F-18-fluorodeoxyglucose positron emission tomography in differentiating malignant from benign pancreatic cysts: A prospective study

The differential diagnosis between benign and malignant pancreatic cystic lesions may be very difficult. We recently found that F-18-.uorodeoxyglucose positron emission tomography (18-FDG PET) was useful for the preoperative work-up of pancreatic cystic lesions. This study was undertaken to confirm these results. From February 2000 to July 2003, 50 patients with a pancreatic cystic lesion were prospectively investigated with 18-FDG PET in addition to helical computed tomography (CT) and, in some instances, magnetic resonance imaging (MRI). The validation of diagnosis was based on pathologic findings after surgery (n = 31), percutaneous biopsy (n = 4), and according to follow-up in 15 patients. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). The accuracy of FDG PET and CT was determined for preoperative diagnosis of malignant cystic lesions. Seventeen patients had malignant cystic lesions. Sixteen (94%) showed increased 18-FDG uptake (SUV >2.5), including two patients with carcinoma in situ. Eleven patients (65%) were correctly identified as having malignancy by CT. Thirty-three patients had benign tumors: two patients showed increased 18-FDG uptake, and four patients showed CT findings of malignancy. Sensitivity, specificity, positive and negative predictive value, and accuracy of 18-FDG PET and CT in detecting malignant tumors were 94%, 94%, 89%, 97%, and 94% and 65%, 88%, 73%, 83%, and 80%, respectively. 18-FDG PET is accurate in identifying malignant pancreatic cystic lesions and should be used in combination with CT in the preoperative evaluation of patients with pancreatic cystic lesions. A negative result with 18-FDG PET may avoid unnecessary operation in asymptomatic or high-risk patients. Presented at the Forty-Fifth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, Louisiana, May 15–19, 2004 (oral presentation). This study was supported by the Ministero Università e Ricerca Scientifica (Cofin 2001068593-001), Rome, Italy.     

18-fluorodeoxyglucose positron emission tomography enhances computed tomography diagnosis of malignant intraductal papillary mucinous neoplasms of the pancreas

OBJECTIVE: To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and its contribution to surgical decision making. SUMMARY BACKGROUND DATA: Pancreatic IPMNs are increasingly recognized, often as incidental findings, especially in people over age 70 and 80. Computed tomography (CT) and magnetic resonance (MR) are unreliable in discriminating a benign from a malignant neoplasm. 18-FDG PET as imaging procedure based on the increased glucose uptake by tumor cells has been suggested for diagnosis and staging of pancreatic cancer. METHODS: From January 1998 to December 2005, 64 patients with suspected IPMNs were prospectively investigated with 18-FDG PET in addition to conventional imaging techniques [helical-CT in all and MR and magnetic resonance cholangiopancreatography (MRCP) in 60]. 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value (SUV). The validation of the diagnosis was made by a surgical procedure (n = 44), a percutaneous biopsy (n = 2), main duct cytology (n = 1), or follow-up (n = 17). Mean and median follow-up times were 25 and 27.5 months, respectively (range, 12-90 months). RESULTS: Twenty-seven patients (42%) were asymptomatic. Forty-two patients underwent pancreatic resection, 2 palliative surgery, and 20 did not undergo surgery. An adenoma was diagnosed in 13 patients, a borderline tumor in 8, a carcinoma in situ in 5, and an invasive cancer in 21; in 17 patients a tumor sampling was not performed and therefore the histology remained undetermined. Positive criteria of increased uptake on 18-FDG PET was absent in 13 of 13 adenomas and 7 of 8 borderline IPMNs, but was present in 4 of 5 carcinoma in situ (80%) and in 20 of 21 invasive cancers (95%). Conventional imaging technique was strongly suggestive of malignancy in 2 of 5 carcinomas in situ and in 13 of 21 invasive carcinomas (62%). Furthermore, conventional imaging had findings that would be considered falsely positive in 1 of 13 adenomas (8%) and in 3 of 8 borderline neoplasms (37.5%). Therefore, positive 18-FDG PET influenced surgical decision making in 10 patients with malignant IPMN. Furthermore, negative findings on 18-FDG PET prompted us to use a more limited resection in 15 patients, and offered a follow-up strategy in 18 patients (3 positive at CT scan) for the future development of a malignancy. CONCLUSIONS: 18-FDG PET is more accurate than conventional imaging techniques (CT and MR) in distinguishing benign from malignant (invasive and noninvasive) IPMNs. 18-FDG PET seems to be much better than conventional imaging techniques in selecting IPMNs patients, especially when old and asymptomatic, for surgical treatment or follow-up.     

Value of 18-Fluorodeoxyglucose Positron Emission Tomography in the Management of Patients With Cystic Tumors of the Pancreas

OBJECTIVE: To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant cystic lesions of the pancreas. SUMMARY BACKGROUND DATA: The preoperative differential diagnosis of cystic lesions of the pancreas remains difficult: the most important point is to identify malignant or premalignant cysts that require resection. 18-FDG PET is a new imaging procedure based on the increased glucose metabolism by tumor cells and has been proposed for the diagnosis and staging of pancreatic cancer. METHODS: During a 4-year period, 56 patients with a suspected cystic tumor of the pancreas underwent 18-FDG PET in addition to computed tomography scanning, serum CA 19-9 assay, and in some instances magnetic resonance imaging or endoscopic retrograde cholangiopancreatography. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value. The accuracy of 18-FDG PET and computed tomography was determined for preoperative diagnosis of a malignant cyst. RESULTS: Seventeen patients had malignant tumors. Sixteen patients (94%) showed 18-FDG uptake with a standard uptake value of 2.6 to 12.0. Twelve patients (70%) were correctly identified as having malignancy by computed tomography, CA 19-9 assay, or both. Thirty-nine patients had benign tumors: only one mucinous cystadenoma showed increased 18-FDG uptake (standard uptake value 2.6). Five patients with benign cysts showed computed tomography findings of malignancy. Sensitivity, specificity, and positive and negative predictive values for 18-FDG PET and computed tomography scanning in detecting malignant tumors were 94%, 97%, 94%, and 97% and 65%, 87%, 69%, and 85%, respectively. CONCLUSIONS: 18-FDG PET is more accurate than computed tomography in identifying malignant pancreatic cystic lesions and should be used, in combination with computed tomography and tumor markers assay, in the preoperative evaluation of patients with pancreatic cystic lesions. A positive result on 18-FDG PET strongly suggests malignancy and, therefore, a need for resection; a negative result shows a benign tumor that may be treated with limited resection or, in selected high-risk patients, with biopsy, follow-up, or both.     

Sensitivity and specificity of FDG PET-CT scan in detecting lymph node metastasis in operable periampullary tumours in correlation with the final histopathology after curative surgery

18F-Fluorodeoxyglucose-positron emission tomography/computerised tomography (FDG-PET/CT) was investigated for evaluation of periampullary tumours and other gastrointestinal neoplasms. The aim of this study was to evaluate the utility of FDG-PET/CT for detection of lymph node metastasis in periampullary tumours by comparing the preoperative FDG-PET/CT scan finding with postoperative histopathology of lymph nodes. Study was done on 24 patients with diagnosis of periampullary carcinoma either proven or suspected on conventional radiology. Standard uptake value (SUV) were measured for lymph node areas with uptake in FDG-PET/CT and compared with histopathological lymph node status. For detection of lymph node metastasis, FDG-PET/CT with cutoff value SUV max ≥2.0 had a sensitivity of 71.4 % and specificity of 77.8 % and that for SUV max ≥2.5 and 2.8 were 57.1, 42.9 and 77.8, 77.8 %, respectively. The sensitivity and specificity of FDG-PET/CT at each lymph node groups were 72 and 89 % in peripancreatic area, 100 and 93 % in hepatoduodenal area and 100 and 100 % in aortocaval area at SUV max ≥2.0, respectively. At SUV max ≥2.5 the values were 57 and 89 % in peripancreatic area, 100 and 93 % in hepatoduodenal area and 100 and 93 % in aortocaval area. FDG-PET-CT has a possible role in detection of lymph node metastasis in periampullary carcinomas and may be used as a guide for possible lymphadenectomy during surgery and for prognostic purpose.     

Value of 18-FDG-positron emission tomography/computed tomography before and after transarterial chemoembolization in patients with hepatocellular carcinoma undergoing liver transplantation: initial results

Introduction

Liver transplantation is the treatment of choice for various types of end-stage liver disease and the most appropriate alternative for the treatment of hepatocellular carcinoma (HCC)-associated liver cirrhosis. The aim of this study was to describe our initial experience with the use of 18-FDG positron emission tomography (PET)/computed tomography CT before and after transarterial chemoembolization (TACE) in HCC patients undergoing liver transplantation, seeking to predict the percentage of tumor necrosis achieved by TACE procedures.

Patients and Methods

From January 2007 through December 2009, 39 patients with HCC and liver cirrhosis were included in our liver transplantation program. We selected the 6 subjects who underwent 18-fluorodeoxyglucose PET/CT (18-FDG PET/CT) pre- and post-TACE.

Results

The median SUV (standarized uptake value) in the lesions studied were 4 (range, 2.79-6.95) before TACE with a median post-TACE SUV of 0 (range, 0-4). Among patients whose post-TACE SUV decreased to <3, the percentage of necrosis after studying the hepatectomy was >80%.

Conclusion

Performance of an 18-FDG PET/CT before and after TACE and comparison of SUV in patients with HCC awaiting liver transplantation provided valuable information regarding the effectiveness of TACE.     

Clinical utility of positron emission tomography in the diagnosis and management of periampullary neoplasms

Background This study examined the effect that 18-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) imaging had on the clinical management of patients with suspected periampullary malignancy. Methods Fifty-four patients with suspected pancreatic neoplasms underwent both whole-body¹⁸FDG-PET and abdominal computed tomography (CT). Malignant or benign disease was confirmed pathologically in 47 patients. Results Of the 41 patients with malignancy,¹⁸FDG-PET failed to identify the primary tumor in 5 patients.¹⁸FDG-PET demonstrated increased uptake suggesting primary malignancy in 37 patients. Malignant pathology was confirmed in 36 cases.¹⁸FDG-PET identified malignant locoregional lymph node metastases in six of ten patients. All nodes identified before surgery by¹⁸FDG-PET were also seen on preoperative CT. Six patients who were thought to have resectable disease by CT were found to have distant metastasis at laparotomy.¹⁸FDG-PET did not detect metastasis in any of these cases. Before surgery,¹⁸FDG-PET identified distant metastases that were not detected by CT in one patient. Conclusions Despite high sensitivity and specificity in diagnosing periampullary malignancy,¹⁸FDG-PET did not change clinical management in the vast majority of patients previously evaluated by CT. In addition,¹⁸FDG-PET missed>10% of periampullary malignancies and did not provide the anatomical detail necessary to define unresectability.     

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.     

18F-FDG PET/CT评价伽马刀治疗肿瘤疗效

目的探讨18F-FDG PET/CT在评价伽马刀治疗肿瘤疗效中的价值。方法对39例肿瘤术后复发患者,在伽马刀治疗前和治疗后3个月,根据CT显像的病灶大小、PET显像的平均标准摄取值（SUVmean）变化以及SUV变化率（△SUV）分别进行近期疗效判定。结果治疗前PET/CT全身检查后检出病灶并行伽马刀定位病灶65个,平均直径（3.32±3.57）cm;平均SUVmean5.92±2.62。伽马刀治疗3个月后复查,PET/CT检出病灶50个,平均直径（2.54±2.76）cm;平均SUVmean3.82±3.40。伽马刀治疗后病灶最大直径普遍较前缩小（P〈0.05）,伽马刀治疗后SUVmean显著降低（P〈0.001）。伽马刀治疗后CT显示的总有效率为38.46%（25/65）,PET SUVmean显示总有效率为55.38%（36/65）,二者之间差异有统计学意义（χ2=6.24,P〈0.05）。△SUV的总有效率为49.23%（32/65）。结论 18F-FDG PET/CT可以从病灶的大小和代谢两方面评价伽马刀治疗肿瘤的疗效。     

Noninvasive diagnosis of focal hyperinsulinism of infancy with [18F]-DOPA positron emission tomography

Congenital hyperinsulinism of infancy (CHI) is characterized by severe hypoglycemia due to dysregulated insulin secretion, associated with either focal or diffuse pathology of the endocrine pancreas. The focal condition is caused by a paternally inherited mutation in one of the genes encoding the subunits of the beta-cell ATP-sensitive potassium channel (SUR1/ABCC8 or Kir6.2/KCNJ11) and somatic loss of maternal 11p15 alleles within the affected area. Until now, preoperative diagnostics have relied on technically demanding and invasive catheterization techniques. We evaluated the utility of fluorine-18 l-3,4-dihydroxyphenylalanine ([(18)F]-DOPA) positron emission tomography (PET) to identify focal pancreatic lesions in 14 CHI patients, 11 of which carried mutations in the ABCC8 gene (age 1-42 months). To reduce bias in PET image interpretation, quantitative means for evaluation of pancreatic [(18)F]-DOPA uptake were established. Five patients had a visually apparent focal accumulation of [(18)F]-DOPA and standardized uptake value (SUV) >50% higher (mean 1.8-fold) than the maximum SUV of the unaffected part of the pancreas. When these patients were operated on, a focus of 4-5 x 5-8 mm matching with the PET scan was found, and all were normoglycemic after resection of the focus. The remaining nine patients had diffuse accumulation of [(18)F]-DOPA in the pancreas (SUV ratio <1.5). Diffuse histology was verified in four of these, and pancreatic catheterization was consistent with diffuse pathology in four cases. In conclusion, [(18)F]-DOPA PET is a promising noninvasive method for the identification and localization of the focal form of CHI.     

Factors predictive of survival in ampullary carcinoma.

OBJECTIVE: To review the recent Memorial Sloan-Kettering Cancer Center experience with adenocarcinoma of the ampulla of Vater and to identify clinicopathologic factors that have an impact on patient survival. SUMMARY BACKGROUND DATA: The prognosis for patients with tumors of the ampulla of Vater is improved relative to other periampullary neoplasms. Identification of independent prognostic factors in ampullary tumors has been limited by small numbers of tumors and a lack of pathologic review. METHODS: Data were collected prospectively for patients presenting with periampullary carcinomas to the Memorial Sloan-Kettering Cancer Center between October 15, 1983 and June 30, 1995. The correlation between clinicopathologic variables and survival of ampullary carcinoma was tested by the Kaplan-Meier method and log-rank test, and Cox proportional hazards regression. Survival of patients with periampullary adenocarcinomas was compared by the Kaplan-Meier method. RESULTS: In 123 patients presenting with ampullary carcinoma, 101 tumors (82.1%) were resected. Factors significantly correlated with improved survival were resection (p < 0.01), and in resected tumors, negative nodes (p = 0.04) and margins (p = 0.02) independently predicted for improved survival. In periampullary tumors, the highest rates of resection and overall survival (median, 43.6 months) were found in ampullary carcinomas. CONCLUSIONS: Factors predictive of improved survival in ampullary carcinoma include resection, negative margins, and negative nodes. Improved overall survival in ampullary relative to periampullary adenocarcinoma is due in part to a significantly higher rate of resection.     

Comparison of Linear Array Endoscopic Ultrasound and Helical Computed Tomography for the Staging of Periampullary Malignancies

Background: The purpose of this study was to compare linear array endoscopic ultrasound (EUS) and helical computed tomography (CT) scan in the preoperative local staging evaluation of patients with periampullary tumors.Methods: Patients evaluated with EUS and CT for suspected periampullary malignancies from 1996 to 2000 were analyzed. Surgical/pathology staging results were the reference standard.Results: Forty-eight patients (28 men and 20 women; mean age, 62 ± 4.9 years; range, 18–90 years) were identified. Malignancy was histologically confirmed in 44 patients. Parameters evaluated included tumor size, lymph node metastases, and major vascular invasion. EUS was significantly more sensitive (100%), specific (75%), and accurate (98%) than helical CT (68%, 50%, and 67%, respectively) for evaluation of the periampullary mass (P < .05). In addition, EUS detected regional lymph node metastases in more patients than helical CT. Sensitivity, specificity, and accuracy of EUS were 61%, 100%, and 84%, in comparison to 33%, 92%, and 68%, respectively, with CT. Major vascular involvement was noted in 9 of 44 patients. EUS correctly identified vascular involvement in 100% compared with 45% with CT (P < .05).Conclusions: Linear array EUS was consistently superior to helical CT in the preoperative local staging of periampullary malignancies.Presented in part at the Society of Surgical Oncology Parallel Session, Washington, DC, March 2001.     

Telomerase activity in periampullary tumors correlates with aggressive malignancy

OBJECTIVE: To determine the presence of telomerase activity in a variety of periampullary malignancies and pancreatic diseases and quantify its activity to establish any association with the stage or aggressiveness of malignancy. SUMMARY BACKGROUND DATA: Progressive shortening of telomeres, repetitive DNA sequences at the ends of chromosomes, plays a role in cell senescence. Telomerase catalyzes conservation of telomeric repeats and may promote cell immortality and hence malignancy. It is absent in normal tissues but upregulated in more than 80% of cancers. METHODS: Fresh specimens of 62 periampullary tumors were snap-frozen in liquid nitrogen and adjacent tissue was formalin-fixed for histopathology. The telomerase repeat amplification protocol (TRAP) was used to obtain telomerase DNA products. These were separated with gel electrophoresis, stained with SYBR green, and quantified by densitometry. Findings were confirmed with a fluorometric TRAP assay in which fluorescent primers specific for telomerase were selectively amplified in its presence. RESULTS: Telomerase activity was upregulated in 26 of 33 periampullary malignancies (79%): 17 of 21 pancreatic adenocarcinomas (81%), 2 of 2 cholangiocarcinomas, 2 of 2 duodenal carcinomas, and 5 of 8 ampullary carcinomas (63%). Poorly differentiated periampullary tumors had significantly higher telomerase activity than well-differentiated tumors, and tumors larger than 2 cm had significantly higher telomerase activity than those 2 cm or smaller. Pancreatic ductal adenocarcinomas with lymph node metastases had significantly greater activity than node-negative cancers. Two of 11 intraductal papillary mucinous tumors were positive for telomerase activity, but only in foci of invasive carcinoma. Chronic pancreatitis (n = 7), serous cystadenomas (n = 5), benign mucinous cystic neoplasms (n = 4), neuroendocrine cancer (n = 1), and acinar cell carcinoma (n = 1) had no detectable telomerase activity. CONCLUSION: Telomerase activity is common in periampullary carcinomas. The magnitude of activity correlates with aggressiveness in pancreatic adenocarcinoma and may prove useful as a molecular index for biologic staging.     

18F-FDG Uptake at Initial Staging of the Adrenocortical Cancers: A Diagnostic Tool but Not of Prognostic Value

Background

Adrenocortical carcinoma (ACC) is a rare cancer for which little level evidence exists to guide management. ¹⁸F-FDG PET (¹⁸F-fluorodeoxyglucose positron emission tomography) is an increasingly used diagnostic tool in patients with suspicious or indeterminate adrenal tumors. In some other solid tumors, ¹⁸F-FDG PET may offer prognostic information that can guide optimal patient treatment. The aim of the present study was to evaluate whether preoperative ¹⁸F-FDG PET based on SUVs assessments has a prognostic value in ACC patients.

Methods

A retrospective analysis was performed in patients who underwent ¹⁸F-FDG PET/CT for the evaluation of ACC. Inclusion criteria were an unequivocal diagnosis of ACC; all data from primary diagnosis available; ¹⁸F-FDG PET/CT performed prior to surgery or other treatment of the primary tumor; a minimum of 6-months follow-up for surviving patients. All ¹⁸F-FDG PET/CT procedures were reinterpreted in a blind fashion.

Results

Thirty-seven patients (23 without metastasis [M0], 14 with metastasis [M1]) fulfilled the study criteria. Median uptake values were tumor standardized uptake values (SUV)_max = 11 (range: 3–56) and a tumor/liver SUV_max ratio = 4.2 (range: 1.3–15). Median follow-up was 20 months. Although classic risk factors (tumoral stage, Weiss score) were associated with poor outcome, there was no correlation between primary tumor FDG uptake with overall survival (OS) and disease free survival (DFS) in M0 patients and with overall survival in M1 patients. ¹⁸F-FDG uptake correlated inconsistently with sinister histological features, such as atypical mitoses or necrosis.

Conclusions

At initial staging, primary tumor FDG uptake in ACC patients does not correlate with OS and DFS at 2 years. Patient prognosis and treatment strategy should not be based on uptake values.     

Expanding role of 18F-fluoro-d-deoxyglucose PET and PET/CT in spinal infections

¹⁸F-fluoro-d-deoxyglucose positron emission tomography ([¹⁸F]-FDG PET) is successfully employed as a molecular imaging technique in oncology, and has become a promising imaging modality in the field of infection. The non-invasive diagnosis of spinal infections (SI) has been a challenge for physicians for many years. Morphological imaging modalities such as conventional radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are techniques frequently used in patients with SI. However, these methods are sometimes non-specific, and difficulties in differentiating infectious from degenerative end-plate abnormalities or postoperative changes can occur. Moreover, in contrast to CT and MRI, FDG uptake in PET is not hampered by metallic implant-associated artifacts. Conventional radionuclide imaging tests, such as bone scintigraphy, labeled leukocyte, and gallium scanning, suffer from relatively poor spatial resolution and lack sensitivity, specificity, or both. Initial data show that [¹⁸F]-FDG PET is an emerging imaging technique for diagnosing SI. [¹⁸F]-FDG PET appears to be especially helpful in those cases in which MRI cannot be performed or is non-diagnostic, and as an adjunct in patients in whom the diagnosis is inconclusive. The article reviews the currently available literature on [¹⁸F]-FDG PET and PET/CT in the diagnosis of SI.     

Factors influencing survival after resection for periampullary neoplasms

BACKGROUND: The purpose of this study was to determine predictors of survival after resection for periampullary neoplasms. METHODS: Over a 15-year period, 208 patients underwent laparotomy for periampullary neoplasms. Data were analyzed to assess predictors of survival. RESULTS: Pathologic examination showed pancreatic cancer (n = 136; 65%), ampullary cancer (n = 28; 13%), distal common bile duct cancer (n = 10; 5%), duodenal cancer (n = 4; 2%), neuroendocrine tumor (n = 11; 5%), cystadenocarcinoma (n = 4; 2%), cystadenoma (n = 5; 2%), and other (n = 10; 5%). A total of 129 patients underwent pancreatic resection (71 Whipples, 35 total pancreatectomies, 21 distal pancreatectomies, and 2 partial pancreatectomies) whereas 79 patients were found to be unresectable and underwent palliative bypass and/or biopsy. Median survival was 20.4 months for resectable patients versus 4.5 months for unresectable patients (P<0.001). Of the 129 resected patients, factors significantly (P<0.05) favoring long-term survival on univariate analysis included well-differentiated histology, common bile duct or ampullary adenocarcinoma, early stage, tumor diameter <2 cm, negative margins, and absence of lymph node metastases, perineural, or vascular invasion. Age, sex, race, and type of procedure had no influence on survival. On multivariate analysis, only tumor differentiation appeared independently related to survival. Using Kendall's tau analysis, tumor type and grade correlated significantly with all other predictors. CONCLUSIONS: Of all variables studied, tumor type and poor tumor differentiation in periampullary neoplasms appear to be markers that predict a constellation of other adverse findings.     

Detection of incidental colorectal tumours with 18F‐labelled 2‐fluoro‐2‐deoxyglucose positron emission tomography/computed tomography scans: results of a prospective study

Aim This study assessed the clinical significance of incidental colorectal 2‐fluoro‐2‐deoxyglucose (FDG) uptake using ¹⁸F‐FDG positron emission tomography/computed tomography (PET/CT) scans and evaluated the importance of colonoscopy when incidental colorectal FDG uptake was observed. Method A prospective study was designed and conducted at a single institution over a 2‐year period. In patients undergoing PET/CT scans, all with FDG uptake in the colorectum were assigned to have colonoscopy and biopsy. The value of PET/CT scanning was studied by comparison with the colonoscopy and biopsy results. Results Among 10 978 PET/CT scans, one or more focal uptakes of FDG in the colorectum were observed in 148 (1.35%) patients. In 136 valid patients, malignant colorectal tumours and polyps were found in 23.5% and 20.5%, respectively,, while the colon in the other 56% was normal. A higher false‐positive rate was found in the right colon compared with the distal colorectum (66.2%vs 36.7%, P = 0.004). A significant increase of the maximum standardized uptake (SUVmax) value was found among normal, polyps and cancer groups. Multivariate analysis revealed that SUVmax was the risk factor for predicting colorectal cancer or polyps and FDG uptake in the right colon was a negative predictive factor for finding cancers or polyps. Conclusions Our study proves the necessity of colonoscopy when incidental FDG uptake is found on PET/CT imaging. The false‐positive FDG uptake is more commonly observed in the right colon. Although the SUVmax value is higher in cancer patients, a high SUVmax value does not necessarily result in malignancies.     

Ampullary but not periampullary duodenal diverticula are an etiologic factor for chronic pancreatitis

BACKGROUND: Duodenal diverticula are common incidental findings. Although a definite treatment is rarely required, an association with biliary and pancreatic diseases is often suggested. Our aim was to determine the frequency of complications in relation to the location of the diverticulum. METHODS: We reviewed 64 patients with extraluminal duodenal diverticula. In 24 of these patients the diverticulum was treated surgically. The incidence of symptoms and complications is analyzed and follow-up in 88% of operated patients is presented. RESULTS: Thirty-one patients presented with ampullary, 36 patients with periampullary diverticula. Three patients had both types of diverticula. The indication for surgery in 24 patients was chronic pancreatitis (n = 12), chronic pain (n = 6), diverticular perforation (n = 3), bleeding (n = 2), or jaundice (n = 1). In 7 out of 31 patients with ampullary and none out of 36 patients with periampullary diverticula, chronic pancreatitis was considered to be induced by the diverticulum. Morbidity in 24 operated patients was 17%, no patient died. At follow-up all patients were free of symptoms. CONCLUSION: Extraluminal duodenal diverticula are frequently found. They rarely cause symptoms and need no surgical treatment. While ampullary duodenal diverticula can cause chronic pancreatitis, periampullary duodenal diverticula are no etiologic factor.     

Positron-emission tomography as a prognostic tool for early-stage lung cancer

BACKGROUND: Positron-emission tomography (PET) shows tissue metabolic activity in the form of the standard uptake value (SUV). This study examines the prognostic value of the SUV for early-stage lung cancer. METHODS: A retrospective review of 187 patients undergoing PET for potential lung cancer. Data collected included patient demographics, tumor pathology, and survival information. Data were correlated with PET results to determine if a prognostic relationship exists. RESULTS: The sensitivity and specificity of PET for detecting malignant lesions were 98% and 24%. Malignant lesions had a higher SUV than benign lesions (5.9 +/- 6.2 versus 2.2 +/- 1.8, P < .0001). The average SUV of well-differentiated tumors was 2.6 +/- 3.1 versus 5.9 +/- 5.5 for other tumors (P = .010). There was a strong correlation between tumor stage and SUV (analysis of variance, P < .0001). There was no difference in tumor SUV for survivors versus nonsurvivors. CONCLUSIONS: The SUV correlates with prognostic indicators, such as tumor stage and grade. The SUV alone was not an independent predictor of survival.     

Influence of site of origin and mucin production on survival in ampullary carcinoma.

We studied a series of 26 cases of carcinoma of the ampulla of Vater. There were 24 adenocarcinomas and two neuroendocrine tumors. Histologically the carcinomas could be divided into tumors arising from periampullary duodenal mucosa and those arising within the ampulla. True ampullary tumors had a significantly better 5-year survival rate (p = 0.028) than periampullary tumors. The type of mucin produced was investigated histochemically. Patients with true ampullary tumors producing predominantly sialomucins had a better prognosis than those with tumors secreting sulphated mucins (p = 0.045), but the numbers were small. We hypothesize that the most favorable type of ampullary carcinoma arises from biliary-type epithelium within the ampulla.