scholarly journals Positron Emission Tomography as a Surrogate Marker for Evaluation of Treatment Response in Patients with Desmoid Tumors under Therapy with Imatinib

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bernd Kasper ◽  
Antonia Dimitrakopoulou-Strauss ◽  
Lothar R. Pilz ◽  
Ludwig G. Strauss ◽  
Christos Sachpekidis ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Progressive Disease ◽  
Surrogate Marker ◽  
Standardized Uptake Value ◽  
Response Prediction ◽  
Emission Tomography ◽  
Desmoid Tumors ◽  
Positron Emission ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri

We used 2-deoxy-2-[18F] fluoro-D-glucose (FDG) positron emission tomography (PET) to evaluate patients with desmoid tumors undergoing therapy with imatinib. The study included 22 patients with progressive disease (PD) of a biopsy proven desmoid tumor treated orally with imatinib 800 mg daily. Patients were examined using PET prior to onset of therapy and during treatment. Restaging was performed in parallel using computed tomography (CT) and/or magnetic resonance imaging (MRI). Outcome of 22 evaluable patients was as follows: five patients with partial response (PR); twelve patients with stable disease (SD) accounting for 77% with non-progressive disease; five patients showed PD. A 30% decrease of the mean average standardized uptake value (SUV) of sequential PET examinations could be demonstrated; no patient demonstrated a substantial increase in SUV. Patients with PR/SD were matched to a group of nonprogressive disease and tested versus PD. The initial average SUV and seem to be candidates for a response prediction with an approximate -value of0.06553and0.07785, respectively. This is the first larger series of desmoid patients monitored using PET showing that early SUV changes may help to discriminate responders from nonresponders and, thus, to decide whether imatinib therapy should be continued.

Usefulness of positron emission tomography for differentiating gliomas according to the 2016 World Health Organization classification of tumors of the central nervous system

2020 ◽  
Vol 133 (4) ◽  
pp. 1010-1019 ◽  
Author(s):  
Hiroaki Takei ◽  
Jun Shinoda ◽  
Soko Ikuta ◽  
Takashi Maruyama ◽  
Yoshihiro Muragaki ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Who Classification ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
World Health ◽  
Pet Tracers ◽  
Positron Emission ◽  
Significant Difference ◽  
The Mean

OBJECTIVEPositron emission tomography (PET) is important in the noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 WHO classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification). Here, the authors investigated the relationship between uptake of 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) on PET imaging and isocitrate dehydrogenase (IDH) status (wild-type [IDH-wt] or mutant [IDH-mut]) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.METHODSIn total, 105 patients with newly diagnosed cerebral gliomas (6 diffuse astrocytomas [DAs] with IDH-wt, 6 DAs with IDH-mut, 7 anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, 5 GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake value (SUV) of the tumor/mean SUV of normal cortex (T/N) ratios for MET, CHO, and FDG were calculated, and the mean T/N ratios of DA, AA, and GBM with IDH-wt and IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the 3 PET tracers.RESULTSThere were significant differences in the mean T/N ratios for all 3 PET tracers between the IDH-wt and IDH-mut groups of all histological classifications (p < 0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all 3 PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all 3 PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p < 0.01). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that in the IDH-mut group for both MET (p = 0.034) and CHO (p = 0.01). However, there was no significant difference in the ratio for FDG.CONCLUSIONSPET imaging using MET, CHO, and FDG was suggested to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.

The Relevance of Increased Tonsil Uptake When Restaging Lymphoma with Positron Emission Tomography

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3133-3133
Author(s):  
Javier Munoz ◽  
Belisario Arango ◽  
Jessica Schering ◽  
James Morrison ◽  
Ishani Dalal ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Conflicts Of Interest ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
Invasive Approach ◽  
Fdg Uptake ◽  
Tonsillar Tissue ◽  
Positron Emission ◽  
Lymphomatous Involvement ◽  
The Mean

Abstract Abstract 3133 Introduction: Significant tonsil uptake is sometimes observed in F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) after treatment. Some patients undergo tonsillectomy or FNA (fine needle aspiration) to rule out malignant involvement particularly when management depends on restaging (Figure 1). Our study describes the incidence and degree of tonsil FDG uptake in a large group of lymphoma patients that underwent PET scanning. Patients and Methods: Single institution, retrospective chart review by ICD code, 617 lymphoma patients that underwent PET at our institution from 2004 to 2009. Results of PET were compared to pathological diagnosis of tonsillectomy (Table 1) or FNA biopsy (Table 2) when available which was performed at physician's discretion. Patients that were diagnosed with lymphoma during restaging studies performed for a different primary malignancy were excluded. Results and Discussion: All 8 tonsillectomies and FNA biopsies performed after a restaging PET that showed increased tonsil uptake were negative for malignancy (Figure 2). All of these 8 patients had an initial previous PET that did not show increased tonsil uptake and also these 8 patients remained in remission from their lymphoma after the procedure was performed. In contrast, 6 out of 7 patients that underwent tonsillectomy or FNA at diagnosis were positive for malignancy (Table 3). Differences among tonsil FDG uptake has been thought to reflect differences in activity of “physiological” inflammation of the palatine tonsils. Increased glucose metabolism during active inflammation in the case of chronic tonsillitis or lymphocyte proliferation in the case of a patient that has received prior chemotherapy (likely experiencing compensatory extra medullar lymphoid hyperplasia) were thought to be causes of high FDG uptake in the tonsils. The significance of such increased tonsil FDG uptake is currently unknown however previous studies suggest that normal pharyngeal palatine tonsil uptake was generally symmetrical and that the difference in maximal standardized uptake value (SUVmax) between right and left tonsils (right-to-left ratio or a surrogate of symmetry) in the same patient might be helpful in detecting malignant tissue. The mean right-to-left ratio of tonsillar SUV was 4.55 in patients with confirmed malignant pathology and 1.53 in patients with documented benign tonsillar tissue (Table 4). The mean tonsillar SUVmax was 15.35 in patients with confirmed malignant pathology and 7.05 in patients with documented benign tonsillar tissue hence SUVmax seems to be useful in differentiating tumor from physiological accumulation. Younger patients with low SUV max symmetric tonsillar uptake and no other abnormal FDG areas seen during restaging PET could probably be watched non-invasively. Conclusions: At the time of initial staging PET, increased tonsil uptake showed true lymphomatous involvement in most cases. At restaging, increased tonsil uptake displayed no cases positive for lymphomatous involvement as all tonsillectomies and FNA biopsies were negative for malignancy. These findings seem to be valid irrespective of the subtype of lymphoma. Our study supports a conservative non-invasive approach because physiologic uptake is the most common cause of increased tonsil uptake when restaging lymphoma patients after treatment has been completed. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Posterior acetabular uptake on 18F-fluoride positron emission tomography/computed tomography reveals a putative contrecoup region in patients with femoroacetabular impingement

2019 ◽  
Vol 27 (3) ◽  
pp. 230949901986892
Author(s):  
Takayuki Oishi ◽  
Naomi Kobayashi ◽  
Hyonmin Choe ◽  
Taro Tezuka ◽  
Daigo Kobayashi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
Study Cohort ◽  
Entire Study ◽  
Positron Emission ◽  
Pet Ct ◽  
The Mean ◽  
Cam Morphology

Background and purpose: The pathology of the posterior acetabular lesions, so-called “contrecoup regions”, in femorocacetabular impingement (FAI) has not been elucidated fully. 18F-fluoride positron emission tomography/computed tomography (PET/CT) can visualize abnormal uptake caused by impingement. Therefore, we aimed to evaluate posterior acetabular uptake on PET/CT in FAI patients. Patients and methods: Patients with FAI who underwent 18F-fluoride PET/CT between October 2014 and October 2016 were retrospectively evaluated. The maximum standardized uptake value (SUVmax) in the posterior acetabulum was evaluated. The mean SUVmax of FAI with cam morphology (the cam group) was compared with that of FAI with pincer morphology (the pincer group). In addition, the numbers of cases with SUVmax ≥ 6 and SUVmax < 6 in each group were evaluated. The entire study cohort was also grouped according to SUVmax, and the mean α and center edge angles were evaluated. Results: In total, 41 hips were analyzed (34 hips in the cam group and 7 in the pincer group). The mean SUVmax of the cam group (11.2 ± 7.4) was significantly higher than that of the pincer group (4.9 ± 1.9) ( p < 0.01). The incidence of cases with SUVmax ≥ 6 in the cam group was significantly high ( p < 0.01). In the overall cohort, the mean α angle of the SUVmax ≥ 6 group was significantly higher than that of the SUVmax < 6 group ( p < 0.01). Conclusion: Evaluation of posterior acetabular uptake suggests an association between cam morphology and increased posterior acetabular uptake.

scholarly journals Imaging Assessment of Tumor Response in the Era of Immunotherapy

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1041
Author(s):  
Jun Nakata ◽  
Kayako Isohashi ◽  
Yoshihiro Oka ◽  
Hiroko Nakajima ◽  
Soyoko Morimoto ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Solid Tumors ◽  
False Positive ◽  
Progressive Disease ◽  
Tumor Response ◽  
Metabolic Response ◽  
Evaluation Criteria ◽  
Emission Tomography ◽  
Response Criteria ◽  
Positron Emission

Assessment of tumor response during treatment is one of the most important purposes of imaging. Before the appearance of immunotherapy, response evaluation criteria in solid tumors (RECIST) and positron emission tomography response criteria in solid tumors (PERCIST) were, respectively, the established morphologic and metabolic response criteria, and cessation of treatment was recommended when progressive disease was detected according to these criteria. However, various types of immunotherapy have been developed over the past 20 years, which show novel false positive findings on images, as well as distinct response patterns from conventional therapies. Antitumor immune response itself causes 18F-fluorodeoxyglucose (FDG) uptake in tumor sites, known as “flare phenomenon”, so that positron emission tomography using FDG can no longer accurately identify remaining tumors. Furthermore, tumors often initially increase, followed by stability or decrease resulting from immunotherapy, which is called “pseudoprogression”, so that progressive disease cannot be confirmed by computed tomography or magnetic resonance imaging at a single time point. As a result, neither RECIST nor PERCIST can accurately predict the response to immunotherapy, and therefore several new response criteria fixed for immunotherapy have been proposed. However, these criteria are still controversial, and also require months for response confirmation. The establishment of optimal response criteria and the development of new imaging technologies other than FDG are therefore urgently needed. In this review, we summarize the false positive images and the revision of response criteria for each immunotherapy, in order to avoid discontinuation of a truly effective immunotherapy.

Hyperosmolar blood-brain barrier disruption in baboons: an in vivo study using positron emission tomography and rubidium-82

1996 ◽  
Vol 84 (3) ◽  
pp. 494-502 ◽  
Author(s):  
Bernhard Zünkeler ◽  
Richard E. Carson ◽  
Jeffrey Olson ◽  
Ronald G. Blasberg ◽  
Mary Girton ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Brain Tumors ◽  
Blood Brain Barrier ◽  
Emission Tomography ◽  
Brain Barrier ◽  
Blood Brain ◽  
Positron Emission ◽  
The Mean ◽  
Rubidium 82

✓ Hyperosmolar blood-brain barrier (BBB) disruption remains controversial as an adjuvant therapy to increase delivery of water-soluble compounds to extracellular space in the brain in patients with malignant brain tumors. To understand the physiological effects of BBB disruption more clearly, the authors used positron emission tomography (PET) to study the time course of BBB permeability in response to the potassium analog rubidium-82 (82Rb, halflife 75 seconds) following BBB disruption in anesthetized adult baboons. Mannitol (25%) was injected into the carotid artery and PET scans were performed before and serially at 8- to 15-minute intervals after BBB disruption. The mean influx constant (K1), a measure of permeability-surface area product, in ipsilateral, mannitol-perfused mixed gray- and white-matter brain regions was 4.9 ± 2.4 µl/min/ml (± standard deviation) at baseline and increased more than 100% (ΔK1 = 9.4 ± 5.1 µl/min/ml, 18 baboons) in brain perfused by mannitol. The effect of BBB disruption on K1 correlated directly with the total amount of mannitol administered (p < 0.005). Vascular permeability returned to baseline with a halftime of 24.0 ± 14.3 minutes. The mean brain plasma volume rose by 0.57 ± 0.34 ml/100 ml in ipsilateral perfused brain following BBB disruption. This work provides a basis for the in vivo study of permeability changes induced by BBB disruption in human brain and brain tumors.

scholarly journals Density Estimation for Positron Emission Tomography

2005 ◽  
Vol 4 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Barbara Pawlak ◽  
Richard Gordon
Keyword(s):  
Positron Emission Tomography ◽  
Density Estimation ◽  
3D Imaging ◽  
Diagnostic Techniques ◽  
Emission Tomography ◽  
Experimental Phase ◽  
Positron Emission ◽  
Coincidence Event ◽  
The Mean ◽  
Traditional Approaches

PET (positron emission tomography) scans are still in the experimental phase, as one of the newest breast cancer diagnostic techniques. There are two traditional approaches to the computation of images from data collected in PET. In the first, standard CT (computed tomography) algorithms are used on rays designated by pairs of detectors receiving coincidence events. The problem generated by this approach is that generally only the mean can be used by such algorithms. With the relatively small numbers of events in PET, and with Poisson statistics for which variance equals the mean, the noise sensivity of standard CT algorithms becomes limiting. This is exasperated further by 3D imaging with cylindrical arrays of detectors. Statistical CT algorithms take the variance into account. As in the list-mode approach, we consider each coincidence event individually. However, we estimate the location of the annihilation event that caused each coincidence event, one by one, based on the previously assigned location of events processed earlier. The estimated annihilation locations form the image. To accomplish this, we construct a probability distribution along each coincidence line. This is generated from previous annihilation points by density estimation. In this paper we present our density estimation approach to positron emission tomography. Nonparametric methods of density estimation are overviewed followed by numerical examples. Our goal here is to determine which density estimation approach is most suitable for PET.

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