Multiple ectopic lesions of focal islet adenomatosis identified by positron emission tomography scan in an infant with congenital hyperinsulinism

Congenital hyperinsulinism (HI) exists in 2 histologic forms, focal and diffuse, and rarely has been attributed to lesions in ectopic pancreatic tissue. The ability to distinguish focal from diffuse HI and locate focal lesions has been difficult, thus limiting the optimal management of HI. We present a case of HI resulting from focal pancreatic and ectopic pancreatic lesions. After a near-total pancreatectomy failed to improve the patient's condition, a positron emission tomography (PET) scan performed with ¹⁸F-fluoro-l-dihydroxyphenylalanine demonstrated a focal lesion remaining in the head of the pancreas as well as 4 hot spots inferior to the remaining pancreas. Surgical exploration found pancreatic rests in the jejunum responsible for the hot spots seen on PET. Resection of the remainder of the pancreas as well as the small intestinal lesions resulted in correction of the patient's HI. Pathology confirmed the presence of focal HI lesions in the pancreatic head and small intestinal specimens. This case supports the ability of ectopic pancreatic tissue to contribute to the pathology of HI. It highlights the ability of PET to successfully identify focal lesions, including ectopic tissue, responsible for hyperinsulinemic hypoglycemia.     

Clinical usefulness of 18-fluorodeoxyglucose positron emission tomography in the management of patients with nonpancreatic periampullary neoplasms

BACKGROUND: 18-Fluorodeoxyglucose positron emission tomography (18-FDG PET) has been investigated for the diagnosis and staging of gastrointestinal malignancies including pancreatic adenocarcinoma. The aim of this study was to examine the clinical usefulness of 18-FDG PET in the diagnosis and follow-up evaluation of patients with periampullary neoplasms. METHODS: Twenty-five patients underwent whole-body 18-FDG PET and abdominal computed tomography (CT). Pathologic confirmation was obtained in all patients by surgical resection or biopsy examination. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). Positivity was assumed when a focal uptake occurred with an SUV of 2.5 or greater. RESULTS: Between January 1998 and December 2003, 14 ampullary, 7 bile duct, and 4 duodenal tumors were included in the study. PET showed increased focal uptake in 22 patients (88%): 11 of 14 (79%) ampullary tumors, and 100% of bile duct and duodenal tumors. PET showed a focal uptake in 11 of 12 patients without detectable mass at CT scan, and lymph node metastases in 6 patients. An SUV value of 2.7 discriminated adenomas or noninvasive cancers (n = 6) from invasive malignancies (n = 14). Follow-up evaluation including CT scan and PET was performed in 12 patients: PET showed recurrent disease not seen by CT in 4 patients, confirmed CT findings in 6 patients, and showed an unsuspected primary lung cancer in 1 patient and colon cancer in another patient. CONCLUSIONS: 18-FDG PET is very sensitive for detecting periampullary neoplasms. It may be useful to differentiate benign or borderline lesions from invasive tumors when no mass has been identified by traditional imaging. Finally, it is very useful in the follow-up evaluation of resected patients to identify recurrent disease or other malignancies.     

Use of 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) imaging for the evaluation of muscle metabolic activity in ruptured rotator cuffs: Identification of shoulder muscles by fusion imaging studies involving both FDG PET and magnetic resonance imaging

The uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) into shoulder muscles was studied in 11 patients with rotator cuff tears. FDG was injected under resting conditions, and cuff muscle exercises were performed followed by evaluation of the standardized uptake value (SUV) in shoulder muscles bilaterally. Analysis was performed with a subtracted SUV, obtained by subtracting the SUV of the muscle at rest from that after exercise. Fusion imaging studies involving FDG positron emission tomography (PET) and magnetic resonance imaging would provide a novel strategy with the potential of improving on the limited resolution of PET images. In this study this relatively new strategy revealed a similar decrease in the supraspinatus SUV in cases involving both complete and partial tears. The SUV in the infraspinatus and subscapularis also decreased, regardless of whether these muscles were intact or ruptured; the SUV in the deltoid remained basically unchanged. With the use of this exercise protocol, FDG PET might prove useful for objective evaluation of rotator cuff muscle activity.     

The predictive value of preoperative fluorine-18-L-3,4-dihydroxyphenylalanine positron emission tomography-computed tomography scans in children with congenital hyperinsulinism of infancy

Background/Purpose

In congenital hyperinsulinism (CHI) of infancy, the use of preoperative fluorine-18-l-3,4-dihydroxyphenylalanine-positron emission tomography-computed tomography (¹⁸F-DOPA-PET-CT) scan has recently been reported. The aim of this study was to evaluate the accuracy of this technique in discriminating between diffuse and focal CHI and the anatomical localization of focal lesions.

Methods

Between 2006 and 2010, ¹⁸F-DOPA-PET scan was performed in 19 children with CHI (median age, 2 months; range, 1-12 months) who were not responding to medical therapy and underwent laparoscopic or open surgery. The findings of ¹⁸F-DOPA-PET scan were correlated with histology.

Results

In 5 children, ¹⁸F-DOPA-PET scan showed diffuse pancreatic uptake, confirmed at histology and supporting the genetic suspicion of diffuse disease. In 14 children, ¹⁸F-DOPA-PET scan indicated focal pancreatic uptake, which corresponded to histology. However, in 5 patients (36%), ¹⁸F-DOPA-PET scan was inaccurate in defining the location of the lesion (n = 3), size of the lesion (n = 1), or both location and size (n = 1), leading to an inaccurate pancreatic resection.

Conclusions

Fluorine-18-l-3,4-dihydroxyphenylalanine-positron emission tomography-computed tomography scan discriminates between diffuse and focal forms of CHI. In focal forms, ¹⁸F-DOPA-PET scan is useful in 2/3 of patients in defining the site and dimension of the focal lesion. Intraoperative histologic confirmation of complete focal lesion resection is needed.     

Is positron emission tomography using 18F-fluorodeoxyglucose and 11C-acetate valuable in diagnosing indeterminate pancreatic masses?

BACKGROUND: It can be impossible to differentiate a mass forming chronic pancreatitis from adenocarcinoma of the pancreas using standard anatomical imaging. Positron emission tomography using 2-[18F] fluoro-2deoxy-D-glucose (18FDG-PET) and 1-[11C]-acetate (11C-acetate-PET) are methods taking advantage of the metabolic differences between benign and malignant tissues. AIMS: To determine the diagnostic accuracy of 18FDG-PET and 11C-acetate-PET in indeterminate pancreatic masses. METHODS: Twenty patients with an indeterminate mass of the head of the pancreas were prospectively studied. All patients underwent 18FDG-PET and eighteen of them 11C-acetate-PET. Scans were evaluated qualitatively and quantitatively; the later by using regional standardised uptake value (SUV). Final diagnosis was established using histopathologic evaluation of resected specimen or biopsy. RESULTS: Adenocarcinoma was diagnosed in twelve patients and chronic pancreatitis in eight. Qualitative evaluation of 18FDG-PET imaging revealed three false negative and one false-positive results. The sensitivity, specificity, and diagnostic accuracy were 75 %, 88 %, and 80 %, respectively. The cut-off SUV to differentiate malignant from benign disease was 3,5 demonstrating a sensitivity of 91.7 % and a specificity of 75 %. CONCLUSION: 18FDG-PET imaging could not confirm or exclude malignancy in indeterminate masses of the head of the pancreas with high sensitivity and diagnostic accuracy. 11C-acetate-PET provided no additional diagnostic benefits.     

慢性肿块型胰腺炎的18F-FDG PET/CT影像学表现

目的探讨慢性肿块型胰腺炎18F-FDG PET/CT影像学表现。方法回顾性分析6例经手术病理证实的慢性肿块型胰腺炎的18F-FDG PET/CT影像资料和临床资料。结果 6例共检出6个病灶,3个位于胰头,3个位于胰尾;平均大小3.0cm×2.7cm。CT平扫6个病灶呈均匀等密度,未见钙化灶,平均CT值约为36HU;增强扫描全部病灶呈延迟期强化。全部病灶18F-FDG摄取呈局灶性增高,最大标准摄取值（SUVmax）1.6～5.3,平均SUVmax3.92±1.49,高于正常胰腺组织的2.05±0.39（t=-3.648,P=0.015）。3例病灶累及胰头,胆总管及胰管不同程度扩张,呈双管征,胰体尾部轻度萎缩;3例病灶累及胰尾,胆总管及胰管未见扩张,胰体尾部未见萎缩。病灶邻近的主要血管均未受侵。全部病例胰周及腹膜后淋巴结未见18F-FDG局灶性摄取增高,未见远处脏器或（和）组织转移。结论 18 F-FDG PET/CT对诊断慢性肿块型胰腺炎具有一定价值。     

The utility of F-18 fluorodeoxyglucose whole body PET imaging for determining malignancy in cystic lesions of the pancreas

Previous studies have suggested that whole body positron-emission tomography (PET) can distinguish between benign and malignant cysts of the pancreas. Patients were identified (n=68) who had undergone whole body PET imaging for a cystic lesion of the pancreas between Jan. 1997 and May 2005. Cross-sectional imaging studies were reviewed by a single blinded radiologist, and positive PET studies were reviewed by a blinded nuclear medicine physician. Operative resection was performed in 21 patients (31%), and 47 patients were managed with radiographic follow-up. F-18 Fluorodeoxyglucose (FDG)-avid lesions were identified in eight of the 68 patients (12%). Within the resected group of patients (n=21), four of the seven patients (57%) with either in situ or invasive malignancy (adenocarcinoma: 3 of 5, papillary mucinous carcinoma: 1 of 2) had positive PET imaging (mean SUV, 5.9; range 2.5-8.0), and 2 of the 14 patients (14%) with benign lesions had positive PET imaging (serous cystadenoma, n=1, SUV=3.3; pseudocyst n=1, SUV=2.7). All lesions proven to be malignant with increased FDG uptake had highly suspicious findings on cross-sectional imaging. Within the group of resected patients, the sensitivity of PET for identifying malignant pathology was 57%, and the specificity was 85%. The sensitivity and specificity of PET for malignancy in this study was lower than previously reported, and PET findings did not identify otherwise occult malignant cysts. We do not believe whole body FDG-PET to be essential in the evaluation of cystic lesions of the pancreas.     

Value of [11C]choline-positron emission tomography for re-staging prostate cancer: a comparison with [18F]fluorodeoxyglucose-positron emission tomography

PURPOSE: We compared [11C]choline-positron emission tomography (PET) with [18F]fluorodeoxyglucose-PET for re-staging prostate cancer in a group of 100 patients. MATERIALS AND METHODS: A total of 100 consecutive patients referred for whole body [18F]fluorodeoxyglucose-PET for clinical prostate re-staging after radical treatment for prostate cancer were retrospectively included in the study. Mean prostate specific antigen (PSA) was 6.57 ng./ml. In all cases [11C]choline-PET was also performed. PET studies were done with a multiring device 5 minutes after intravenous injection of approximately 370 MBq. [11C]choline and 60 minutes after injection of approximately 370 MBq. [18F]fluorodeoxyglucose. PET findings were compared with those obtained with different conventional imaging and with PSA assessed at the time of PET and 1 year later. RESULTS: Areas of abnormal focal increases were noted in 47% of patients on [11C]choline-PET and in 27% on [18F]fluorodeoxyglucose-PET. Of the 100 patients 49 had positive conventional imaging findings. All except 14 [11C]choline-PET findings were concordant with conventional imaging, including 6 negative and 8 positive conventional imaging results. All except 1 [11C]choline-PET negative cases also had negative conventional imaging after 1 year. PSA at 1 year remained stable or decreased in 80% and 62% of [11C]choline-PET negative and positive cases, respectively. CONCLUSIONS: [11C]choline-PET seems to be useful for re-staging prostatectomy cases with increasing serum PSA levels. It is superior to [18F]fluorodeoxyglucose-PET and complementary to conventional imaging but with the advantage of staging disease at a single step.     

Pancreatic surgery in infants with Beckwith–Wiedemann Syndrome and Hyperinsulinism

PurposeTo present our experience in the care of infants with Beckwith–Wiedemann syndrome (BWS) who required pancreatectomy for the management of severe Congenital Hyperinsulinism (HI).MethodsWe did a retrospective chart review of patients with BWS who underwent pancreatectomy between 2009 and 2012.ResultsFour patients with BWS and severe HI underwent pancreatectomy, 3 females and one male. Eight other BWS patients with HI could be managed medically. The diagnosis of BWS was established by the presence of mosaic 11p15 loss of heterozygosity and uniparental disomy in peripheral blood and/or pancreatic tissue. All patients had hypoglycemia since birth that did not respond to medical management with diazoxide or octreotide, and required glucose infusion rates of up to 30 mg/kg/min. Preoperative 18-F-DOPA PET/CT scans showed diffuse uptake of the radiotracer throughout an enlarged pancreas in three patients and a normal sized pancreas with a large area of focal uptake in the pancreatic body in one patient. None of the patients had mutations in the ABCC8 or KCNJ1 genes that are typically associated with diazoxide-resistant HI. Age at surgery was 1, 2, 4, and 12 months and the procedures were 85%, 95%, 90%, and 75% pancreatectomy, respectively, with the pancreatectomy extent tailored to HI severity. Pathologic analysis revealed marked diffuse endocrine proliferation throughout the pancreas that occupied up to 80% of the parenchyma with scattered islet cell nucleomegaly. One patient had a small pancreatoblastoma in the pancreatectomy specimen. The HI improved in all cases after the pancreatectomy, with patients being able to fast safely for more than 8 h. All patients are under close surveillance for embryonal tumors. One patient developed a hepatoblastoma at age 2.ConclusionThe pathophysiology of HI in BWS patients is likely multifactorial and is associated with a dramatic increase in pancreatic endocrine tissue. Severe cases of HI that do not respond to medical therapy improve when the mass of endocrine tissue is reduced by subtotal or near-total pancreatectomy.     

18F-FDG PET在胰腺癌患者预后评估中的价值

目的 评估18F-FDG PET判断胰腺癌患者预后的价值.方法 回顾性分析54例胰腺癌病例资料.取所有病例PET检查的标准摄取值(standard uptake value,SUV)平均值4为截断点分组,A组22例(SUV≤4),B组32例(SUV＞4),分析两组患者的预后.结果 A组1、3年生存率为68.18%、34.91%;B组1、3年生存率为33.61%、11.95%,两组生存率比较差异有统计学意义(P=0.01);Cox回归分析提示肿瘤分期和SUV是胰腺癌患者预后的独立危险因素.结论 18F-FDG PET在判断胰腺癌预后方面有一定的价值.     

Evaluation of segmental pancreatic function using 11C-methionine positron emission tomography for safe operation of living donor pancreas transplantation

For the safe operation of living donor pancreas transplantation, we investigated the utility of ¹¹C-methionine positron emission tomography (PET) to examine the function of the residual pancreatic head in patients with pancreatic disease undergoing distal pancreatectomy and in living donors of pancreas transplantation. After 6 hours of fasting, we intravenously injected 370 to 740 MBq ¹¹C-methionine. PET was scanned 30 minutes after injection. ¹¹C-methionine PET uptake by the pancreatic head versus body/tail was expressed as a standardized uptake value (SUV). The SUVs of the pancreatic head were compared before versus after surgery. The SUVs of the pancreatic head in patients before and after distal pancreatectomy were 15.3 ± 6.0 and 18.2 ± 2.4, respectively. The SUVs of the pancreatic head in donors before and after distal pancreatectomy were 16.1 ± 1.0 and 14.7 ± 1.4, respectively. Both patients and donors showed no significant difference in SUVs of the pancreatic head before and after surgery. However, the SUVs of the residual pancreatic head were elevated after distal pancreatectomy in 80% of patients and 50% of donors. These data indicated that the function of the pancreatic head may be maintained or improved after distal pancreatectomy. ¹¹C-methionine PET may become a potent modality to evaluate segmental pancreatic function for a safe living donor operation.     

Evaluation of positron emission tomography with 2-[18F]fluoro-2-deoxy-D-glucose for the differentiation of chronic pancreatitis and pancreatic cancer

BACKGROUND: The clinical presentation of patients with pancreatic cancer may resemble the clinical picture of chronic pancreatitis. A definitive preoperative diagnosis is not always obtained in patients with a history of chronic pancreatitis despite the use of modern imaging techniques. Operative strategy therefore remains unclear before operation in these patients. METHODS: Positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) was introduced recently into clinical oncology because of its ability to demonstrate metabolic changes associated with various disease processes. The impact of FDG-PET on the differentiation of chronic pancreatitis and pancreatic cancer was investigated. FDG-PET was performed in 48 patients with chronic pancreatitis (n = 12), acute pancreatitis (n = 3) and pancreatic cancer (n = 27), and in controls (n = 6). Histological examination was undertaken in all cases except controls. The FDG-PET results were obtained without knowledge of results of other imaging procedures. The results were then compared with those of computed tomography, ultrasonography, endoscopic retrograde cholangiopancreaticography, operative findings and histology. PET images were analysed semiquantitatively by calculating a standard uptake value (SUV) 90-120 min after application of the tracer. RESULTS: Cut-off values were validated as follows: SUV greater than 4.0 for pancreatic cancer, SUV of 3.0-4.0 for chronic pancreatitis, and SUV of less than 3.0 for controls. Sensitivity and specificity of PET imaging were 0.96 and 1.0 for pancreatic cancer, and 1.0 and 0.97 for chronic pancreatitis. In five cases only FDG-PET led to the correct preoperative diagnosis. CONCLUSION: The results give further evidence that FDG-PET is an important non-invasive method for the differentiation of chronic pancreatitis and pancreatic cancer. Delayed image acquisition in the glycolysis plateau phase permits improved diagnostic performance. This imaging technique is extremely helpful before operation in patients with an otherwise unclear pancreatic mass, despite its costs.     

Evaluation of Insulin Independence Using C-Methionine Positron Emission Tomography After Living-donor and Brain-dead Donor Pancreas Transplantation

We recently reported that ¹¹C-methionine positron-emission tomography (PET) is clinically useful for the evaluation of the pancreatic function of the living donor. The objective of this study was to evaluate the postoperative insulin independence in 10 living donor (LD) and 10 brain-dead donor (BD) pancreas transplantations for 20 patients with type I diabetes mellitus by using ¹¹C-methionine PET. After 6 months, PET/computed tomography was performed 30 minutes after ¹¹C-methionine (370–740 MBq) injection. The uptake in the pancreas was expressed as the standardized uptake value (SUV). Patient survival rates were 100% at 5 years for LD transplantations and at 2 years for BD transplantations. Insulin independence was 60% for LD transplantations at 5 years and 75% for BD transplantations at 2 years. There were no major surgical complications such as vascular thrombosis, intra-abdominal abscess, and graft pancreatitis. The SUVs for LD and BD pancreas transplantations with insulin independence were 7.2 ± 1.8 and 10.4 ± 2.3, respectively. The SUVs for LD pancreas transplantations with insulin dependence and BD pancreas transplantations with graft failure were 3.6 ± 1.1 and 2.9 ± 1.0, respectively. At 5 years after transplantation, for the LD transplants, the insulin-independent rate was 100% for the graft recipients with an SUV higher than 5, and the median insulin independence duration of the graft recipients with an SUV less than 5 was 7 months (P < .01). The ¹¹C-methionine PET may be a potent modality to predict long-term insulin independence and the avoidance of pancreas graft failure.     

The surgical management of congenital hyperinsulinemic hypoglycemia in infancy

Background

Congenital hyperinsunlinism (CHI) is characterized by profound hypoglycaemia caused by inappropriate insulin secretion. CHI is a heterogeneous disorder with at least 2 histologic lesions and several implicated genes. If CHI is caused by a focal lesion, elective surgery is the only treatment because it leads to complete recovery without diabetes; on the contrary, diffuse CHI can only be cured by near-total pancreatectomy, and medical treatment, if efficient, is preferable. It is therefore mandatory to distinguish the 2 forms of CHI, and the surgeon has to fullfill his role in the multidisciplinary team that deals with CHI.

Methods

A total of 134 patients with CHI were investigated both radiologically and with molecular biology. Pathology was the only proof of focal or diffuse lesions, and the pancreatic tissue could be studied by electrophysiology (Katp and Ca channels) and gene study.

Results

In 59 infants with CHI, a focal lesion was suspected by radiology and proved by extemporaneous pathology; partial pancreatectomy (33 tail +/− body, 19 head, 5 isthmus resections) was performed, and molecular biology and histochemistry confirmed the genetic lesion specific to the focal disease; 75 near-total pancreatectomies were necessary in diffuse disease to prevent brain damage.

Conclusions

CHI is a severe brain-threatening disease. Surgery is indicated in all focal diseases, providing they are diagnosed preoperatively. In diffuse disease with resistance to medical treatment, near-total pancreatectomy is a last resort option that hopefully will be improved in the future with culture of β cells and genetic modification of the β cell disease before autograft.     

(18)F]Fluorodeoxyglucose positron emission tomography and its prognostic value in lung cancer.

OBJECTIVE: Positron emission tomography (PET) is being increasingly used as an accurate and non-invasive modality in diagnosis, staging and post-therapy assessment in patients with lung cancer. In this study, we examine whether the uptake of [(18)F]fluorodeoxyglucose (FDG), a marker of increased glucose metabolism in neoplastic cells, is of prognostic value in patients with primary lung cancer. METHODS: We have retrospectively analyzed 77 patients (mean age, 63. 0 years; male/female ratio, 53:24) with primary lung cancers who underwent whole body and localized thoracic PET as part of their diagnostic and staging procedures prior to consideration of surgical resection. The standardized uptake value (SUV) of injected FDG for each primary lesion was correlated with tumour histology and the patient's clinical outcome. RESULTS: A SUV of 20 or greater was found to be of significant prognostic value. The chance of survival (with 95% confidence intervals (CI)) at 12 months post-surgery for the various SUV groups was as follows: 75.2% (59.6-85.5) for SUV<10; 67.5% (29.0-88.2) for SUV 10-<12; 63.6% (29.7-84.5) for SUV 12-<15; 66.7% (19.5-90.4) for SUV 15-<20; 16.7% (0.01-0.52) for SUV>20. A SUV of 20 or more is associated with a 4.66 times increase in hazard, compared with lower levels of SUV. We found no significant correlation between tumour histology and SUV. CONCLUSION: We have previously reported on the significant advantages of PET in the staging and surgical care of patients with lung cancer. The present study adds further support for an additional prognostic role for PET in the management of thoracic malignancy as determined by the amount of labelled-FDG taken up by the primary lesion.     

Surgical target selection in cerebral glioma surgery: linking methionine (MET) PET image fusion and neuronavigation.

OBJECTIVE: The objective of this study was to investigate the histological correlate of (11)C-methionine (MET) PET uptake of brain gliomas by image fusion for navigated surgery. METHODS: Twenty-seven patients (18 male, 9 female; mean age 42 years; range 11-77 years; 8 low-grade and 11 high-grade astrocytomas or mixed gliomas, 8 oligodendrogliomas) underwent MET PET studies preoperatively. RESULTS: MET PET tumor uptake was detected in 26 of 27 patients (96.3%). The quantitative MET tumor standardized uptake value (SUV) ratio was significantly higher in malignant gliomas and oligodendrogliomas than in low-grade gliomas (2.76/2.62 vs. 1.67, p=0.03). Generally, qualitative visual grading of MET uptake revealed 2 main patterns: focal MET uptake in 12 and uniform global MET uptake in 11 patients. Focal uptake corresponded to malignant glioma histology in 66.7%, and uniform global uptake to oligodendroglial histology in 72.7%. In oligodendrogliomas, global MET uptake constituted 81.5% (range 53.8-135%) of the MRI T(1) tumor volume on average and was limited to the MRI FLAIR tumor volume in 86% (7/8) of patients. Tissue samples of focal MET uptake areas correlated with histological anaplasia in 66.6% (8/12 glioma patients), although 62.5% (5/8 patients) lacked MRI contrast enhancement. CONCLUSION: MET PET image fusion may facilitate the targeting of anaplastic foci in homogeneous MRI non-enhancing gliomas for biopsy, may identify oligodendroglial histology preoperatively as well as characterize biologically active tumor volumes within MRI T(1)/FLAIR tumor areas of candidate patients for resection.     

特殊示踪剂正电子发射体层显像在肺部病变诊断中的应用

目的 探讨胆碱、甲硫氨酸、脱氧胸腺嘧啶核苷、乙酸盐为示踪剂的正电子发射体层显像(PET)在肺部病变诊断中的应用价值.方法 2002年6月至2007年6月对100例肺部占位病变的患者行PET检查.其中~(11)C-胆碱(CH)-PET检查58例,~(11)C-甲硫氨酸(MET)-PET检查16例,~(18)F-脱氧胸腺嘧啶核苷(FLT)-PET检查22例,~(11)C-乙酸盐(AC)-PET检查4例.结果 采用目测法判读,半定量分析法测量病变标准摄取值,结果与病理诊断及随访结果对照.结果CH-PET定性诊断灵敏度、特异度、符合率分别为84.2%(32/38)、57.9%(11/19)、75.4%(43/57).MET-PET定性诊断灵敏度、特异度、符合率分别为6/7、6/9、75.0%(12/16).FLT-PET检查定性诊断灵敏度、特异度、符合率分别为85.7%(12/14)、2/8、63.6%(14/22).CH.PET、MET-PET及FLT-PET中肿瘤标准摄取值与肿瘤大小、患者年龄不相关.AC.PET检查仅1例透明细胞癌肺转移显影,2例鳞状细胞癌、1例腺癌没有显影.结论 这些示踪剂PET对肺部病变的定性诊断有帮助,但存在假阳性和假阴性结果.     

Surgical outcome of solid pseudopapillary tumor of the pancreas

BACKGROUND/PURPOSE: The best surgical treatment for solid pseudopapillary tumor of the pancreas is a matter of debate. METHODS: Fourteen patients with solid pseudopapillary tumor of the pancreas who underwent surgical resection, including enucleation, between June 1996 and January 2007 were retrospectively analyzed to evaluate the effect of the treatment. RESULTS: The mean age of the patients was 39 years (range, 15 to 59 years). The mean size of the tumor was 4.4 cm (range, 2.0 to 12 cm). Ten tumors (71%) had a well-defined capsule, and 6 tumors (43%) extended beyond the pancreas. Eight of the 14 tumors (57%) had a cystic component, and calcification was observed in 6 tumors (43%). The frequency of microscopic venous invasion, lymphatic invasion, and nerve invasion was 29% (4 of 14), 0%, and 21% (3 of 14), respectively. No lymph node involvement or liver metastasis was observed. Six patients underwent positron emission tomography with 2-deoxy-2-[(18)F] fluoro-D-glucose (FDG), and stronger FDG accumulation compared with the surrounding pancreatic parenchyma was observed in 5 of the 6 patients. The median standardized uptake value (SUV) was 6.3 (range, 0.9 to 42.8). Distal pancreatectomy (n = 5), subtotal stomach-preserving pancreatoduodenectomy (n = 3), local resection (n = 3), enucleation (n = 2), and duodenum-preserving pancreatic head resection (n = 1) were performed. Overall morbidity and mortality rates were 43% and 0%, respectively. All patients were still alive without recurrent disease after a median follow-up of 46 months. CONCLUSIONS: Patients with solid pseudopapillary tumor of the pancreas had a favorable outcome after surgical treatment, including enucleation.     

Clinical significance of incidental focal colorectal 18F‐fluorodeoxyglucose uptake: our experience and a review of the literature

Aim The aims of the present study were: (i) to evaluate the focal incidental colorectal uptake of ¹⁸F‐fluorodeoxyglucose ([¹⁸F]FDG) and to correlate it with colonoscopy and histological findings; (ii) to evaluate the relationship between the presence/absence of neoplastic disease and clinical data and the anatomical site of [¹⁸F]FDG uptake; and (iii) to compare our results with those reported for incidental colorectal uptake of [¹⁸F]FDG in the literature and those obtained from various screening programmes for colorectal cancer. Method The database of 6000 patients referred for [¹⁸F]FDG positron emission tomography/computed tomography (PET‐CT) to our centre was retrospectively reviewed for incidental colorectal uptake of [¹⁸F]FDG. Patients with focal uptake were selected and the aetiology of PET findings was verified with a subsequent colonoscopy and histopathological analysis when available. Results Incidental colorectal uptake of [¹⁸F]FDG was seen in 144 (2.4%) patients, of whom 64 (1.1%) had focal uptake; 48 out of these 64 patients underwent colonoscopy, which showed malignant tumours in 12 (25%), premalignant lesions in 19 (40%), non‐neoplastic lesions in six (12%) and lesions not confirmed by colonoscopy in 11 (23%). Our data agreed with previously published data. Statistical analysis did not show any significant relationship between the presence/absence of neoplastic disease and patient sex or age, type of primary disease and anatomical site of [¹⁸F]FDG uptake. Comparing our data with various screening programmes, a significant difference was found only with series in which colonoscopy was performed in patients at high risk for colorectal cancer. Conclusion Focal incidental colorectal uptake of [¹⁸F]FDG is observed in about 1% of PET/CT studies and carries a high risk of neoplastic disease. A PET‐CT report should suggest colonoscopy when abnormal findings are reported.     

Evaluation of segmental pancreatic function using 11C-methionine positron emission tomography for safe living donor operation of pancreas transplantation

For a safe living pancreas donoration for transplantation, we evaluated the function of the residual pancreas head using 11C-methionine positron emission tomography (PET) in 13 cases before and after distal pancreatectomy. After 6 hours of fasting, we intravenously administered 11C-methionine (370 to 740 MBq), performing PET at 30 minutes thereafter. 11C-methionine PET uptake in the pancreas head was expressed as a standardized uptake value (SUV) for comparison before versus after surgery: 17.3 ± 2.5 versus 17.4 ± 4.9, respectively, demonstrating no significant difference. However, the changes in SUVs of the residual pancreas head showed three patterns after surgery. The SUVs were elevated in three donors after surgery, hypermetabolite type; maintained in five donors, normometabolite type; and decreased in five donors hypometabolite type. The percentages of subjects with a postoperative HbA1c value more than 5.8%, the upper normal limit, were 33% in hypermetabolite type; 40% in the normometabolite type; and 60% in the hypometabolite type. Although diabetes mellitus has not developed in any of the 13 donors, the pancreatic head function after distal pancreatectomy was slightly decreased, especially among the hypometabolite type. To avoid postoperative diabetes mellitus for a prolonged period, donors who show decreased SUVs after surgery should be strictly followed. In conclusion, 11C-methionine PET may be a potent modality to evaluate segmental pancreatic function for a safe living donor pancreatectomy.