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As the preparation phase of a multicenter clinical trial using (18)F-fluoro-2-deoxy-d-glucose ((18)F-FDG), (18)F-fluoromisonidazole ((18)F-FMISO), and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) in non-small cell lung cancer (NSCLC) patients, we investigated whether 18 nuclear medicine centers would score tracer uptake intensity similarly and define hypoxic and proliferative volumes for 1 patient and we compared different segmentation methods.Ten (18)F-FDG, ten (18)F-FMISO, and ten (18)F-FLT PET/CT examinations were performed before and during curative-intent radiotherapy in 5 patients with NSCLC. The gold standards for uptake intensity and volume delineation were defined by experts. The between-center agreement (18 nuclear medicine departments connected with a dedicated network, SFMN-net [French Society of Nuclear Medicine]) in the scoring of uptake intensity (5-level scale, then divided into 2 levels: 0, normal; 1, abnormal) was quantified by κ-coefficients (κ). The volumes defined by different physicians were compared by overlap and κ. The uptake areas were delineated with 22 different methods of segmentation, based on fixed or adaptive thresholds of standardized uptake value (SUV).For uptake intensity, the κ values between centers were, respectively, 0.59 for (18)F-FDG, 0.43 for (18)F-FMISO, and 0.44 for (18)F-FLT using the 5-level scale; the values were 0.81 for (18)F-FDG and 0.77 for both (18)F-FMISO and (18)F-FLT using the 2-level scale. The mean overlap and mean κ between observers were 0.13 and 0.19, respectively, for (18)F-FMISO and 0.2 and 0.3, respectively, for (18)F-FLT. The segmentation methods yielded significantly different volumes for (18)F-FMISO and (18)F-FLT (P0.001). In comparison with physicians, the best method found was 1.5 × maximum SUV (SUVmax) of the aorta for (18)F-FMISO and 1.3 × SUVmax of the muscle for (18)F-FLT. The methods using the SUV of 1.4 and the method using 1.5 × the SUVmax of the aorta could be used for (18)F-FMISO and (18)F-FLT. Moreover, for (18)F-FLT, 2 other methods (adaptive threshold based on 1.5 or 1.6 × muscle SUVmax) could be used.The reproducibility of the visual analyses of (18)F-FMISO and (18)F-FLT PET/CT images was demonstrated using a 2-level scale across 18 centers, but the interobserver agreement was low for the (18)F-FMISO and (18)F-FLT volume measurements. Our data support the use of a fixed threshold (1.4) or an adaptive threshold using the aorta background to delineate the volume of increased (18)F-FMISO or (18)F-FLT uptake. With respect to the low tumor-on-background ratio of these tracers, we suggest the use of a fixed threshold (1.4).

In patients treated for differentiated thyroid cancer with radioiodine (131I), abnormal uptake on post-therapeutic whole-body scan may lead to repeated administration of 131I. Uptake not linked to thyroid cancer but to other conditions should be recognized so that patients are not overtreated. We describe 3 cases of unilateral thoracic 131I uptake in patients previously treated by pneumonectomy for lung cancer, without evidence of persistent lung cancer.

Regional axillary lymph node status has remained the single most independent variable to predict prognosis both in terms of disease recurrence and survival. This study aimed to prospectively assess sequential [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) findings as early predictors of axillary lymph node response to neoadjuvant chemotherapy in stage II and III breast cancer patients.Images were acquired with a PET/CT scanner in 52 patients after administration of FDG (5 MBq/kg) at baseline and after the first, second, third and sixth course of chemotherapy before surgery. Clinical examination and ultrasound (US) were used to assess the size of axillary nodes. Decrease in the standardized uptake value (SUV) with PET corrected or not for partial volume effects was compared to the pathological response.The sensitivity, specificity and accuracy of axillary node staging was higher with PET (75, 87 and 80%) than with US (50, 83 and 65%), and even more so when PET images were corrected for partial volume effects (86, 83 and 84%). While FDG uptake did not vary much in non-responders, as confirmed by histopathological analysis, it markedly decreased to baseline levels in responders (p 10(-5)). Fifty per cent of baseline SUV was considered the best cutoff value to distinguish responders from non-responders. The sensitivity, specificity, negative predictive value and accuracy of FDG PET after one course of chemotherapy were, respectively, 96, 75, 95 and 84%.The pathological status of regional axillary lymph nodes in stage II and III breast cancer patients could be accurately predicted after one course of neoadjuvant chemotherapy based on FDG PET images.

The aim of this retrospective study was to evaluate the contribution of (18)F-FDG PET to the clinical management and survival outcome of patients suspected of recurrent cervical carcinoma and in line with the hypothesis that early diagnosis of recurrent cervical cancer may improve overall survival.A total of 40 patients underwent conventional imaging (CI) and FDG PET/CT for suspected cervical cancer. Clinical management decisions were recorded with CI and additional PET/CT. Discordances and concordances between CI and PET/CT results were compared to the final diagnosis as based on histopathology analysis or follow-up considered as the gold standard.The final diagnosis was established pathologically (n = 25) or by median clinical follow-up for 48 months after the PET (n = 15). The PET/CT was positive in 76% (20/26) of patients compared to 19% (6/26) with CI. Globally PET/CT modified the treatment plan in 55% (22/40) of patients and in 75% (18/24) when the CI was negative prior to PET/CT. These changes led to the use of previously unplanned therapeutic procedures in 37.5% (15/40). When FDG PET was positive for recurrence (3 foci), the median overall survival was 12 months (2-70) compared to patients with PET findings withor = 1 focus for which the median survival was not attained (p = 0.007). A multivariate analysis of prognostic factors demonstrated that abnormal FDG uptake (3 foci) was the most significant factor (p0.03) for death from cervical cancer.FDG PET is a valuable tool in the case of suspected recurrence of cervical cancer on account of its impact on treatment planning and especially in predicting patient outcome.

Purpose To address the impact of positron emission tomography with [18F]fluorodeoxyglucose (PET-FDG) on the initial staging and management of patients with head and neck squamous cell carcinoma (HNSCC). Patients and Methods This multicenter, prospective study included 233 patients with newly diagnosed and untreated HNSCC. TNM stage and therapeutic decision were first determined based on the conventional work-up (including physical examination, computed tomography [CT]/magnetic resonance imaging of the head and neck region, and thoracic CT) and sealed in envelope 1. Whole-body PET-FDG was then performed, and subsequent TNM stage and therapeutic decision were written in envelope 2. Changes in TNM stages and in patient management as a result of PET-FDG imaging were recorded. Clinical outcome and histopathology were used as gold standards to validate the TNM stage. Conventional and PET stages were compared using the McNemar test. Results Conventional and PET stage were discordant in 100 (43%) of 233 patients. PET proved to be accurate in 47 patients and inaccurate in 13 patients. TNM status was left unconfirmed in 40 patients because no therapeutic change was expected from the stage difference. Conventional + PET TNM classification (envelope 2) was significantly more accurate than conventional classification (envelope 1; P < .0001, McNemar test). PET-FDG altered the therapeutic plan in 32 (13.7%) of 233 patients. Conclusion Adding whole-body PET-FDG to the pretherapeutic conventional staging of HNSCC improved the TNM classification of the disease and altered the management of 13.7% of patients. These findings support the implementation of PET-FDG in the routine imaging work-up of HNSCC.

Objective: Mediastinal lymph node staging determines the treatment strategy for non-small-cell lung cancer. This study aims to evaluate prospectively the accuracy of preoperative integrated 18-fluoro-2-deoxy-D-glucose positron emission tomography—computerised tomography ( 18 FDG PET-CT) for mediastinallymph node staging.Methods:Preoperative integrated 18 FDG PET-CTwas used to analyse mediastinallymph nodes in patients with non-small-cell lung cancer. Nodal stations were identified according to the American Thoracic Society mapping system. Lymph nodes with a standardised uptake value (SUVmax) >3 were considered to be positive. The mediastinal lymph nodes were harvested during lung resection and the results of integrated 18 FDG PET-CT were compared to the mediastinal lymph node histology results. Results: A total of 51 patients were enrolled in this study. The mean interval between integrated 18 FDG PET-CTand surgery was 31 15.8 days (range: 2—78 days). The mean mediastinal lymph node harvested and station number per patient during surgery were 11.8 5.6 (range: 2—27) and 3.8 1 (range: 2—6), respectively. The incidence of N2 pathological disease was 19.6%. The integrated 18 FDG PET-CT sensitivity and specificity were 40 30% and 85 11%, respectively. Thepositiveandnegativepredictivevalueswere 40 30%and85 11%,respectively. False-positive results(sixpatients) were mainly due to inflammatory lymph nodes. False-negative results (six patients) were mainly due to infra-centimetrical, malignant lymph node invasion. Conclusion: The sensitivity of integrated 18 FDG PET-CT for mediastinal lymph node staging in patients selected for surgery is low. When positive mediastinal lymph nodes are detected, invasive mediastinal staging must be performed. On the other hand, the specificity is high: patients with negative integrated 18 FDG PET-CT can be operated upon without invasive mediastinal staging. # 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Background 18-F-fluoro-2-deoxyglucose positron emission tomography (18FDG-PET) is useful in the detection of iodine-negative differentiated thyroid carcinoma (DTC). The aim of this prospective study was to assess therapeutic impact of 18FDG-PET imaging using a PET/computed tomography (CT) system in patients with iodine-negative recurrence of DTC. Methods From 2002 to 2006, patients with recurrence of DTC diagnosed by elevated thyroglobulin level and negative 131-I whole-body scan were included. Results Forty-five patients (31 women, 14 men), with a mean age of 55 years, with 36 papillary, 5 follicular, and 4 Hurthle carcinomas, were studied. All patients had previously undergone total thyroidectomy and postoperative thyroid remnant ablation with 131-I. The findings of 18FDG-PET/CT were positive in 31 patients (68.8%) and negative in 14 (32.2%). Results were true positive in 24 of 31 patients. The sensitivity, positive predictive value, and accuracy of 18FDG-PET/CT were 63%, 77%, and 53%, respectively. Twenty patients were operated on, 19 had neck surgery with mediastinal lymph node dissection (1 case) and lung resection (1 case), and 1 underwent lung resection. Seven patients had a stimulated thyroglobulin level Conclusion 18FDG-PET/CT is able to select patients who can benefit from surgery. Normalization of thyroglobulin is observed in one third of operated patients.

Purpose This study aimed to assess prospectively the efficacy of sequential [18F]fluorodeoxyglucose positron emission tomography (FDG PET) to evaluate early response to neoadjuvant chemotherapy in stage II and III breast cancer patients. Patients and Methods Images were acquired with a PET/computed tomography scanner in 64 patients after administration of FDG (5 MBq/kg) at baseline and after the first, second, third, and sixth course of chemotherapy. Ultrasound and mammography were used to assess tumor size. Decrease in the standardized uptake value (SUV) with PET was compared with the pathologic response. Results Surgery was performed after six courses of chemotherapy and pathologic analysis revealed gross residual disease in 28 patients and minimal residual disease in 36 patients. Although SUV data did not vary much in nonresponders (based on pathology findings), they decreased markedly to background levels in 94% (34 of 36) of responders. When using 60% of SUV at baseline as the cutoff value, the sensitivity, specificity, and negative predictive value of FDG PET were 61%, 96%, and 68% after one course of chemotherapy, 89%, 95%, and 85% after two courses, and 88%, 73%, and 83% after three courses, respectively. The same parameters with ultrasound (US) and mammography were 64%, 43%, and 55%, and 31%, 56%, and 45%, respectively. Assessment of tumor response with US or mammography was never significant whatever the cutoff. Conclusion Pathologic response to neoadjuvant chemotherapy in stage II and III breast cancer can be predicted accurately by FDG PET after two courses of chemotherapy.

Background Fluorine 18–fluoro-2-deoxyglucose (FDG) positron emission tomography ( 18 F-FDG PET) can be used to visualize metastases in patients with differentiated thyroid carcinoma that does not take up radioiodine ( 131 I). This study was aimed at evaluating the feasibility of 18 F-FDG radio-guided surgery in patients with radioiodine-negative differentiated thyroid cancer. Methods Ten patients received a mean activity of 265 MBq of 18 F-FDG 30 minutes before operation. Radioactivity uptake (counts per second [cps], with a pretime of 10 seconds) in tumor and normal tissues was measured before and after resection. Results Patients with 1 to 5 foci detected by FDG-PET were included in the study. Six of these patients were injected with recombinant human thyroid-stimulating hormone (TSH) preoperatively. Abnormal findings detected by preoperative 18 F-FDG PET were also detected with the gamma probe in all patients. The mean tumor activity in vivo was 3,272 cps, and tumor-to-neck and tumor-to-shoulder ratios were, respectively, 1.40 and 1.73. Tumor resection was incomplete in 3 patients. When resection was complete, mean radioactivity at the tumor site was decreased by 22%. The ex vivo mean tumor-to-normal tissue ratio was 2.4. All positive tissues detected with the probe were confirmed histologically to be differentiated thyroid cancer. The surgeon's hands were exposed to 90 to 270 μSv. Conclusions These results show the feasibility and benefit of 18 F-FDG radio-guided surgery with a gamma probe in the management of differentiated thyroid cancer patients with radioiodine-negative recurrence.

Background. PET/CT may be particularly useful to detect the primary cancer in paraneoplastic cerebellar degeneration (PCD) with anti-Yo which is most commonly associated with breast, ovarian and other gynecological cancers. Case. A 60-year-old woman developed a PCD associated with anti-Yo antibodies in serum and cerebrospinal fluid. Conventional imaging was negative. FDG-PET showed an abnormal hot spot in the right ovarian area associated with lombo aortic lymph nodes. The diagnosis was confirmed by surgery as an ovarian adenocarcinoma. Conclusion. In this case report, FDG-PET played a crucial role in detecting the unknown primary tumor in a patient with PCD.

It has recently been suggested that FDG accumulation in the brown adipose tissue varies as a function of age, sex and outdoor temperature. The aim of this study was to assess changes in FDG uptake in brown fat in patients based on serial PET/CT scans and to compare our results with previous findings. Early response to neoadjuvant chemotherapy in 33 female breast cancer patients was assessed by FDG PET. Five PET/CT scans were performed for each patient. PET/CT images were analysed retrospectively. PET scans were considered positive when diffuse, symmetrical, abnormal “USA” (uptake in supraclavicular area) fat was detected. A total of 163 PET images were analysed. Seventy-four PET scans (45%) revealed abnormal FDG uptake in the supraclavicular area. These foci were present on uncorrected and attenuation-corrected images. FDG uptake was identical on all five scans in only five patients. No significant relationship was found between abnormal FDG uptake and outdoor temperature, age or time interval between chemotherapy and PET. Abnormal FDG uptake in the neck seemed to predominantly occur in patients with a low body mass index (p

This study aimed at evaluating the relationship between the nonvisualization of sentinel nodes (SNs) at lymphoscintigraphy and the intraoperative detection rate, radioactive counts in vivo, and histological status of SNs. Two hundred eighty patients with infiltrating breast carcinoma (T0, T1/T2) underwent preoperative lymphoscintigraphy before gamma probe–guided SN biopsy. The surgical identification rate with a gamma probe was 84.6% (56 of 280) in lymphoscintigraphy-negative patients and 93.2% (224 of 280) in lymphoscintigraphy-positive patients (P < .05) after two subdermal periareolar injections. The average number of SNs per patient was 1.7 in lymphoscintigraphy-negative patients and 2.2 in lymphoscintigraphy-positive patients (P < .01), as assessed by gamma detection. The mean age of lymphoscintigraphy-negative patients was 62 ± 10 years, versus 55 ± 13 years for lymphoscintigraphy-positive patients (P < .001). The median radioactive count in dissected SNs identified by gamma detection was 204 cps (range, 4–618 cps) in lymphoscintigraphy-negative patients, versus 606 cps (range, 43–16,928 cps) in lymphoscintigraphy-positive patients (P < .001). The rate of macrometastatic SNs was 40% in lymphoscintigraphy-negative patients, versus 30% in lymphoscintigraphy-positive patients (not significant), whereas the size of involved SNs was 16.6 mm in lymphoscintigraphy-negative patients, versus 13.1 in lymphoscintigraphy-positive patients (P < .05). The micrometastasis detection rate in SNs from lymphoscintigraphy-negative patients was 6.25%, versus 23.3% in lymphoscintigraphy-positive patients (P < .01). Negative lymphoscintigraphy was observed in 20% of patients and was more frequent in elderly patients. Negative lymphoscintigraphy was predictive of a lower surgical identification rate and fewer detected SNs. These SNs had fewer micrometastases, were fairly large, and tended to harbor metastases.

Background. This is the first report of FDG-PET findings in a case of vaginal melanoma. Case. The tumor arose from the anterior wall of the vaginal canal. As the tumor was limited to the vaginal wall and as there was no evidence of distant metastases, the disease was staged as IIC (AJCC 2002). PET-CT images showed two mediastinal foci localized to the left highest mediastinal and subcarinal nodes on fusion PET/CT images. As it was metastatic, the disease was staged IV (AJCC 2002). Conclusion. In comparison to conventional imaging, FDG-PET provides a more accurate assessment of the extent of disease spread in patients with vaginal melanoma as with cutaneous melanoma. Significant alterations in the surgical management and treatment were made based on PET results.

Purpose/Objective: Our objectives were (i) to investigate whether different Nuclear Medicine centres would rate similarly 18 Fmisonidasole (F-miso hypoxia) or 18fluorothymidine (FLT proliferation) uptake and (ii) to compare different segmentation methods, using F-miso and FLT. Materials and Methods: Twenty PET-CT (10 F-miso and 10 FLT) were performed before and during curative-intent radiotherapy in 5 patients with NSCLC. The images were electronically sent to 18 centres of Nuclear Medicine connected through the French Society of Nuclear Medicine network (SFMNnet). In a first phase, each centre had to rank the F-miso and FLT uptake intensity on a 5-level scale, and secondly into a 2-level scale (0=normal, 1=pathologic). The concordance between readers was quantified by weighted kappa tests (K). The presence or absence of F-miso and FLT uptake defined by experts was used as gold standard. In a second phase, potential target F-miso and FLT volumes were delineated with 22 different methods of segmentation: a threshold of 40% and 50% of the maximum standardized uptake value (SUVmax), a threshold fixed at 1.2 and 1.4 of the SUVmax, and 3 methods using an adaptive thresholding related to the SUVmax or SUVmean of a reference tissue (muscle, aorta and lung). Results: As for uptake intensity, the K values between the centres were 0.44 for F-miso and 0.43 for FLT with a 5-level scale, and 0.77 for F-miso and FLT with a 2-level scale. The various segmentation methods yielded significantly different volumes for F-miso and FLT (p max of aortic uptake (sensitivity: 0.87 and 0.71, specificity: 0.72 and 0.96 respectively). For FLT, 6 methods (fixed threshold at 1.4, adaptive threshold based on 1.5 or 1.6 of aortic SUVmax, and adaptive threshold on based 1.3, 1.5 or 1.6 muscle SUVmax) gave the best agreement. Conclusions: The 18 centres were able to reproducibly grade F-miso and FLT uptake on a 2-level (positive/negative) scale. Our data support a fixed threshold (1.4 of aortic SUVmax) to delineate increased F-miso uptake and an adaptive threshold using the aorta and muscle SUVmax background for FLT.

10500 Background: Regional axillary lymph node status has remained the single most independent variable to predict prognosis both in terms of disease recurrence and survival. This study aimed to prospectively assess sequential FDG PET findings as early predictors of axillary lymph node response to neoadjuvant chemotherapy in locally advanced breast cancer patients. Methods: A total of 255 attenuation-corrected scans were obtained from 51 patients. Images were acquired with a PET/CT scanner (GE Discovery LS) following administration of FDG (5 MBq/kg) at baseline, and after the first, second, third, and sixth course of chemotherapy. Clinical examination and US were used to assess the size of axillary lymph nodes. PET data were interpreted using standardized uptake values (SUV) corrected or not for partial volume effects. Changes in the SUV were considered as surgical/histopathological responses. Results: This study focused on axillary lymph node staging, therefore, primary breast tumor data were not considered in the analysis. The sensitivity, specificity, and accuracy of axillary node staging was higher with PET (75%, 87%, 80%) than with clinical examination and US (50%, 78%, 63%, and 50%, 83%, and 65%, respectively), and even the more so when PET images were corrected for partial volume effects (86%, 83%, 84%). Significant differences between absolute FDG uptake values in responders and non-responders were observed at baseline (p < 0.05). While FDG uptake did not vary much in non-reponders, as confirmed by histopathology, it markedly decreased to baseline levels in responders (p < 10−5). Fifty percent of baseline SUV was considered the best cut-off value to distinguish responders from non-responders. The sensitivity, specificity, negative predictive value, and accuracy of FDG PET after one course of chemotherapy were respectively, 96%, 75%, 95%, and 84%. Tumor response assessment by clinical examination or US was never statistically significant whatever the cut-off. Conclusions: The pathological status of regional axillary lymph nodes in locally advanced breast cancer patients can be accurately predicted after one course of neoadjuvant chemotherapy based on FDG PET images. No significant financial relationships to disclose.

2022 Background: [F18]-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is commonly used in the diagnosis and staging of cancer. Clinical and radiological evaluation of response to...