scholarly journals Impact of the Q.Clear reconstruction algorithm on the interpretation of PET/CT images in patients with lymphoma

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michał Wyrzykowski ◽  
Natalia Siminiak ◽  
Maciej Kaźmierczak ◽  
Marek Ruchała ◽  
Rafał Czepczyński
2020 ◽  
Author(s):  
Michał Wyrzykowski ◽  
Natalia Siminiak ◽  
Maciej Kaźmierczak ◽  
Marek Ruchała ◽  
Rafał Czepczyński

Abstract Background. Q.Clear is a new Bayesian penalised-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final response to treatment is evaluated, aim of the study was to systematically analyze the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma. Methods. 280 18F-FDG PET/CT scans in patients with lymphoma performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a lymphoma relapse was suspected (rPET) were retrospectively analyzed. Scans separately reconstructed with two algorithms: Q.Clear and OSEM were compared. Results. The lymphoma stage was concordantly diagnosed in 69/70 patients with both algorithms in sPET. Discordant assessment of Deauville score (p < 0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from negative to positive scan by Q.Clear resulted in case of 3 (4.3%) iPET scans and 7 (10.0%) ePET scans that resulted in alteration of management. Results of all 70 r-PET scans were concordant. SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than with OSEM in 88.8% scans. Conclusion. Although the Q.Clear algorithm may alter interpretation of PET/CT only in a small proportion of patients, we recommend to use standard OSEM reconstruction for assessment of treatment response.


2020 ◽  
Author(s):  
Michał Wyrzykowski ◽  
Natalia Siminiak ◽  
Maciej Kaźmierczak ◽  
Marek Ruchała ◽  
Rafał Czepczyński

Abstract Background. Q.Clear is a new Bayesian penalized-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases the SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final responses to treatment are evaluated. The aim of the study was to systematically analyse the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma.Methods. A total of 280 18F-FDG PET/CT scans in patients with lymphoma were performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a relapse of lymphoma was suspected (rPET). Scans were separately reconstructed with two algorithms, Q.Clear and OSEM, and further compared.Results. The stage of lymphoma was concordantly diagnosed in 69/70 patients with both algorithms on sPET. Discordant assessment of the Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from a negative to a positive scan by Q.Clear occurred in 3 cases (4.3%) of iPET scans and 7 cases (10.0%) of ePET. The results of all 70 r-PET scans were concordant. The SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than those measured with OSEM in 88.8% of scans. Conclusion. Although the Q.Clear algorithm may alter interpretations of PET/CT in only a small proportion of patients, we recommend using standard OSEM reconstruction for the assessment of treatment response.


2020 ◽  
Author(s):  
Michał Wyrzykowski ◽  
Natalia Siminiak ◽  
Maciej Kaźmierczak ◽  
Marek Ruchała ◽  
Rafał Czepczyński

Abstract Background. Q.Clear is a new Bayesian penalized-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final response to treatment is evaluated. The aim of the study was to systematically analyze the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma.Methods. 280 18F-FDG PET/CT scans in patients with lymphoma were performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a relapse of the lymphoma was suspected (rPET). Scans were separately reconstructed with two algorithms: Q.Clear and OSEM and further compared.Results. The stage of lymphoma was concordantly diagnosed in 69/70 patients with both algorithms in sPET. Discordant assessment of Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from negative to positive scan by Q.Clear resulted in 3 cases (4.3%) of iPET scans and 7 (10.0%) of ePET. Results of all 70 r-PET scans were concordant. SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than with OSEM in 88.8% scans. Conclusion. Although the Q.Clear algorithm may alter interpretation of PET/CT only in a small proportion of patients, we recommend to use standard OSEM reconstruction for the assessment of treatment response.


2020 ◽  
Author(s):  
Michał Wyrzykowski ◽  
Natalia Siminiak ◽  
Maciej Kaźmierczak ◽  
Marek Ruchała ◽  
Rafał Czepczyński

Abstract Background Q.Clear is a new Bayesian penalised-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final response to treatment is evaluated, aim of the study was to systematically analyze the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma. Methods 280 18 F-FDG PET/CT scans in patients with lymphoma performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a lymphoma relapse was suspected (rPET) were retrospectively analyzed. Scans separately reconstructed with two algorithms: Q.Clear and OSEM were compared. Results The lymphoma stage was concordantly diagnosed in 69/70 patients with both algorithms in sPET. Discordant assessment of Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from negative to positive scan by Q.Clear resulted in case of 3 (4.3%) iPET scans and 7 (10.0%) ePET scans that resulted in alteration of management. Results of all 70 r-PET scans were concordant. SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than with OSEM in 88.8% scans. Conclusion Although the Q.Clear algorithm may alter interpretation of PET/CT only in a small proportion of patients, we recommend to use standard OSEM reconstruction for assessment of treatment response.


2013 ◽  
Vol 54 (10) ◽  
pp. 1703-1709 ◽  
Author(s):  
N.-M. Cheng ◽  
Y.-H. Dean Fang ◽  
J. Tung-Chieh Chang ◽  
C.-G. Huang ◽  
D.-L. Tsan ◽  
...  

Author(s):  
Jieling Zheng ◽  
Huaning Chen ◽  
Kaixian Lin ◽  
Shaobo Yao ◽  
Weibing Miao
Keyword(s):  
Fdg Pet ◽  
Pet Ct ◽  
18F Fdg ◽  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Johan Economou Lundeberg ◽  
Jenny Oddstig ◽  
Ulrika Bitzén ◽  
Elin Trägårdh

Abstract Background Lung cancer is one of the most common cancers in the world. Early detection and correct staging are fundamental for treatment and prognosis. Positron emission tomography with computed tomography (PET/CT) is recommended clinically. Silicon (Si) photomultiplier (PM)-based PET technology and new reconstruction algorithms are hoped to increase the detection of small lesions and enable earlier detection of pathologies including metastatic spread. The aim of this study was to compare the diagnostic performance of a SiPM-based PET/CT (including a new block-sequential regularization expectation maximization (BSREM) reconstruction algorithm) with a conventional PM-based PET/CT including a conventional ordered subset expectation maximization (OSEM) reconstruction algorithm. The focus was patients admitted for 18F-fluorodeoxyglucose (FDG) PET/CT for initial diagnosis and staging of suspected lung cancer. Patients were scanned on both a SiPM-based PET/CT (Discovery MI; GE Healthcare, Milwaukee, MI, USA) and a PM-based PET/CT (Discovery 690; GE Healthcare, Milwaukee, MI, USA). Standardized uptake values (SUV) and image interpretation were compared between the two systems. Image interpretations were further compared with histopathology when available. Results Seventeen patients referred for suspected lung cancer were included in our single injection, dual imaging study. No statically significant differences in SUVmax of suspected malignant primary tumours were found between the two PET/CT systems. SUVmax in suspected malignant intrathoracic lymph nodes was 10% higher on the SiPM-based system (p = 0.026). Good consistency (14/17 cases) between the PET/CT systems were found when comparing simplified TNM staging. The available histology results did not find any obvious differences between the systems. Conclusion In a clinical setting, the new SiPM-based PET/CT system with a new BSREM reconstruction algorithm provided a higher SUVmax for suspected lymph node metastases compared to the PM-based system. However, no improvement in lung cancer detection was seen.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoichi Shimizu ◽  
Yukihiro Nakai ◽  
Hiroyuki Watanabe ◽  
Shimpei Iikuni ◽  
Masahiro Ono ◽  
...  

Abstract Background [18F]Fluoromisonidazole ([18F]FMISO) is a PET imaging probe widely used for the detection of hypoxia. We previously reported that [18F]FMISO is metabolized to the glutathione conjugate of the reduced form in hypoxic cells. In addition, we found that the [18F]FMISO uptake level varied depending on the cellular glutathione conjugation and excretion ability such as enzyme activity of glutathione-S-transferase and expression levels of multidrug resistance-associated protein 1 (MRP1, an efflux transporter), in addition to the cellular hypoxic state. In this study, we evaluated whether MRP1 activity affected [18F]FMISO PET imaging. Methods FaDu human pharyngeal squamous cell carcinoma cells were pretreated with MRP1 inhibitors (cyclosporine A, lapatinib, or MK-571) for 1 h, incubated with [18F]FMISO for 4 h under hypoxia, and their radioactivity was then measured. FaDu tumor-bearing mice were intravenously injected with [18F]FMISO, and PET/CT images were acquired at 4 h post-injection (1st PET scan). Two days later, the same mice were pretreated with MRP1 inhibitors (cyclosporine A, lapatinib, or MK-571) for 1 h, and PET/CT images were acquired (2nd PET scan). Results FaDu cells pretreated with MRP1 inhibitors exhibited significantly higher radioactivity than those without inhibitor treatment (cyclosporine A: 6.91 ± 0.27, lapatinib: 10.03 ± 0.47, MK-571: 10.15 ± 0.44%dose/mg protein, p < 0.01). In the in vivo PET study, the SUVmean ratio in tumors [calculated as after treatment (2nd PET scan)/before treatment of MRP1 inhibitors (1st PET scan)] of the mice treated with MRP1 inhibitors was significantly higher than those of control mice (cyclosporine A: 2.6 ± 0.7, lapatinib: 2.2 ± 0.7, MK-571: 2.2 ± 0.7, control: 1.2 ± 0.2, p < 0.05). Conclusion In this study, we revealed that MRP1 inhibitors increase [18F]FMISO accumulation in hypoxic cells. This suggests that [18F]FMISO-PET imaging is affected by MRP1 inhibitors independent of the hypoxic state.


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