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Purpose: Interim 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) has shown to be an accurate predictor of prognosis in Hodgkin's lymphoma (HL). However, FDG PET response criteria are a matter of ongoing debate. The aim of this study was to confirm the prognostic value of interim PET/CT in HL patients treated with an interim response-adapted strategy and to compare the respective performances of different published criteria., Methods: Newly diagnosed patients with HL underwent interim PET/CT after four courses of Adriamycin, bleomycin, vinblastine and dacarbazine (ABVD). The treatment strategy was adapted according to prognostic factors at diagnosis and interim PET/CT and CT results. PET images were prospectively interpreted visually: a negative result was defined as no residual uptake above local background. All other findings were considered as positive. Retrospectively, interim PET/CT was analysed according to International Harmonization Project (IHP), Gallamini and London criteria, Results: The analysis included 90 patients; 6 of 31 patients with positive interim PET/CT and 7 of 59 patients with negative interim result presented treatment failure. The negative predictive value (NPV) and positive predictive value (PPV) for predicting 2-year progression-free survival (PFS) was 95 and 16%, respectively. With the other criteria, NPV remained very high (from 95 to 96%). The PPV increased from 19 to 45% according to the threshold used. Interim PET/CT was significantly correlated with PFS with Gallamini (p = 0.01) and London criteria (p < 0.0001)., Conclusion: Our study confirms the high NPV of interim PET/CT for predicting treatment outcome in HL and a probably better prognostic value using a higher threshold for positivity even after four cycles of chemotherapy as used in Gallamini and London criteria.

Background: In 2008, American consensus recommendations for performing gastric emptying (GE) scintigraphy were published. It was recommended that data are acquired only at 0, 1, 2, and 4 h and that the results are expressed as percentages of meal retention. Until now, it was established that the GE time-activity curves should have many points (every 10, 15, or 20 min) to reflect the GE process accurately and to be optimally adjusted by a mathematical model. In this study, we have evaluated the curve fitting using only a few points as proposed by the consensus protocol., Materials and Methods: GE scintigraphy tests of 224 patients were retrospectively analyzed. Two curve fittings were done for each patient, either using data acquired every 20 min or using data acquired every hour. A comparison of these two methods was made based on the values of the computed GE parameters., Results: We observed strong correlations between the two methods (r=0.81-0.99, P<0.05). Using the Bland-Altman analysis, more than 95% of the differences were included in the mean difference 95% confidence interval. The mean differences were weak with a relatively small SD and Cohen's k coefficients ranging from 0.84 to 0.93, indicating an excellent agreement between the two methods., Conclusion: Our results showed the feasibility and accuracy of curve fitting using only a few points. The curve fitting is easy to perform and allows the computation of reliable and reproducible parameters that reflect the whole GE process.

Objectives: To assess the added benefit of scanning lower limbs in addition to the usual whole-body positron emission tomography/computed tomography (PET/CT) scan in patients with no known or suspected primary or metastatic melanoma involving the lower limbs., Materials and Methods: This is a retrospective study of 122 consecutive patients [174 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) PET/CT] who underwent FDG PET/CT for staging of melanoma at different time points in the course of the disease from October 2005 to February 2009 at the Brest University Hospital. Reports of whole-body PET/CT scans including lower limbs were reviewed. PET/CT abnormalities on the lower extremities were tabulated by location and correlated with pathology, other imaging studies and at least a 6-month clinical follow-up. The usefulness of lower limbs acquisition in clinical management was evaluated according to imagery findings., Results: Among the 174 consecutive PET/CT scans performed in 122 patients, 33 scans in 28 patients highlighted abnormal FDG uptakes considered as equivocal or suggestive of malignancy in the lower limbs. In 28 cases, uptakes were located at once in the lower limbs and in the rest of the body (lung, liver, mediastinal and sub-diaphragmatic lymph nodes, adrenal glands, bone) corresponding to disseminated disease. In five cases, PET/CT uptakes were located only in lower limbs; each pathological uptake corresponded to benign lesions. Lower limbs findings never impacted clinical and therapeutic decision., Conclusion: Lower limbs additional PET/CT acquisition seems to offer poor additional benefit with none unexpected lesion detected and routine skull base to upper thigh images might be sufficient for this subset of patients.

Objective: To determine the value of quantitative radioscintigraphy (QRS) in the diagnosis of wrist trauma occult fractures., Purpose: Because of the risk of non-union, the diagnosis of wrist fractures, including scaphoid fractures, is essential but remains difficult despite many imaging modalities. The aim of the study was to assess the benefits of QRS in the diagnosis of occult post-trauma wrist fractures., Methods: This prospective study included all patients presenting at the orthopaedic department at Brest University Hospital for wrist pain after trauma with initial normal plain radiographs. Patients with normal radiographs but strongly suspected of fracture underwent QRS consisting of three-phase bone scintigraphy with quantitative analysis. When a fracture was suspected the radiograph and scintigraphy were fused to precisely locate the fracture if the index was higher than 2. If the index was lower than 1.9, fracture was excluded. Between these two indices, other investigations, such as magnetic resonance imaging, were performed. All patients were followed for at least 3 months and reviewed by the same surgeon. Patients underwent a physical examination and possibly other investigations., Results: From April 2006 to July 2008, 87 patients were enrolled (34 women, 53 men; median age 29 years; range, 15-87 years). Among the 46 pathologic bone scintigrams, 55 occult fractures were highlighted. At follow-up, none presented non-union. One had an undetermined QRS. Among the 40 negative results for QRS at follow-up, only one had a non-union. Sensitivity and negative predictive value were 97 and 98%, respectively for carpal fractures., Conclusion: This study highlights the benefit of QRS, which allows the detection of most occult carpal fractures and reduces the risks of complications such as pseudoarthritis.

Unlabelled: Posttreatment surveillance for the recurrence of head and neck squamous cell carcinoma (HNSCC) is a diagnostic challenge. Tissue distortion from radiation and surgery can obscure early detection of recurrence by conventional follow-up approaches such as physical examination, CT, and MRI. Several studies have shown that 18F-FDG PET may be an effective technique for the detection of persistent, recurrent, and distant metastatic HNSCC after treatment. The aim of this prospective study was to determine the benefits of hybrid 18F-FDG PET/CT in detecting a subclinical locoregional recurrence of HNSCC and distant metastases. The study patients were considered cured of HNSCC on the basis of 12 mo of negative findings on conventional follow-up. We also assessed the diagnostic accuracy of 18F-FDG PET/CT in these patients., Methods: Ninety-one patients cured of HNSCC without any clinical evidence of recurrence were included. Whole-body 18F-FDG PET/CT examination was performed 11.6+/-4.4 mo after the end of the treatment. The gold standard was histopathology or 6 mo of imaging follow-up., Results: The whole-body 18F-FDG PET/CT examinations had negative results in 52 patients and positive results in 39. Nine of these patients who exhibited abnormal 18F-FDG uptake in the head and neck area did not have recurrent HNSCC (false-positive). Thirty had proven recurrence. The sensitivity and specificity of 18F-FDG PET/CT in this study for the diagnosis of HNSCC recurrence were 100% (30/30) and 85% (52/61), respectively. The positive predictive value was 77% (30/39). The negative predictive value was 100% (52/52). The overall accuracy was 90% (82/91)., Conclusion: The results of our study confirm the high effectiveness of 18F-FDG PET/CT in the assessment of HNSCC recurrence and suggest that 18F-FDG PET/CT is more accurate than conventional follow-up physical examination alone in the assessment of recurrence after previous curative treatment for HNSCC and could be proposed systematically at 12 mo of the usual follow-up.

Background: The aim of this study was to determine the benefits of 18fluoro-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the detection of head and neck squamous cell carcinoma (HNSCC) recurrence in patients with negative clinical follow-up., Methods: Whole-body 18FDG-PET was performed in 30 patients treated for HNSCC without any clinical element for recurrence., Results: Twenty-one negative PET and 9 positive results were seen. One patient with abnormal 18F-FDG uptake in the laryngeal area did not have recurrent HNSCC (false positive). Eight had proven recurrence. The sensitivity and specificity of 18F-FDG PET for the diagnosis of HNSCC recurrence were 100% (8/8) and 95% (21/22), respectively. The positive predictive value was 89% (8/9). The negative predictive value was 100% (21/21). The overall accuracy was 97% (29/30)., Conclusion: The results of our study confirm the high effectiveness of 18F-FDG PET in assessment of HNSCC recurrence and suggest that it is more accurate than conventional physical examination follow-up alone.

Early therapy response assessment with metabolic imaging is potentially useful to determine prognosis in aggressive lymphoma and, thus, can guide first-line therapy. Forty-eight patients with aggressive lymphoma [24 Hodgkin's disease (HD); 24 non-Hodgkin's lymphoma (NHL)] underwent fluoro-deoxyglucose positron emission tomography (FDG-PET) before chemotherapy (PET1) and at mid-treatment (PET2). Therapeutic response was evaluated using conventional methods at mid-treatment. PET2 results were related to event-free survival (EFS) and overall survival (OS) using Kaplan-Meier analyses. PET1 was positive in all patients. PET2 was negative in 38 patients (18 NHL-20 HD) and positive in 10 (6 NHL-4 HD). Of the PET-negative patients, 61 and 65% achieved complete remission, and only 50 and 25% of PET-positive patients, respectively, for NHL and HD, achieved complete remission. Significant associations were found between PET2 and EFS (p = 0.0006) and OS (p = 0.04) for NHL, and EFS (p < 0.0001) for HD (but not for OS, because no HD patient died). FDG-PET at mid-treatment can predict the outcome of patients with aggressive lymphoma and should be a useful tool to modify an ineffective therapy.

Background: The purpose of this study was to assess the rate of gastric emptying (GE) in cystic fibrosis patients scheduled for lung transplantation., Methods: Thirty patients (20 males, 10 females, 22.6 +/- 6.4 years) were evaluated by GE scintigraphy before (1.58 +/- 1.11 years) and early after (5.8 +/- 2.6 weeks) heart-lung transplantation (n = 13) or lung transplantation (n = 17). Solid retention rates at 2 hours (RR2) and 3 hours (RR3) and half-emptying times (T50) of solids and liquids obtained before transplantation were compared with those after transplantation. Data were also compared with those obtained from a control group of 53 healthy volunteers., Results: Before surgery, 20 patients (67%) showed a delayed GE (T50 of solids: patients 160.86 +/- 59.21 minutes vs controls 75.43 +/- 15.13 minutes, p < 0.0001), and 4 of them also had a delayed T50 of liquids. After surgery, the T50 of solids was considered unreliable (too much stasis) in 24 patients. Thus, analyses were done on the basis of solid retention rates. Twenty-nine patients (97%) showed very delayed GE compared with controls (p < 0.0001), 20 of whom also had a delayed T50 of liquids. RR2 and RR3 were significantly higher after surgery than before (RR2 = 86 +/- 17% and RR3 = 77 +/- 22% vs 50 +/- 24% and 27 +/- 24% after and before surgery, respectively, p < 0.0001). However, there was no correlation between pre- and post-transplantation scintigraphy results., Conclusions: Delayed GE of solids was a frequent abnormality in patients with end-stage cystic fibrosis, with a dramatic delay after surgery in almost all patients. These results emphasize the need for early management of such patients by dietary manipulation or prokinetic medications.

Purpose: Using gastric emptying scintigraphy the gastric retention rate is commonly calculated within a gastric region of interest (intragastric method). This technique may have significant limitations when left oblique anterior views are acquired, due in part to attenuation resulting from intragastric redistribution. To minimize these drawbacks, it was proposed to express the intragastric content as a percentage of the abdominal radioactivity (abdominal method). Our goal was to compare these two methods when anterior-posterior scanning is used., Methods: Antero-posterior scintigraphic data of 272 consecutive patients were analysed by both methods. Retention rates were obtained by both observation and calculation by power exponential fit. Gastric emptying parameters (half-emptying time of solids (T(50,S)) and liquids (T(50,L)), lag phase (T(lag)) time and real emptying time (T(RE))), and quality of fit were also computed and compared., Results: For solids, the intragastric method resulted in weakly higher experimental retention rates, whereas retention rates were quite similar for liquids. Differences between experimental and calculated retention rates were smaller for abdominal method, for both liquids and solids. As a result, values for the quality of fit were higher for the abdominal method. Significant differences were observed only for calculated T(50,S) (122+/-46 min vs. 124+/-48 min, mean difference 2+/-2 min, P<0.00001) and T(RE) (163+/-64 min vs. 168+/-68 min, mean difference 4.5+/-3.8 min, P<0.05), respectively, for the abdominal and the intragastric methods. However, the Bland-Altman statistical method revealed good agreements (<5% outliers)., Conclusion: Intragastric and abdominal methods can be used indifferently to treat antero-posterior data of gastric scintigraphy.

Background: The reliability of solid phase gastric emptying measurements by scintigraphy requires a marker that remains within the solid component of the test meal, and which is not degraded by the gastric juice throughout the scintigraphic procedure. In Europe, foods are most often labelled with 99mTc rhenium sulfide macrocolloid (RSMC) but this solid phase marker was withdrawn from the market in January 2004., Objective: To test other potential solid phase markers and to compare them to the reference marker RSMC. These markers were rhenium sulfide nanocolloid (RSNC), tin fluoride colloid (TFC), phytates and two albumins (Alb and AlbC). All were radiolabelled with 99mTc., Methods: After quality control, each 99mTc marker was incorporated into the albumin of one egg. Then, egg white and yolk were mixed together, and a well-cooked omelette was prepared. Aliquots of the omelette were incubated with an acidic solution of pepsin at 37 degrees C which mimicked gastric juice. Unbound radioactivity in the supernatant fraction was measured at various times up to 3 h., Results: The radiochemical purity was > 95% for all radiopharmaceuticals. During the in-vitro incubation, the percentage of 99mTc labelled colloids released from the omelette increased continuously: after 3 h, 5% for TFC and RSMC, 8% for phytates, and > 9% for the two albumins and RSNC., Conclusion: Considering quality controls and release of 99mTc during in-vitro incubation of the omelette, TFC showed the same behaviour as the reference marker RSMC. Thus, TFC seems to be the best candidate to replace RSMC for the radiolabelling of the solid phase of the gastric emptying test meal.

Aim: To assess the clinical performance of parameters of liquid-solid gastric emptying (GE) scintigraphy., Methods: Fifty-three controls and 476 patients underwent GE scintigraphy using a liquid-solid test meal (non-ulcer dyspepsia, n=180; gastro-oesophageal reflux disease, n=123; dyspepsia after anti-reflux surgery, n=29; diabetes mellitus, n=96; cystic fibrosis prior to heart-lung transplantation, n=48). Time-activity curves were fitted by a power exponential function and half-emptying times (T1/2) were computed. The lag phase (Tlag) and constant emptying (TRE) times of solid emptying were also calculated using a mathematical method (maximum slope tangent method)., Results: TRE and T1/2 of solids were higher in each subgroup of patients vs. controls (P=0.0001) and in cystic fibrosis patients vs. gastro-oesophageal reflux patients (P=0.0001). Tlag was significantly higher only in non-ulcer dyspepsia patients vs. controls (P=0.001). There was no significant difference for liquid parameters. Using the mean+/-1.96 SD of the solid and liquid T1/2 values obtained in controls, GE was normal (n=251; 53%), delayed (n=183; 38%), accelerated (n=33; 7%) or mixed (n=9; 2%). Delayed solid T1/2 was the most prominent alteration (n=189), and alterations of liquid GE alone were present in only 24 (5%) patients. A good correlation was found between solid T1/2 and TRE (r=0.88), but no correlation between Tlag and TRE, suggesting that these estimates represent independent phases of GE. In 26 patients, all GE parameters of solids and liquids were normal except Tlag (n=8) or TRE (n=18). The lack of significant differences between the different patient subgroups did not allow emptying profiles to be drawn according to patient pathology., Conclusion: Liquid GE scintigraphy provided poor and unreliable information in terms of patient discrimination and the drawing of pathophysiological profiles of abnormal GE. Tlag and TRE may confirm GE alteration, especially when solid T1/2 values are at the superior limit of normality, and may improve the performance of GE scintigraphy, rather than using liquid parameters.