containing necrotic and/or fibrotic tissue and residual neoplastic cells. 18F FDG-PET and 18F FDG-PET/CT has been shown to be useful in identifying residual masses in 30–64 % of patients, by demonstration of persistent metabolic activity on FDG-PET. Between 62–100 % of patients with residual FDG-positive masses have been shown to relapse after first-line chemotherapy. Identification of patients with partial response to chemotherapy indicates the need for continued treatment. New radiopharmaceuticals for the diagnosis of lymphoma and evaluation of therapy effectiveness are developed. Such promising radiopharmaceuticals are 18F fluorothymidine, a biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker.

The article shows the feasibility of detecting and monitoring primary breast diffuse large B-cell lymphoma using single-photon emission computed tomography (SPECT) with 99mTc-1-thio-D-glucose (99mТс-TG), a new radiopharmaceutical. The innovative radiopharmaceutical makes it possible to evaluate the metabolism of tumor tissue without using positron emission tomography. The findings of 99mTc-TG SPECT obtained during diagnosis and monitoring of the patient were confirmed by the results of computed tomography. A comprehensive examination of the patient, including 99mTc-TG SPECT, made it possible to diagnose a rare case of primary breast lymphoma. Primary breast lymphoma accounts for 1.7–2.2 % of all extranodal nonHodgkin lymphomas. Diffuse large B-cell lymphoma is the most common histological type occurring usually as a unilateral palpable tumor in middle-aged women. Extranodal lymphomas account for less than 0.5 % of all malignant neoplasms of the breast. After 6 courses of immunochemotherapy, the patient underwent 99mTc-TG SPECT, which demonstrated persistent hypermetabolic activity in the breast. The patient received radiation therapy to the remaining tumor of the left breast. The patient is in remission and followed up at the Cancer Research Institute of Tomsk National Research Medical Center. Thus, 99mTc-TG SPECT is believed to be a promising method for visualizing primary breast lymphomas and assessing their treatment outcomes. It is an alternative to the standard approach using 18F-FDG positron emission tomography. The method compares favorably with positron emission tomography with its wide availability and low cost of study.