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

Prognostic significance of metabolic tumor burden by positron emission tomography/computed tomography in patients with relapsed/refractory diffuse large B-cell lymphoma

The aim of the present study was to investigate the feasibility of measuring metabolic tumor burden using [F-18] fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) treated with bendamustine–rituximab. Because the standardized uptake value is a critical parameter of tumor characterization, we carried out a phantom study of ¹⁸F-FDG PET/CT to ensure quality control for 28 machines in the 24 institutions (Japan, 17 institutions; Korea, 7 institutions) participating in our clinical study. Fifty-five patients with relapsed or refractory DLBCL were enrolled. The ¹⁸F-FDG PET/CT was acquired before treatment, after two cycles, and after the last treatment cycle. Treatment response was assessed after two cycles and after the last cycle using the Lugano classification. Using this classification, remission was complete in 15 patients (27%) and incomplete in 40 patients (73%) after two cycles of therapy, and remission was complete in 32 patients (58%) and incomplete in 23 patients (42%) after the last treatment cycle. The percentage change in all PET/CT parameters except for the area under the curve of the cumulative standardized uptake value–volume histogram was significantly greater in complete response patients than in non-complete response patients after two cycles and the last cycle. The Cox proportional hazard model and best subset selection method revealed that the percentage change of the sum of total lesion glycolysis after the last cycle (relative risk, 5.24; P = 0.003) was an independent predictor of progression-free survival. The percent change of sum of total lesion glycolysis, calculated from PET/CT, can be used to quantify the response to treatment and can predict progression-free survival after the last treatment cycle in patients with relapsed or refractory DLBCL treated with bendamustine–rituximab.

Correlation of metabolic tumor volume and 11C-choline uptake with the pathology of prostate cancer: evaluation by use of simultaneously recorded MR and PET images

PURPOSE

This study was conducted to assess the relationship between (11)C-choline uptake and pathologic findings obtained by combined use of magnetic resonance (MR) and positron emission tomography (PET) imaging of patients with prostate cancer.

MATERIALS AND METHODS

We retrospectively evaluated 69 patients with prostate cancer who underwent (11)C-choline PET-CT and magnetic resonance imaging before radical prostatectomy. Combined MR-PET images were acquired to obtain precise anatomic information. The maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) were compared with pathologic findings from resected specimens as the reference standard.

RESULTS

The mean and standard deviation of tumor SUVmax and MTV were 3.9 ± 1.8 and 12.9 ± 16.4, respectively. Tumors with high MTV (≧8.2) were more likely to be admixed with prostatic intraepithelial neoplasia (PIN) (p < 0.0001) or hyperplasia (p < 0.0001) in the background than those without these findings. Multiple regression analysis also revealed that the presence of hyperplasia (OR; 4.25, 95% CI 1.25-14.4, p = 0.02) and PIN (OR; 9.22, 95% CI 2.60-32.7, p = 0.001) were associated with tumors with high MTV.

CONCLUSION

We have demonstrated, by pathologic evaluation of patients with prostate cancer, that (11)C-choline uptake volume is greater for prostate cancer admixed with PIN and hyperplasia than that without.

Whole-Body (18) FDG-PET in an Arthritis Paraneoplastic Syndrome Revealed an Underlying Hematological Neoplasm

We showed the first image of ¹⁸FDG-PET, which leads to a diagnosis of lymphoma in an atypical polyarthritis. About 4% of patients with lymphoma or leukemia suffered from rheumatologic paraneoplastic symptoms like arthralgia and about 10% of the patients with rheumatologic or neurologic clinical symptoms develop a solid cancer or hematological neoplasm. ¹⁸FDG-PET is an interesting exam to identify an underlying malignancy when a paraneoplastic syndrome is suspected; it can detect the primitive lesion and/or the metastasis lesions. The use of the ¹⁸FDG-PET can help to detect earlier hematological neoplasm in cases of paraneoplastic syndrome without a determined cause and to treat more rapidly and specifically the patient.

Diagnostic role of 18F-fluorodeoxyglucose positron emission tomography for follicular lymphoma with gastrointestinal involvement

AIM: To investigate the capacity for 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to evaluate patients with gastrointestinal lesions of follicular lymphoma.

METHODS: This retrospective case series consisted of 41 patients with follicular lymphoma and gastrointestinal involvement who underwent 18F-FDG-PET and endoscopic evaluations at ten different institutions between November 1996 and October 2011. Data for endoscopic, radiological, and biological examinations performed were retrospectively reviewed from clinical records. A semi-quantitative analysis of 18F-FDG uptake was performed for each involved area by calculating the maximum standardized uptake value (SUVmax). Based on the positivity of 18F-FDG uptake in the gastrointestinal lesions analyzed, patients were subdivided into two groups. To identify potential predictive factors for 18F-FDG positivity, these two groups were compared with respect to gender, age at diagnosis of lymphoma, histopathological grade, pattern of follicular dendritic cells, mitotic rate, clinical stage, soluble interleukin-2 receptor levels detected by 18F-FDG-PET, lactate dehydrogenase (LDH) levels, hemoglobin levels, bone marrow involvement, detectability of gastrointestinal lesions by computed tomography (CT) scanning, and follicular lymphoma international prognostic index (FLIPI) risk.

RESULTS: Involvement of follicular lymphoma in the stomach, duodenum, jejunum, ileum, cecum, colon, and rectum was identified in 1, 34, 6, 3, 2, 3, and 6 patients, respectively. No patient had esophageal involvement. In total, 19/41 (46.3%) patients exhibited true-positive 18F-FDG uptake in the lesions present in their gastrointestinal tract. In contrast, false-negative 18F-FDG uptake was detected in 24 patients (58.5%), while false-positive 18F-FDG uptake was detected in 5 patients (12.2%). In the former case, 2/19 patients had both 18F-FDG-positive lesions and 18F-FDG-negative lesions in the gastrointestinal tract. In patients with 18F-FDG avidity, the SUVmax value of the involved gastrointestinal tract ranged from 2.6 to 17.4 (median: 4.7). For the 18F-FDG-negative (n = 22) and -positive (n = 19) groups, there were no differences in the male to female ratios (10/12 vs 4/15, P = 0.186), patient age (63.6 ± 2.4 years vs 60.1 ± 2.6 years, P = 0.323), presence of histopathological grade 1 vs 2 (20/2 and 17/2, P = 1.000), follicular dendritic cell pattern (duodenal/nodal: 13/5 vs 10/3, P = 1.000), mitotic rate (low/partly high, 14/1 vs 10/3, P = 0.311), clinical stage according to the Ann Arbor system (stages IE and IIE/other, 15/7 vs 15/4, P = 0.499), clinical stage according to the Lugano system (stages I and II-1/other, 14/8 vs 14/5, P = 0.489), soluble interleukin-2 receptor levels (495 ± 78 vs 402 ± 83, P = 0.884), LDH levels (188 ± 7 vs 183 ± 8, P = 0.749), hemoglobin levels (13.5 ± 0.3 vs 12.8 ± 0.4, P = 0.197), bone marrow involvement (positive/negative, 1/8 vs 1/10, P = 1.000), detectability by CT scanning (positive/negative, 1/16 vs 4/13, P = 0.335), and FLIPI risk (low risk/other, 16/6 vs 13/6, P = 0.763), respectively in each case.

CONCLUSION: These findings indicate that it is not feasible to predict 18F-FDG-avidity. Therefore, 18F-FDG-PET scans represent a complementary modality for the detection of gastrointestinal involvements in follicular lymphoma patients, and surveillance of the entire gastrointestinal tract by endoscopic examinations is required.