Evaluation of thoracic tumors with 18F‐FMT and 18F‐FDG PET‐CT: A clinicopathological study

L‐[3‐¹⁸F]‐α‐methyltyrosine (¹⁸F‐FMT) is an aminoacid tracer for positron emission tomography (PET). The aim of this study was to determine whether PET‐CT with ¹⁸F‐FMT provides additional information for the preoperative diagnostic workup as compared with ¹⁸F‐FDG PET. PET‐CT studies with ¹⁸F‐FMT and ¹⁸F‐FDG were performed as a part of the preoperative workup in 36 patients with histologically confirmed bronchial carcinoma, 6 patients with benign lesions and a patient with atypical carcinoid. Expression of L‐type amino acid transporter 1 (LAT1), CD98, Ki‐67 labeling index, VEGF, CD31 and CD34 of the resected tumors were analyzed by immunohistochemical staining, and correlated with the uptake of PET tracers. For the detection of pulmonary malignant tumors, ¹⁸F‐FMT PET exhibited a sensitivity of 84% whereas the sensitivity for ¹⁸F‐FDG PET was 89% (p = 0.736). ¹⁸F‐FMT PET‐CT and ¹⁸F‐FDG PET‐CT agreed with pathological staging in 85 and 68%, respectively (p = 0.151). ¹⁸F‐FMT uptake was closely correlated with LAT1, CD98, cell proliferation and angiogenesis. The specificity of ¹⁸F‐FMT PET for diagnosing thoracic tumors was higher than that of ¹⁸F‐FDG PET. Our results suggest that coexpression of LAT1 and CD98 in addition to cell proliferation and angiogenesis is relavant for the progression and metastasis of lung cancer. © 2008 Wiley‐Liss, Inc.     

18F‐Fluorodeoxyglucose positron emission tomography/computed tomography for the detection of recurrent bone and soft tissue sarcoma

BACKGROUND:

The clinical utility of modern hybrid imaging modalities for detecting recurrent bone or soft tissue sarcoma remains to be determined. In this report, the authors present a clinical study on the diagnostic accuracy and incremental value of integrated ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in patients with a history of sarcoma who have clinically suspected disease recurrence.

METHODS:

Forty‐three patients who had a history of bone or soft tissue sarcoma and had documented complete remission underwent ¹⁸F‐FDG PET/CT. Image analysis was performed independently for ¹⁸F‐FDG PET (n = 43) and for contrast‐enhanced spiral CT (CE‐CT) (n = 30) by 2 separate readers, whereas combined ¹⁸F‐FDG PET/CT (n = 43) images were analyzed in consensus by both readers. Imaging findings were rated on a 5‐point scale and finally were reported as malignant, benign, or equivocal. Imaging findings were validated either by histopathology (n = 24) or by clinical follow‐up (n = 19).

RESULTS:

¹⁸F‐FDG PET/CT had greater sensitivity and specificity compared with CE‐CT alone (94% and 92% vs 78% and 67%, respectively), resulting in significantly greater accuracy (93% vs 73%; P = .03). ¹⁸F‐FDG PET/CT was particularly superior regarding detection of local recurrence or soft tissue lesions (sensitivity and specificity: 83% and 100% vs 50% and 100%, respectively) or bone metastases (100% and 100% vs 85% and 88%, respectively).

CONCLUSIONS:

¹⁸F‐FDG PET/CT had greater diagnostic accuracy in the detection of recurrent bone or soft tissue sarcoma compared with CE‐CT alone. The detection of local recurrence was the most evident advantage of ¹⁸F‐FDG PET/CT over CE‐CT. Cancer 2013. © 2012 American Cancer Society.     

Dual‐tracer PET/CT scan after injection of combined [18F]NaF and [18F]FDG outperforms MRI in the detection of myeloma lesions

The detection rates of whole‐body combined [¹⁸F]NaF/[¹⁸F]FDG positron emission tomography combined with computed tomography (PET/CT), CT alone, whole‐body magnetic resonance imaging (WB‐MRI), and X‐ray were prospectively studied in patients with treatment‐requiring plasma cell disorders The detection rates of imaging techniques were compared, and focal lesions were classified according to their anatomic location. Twenty‐six out of 30 initially included patients were assessable. The number of focal lesions detected in newly diagnosed patients (n = 13) and in relapsed patients (n = 13) were 296 and 234, respectively. The detection rate of PET/CT was significantly higher than those of WB‐MRI (P < 0.05) and CT (P < 0.0001) both in patients with newly diagnosed and in those with relapsed multiple myeloma (MM). The X‐ray detection rate was significantly lower than those of all other techniques, while CT detected more lesions compared with WB‐MRI at diagnosis (P = 0.025). With regard to the infiltration patters, relapsed patients presented more diffuse patterns, and more focal lesions located in the limbs compared with newly diagnosed patients. In conclusion, the detection rate of [¹⁸F]NaF/[¹⁸F]FDG PET/CT was significantly higher than those of CT, MRI, and X‐ray, while the detection rate of X‐rays was significantly lower than those of all other imaging techniques except for focal lesions located in the skull.     

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non–small‐cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non–small‐cell lung cancer (NSCLC) patients. The aim of this meta‐analysis was to assess the diagnostic value of ¹⁸F‐FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta‐analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver‐operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65–0.78] and 0.91 (95% CI: 0.86–0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60–0.80) and 0.83 (95% CI: 0.77–0.88) in intrathoracic staging; 0.78 (95% CI: 0.64–0.87) and 0.90 (95% CI: 0.84–0.94) in intrathoracic staging on a per‐node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of ¹⁸F‐FDG PET/CT were 0.77 (95% CI: 0.47–0.93) and 0.95 (95% CI: 0.92–0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80–0.97) and 0.98 (95% CI: 0.94–0.99) for bone metastases. ¹⁸F‐FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. ¹⁸F‐FDG PET/CT confers significantly higher sensitivity and specificity than contrast‐enhanced CT (both p < 0.01) and higher sensitivity than ¹⁸F‐FDG PET in staging NSCLC (p < 0.05).     

A prospective evaluation of the utility of 2‐deoxy‐2‐[18F]fluoro‐D‐glucose positron emission tomography and computed tomography in staging locally advanced gastric cancer

BACKGROUND:

The aim of this study was to examine prospectively the utility of adding preoperative [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG‐PET)/computed tomography (CT) to routine CT, endoscopic ultrasound (EUS), and laparoscopic staging of localized gastric cancer.

METHODS:

Patients with locally advanced gastric/gastroesophageal cancer were screened for 2 institutional review board–approved Memorial Sloan‐Kettering Cancer Center neoadjuvant chemotherapy protocols. Locally advanced disease was defined as T3 or T4, or lymph node–positive, based on EUS and high‐resolution CT scan. All patients underwent both standard FDG‐PET/CT and laparoscopy with cytological examination of washings. The sensitivity and specificity of FDG‐PET/CT for the identification of metastatic disease not seen on CT was determined. An economic model using Medicare/Medicaid reimbursement charges was developed to assess the cost‐effectiveness of these interventions.

RESULTS:

A total of 113 patients were enrolled from 2003 to 2010. All patients were assessed as having locally advanced disease by CT/EUS. FDG uptake in the primary tumor was associated with male sex, proximal tumors, and nondiffuse Lauren's subtype. 31 (27%) patients had occult metastatic disease detected by PET/CT (n = 11, 10%) and/or laparoscopy (n = 21, 19%), with a single overlap. Economic modeling suggests that the addition of FDG‐PET/CT to the standard staging evaluation of patients with locally advanced gastric cancer resulted in an estimated cost savings of ～US $13,000 per patient.

CONCLUSIONS:

FDG‐PET/CT identifies occult metastatic lesions in approximately 10% of patients with locally advanced gastric cancer. Because of reduced morbidity from fewer futile surgeries and lower patient care costs, PET/CT should be considered as a component of the standard staging algorithm for localized gastric cancer. Cancer 2012. © 2012 American Cancer Society.     

Prognostic value of 18F‐fluoroazomycin arabinoside PET/CT in patients with advanced non‐small‐cell lung cancer

This study evaluated the prognostic value of positron emission tomography/computed tomography (PET/CT) using ¹⁸F‐fluoroazomycin arabinoside (FAZA) in patients with advanced non‐small‐cell lung cancer (NSCLC) compared with ¹⁸F‐fluorodeoxyglucose (FDG). Thirty‐eight patients with advanced NSCLC (stage III, 23 patients; stage IV, 15 patients) underwent FAZA and FDG PET/CT before treatment. The PET parameters (tumor‐to‐muscle ratio [T/M] at 1 and 2 h for FAZA, maximum standardized uptake value for FDG) in the primary lesion and lymph node (LN) metastasis and clinical parameters were compared concerning their effects on progression‐free survival (PFS) and overall survival (OS). In our univariate analysis of all patients, clinical stage and FAZA T/M in LNs at 1 and 2 h were predictive of PFS (P = 0.021, 0.028, and 0.002, respectively). Multivariate analysis also indicated that clinical stage and FAZA T/M in LNs at 1 and 2 h were independent predictors of PFS. Subgroup analysis of chemoradiotherapy‐treated stage III patients revealed that only FAZA T/M in LNs at 2 h was predictive of PFS (P = 0.025). The FDG PET/CT parameters were not predictive of PFS. No parameter was a significant predictor of OS. In patients with advanced NSCLC, FAZA uptake in LNs, but not in primary lesions, was predictive of treatment outcome. These results suggest the importance of characterization of LN metastases in advanced NSCLC patients.     

Prognostic role of baseline 18F‐FDG PET/CT parameters in MALT lymphoma

Mucosa‐associated lymphoid tissue (MALT) lymphoma is an indolent lymphoma with good prognosis and variable fluorine‐18 fluorodeoxyglucose (¹⁸F‐FDG) avidity. Many possible prognostic factors have been investigated with controversial results, but the possible prognostic role of ¹⁸F‐FDG positron emission tomography/computed tomography (PET/CT) remains unclear. Our aim was to evaluate the prognostic impact of qualitative and semiquantitative baseline PET/CT parameters on outcome of MALT lymphoma. We retrospectively enrolled 161 patients with histologically confirmed MALT lymphoma who underwent ¹⁸F‐FDG PET/CT before any treatment. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan‐Meier method was used to estimate the progression‐free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determine the relation between PET/CT features and OS and PFS. Ninety‐eight patients had positive ¹⁸F‐FDG PET/CT showing ¹⁸F‐FDG uptake (mean SUVbw, 10.1; SUVlbm, 7.2; SUVbsa, 2.7; MTV, 88.8; and TLG, 526); the remaining 63 were not ¹⁸F‐FDG avid. ¹⁸F‐FDG avidity was significantly correlated with tumor size and Ki‐67 score. Relapse/progression of disease occurred in 47 patients with an average time of 40.2 months; death occurred in 12 patients with an average of 59 months. At a median follow‐up of 62 months, median PFS and OS were 52 and 62 months, respectively. Advanced tumor stage and extragastric site were demonstrated to be independent prognostic factors for PFS, while only tumor stage for OS. Instead, PET/CT parameters were not related to survival, despite positive correlation at univariate analysis between MTV and TLG with PFS and positive PET/CT with PFS and OS. In conclusion, a 61% rate of PET avidity in biopsy‐confirmed MALT lymphoma was found, and it was correlated with tumor size and Ki‐67 score. Only tumor stage and localization were independently correlated with PFS and OS.     

Comparison of magnetic resonance spectroscopy and positron emission tomography in detection of tumor recurrence in posttreatment of glioma: A diagnostic meta‐analysis

It is important to distinguish between tumor recurrence and treatment effects in posttreatment patients with high‐grade gliomas. Several imaging modalities have been reported in differentiating between tumor recurrence and treatment effects. However, there were no consistent conclusions between different studies. We performed a meta‐analysis of 23 studies that compared the diagnostic values of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) and ¹¹C‐methionine (¹¹C‐MET) PET (positron emission tomography) or PET/CT (computed tomography) and magnetic resonance spectroscopy (MRS) in predicting tumor recurrence of gliomas. The pooled estimated sensitivity, specificity, positive likelihood ratios, negative likelihood ratios and summary receiver operating characteristic curves of ¹⁸F‐FDG and ¹¹C‐MET PET or PET/CT and MRS in detecting tumor recurrence were calculated. In conclusion, MRS is highly sensitive in the detection of tumor recurrence in glioma.¹⁸F‐FDG PET or PET/CT is highly specific in recurrence diagnosis. ¹¹C‐MET does not have noticeable advantage over ¹⁸F‐FDG. The current evidence shows no statistical difference between MRS and PET on the accuracy.     

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.     

Imaging with F‐18 FDG PET is superior to Tl‐201 SPECT in the staging of non‐small cell lung cancer for radical radiation therapy*

Thallium‐201 (Tl‐201) single photon emission computed tomography (SPECT) is funded for evaluation of malignancy in Australia and may have utility for staging of non‐small cell lung cancer (NSCLC) if CT results are equivocal. Fluorine‐18 fluorodeoxyglucose (F‐18 FDG) positron emission tomography (PET) is superior to CT for staging NSCLC but is more expensive and less widely available than Tl‐201 SPECT. Therefore, these techniques were prospectively compared in 27 radical radiation therapy candidates. Patients were allocated a conventional, PET and Tl‐201 stage. Tumour to background ratios (TBR) were recorded for the primary on both techniques. Metastatic disease was confirmed by surgical pathology, serial imaging or clinical follow up. Tumour to background ratios were consistently higher for FDG PET than Tl‐201 SPECT (P < 0.0001). Positron emission tomography detected all known primary tumours but Tl‐201 failed to image four primary tumours (15%). In 10 of 18 cases of discordance between PET and Tl‐201 SPECT regarding stage, corroboration was available from pathology or disease progression. Positron emission tomography was shown to have a 100% positive predictive value, including all three patients with PET‐detected distant metastases (P = 0.002). Results indicate that PET is superior to Tl‐201 SPECT scanning in the staging of NSCLC for radical radiation therapy, and that the low sensitivity for detection of local and metastatic disease is likely to limit the clinical impact and cost‐effectiveness of this technique despite its lower cost.     

18F‐FDG PET/CT vs. human papillomavirus,p16 and Epstein–Barr virus detection in cervical metastatic lymph nodes for identifying primary tumors

Squamous cell carcinoma of unknown primary of the head and neck (SCCUP) is a heterogeneous disease entity that requires careful examination to locate the occult primary. We examined the diagnostic value of expression of biomarkers, such as human papillomavirus (HPV), p16 and Epstein–Barr virus (EBV), in metastatic lymph nodes vs. ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography/computed tomography (PET/CT). We prospectively enrolled 54 consecutive SCCUP patients who received HPV, p16 and EBV analyses of lymph node fine‐needle aspirates and ¹⁸F‐FDG PET/CT scans and subsequently underwent examinations and biopsies under general anesthesia to detect primary tumors. The diagnostic performance of the biomarkers and ¹⁸F‐FDG PET/CT were compared by using receiver operating characteristics (ROC) curve analyses with histopathological results for identification of primary tumors. Primary tumors were identified in 28 (51.9%) of 54 patients: the palatine tonsil in 24, base of the tongue in 1, nasopharynx in 2, and hypopharynx in 1. The sensitivity of p16 (85.7%) and accuracy of HPV (85.2%) were higher than those (42.9% and 68.5%) of ¹⁸F‐FDG PET/CT (p < 0.05). The area under the ROC curve of HPV was higher than that of ¹⁸F‐FDG PET/CT (0.857 vs. 0.666, p = 0.007). The disease‐free survival rates were higher in the patients with primary tumor detection or p16 nodal immunopositivity than in the other patients (p < 0.05). The results showed that HPV and p16 detection in metastatic lymph nodes can help locate hidden primary tumors, guide definitive treatment and predict patient survival.     

18F‐FDG uptake and its clinical relevance in primary gastric lymphoma

We studied the clinical relevance of ¹⁸F‐fluorodeoxyglucose (¹⁸F‐FDG) uptake in patients with primary gastric lymphoma underwent positron emission tomography (PET)/ computed tomography (CT) scan. Forty‐two patients with primary gastric lymphoma were analysed: 32 diffuse large B‐cell lymphomas (DLBCL) and 10 extranodal marginal zone B‐cell lymphomas of mucosa‐associated lymphoid tissue (MALT lymphomas). The PET/CT scans were compared with clinical and pathologic features, and the results of CT and endoscopy. Nine patients were up‐staged based on the results of their PET/CT scan compared to CT (seven DLBCLs, two MALT lymphomas) while six patients were down‐staged by the PET/CT scan. The standard uptake value (SUV) was used as an indicator of a lesion with a high metabolic rate. The high SUVmax group, defined as an SUVmax ≥ median value, was significantly associated with an advanced Lugano stage (p < 0.001). Three patients with DLBCL, who showed an initially high SUVmax, died of disease progression. Among 24 patients for whom follow‐up PET/CT scan with endoscopy was performed, 11 patients with ulcerative or mucosal lesions showed residual ¹⁸F‐FDG uptake. All of these gastric lesions were grossly and pathologically benign lesions without evidence of lymphoma cells. In conclusion, PET/CT scan can be used in staging patients with primary gastric lymphoma; however, the residual ¹⁸F‐FDG uptake observed during follow‐up should be interpreted cautiously and should be combined with endoscopy and multiple biopsies of the stomach. Copyright © 2009 John Wiley & Sons, Ltd.     

Prevalence of non 18F‐fluorodeoxyglucose‐avid incidental findings of clinical significance on whole body positron emission tomography/computed tomography: A review of 500 consecutive cases

Introduction

The prevalence of incidental ¹⁸F‐fluorodeoxyglucose (FDG)‐avid findings on positron emission tomography–computed tomography (PET/CT) has been extensively described. Few studies, however, have assessed the prevalence and significance of non‐FDG‐avid findings; pathology that is identified on review of the low‐dose, non‐contrast CT. The aim of this study was to determine the overall prevalence of non FDG‐avid incidental findings on PET/CT and the prevalence of ‘clinically significant’ non FDG‐avid pathology.

Methods

Five hundred consecutive whole body PET/CT studies performed in 2016 at a university affiliated tertiary hospital were retrospectively reviewed by two radiologists experienced in reporting PET/CT. Findings were categorized according to potential clinical relevance, and a targeted follow‐up of clinically significant incidental findings was performed.

Results

Incidental findings were encountered in 463 of 500 (92.6%) patients. In 226 patients, these findings had been detected on previous imaging studies, with unknown incidental findings present in 237 of 500 (47.4%) patients. 113 of 500 (22.6%) patients had non‐avid incidental findings of potentially major clinical significance, and in 35 patients (7.0%) these findings were considered previously unknown. The most common non‐avid findings of potentially major significance were pulmonary nodules (6 mm or larger), moderate or large size pleural effusions, and vascular aneurysms. Unknown incidental findings of potentially major clinical significance were significantly higher in patients imaged for melanoma staging (P= 0.004).

Conclusion

The prevalence of incidental findings of clinical significance that do not accumulate FDG in PET/CT is not insignificant. Routine systematic review of the low‐dose CT is required to avoid missing potentially clinically important findings, in particular pleural effusions, vascular aneurysms and metastatic pulmonary nodules.     

Evaluation of pulmonary nodules and lung cancer with one‐inch crystal gamma coincidence positron emission tomography/CT versus dedicated positron emission tomography/CT

Dedicated positron emission tomography (PET)/CT scanners using BGO and related detectors (d‐PET) have become standard imaging instruments in many malignancies. Hybrid gamma camera systems using NaI detectors in coincidence mode (g‐PET) have been compared to d‐PET but reported usefulness has been variable when gamma cameras with half‐inch to three‐fourth‐inch thick crystals have been used without CT. Our aim was to compare g‐PET with a 1‐in.‐thick crystal and inbuilt CT for lesion localization and attenuation correction (g‐PET/CT) and d‐PET/CT in patients presenting with potential and confirmed lung malignancies. One hour after ¹⁸F‐fluorodeoxyglucose (FDG), patients underwent BGO d‐PET/CT from jaw to proximal thigh. This was followed by one to two bed position g‐PET/CT 194 ± 27 min after FDG. Each study pair was independently analysed with concurrent CT. d‐PET/CT was interpreted by a radiologist experienced in both PET and CT, and g‐PET/CT by consensus reading of an experienced PET physician and an experienced CT radiologist. A TNM score was assigned and studies were then unblinded and compared. Fifty‐seven patients underwent 58 scan pairs over 2 years. Eighty‐nine per cent concordance was shown between g‐PET/CT and d‐PET/CT for the assessment of intrapulmonary lesions, with 100% concordance for intrapulmonary lesions >10 mm (36 of 36). Eighty‐eight per cent (51 of 58) concordance was shown between g‐PET/CT and d‐PET/CT for TNM staging. Coincidence imaging using an optimized dual‐head 1‐in.‐thick crystal gamma camera with inbuilt CT compares reasonably well with dedicated PET/CT for evaluation of indeterminate pulmonary lesions and staging of pulmonary malignancies and may be of some value when d‐PET/CT is not readily available.     

Detection rate of fluorine‐18‐fluorodeoxyglucose positron emission tomography in patients with marginal zone lymphoma of MALT type: a meta‐analysis

The aim of this article is to meta‐analyse published data about the detection rate (DR) of fluorine‐18‐fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the evaluation of patients with marginal zone lymphoma of the mucosa‐associated lymphoid tissue (MALT). A comprehensive literature search of studies published through February 2014 was performed. Pooled DR of ¹⁸F‐FDG PET or PET/CT including 95% confidence intervals (95% CI) was calculated on a per‐patient‐based analysis. Twenty studies including 376 patients with MALT lymphoma were selected. The pooled DR of ¹⁸F‐FDG PET or PET/CT was 71% (95% CI: 61–80%). A significant difference between the DR of PET/CT (69%; 95% CI: 61–80%) and that of PET alone (73%; 95% CI: 60–84%) was not demonstrated. A better DR of ¹⁸F‐FDG PET or PET/CT in bronchial (94%; 95% CI: 85–99%) and head‐and‐neck (90%; 95% CI: 78–98%) MALT lymphomas compared with gastric (62%; 95% CI: 46–77%) and ocular (49%; 95% CI: 36–63%) MALT lymphomas was found. This meta‐analysis demonstrates that MALT lymphoma is an ¹⁸F‐FDG‐avid tumour in most of the cases, suggesting a potential clinical role of ¹⁸F‐FDG PET or PET/CT in the initial evaluation of these patients. In particular, the DR of ¹⁸F‐FDG PET or PET/CT is related to the primary site of the MALT lymphoma. Copyright © 2014 John Wiley & Sons, Ltd.     

Consequence of the introduction of routine FCH PET/CT imaging for patients with prostate cancer: a dual centre survey

Background

Fluorocholine(18F) (FCH) was introduced at the beginning of April 2010 in France, Slovenia and three other EU member states for the localisation of bone metastases of prostate cancer with PET. The aim of the study was to compare the evolution of diagnostic imaging in patients with prostate cancer using a new radiopharmaceutical FCH, observed in France and in Slovenia, and to quantify the consequence of the results of new imaging modality on the detection rate of abnormal metastases and recurrences of prostate cancer.

Patients and methods

In two centres (France/Slovenia), a survey of the number of nuclear medicine examinations in patients with prostate cancer was performed, covering 5 quarters of the year since the introduction of FCH. For each examination, the clinical and biological circumstances were recorded, as well as the detection of bone or soft tissue foci.

Results

Six hundred and eighty-eight nuclear medicine examinations were performed impatients with prostate cancer. Nuclear medicine examinations were performed for therapy monitoring and follow-up in 23% of cases. The number of FCH PET/CT grew rapidly between the 1^st and 5^th period of the observation (+220%), while the number of bone scintigraphies (BS) and fluoride(18F) PET/CTs decreased (−42% and −23% respectively). Fluorodeoxyglucose(18F) (FDG) PET/CT remained limited to few cases of castrate-resistant or metastatic prostate cancer in Paris. The proportion of negative results was significantly lower with FCH PET/CT (14%) than with BS (49%) or fluoride(18F) PET/CT (54%). For bone metastases, the detection rate was similar, but FCH PET/CT was performed on average at lower prostate-specific antigen (PSA) levels and was less frequently doubtful (4% vs. 28% for BS). FCH PET/CT also showed foci in prostatic bed (53% of cases) or in soft tissue (35% of cases).

Conclusions

A rapid development of FCH PET/CT was observed in both centres and led to a higher detection rate of prostate cancer lesions.     

Single-Center Comparison of [64Cu]-DOTAGA-PSMA and [18F]-PSMA PET–CT for Imaging Prostate Cancer

Introduction: the diagnostic performance of [⁶⁴Cu]-DOTAGA-PSMA PET–CT imaging was compared retrospectively to [¹⁸F]-PSMA PET–CT in prostate cancer patients with recurrent disease and in the primary staging of selected patients with advanced local and possible metastatic disease. Methods: We retrospectively selected a total of 100 patients, who were consecutively examined in our department, with biochemical recurrence after radical prostatectomy or who had progressive local and possible metastatic disease in the last 3 months prior to this investigation. All patients were examined with a dedicated PET–CT scanner (Biograph; Siemens Healthineers). A total of 250 MBq (3.5 MBq per kg bodyweight, range 230–290 MBq) of [⁶⁴Cu]-DOTAGA-PSMA or [¹⁸-F]-PSMA was applied intravenously. PET images were performed 1 h post-injection (skull base to mid-thigh). The maximum standardized uptake values (SUVmax) of PSMA-positive lesions and the mean standardized uptake value (SUVmean) of the right liver lobe were measured. Results: All but 9/50 of the patients (18%; PSA range: 0.01–0.7 µg/L) studied with [⁶⁴Cu]-DOTAGA-PSMA and 6/50 of the ones (12%; PSA range: 0.01–4.2) studied with [¹⁸F]-PSMA had at least one positive PSMA lesion shown by PET–CT. The total number of lesions was higher with [⁶⁴Cu]-DOTAGA-PSMA (209 vs. 191); however, the median number of lesions was one for [⁶⁴Cu]-DOTAGA-PSMA and two for [¹⁸F]-PSMA. Interestingly, the median SUVmean of the right liver lobe was slightly higher for [¹⁸F]-PSMA (11.8 vs. 8.9). Conclusions: [⁶⁴Cu]-DOTAGA-PSMA and [¹⁸F]-PSMA have comparable detection rates for the assessment of residual disease in patients with recurrent or primary progressive prostate cancer. The uptake in the liver is moderately different, and therefore at least the SUVs of the lesions in both studies would not be comparable.     

The diagnostic and prognostic utility of positron emission tomography/computed tomography‐based follow‐up after radiotherapy for head and neck cancer

BACKGROUND:

The detection of subclinical head and neck cancer recurrence or a second primary tumor may improve survival. In the current study, the authors investigated the clinical value of a follow‐up program incorporating serial ¹⁸F?fluorodeoxyglucose?positron emission tomography integrated with computed tomography (PET/CT) in the detection of recurrent disease in patients with head and neck cancer.

METHODS:

A total of 240 PET/CT scans were reviewed in 80 patients with head and neck cancer who were treated with radiotherapy (RT) from July, 2005 through August, 2007. All patients were followed with clinical examination, PET/CT, and correlative imaging for a minimum of 11 months (median follow?up, 21 months).

RESULTS:

The sensitivity, specificity, and positive and negative predictive values of PET/CT‐based follow‐up for detecting locoregional recurrence were 92%, 82%, 42%, and 98%, respectively. Corresponding values for distant metastases or second primary tumors were 93%, 96%, 81%, and 98%, respectively. Eight patients (10%) developed disease recurrences or second primary tumors that were amenable to salvage surgery with negative surgical margins. The 2‐year progression‐free survival and 2‐year overall survival rates were significantly different between patients who had a negative and those with a positive PET/CT result within 6 months of the completion of RT (93% vs 30% [P<.001] and 100% vs 32% [P<.001], respectively).

CONCLUSIONS:

Although post‐therapy follow‐up using PET/CT is reportedly associated with a high false‐positive rate in the irradiated head and neck, PET/CT appears to be a highly sensitive technique for the detection of recurrent disease. Furthermore, negative PET/CT results within 6 months of the completion of RT offer significant prognostic value. Cancer 2009. © 2009 American Cancer Society.     

Non‐invasive estimation of 10B‐4‐borono‐L‐phenylalanine‐derived boron concentration in tumors by PET using 4‐borono‐2‐18F‐fluoro‐phenylalanine

In boron neutron capture therapy (BNCT), ¹⁰B‐4‐borono‐L‐phenylalanine (BPA) is commonly used as a ¹⁰B carrier. PET using 4‐borono‐2‐¹⁸F‐fluoro‐phenylalanine (¹⁸F‐FBPA PET) has been performed to estimate boron concentration and predict the therapeutic effects of BNCT; however, the association between tumor uptake of ¹⁸F‐FBPA and boron concentration in tumors remains unclear. The present study investigated the transport mechanism of ¹⁸F‐FBPA and BPA, and evaluated the utility of ¹⁸F‐FBPA PET in predicting boron concentration in tumors. The transporter assay revealed that 2‐aminobicyclo‐(2.2.1)‐heptane‐2‐carboxylic acid, an inhibitor of the L‐type amino acid transporter, significantly inhibited ¹⁸F‐FBPA and ¹⁴C‐4‐borono‐L‐phenylalanine (¹⁴C‐BPA) uptake in FaDu and LN‐229 human cancer cells. ¹⁸F‐FBPA uptake strongly correlated with ¹⁴C‐BPA uptake in 7 human tumor cell lines (r = .93; P < .01). PET experiments demonstrated that tumor uptake of ¹⁸F‐FBPA was independent of the administration method, and uptake of ¹⁸F‐FBPA by bolus injection correlated well with BPA uptake by continuous intravenous infusion. The results of this study revealed that evaluating tumor uptake of ¹⁸F‐FBPA by PET was useful for estimating ¹⁰B concentration in tumors.     

Role of (18)F-choline PET/CT in evaluation of patients with prostate carcinoma

Background

Choline presents a high affinity for malignant prostate tissue. It can be labelled with positron emitting ¹⁸F, and used for the evaluation of patients with prostate carcinoma by PET/CT imaging. The aim of this paper is to summarise our experience with fluoromethylcholine (¹⁸F-choline) PET/CT in patients with prostate cancer.

Methods

In 4 months we investigated the patients with histopathological (or cytological) confirmed prostate cancer. Two observers evaluated the early and late ¹⁸F-choline PET images in correlation with corresponding localising CT images and using the semiquantitative standard uptake value (SUV) calculation.

Results

The ¹⁸F-choline PET/CT was made in 50 patients with prostate cancer. There were 18 patients after radical prostatectomy and 32 without surgery. In all patients without surgery the pathological uptake was seen in the prostate. In 14 (44 %) patients of this group there was evidence of metastatic spread in local or distant lymph nodes and/or bones. In out of 18 patients after radical prostatectomy the local recurrence was detected in 6 patients (33%) and distant metastases were present in 2 patients (10%).

Conclusions

¹⁸F-choline PET/CT seems to be useful imaging modality in patients with prostate carcinoma; it can demonstrate spread of the disease preoperatively and detect the local recurrence after radical prostatectomy.