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Purpose To assess prospectively the prognostic value of FDG PET/CT during curative-intent radiotherapy (RT) with or without concomitant chemotherapy in patients with non-small-cell lung cancer (NSCLC). Methods Patients with histological proof of invasive localized NSCLC and evaluable tumour, and who were candidates for curative-intent radiochemotherapy (RCT) or RT were preincluded after providing written informed consent. Definitive inclusion was conditional upon significant FDG uptake before RT (PET 1 ). All included patients had a FDG PET/CT scan during RT (PET 2 , mean dose 43 Gy) and were evaluated by FDG PET/CT at 3 months and 1 year after RT. The main endpoint was death (from whatever cause) or tumour progression at 1 year. Results Of 77 patients preincluded, 52 were evaluable. Among the evaluable patients, 77 % received RT with induction chemotherapy and 73 % RT with concomitant chemotherapy. At 1 year, 40 patients (77 %) had died or had tumour progression. No statistically significant association was found between stage (IIIB vs. other), histology (squamous cell carcinoma vs. other), induction or concomitant chemotherapy, and death/tumour progression at 1 year. The SUV max in the PET 2 scan was the single variable predictive of death or tumour progression at 1 year (odds ratio 1.97, 95 % CI 1.25 – 3.09, p  = 0.003) in multivariate analysis. The area under the receiver operating characteristic curve was 0.85 (95 % CI 0.73 – 0.94, p  < 10 −4 ). A SUV max value of 5.3 in the PET 2 scan yielded a sensitivity of 70 % and a specificity of 92 % for predicting tumour progression or death at 1 year. Conclusion This prospective multicentre study demonstrated the prognostic value in terms of disease-free survival of SUV max assessed during the 5th week of curative-intent RT or RCT in NSCLC patients (NCT01261598; RTEP2 study).

Context:Few prospective studies have evaluated the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the characterization of adrenal masses.Objective:To assess the performance of 18F-FDG PET/CT in the malignancy diagnosis of adrenal masses in noncancer patients.Design:Prospective multicenter study.Material and Methods:The study population consisted of 87 patients (87 adrenal masses) referred to endocrine surgeons: 56 with mass diameter ≥40 mm and 31 with a diameter <40 mm and of indeterminate nature based on unenhanced and washout CT attenuation densities. Fourteen patients had hypercortisolism. Adrenal masses were characterized by 18F-FDG PET/CT. Histology was the gold standard for the diagnosis of malignancy. In the absence of pathological proof (n = 23), the nature of the lesion was based on the 12-month imaging follow-up.Results:Fifteen adrenal masses were classified as malignant (including 11 adrenocortical carcinomas) and 72 as benign. Compared with benign lesions, malignant lesions were larger in size (P = 0.003), had higher unenhanced densities (P = 0.002), lower relative washout values (P = 0.007), and higher 18F-FDG uptake parameters (P < 10−3). The optimal threshold value of (Tumor SUVmax:Liver SUVmax) the ratio for malignancy was >1.5 with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 86.7%, 86.1%, 56.5%, 96.9%, and 86.2%, respectively.Conclusions:Our results show that 18F-FDG PET/CT complements adrenal washout CT in the evaluation of adrenal masses and should be recommended in the evaluation of large and/or indeterminate adrenal masses.We studied the performance of 18F-FDG PET/CT in the characterization of adrenal masses in noncancer patients and found that 18F-FDG PET/CT enabled accurate estimation of malignancy risk.

Purpose FDG PET has been suggested to have predictive value in the prognosis of oesophageal carcinoma. However, the retrospective studies reported in the literature have shown discordant results. Additionally, only four studies have evaluated FDG PET during chemoradiotherapy (CRT) in patients with different histological lesions. The purpose of this study was to investigate the predictive value of FDG PET performed early during CRT (on day 21) in a population of patients with oesophageal squamous cell carcinoma. Methods Included in this prospective study were 57 patients with a histological diagnosis of squamous cell carcinoma of the oesophagus. Of these 57 patients, 48 (84 %) were evaluated (aged 63 ± 11 years; 44 men, 4 women). Each patient underwent FDG PET (4.5 MBq/kg) before CRT, according to the Herskovic protocol (t0; PET 1 ) and on day 21 ± 3 from the start of CRT (d21; PET 2 ). The response assessment included a clinical examination, CT scan or FDG PET and histological analysis 3 months and 1 year after PET 1 . The patients were classified as showing a complete response (CR) or a noncomplete response. A quantitative analysis was carried out for PET 1 and PET 2 using the following parameters: SUVmax, SUVmean (with SUVmean 40 as the 3-D volume at an SUVmax threshold of 40 % and SUVmean p as that defined by a physician), tumour volume (TV, with TV 40 defined as the TV at 40 % of SUVmax, and TV p as that defined by a physician); and the total lesion glycolysis (TLG, SUVmean × TV, with TLG 40 defined as the TLG at 40 % of SUVmax, and TLG p as that defined by a physician). The differences in responses at 3 months and 1 year between PET 1 (t0) and PET 2 (d21) were assessed in terms of variations in SUV, TV and TLG using a repeated measures of variance (ANOVA). Results SUVmax, SUVmean and TLG decreased significantly between PET 1 (t0) and PET 2 (d21; p  < 0.0001). The TV significantly decreased only when assessed as TV p ( p  = 0.02); TV 40 did not decrease significantly. With respect to the predictive value of PET 1 , only TV 40_1 and TV p_1 values, and therefore TLG 40_1 and TLG p_1 , but not the SUV values, were significantly lower in patients with CR at 3 months. SUVmax 1 , TV p_1 and TLG p_1 were significantly lower in patients with CR at 1 year. With respect to the predictive value of PET 2 , only TV 40_2 and TV p_2 values, and therefore TLG 40_2 and TLG p_2 , but not the SUV values, were significantly lower in patients with CR at 3 months. None of the PET 2 parameters had significant value in predicting patient outcome at 1 year. The changes in SUVmax, TV 40 , TV p , TLG 40 and TLG p between PET 1 and PET 2 had no relationship to patient outcome at 3 months or 1 year. Conclusion This prospective, multicentre study performed in a selected population of patients with oesophageal squamous cell cancer demonstrates that the parameters derived from baseline PET 1 are good predictors of response to CRT. Specifically, a high TV and TLG are associated with a poor response to CRT at 3 months and 1 year, and a high SUVmax is associated with a poor response to CRT at 1 year. FDG PET performed during CRT on day 21 appears to have less clinical relevance. However, patients with a large functional TV on day 21 of CRT have a poor clinical outcome (ClinicalTrials.gov NCT 00934505).

Tumor delineation is a critical aspect in radiotherapy treatment planning and is usually performed with the anatomical images of a computed tomography (CT) scan. For non‐small cell lung cancer, it has been recommended to use functional positron emission tomography (PET) images to take into account the biological target characteristics. However, today, there is no satisfactory segmentation technique for PET images in clinical applications. In the present study, a solution to this problem is proposed. The development of the segmentation technique is based on the threshold's adjustment directly from patients, rather than from phantoms. To this end, two references were chosen: measurements performed on CT images of the selected lesions, and histological measurements of surgically removed tumors. The inclusion and exclusion criteria were chosen to produce references that are assumed to have measured tumor sizes equal to the true in vivo tumor sizes. In total, for the two references, 65 lung lesions of 54 patients referred for FDG‐PET/CT exams were selected. For validation, measurements of segmented lesions on PET images using this technique were also compared to CT and histological measurements. For lesions greater than 20 mm, our segmentation technique showed a good estimation of histological measurements (mean difference between measured and calculated data equal to −0.8±9.0%) and an acceptable estimation of CT measurements. For lesions smaller than or equal to 20 mm, the method showed disagreement with the measurements derived from histological or CT data. This novel segmentation technique shows high accuracy for the lesions with largest axes between 2 and 4.5 cm. However, it does not correctly evaluate smaller lesions, likely due to the partial volume effect and/or respiratory motions. PACS numbers: 87.53.Bn, 87.53.Kn, 87.55.D, 87.57.nm, 87.57.U

The aim of this study was to evaluate the diagnostic value of a new somatostatin analog, 99mTc-P829, compared with that of 111In-pentetreotide. Forty-three patients (32 men, 11 women; age range, 24-78 y; mean age, 56 y) with biologically or histologically proven neuroendocrine tumors were prospectively included: 11 patients with Zollinger-Ellison syndrome, 16 patients with carcinoid tumors, and 16 patients with other types of functioning (n = 6) or nonfunctioning (n = 10) endocrine tumors. 111In-Pentetreotide planar images (head, chest, abdomen, and pelvis) were obtained 4 and 24 h after injection of 10 microg somatostatin analog labeled with 148 +/- 17 MBq 111In, and SPECT was performed 24 h after injection. Similar (99m)Tc-P829 planar images were obtained at 1, 4-6, and 24 h after injection of 50 microg peptide labeled with 991.6 +/- 187.59 MBq 99mTc. Abdominal SPECT was performed 4-6 h after injection. 111In-Pentetreotide detected 203 tumoral sites in 39 (91%) of 43 patients, whereas 99mTc-P829 detected 77 sites in 28 (65%) of 43 patients (P < 0.005). In the liver, 129 sites (in 24 patients) were detected by 111In-pentetreotide scintigraphy and 34 sites (in 10 patients) were detected by 99mTc-P829 scintigraphy. In patients with endocrine tumors, the detection rate of 99mTc-P829 scintigraphy was lower than that of 111In-pentetreotide scintigraphy, which appeared to be more sensitive, especially for liver metastases.

Whole-brain activity is often chosen to quantitatively normalize peri-ictal and interictal SPECT scans before their subtraction. This use is not justified, because significant and extended modification of the cerebral blood flow can occur during a seizure. We validated and compared 2 automatic methods able to determine the optimal reference region, using simulation and clinical data. In the first method, the selected reference region is the intersection of peri-ictal-interictal areas with no significantly different z values. The other method relies on a 3-dimensional iterative voxel aggregation. The increase of the selected volume is stopped by using 2 different variance tests (Levene and SE). These algorithms were tested on 39 epileptic patients and were validated using 1 interictal and 10 peri-ictal scans simulated from the mean image of 22 healthy subjects. In the patient studies, the mean relative activity of the selected regions, compared with whole-brain activity (classic normalization), was 122.6%. Their average relative size (compared with the size of the whole brain) was 33.2% for the z map method, 22.8% for the SE test, and 11.8% for the Levene test. After application of our automatic processes, subtraction of the simulated images revealed a recovery of abnormal regions up to 45% larger than the region obtained with classic normalization. These results illustrate the role of normalization on the subtracted peri-ictal and interictal images. Our methods are automatic and objective and give good results on various simulated images. The z map construction is worth considering because it is simple, selects large parts of the brain, and requires little computation time.

Bilateral paramedian thalamic infarcts are characterised initially by the association of acute vigilance disorders and vertical gaze palsy, followed by persisting dementia with severe mnemic disturbance, global aspontaneity and apathy. We describe a patient with a dramatic neuropsychological recovery, confirmed by testing examination and completed by a cerebral metabolism study. The pathophysiology of this type of cognitive deficit is discussed.

There is marked variability in the cerebral blood flow (CBF) between the ictal and interictal state in epilepsy, and it would therefore be desirable to increase the reliability of ictal/interictal single-photon emission tomography (SPET) difference images. We aimed to improve the step of quantitative normalization of images by finding the best possible reference region. In 16 patients (11 with lateralization of the epileptogenic focus, five with bilateral foci) both ictal and inter-ictal SPET scans were performed after injection of technetium-99m labelled tracer. Then, each region among a selected set (brain+cerebellum, brain, cerebellum, hemispheres, and for patients with an expected lateralization, cortical lobe containing the focus and symmetrical contralateral lobe) was investigated by comparison of the regional ictal/inter-ictal variance in counts. Among patients with a suspected lateralized focus, the distribution of CBF in the contralateral cortical lobe appeared to vary less between ictal and inter-ictal states than in other investigated areas. As a consequence, this latter region constitutes the best choice as a reference region. For patients with bilateral foci, the cerebellum appears to be a good compromise even though it presents with significant CBF changes.

The aim of this study was to evaluate the diagnostic value of a new somatostatin analog, 99mTc-P829, compared with that of 111In-pentetreotide. Forty-three patients (32 men, 11 women; age range, 24-78 y; mean age, 56 y) with biologically or histologically proven neuroendocrine tumors were prospectively included: 11 patients with Zollinger-Ellison syndrome, 16 patients with carcinoid tumors, and 16 patients with other types of functioning (n = 6) or nonfunctioning (n = 10) endocrine tumors. 111In-Pentetreotide planar images (head, chest, abdomen, and pelvis) were obtained 4 and 24 h after injection of 10 microg somatostatin analog labeled with 148 +/- 17 MBq 111In, and SPECT was performed 24 h after injection. Similar (99m)Tc-P829 planar images were obtained at 1, 4-6, and 24 h after injection of 50 microg peptide labeled with 991.6 +/- 187.59 MBq 99mTc. Abdominal SPECT was performed 4-6 h after injection. 111In-Pentetreotide detected 203 tumoral sites in 39 (91%) of 43 patients, whereas 99mTc-P829 detected 77 sites in 28 (65%) of 43 patients (P < 0.005). In the liver, 129 sites (in 24 patients) were detected by 111In-pentetreotide scintigraphy and 34 sites (in 10 patients) were detected by 99mTc-P829 scintigraphy. In patients with endocrine tumors, the detection rate of 99mTc-P829 scintigraphy was lower than that of 111In-pentetreotide scintigraphy, which appeared to be more sensitive, especially for liver metastases.