18F-FDG-PET in Finnish patients with clinical suspicion of cardiac sarcoidosis: Female sex and history of atrioventricular block increase the prevalence of positive PET findings.

INTRODUCTION: Fluorodeoxyglucose positron emission tomography (FDG-PET) is a non-invasive imaging modality that has been shown to be a feasible method to demonstrate myocardial inflammation. The aim of this study was to identify the patients suspected of having cardiac sarcoidosis (CS), who are most likely to benefit from PET imaging. MATERIALS AND METHODS: 137 patients suspected of having CS underwent a dedicated cardiac FDG-PET examination at Tampere University Hospital between August 2012 and September 2015. These examinations were retrospectively analyzed. RESULTS: 33 and 12 of the 137 patients had abnormal left and right ventricular (LV and RV) FDG-uptake, respectively. Abnormal LV-uptake and RV-uptake were significantly associated with female sex and a history of advanced AV-block (P < 0.05). Abnormal RV-uptake was also associated with ventricular tachycardia and atrial fibrillation (P < 0.05). 56% of the 27 female patients with a history of AV-block had a pathological PET finding compared to only 6% of the 49 male patients without a history of AV-block. There were 17 female patients with history of both AV-block and ventricular tachycardia, 71% of them had abnormal PET finding. CONCLUSIONS: Abnormal FDG-PET findings were associated with female sex, AV-block, and arrhythmias in this clinical cohort.

Sentinel Node and Ovarian Tumors: A Series of 20 Patients.

OBJECTIVE: Intraoperative detection of ovarian sentinel nodes has been shown to be feasible. We examined the detection rate and locations of sentinel nodes in patients with ovarian tumors. We also aimed to assess the reliability of sentinel node method in predicting regional lymph node metastasis. METHODS: Twenty patients scheduled for laparotomy because of a pelvic mass were recruited to the study. In the beginning of the laparotomy, radioisotope and blue dye were injected under the serosa next to the junction of the ovarian tumor and suspensory ligament. The number and locations of the hot and/or blue nodes/spots were recorded during the operation. If the tumor was malignant according to the frozen section, systematic lymphadenectomies were performed, the sentinel nodes sampled separately, and their status compared with other regional lymph nodes. RESULTS: Eleven patients had a right-sided ovarian tumor, 7 patients a left-sided tumor, and 2 patients had bilateral tumors. A median of 2 sentinel nodes/locations per patient (range, 1-3) were found. Sixty percent of all sentinel nodes were located in the para-aortic region only, compared with 30% in both para-aortic and pelvic areas and 10% in pelvic area only. Both unilateral and bilateral locations were found. In 83% of the cases with more than 1 sentinel node location, they were located in separate anatomical regions. In 3 patients, systematic lymphadenectomies were performed. One of them had nodal metastases in 2 regions and also a metastasis in 1 of her 2 sentinel nodes in 1 of those regions. CONCLUSIONS: In patients with ovarian tumor(s), the detection of sentinel nodes is feasible. They are located in different anatomic areas both ipsilaterally and contralaterally, although most of them are found in the para-aortic region. The reliability of the sentinel node concept should be evaluated in the framework of a multicenter trial.

Early interim PET/CT predicts post-treatment response in diffuse large B-cell lymphoma.

BACKGROUND: (18)F-FDG-PET/CT has been widely used in the staging of malignant lymphomas, and accepted as a tool for response assessment. Among PET parameters, the most frequently studied is maximal standardized uptake value (SUVmax). Metabolic tumor burden (MTB) is a parameter in which both metabolic tumor volume (MTV) and tumor activity are integrated. Here, we analyzed the prognostic value of SUVmax, SUVsum (sum of the SUVmax), whole-body MTV (MTVwb) and MTBwb from baseline and interim PET/CT in patients with diffuse large B-cell lymphoma (DLBCL). MATERIAL AND METHODS: Twenty-nine patients with histologically proven DLBCL were imaged by PET/CT before treatment (Exam I), and one week after the first dose of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy (Exam II). Biopsy specimens were examined by an expert hematopathologist, the Ki-67 proliferation index (PI) was estimated for each biopsy site from the MIB-1 stained sections. The response evaluation was performed after chemotherapy completion (6-8 cycles). RESULTS: All patients had one or more visualized lymphomatous lesions on (18)F-FDG-PET/CT. The SUVmax of the whole-body (BmSUVmax) was higher than the SUVmax at biopsy site (BxSUVmax) (mean: 20.1 vs. 17.3, p < 0.01). The PI correlated with the BxSUVmax (p < 0.05). One week after chemotherapy, SUVmax, SUVsum, MTVwb, and MTBwb decreased significantly (p < 0.01, respectively), SUVsum, MTVwb and MTBwb at Exam II correlated with chemotherapy response at treatment completion (p < 0.05, respectively). CONCLUSION: SUVmax is more accurate to detect tumor aggressiveness than biopsy in DLBCL, since BmSUVmax represents the most aggressive tumor of the patient. Interim PET/CT as early as one week after R-CHOP therapy predicts response. Thus, it could be used as a tool for guidance of risk stratification in DLBCL.

Diffusion-weighted MRI in early chemotherapy response evaluation of patients with diffuse large B-cell lymphoma--a pilot study: comparison with 2-deoxy-2-fluoro- D-glucose-positron emission tomography/computed tomography.

To determine the feasibility of diffusion-weighted MRI (DWI) in the evaluation of the early chemotherapeutic response in patients with aggressive non-Hodgkin's lymphoma (NHL), eight patients with histologically proven diffuse large B-cell lymphoma were imaged by MRI, including DWI, and positron emission tomography/computed tomography (PET/CT) before treatment (E1), and after 1 week (E2) and two cycles (E3) of chemotherapy. In all patients, whole-body screening using T(1) - and T(2) -weighted images in the coronal plane was performed. To quantitatively evaluate the chemotherapeutic response, axial images including DWI were acquired. Apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC value of the tumor was measured. In addition, the tumor volume was estimated on axial T(2) -weighted images. The maximum standardized uptake value (SUV(max) ) and active tumor volume were measured on fused PET/CT images. Lymphomas showed high signal intensity on DW images and low signal intensity on ADC maps, except for necrotic foci. The mean pre-therapy ADC was 0.71 × 10(-3) mm(2) /s; it increased by 77% at E2 (p < 0.05) and 24% more at E3 (insignificant); the total increase was 106% (p < 0.05). The mean tumor volume by MRI was 276 mL at baseline; it decreased by 58% at E2 (p < 0.05) and 65% more at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean SUV(max) of 20. The SUV(max) decreased by 60% at E2 (p < 0.05) and 59% more at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden decreased by 66% at E2 (p < 0.05). At baseline, both central and peripheral tumor ADC values correlated inversely with SUV(max) (p < 0.05), and also correlated inversely with active tumor burden on PET/CT and with tumor volume on MRI at E2 (p < 0.05). In conclusion, the results of DWI in combination with whole-body MRI were comparable with those of integrated PET/CT.

Ovarian sentinel node: is it feasible?

OBJECTIVE: To examine whether the intraoperative combined injection technique is feasible in locating the sentinel node(s) of the ovary. METHODS/MATERIALS: In 16 patients with high-risk uterine cancer and normal postmenopausal ovaries, technetium isotope and blue dye were injected in the right or left ovary during laparotomy, respectively. During the operation, the pelvic and para-aortic lymphatic areas were searched, and the number, method of detection, and location(s) of the hot and/or blue node(s) were recorded. RESULTS: One to 3 sentinel nodes per patient were identified in all but 1 patient (15 of 16, 94%). The sentinel nodes (n = 30) were all located in the para-aortic area. The sentinel nodes of the left ovary were mainly (9 of 14, 64%) located above the inferior mesenteric artery level, as the most sentinel nodes of the right ovary (15 of 16, 94%) were found below the inferior mesenteric artery level (P = 0.001). There were no contralateral or bilateral sentinel nodes. CONCLUSIONS: The combined intraoperative injection technique with radioisotope and blue dye is fast enough to identify the ovarian sentinel node(s). The stained nodes were consistently located on a certain lymphatic area. The sentinel node concept for the early ovarian cancer deserves more attention.

PET imaging in a longitudinal non-Hodgkin's lymphoma study: association with tumor volume.

BACKGROUND: Computed tomography (CT) is generally used in the evaluation of the treatment response of non-Hodgkin's lymphoma (NHL) patients. Instead of morphological images, positron emission tomography (PET) shows metabolic information that is connected to tumor activity, cell proliferation rate, and, thus, prognosis. PURPOSE: To determine the prognostic value of PET for tumor volume reduction measured by CT and magnetic resonance imaging (MRI) along with clinical characteristics in NHL patients. MATERIAL AND METHODS: We imaged 21 B-cell type NHL patients using whole-body 18F-FDG-PET at the onset and the completion of treatment and at six-month follow-up. The maximum standardized uptake value (SUV(max)) was calculated. Morphological tumor volume calculations were assessed using both MRI and CT. Additionally, patients underwent thorough clinical examination including several laboratory tests. RESULTS: A high SUV(max) was able to predict significant tumor volume reduction at the beginning of treatment, but the relation to pure tumor volume was poor. CONCLUSION: The SUV(max) values derived from FDG-PET seemed to correlate with volume changes but not with their absolute values or laboratory tests. Unlike MRI and CT, FDG-PET showed the disappearance of active tumors after treatment.

The Association Between Liver and Tumor [18F]FDG Uptake in Patients with Diffuse Large B Cell Lymphoma During Chemotherapy.

PURPOSE: The aim of this study was to explore the association between liver, mediastinum and tumor 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake during chemotherapy in diffuse large B cell lymphoma (DLBCL). PROCEDURES: Nineteen patients with proven DLBCL underwent positron emission tomography (PET)/X-ray computed tomography scan at baseline, 1 week and 2 cycles after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy, and again after chemotherapy completion. The mean and maximal standardized uptake value (SUVmean and SUVmax) of the liver and mediastinum were measured and correlated with the tumor SUVmax, SUVsum, whole-body metabolic tumor volume (MTVwb), and total lesion glycolysis (TLG). RESULTS: At baseline, both the liver and mediastinum SUVmean and SUVmax correlated inversely with the tumor MTVwb or TLG (p < 0.01 or 0.001). The liver SUVmean and SUVmax increased significantly after 1 week of R-CHOP therapy and remained at the high level until chemotherapy completion. The mediastinum SUVmean and SUVmax remained stable during chemotherapy. The tumor SUVmax, SUVsum, MTVwb, and TLG decreased significantly after 1 week of R-CHOP therapy. The change of the liver SUVmean correlated inversely with the change of tumor MTVwb and TLG after 1 week of chemotherapy (p < 0.05, respectively). The intersubject variability of liver and mediastinum [18F]FDG uptake ranged from 11 to 26 %. CONCLUSIONS: The liver [18F]FDG uptake increased significantly after R-CHOP therapy. One of the possible reasons is the distribution of a greater fraction of the tracer to healthy tissues rather than tumor after effective chemotherapy. The variability of the liver [18F]FDG uptake during chemotherapy might affect the visual analysis of the interim PET scan and this needs to be confirmed in future studies with a large patient cohort. In addition, the intersubject variability of the liver and mediastinum [18F]FDG uptake should be considered.

Correlations between functional imaging markers derived from PET/CT and diffusion-weighted MRI in diffuse large B-cell lymphoma and follicular lymphoma.

OBJECTIVES: To investigate the correlations between functional imaging markers derived from positron emission tomography/computed tomography (PET/CT) and diffusion-weighted magnetic resonance imaging (DWI) in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). Further to compare the usefulness of these tumor markers in differentiating diagnosis of the two common types of Non-Hodgkin's lymphoma (NHL). MATERIALS AND METHODS: Thirty-four consecutive pre-therapy adult patients with proven NHL (23 DLBCL and 11 FL) underwent PET/CT and MRI examinations and laboratory tests. The maximum standardized uptake value (SUV(max)), metabolic tumor volume (MTV), and metabolic tumor burden (MTB) were determined from the PET/CT images. DWI was performed in addition to conventional MRI sequences using two b values (0 and 800 s/mm(2)). The minimum and mean apparent diffusion coefficient (ADC(min) and ADC(mean)) were measured on the parametric ADC maps. RESULTS: The SUV(max) correlated inversely with the ADC(min) (r =  -0.35, p<0.05). The ADC(min), ADC(mean), serum thymidine kinase (TK), Beta 2-microglobulin (B2m), lactate dehydrogenase (LD), and C-reactive protein (CRP) correlated with both whole-body MTV and whole-body MTB (p<0.05 or 0.01). The SUV(max), TK, LD, and CRP were significantly higher in the DLBCL group than in the FL group. Receiver operating characteristic curve analysis showed that they were reasonable predictors in differentiating DLBCL from FL. CONCLUSIONS: The functional imaging markers determined from PET/CT and DWI are associated, and the SUV(max) is superior to the ADC(min) in differentiating DLBCL from FL. All the measured serum markers are associated with functional imaging markers. Serum LD, TK, and CRP are useful in differentiating DLBCL from FL.

Glucose metabolism correlated with cellular proliferation in diffuse large B-cell lymphoma.

Standardized uptake value (SUV) is a marker of tumor glucose metabolism detected by [18F]-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT). The maximum SUV of the whole-body (BmSUV(max)) reflects the tumor aggressiveness in non-Hodgkin lymphoma. To evaluate the correlation between SUV(max) at biopsy site (BxSUV(max)) and proliferation potential of tumor cells in untreated diffuse large B-cell lymphoma (DLBCL), fifteen pre-therapy PET/CT scans in patients with histologically proven DLBCL were retrospectively analyzed together with Ki-67 proliferation index. The BmSUV(max) and BxSUV(max) were evaluated from the fused PET/CT images. Ki-67 proliferation index was measured in the biopsy specimens using an immunohistochemical technique in archival paraffin-embedded sections. The BmSUV(max) was significantly higher than the BxSUV(max) (mean 19.6 vs.16.6, p < 0.01). The BxSUV(max) correlated with the Ki-67 proliferation index (r = 0.7, p < 0.01), but no correlation was detected between the BmSUV(max) and the Ki-67 proliferation index. The results indicate that tumor proliferation potential might be predicted in vivo by FDG-PET/CT images. Thus, PET/CT is useful to guide biopsy by selecting sites with the BmSUV(max) when clinically appropriate.

Early treatment response evaluation in patients with diffuse large B-cell lymphoma--a pilot study comparing volumetric MRI and PET/CT.

PURPOSE: The purpose of this study is to evaluate the time course of early chemotherapy response in patients with aggressive non-Hodgkin's lymphoma (NHL) by magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT). PROCEDURES: Eight patients with histologically proven aggressive NHL were imaged by MRI and PET/CT before treatment (E1), 1 week (E2), and two cycles (E3) after chemotherapy. RESULTS: The mean tumor volume on MRI was 276 mL at baseline; it decreased 58% at E2 (p < 0.05) and 65% further at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean maximum standardized uptake value (SUV(max)) of 20. The SUV(max) decreased 60% at E2 (p < 0.05) and 59% further at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden (mean 229 mL) decreased 66% at E2 (p < 0.05). The tumor volume on MRI correlated with the active tumor volume on fused PET/CT images in the same region of interest at both E1 and E2 (r = 0.88, p < 0.01, respectively). CONCLUSIONS: Standard chemotherapy causes rapid decrease of both tumor metabolic activity and volume as early as 1 week, which continues to decline during therapy. Both volumetric MRI and PET/CT are valuable tools for early treatment response evaluation of aggressive NHL.

No correlation between glucose metabolism and apparent diffusion coefficient in diffuse large B-cell lymphoma: a PET/CT and DW-MRI study.

PURPOSE: Both positron emission tomography/computed tomography (PET/CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) are oncologic feasible techniques for evaluating the malignancy of tumors. Standardized uptake value (SUV) is a marker of tumor glucose metabolism detected by PET/CT. Apparent diffusion coefficient (ADC) measured by DWI can provide information about tissue cellularity. The aim of the study was to evaluate the correlation between SUV and ADC in untreated diffuse large B-cell lymphoma (DLBCL). MATERIALS AND METHODS: Fifteen pre-therapy patients with histologically proven DLBCL underwent PET/CT and DWI examinations within two days. Tumor glucose metabolism was evaluated by the maximum and mean SUV (SUV(max) and SUV(mean)) on the PET/CT images. The mean ADC value was measured directly on the parametric ADC maps. RESULTS: In total, 28 lymphoma lesions with best match PET/CT and DWI were identified and evaluated. The mean SUV(max) and SUV(mean) were 16.8 and 11.1, respectively; the mean ADC was 0.74 × 10(-3)mm(2)/s. There was no correlation between the mean ADC and the SUV(max) or SUV(mean). CONCLUSION: SUV determined from PET/CT and ADC value measured from DWI are different indices for the diagnosis of tumor malignancy, they may provide complimentary functional information of tumor tissue.