Evaluation of 18 F-fluorodeoxyglucose positron emission tomography and computed tomography with histopathologic correlation in the initial staging of head and neck cancer

OBJECTIVE: To prospectively evaluate the use of 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) in the initial staging of squamous cell head and neck carcinoma. SUMMARY BACKGROUND DATA: The status of cervical lymph nodes is an important prognostic factor and determinant of management approach in squamous cell head and neck cancer. METHODS: FDG-PET findings were compared with those of computed tomography (CT) before removal of the primary tumor and/or neck dissection. Histopathologic analysis was used as the gold standard for assessment of the sensitivity and specificity of these modalities. RESULTS: FDG-PET correctly identified the primary tumor in 35 of 40 patients in whom the site of the primary was known clinically and still present (sensitivity 88%). None of four unknown primaries were detected. Tumors not detected by FDG-PET were generally superficial, with depths of less than 4 mm. CT correctly identified 18 of the 35 primary tumors (sensitivity 51%). Eleven of 17 CT false-negative tumors were detected by FDG-PET. The sensitivity and specificity for the presence of metastatic neck disease on FDG-PET were 82% and 100%, respectively; those for CT were 81% and 81%, respectively. FDG-PET was true positive for metastatic neck disease in two of the three CT false-negative patients. CONCLUSIONS: FDG-PET shows promise in the initial staging of head and neck cancer and provides additional accuracy to a conventional staging process using CT.     

PET/CT检查注射~(18)F-FDG方法研究

目的比较PET/CT检查经留置针和头皮针注射~(18)F-2-氟-2-脱氧-D-葡萄糖(~(18)F-FDG)的差异,探讨预置留置针用于PET/CT检查的可行性。方法将120例行PET/CT检查患者按检查时间段分为对照组、模型1组和模型2组,对照组按常规方法采用头皮针注射18F-FDG,模型1组和模型2组采用留置针注射~(18)F-FDG,注射前生理盐水冲洗量均为3 mL,注射后分别为5 mL、5mL、10mL,比较三组残留放射性活度;同期选择45例已预置留置针的患者为实验组,采用留置针注射并不拔除留置针,注射前后生理盐水冲冼量分别为5mL、10mL,与对照组比较放射性浓聚、药物污染、受辐射时间的差异。结果对照组与实验组放射性浓聚及药物污染发生率、受辐射时间比较,差异无统计学意义(均P0.05);模型1组残留放射性活度显著高于对照组(P0.05)。结论 PET/CT检查可经预置留置针注射18F-FDG,使用时须增加冲洗管道的生理盐水量。     

The diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography and computed tomography in staging bladder cancer: a single-institution study and a systematic review with meta-analysis

Purpose

The purpose of this study was to assess the diagnostic accuracy of 18F-fluorodeoxyglucose with positron emission tomography and computed tomography (FDG–PET–CT) to predict nodal metastases in patients with bladder cancer (BC) scheduled to undergo radical cystectomy (RC).

Methods

We retrospectively reviewed records of patients diagnosed with BC and scheduled to undergo RC at our center from January 2011 through February 2015, who also underwent FDG–PET–CT at the time of diagnosis. All patients underwent RC and an extended pelvic lymph node dissection as the reference standard. The primary endpoints were the sensitivity, specificity and overall accuracy of FDG–PET–CT in detecting lymph node metastasis. We also examined its accuracy in identifying distant metastasis. In addition, we conducted a protocol-driven systematic review and meta-analysis of accuracy of FDG–PET–CT for preoperative staging of BC, as compared to CT alone, as reported in individual studies. To assess the methodological quality of eligible studies, we used the QUADAS-2 tool (a revised tool for the Quality Assessment of Diagnostic Accuracy Studies) and pooled diagnostic accuracy measures using Meta-DiSc statistical software.

Results

For detecting nodal metastases in 78 patients, the sensitivity of FDG–PET–CT was 0.56 (95 % CI 0.29–0.80) and the specificity, 0.98 (95 % CI 0.91–1.00). Pooled sensitivity and specificity for detecting lymph node metastasis were 0.57 and 0.95, respectively. Positive likelihood ratio was 9.02. All lesions that were suspicious for distant metastasis were found to be positive on biopsy.

Conclusion

FDG–PET–CT was more accurate than CT alone in staging BC in patients undergoing surgery. Standardization of FDG–PET–CT protocol and cost-effectiveness analysis are required before widespread implementation of this technology.

     

Surgical strategy for aortic prosthetic graft infection with 18F-fluorodeoxyglucose positron emission tomography/computed tomography

A 30-year-old man with Marfan syndrome who underwent Crawford type II extension aneurysm repair about 9 years ago was referred to our hospital with persistent fever. Computed tomography (CT) showed air around the mid-descending aortic prosthetic graft. Because the air did not disappear in spite of intravenous antibiotics, ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was performed. FDG-PET/CT revealed four high-uptake lesions. After dissecting the aortic graft particularly focusing on the high-uptake lesions, this patient underwent in situ graft re-replacement of descending aortic graft with a rifampicin-bonded gelatin-impregnated Dacron graft and omentopexy. The patient remains well without recurrent infection at 3 months after surgery.     

Stereotactic imaging for radiosurgery: localization accuracy of magnetic resonance imaging and positron emission tomography compared with computed tomography

Computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) provide complementary information for treatment planning in stereotactic radiosurgery. We evaluated the localization accuracy of MRI and PET compared with CT. Two kinds of phantoms applicable to the Leksell G stereotactic skull frame (Elekta, Tokyo) were developed. Deviations of measured coordinates at target points (x = 50, 100, 150; y = 50, 100, 150) were determined on different axial planes (z = 30-140 for MRI and CT study and Z = 50-120 for PET and CT study). For MRI, the deviations were no more than 0.8 mm in each direction. For PET, the deviations were no more than 2.7 mm. For both imaging modalities studied, accuracy was at or below the imaging resolution (pixel size) and should be considered useful for clinical stereotactic planning purposes.     

Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography

Objective: To evaluate the accuracy of integrated positron emission tomography with ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) and computed tomography (PET/CT) in preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer (NSCLC) and to ascertain the role of invasive staging in verifying positron emission tomography (PET)/computed tomography (CT) results. Methods: Retrospective, single institution study of consecutive patients with suspected or pathologically proven, potentially resectable NSCLC undergoing integrated PET/CT scanning in the same PET centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station bases. Results: A total of 1001 nodal stations (723 mediastinal, 148 hilar and 130 intrapulmonary) were evaluated in 159 patients. Nodes were positive for malignancy in 48 (30.2%) out of 159 patients (N1 = 17; N2 = 30; N3 = 1) and 71 (7.1%) out of 1001 nodal stations (N1 = 24; N2 = 46; N3 = 1). At univariate analysis, lymph node involvement was significantly associated (p < 0.05) with the following primary tumour characteristics: increasing diameter, maximum standardised uptake value >9, central location and presence of vascular invasion. PET/CT staged the disease correctly in 128 out of 159 patients (80.5%), overstaging occurred in nine patients (5.7%) and understaging in 22 patients (13.8%). The overall sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting metastatic lymph nodes were 54.2%, 91.9%, 74.3%, 82.3% and 80.5% on a per-patient basis, and 57.7%, 98.5%, 74.5%, 96.8% and 95.6% on per-nodal-station basis. With regard to N2/N3 disease, PET/CT accuracy was 84.9% and 95.3% on a per-patient basis and on per-nodal-station basis, respectively. Referring to nodal size, PET/CT sensitivity to detect malignant involvement was 32.4% (12/37) in nodes <10 mm, and 85.3% (29/34) in nodes ≥10 mm. Conclusion: Our data show that integrated PET/CT provides high specificity but low sensitivity and accuracy in intrathoracic nodal staging of NSCLC patients and underscore the continued need for surgical staging.     

11C-choline positron emission tomography/computerized tomography for preoperative lymph-node staging in intermediate-risk and high-risk prostate cancer: comparison with clinical staging nomograms

BACKGROUND: Conventional imaging (CI) techniques are inadequate for lymph node (LN) staging in prostate cancer (PCa). OBJECTIVES: To assess the accuracy of (11)C-Choline positron emission tomography/computerized tomography (PET/CT) for LN staging in intermediate-risk and high-risk PCa and to compare it with two currently used nomograms. DESIGN, SETTING, AND PARTICIPANTS: From January 2007 to September 2007, 57 PCa patients at intermediate risk (n=27) or high risk (n=30) were enrolled at two academic centres. All patients underwent preoperative PET/CT and radical prostatectomy with extended pelvic LN dissection (PLND). Risk of LN metastasis (LNM) was assessed using available nomograms. MEASUREMENTS: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and number of correctly recognized cases for LNM detection at PET/CT were assessed. The accuracy of PET/CT for LNM detection was compared with the accuracy of nomograms for LNM prediction by using receiver operating characteristic (ROC) analysis. RESULTS AND LIMITATIONS: Fifteen patients (26%) had LNMs, and a total of 41 LNMs were identified. On a patient analysis, sensitivity, specificity, PPV, NPV, and number of correctly recognized cases at PET/CT were 60.0%, 97.6%, 90.0%, 87.2%, and 87.7% while, on node analysis, these numbers were 41.4%, 99.8%, 94.4%, 97.2%, and 97.1%. The mean diameter (in mm) of the metastatic deposit of true-positive LNs was significantly higher than that of false-negative LNs (9.2 vs 4.2; p=0.001). PET/CT showed higher specificity and accuracy than the nomograms; however, in pairwise comparison, the areas under the curve (AUCs) were not statistically different (all p values >0.05). CONCLUSIONS: In patients with intermediate-risk and high-risk PCa, (11)C-Choline PET/CT has quite a low sensitivity for LNM detection but performed better than clinical nomograms, with equal sensitivity and better specificity.     

18F-fluorodeoxyglucose positron emission tomography influences management decisions in patients with biliary cancer

BACKGROUND: Although (18)F-fluorodeoxyglucose positron emission tomography (PET) has widespread clinical use, its role in cancers of the biliary tract is ill-defined. The aim of this study was to determine if preoperative PET provided additional staging information in patients with biliary tract cancer, beyond that obtained through conventional anatomic imaging. The role of PET in detecting disease recurrence after resection was also examined. STUDY DESIGN: Between March 2001 and October 2003, 126 patients with biopsy-proved or presumed biliary tract cancer (intrahepatic or extrahepatic cholangiocarcinoma and gallbladder carcinoma) underwent PET in addition to standard imaging evaluation. Histologic confirmation of the diagnosis was used as the reference standard with which PET results were compared. Patient followup information and serial imaging were reviewed for progression of lesions detected by PET. RESULTS: Of the 126 study patients, 93 (74%) underwent preoperative staging PET scans, the results of which changed the stage and treatment in 22 patients (24%): 15 of 62 (24%) with cholangiocarcinoma and 7 of 31 (23%) with gallbladder carcinoma. When used to assess for cancer recurrence (n=33), PET identified disease in 86% of patients but altered treatment in only 9%. So, of the entire study group, the findings of PET influenced management in 20% of patients (24% preoperative staging and 9% cancer recurrence). The sensitivity of PET for identifying the primary tumor was 80% overall: 78% for cholangiocarcinoma, 86% for gallbladder carcinoma. CONCLUSIONS: Most biliary tract cancers are (18)F-fluorodeoxyglucose avid tumors. In patients with potentially resectable tumors based on conventional imaging, PET identified occult metastatic disease and changed management in nearly one-fourth of all patients. PET also helped confirm recurrent cancer after resection.     

Combined positron emission tomography/computed tomography imaging of recurrent thyroid cancer.

OBJECTIVE: The study goal was to evaluate the use of combined positron emission tomography/computed tomography (PET/CT) imaging for localization of recurrent disease in thyroid cancer patients. STUDY DESIGN AND SETTING: Eight patients with suspected recurrence of thyroid cancer on the basis of elevated serum thyroglobulin or calcitonin levels underwent combined PET/CT imaging on a prototype device. All 8 patients had previously undergone total thyroidectomy and (131)I ablation for thyroid carcinoma. Patients with papillary carcinoma had negative (131)I scans. RESULTS: Eight patients underwent combined PET/CT scanning. Four (50%) of 8 patients underwent PET/CT indicating recurrence in the head and neck. A total of 11 lesions in these 4 patients were suspicious for recurrence on combined PET/CT imaging. Three patients with 8 lesions suspicious for recurrence on PET/CT underwent surgical removal of disease. All 3 patients had pathologic confirmation of recurrence, with 6 (75.0%) of 8 lesions being positive. CONCLUSION: Combined PET/CT imaging is a valuable tool for the diagnosis and anatomic localization of recurrent thyroid cancer.     

Prospective evaluation of 11C-choline positron emission tomography/computed tomography and diffusion-weighted magnetic resonance imaging for the nodal staging of prostate cancer with a high risk of lymph node metastases

Background

Contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for lymph node (LN) staging of prostate cancer (PCa) are largely inadequate.

Objective

Our aim was to assess prospectively the sensitivity, specificity, and positive and negative predictive values for the LN staging by ¹¹C-choline positron emission tomography (PET)-CT and MR diffusion-weighted imaging (DWI) of the pelvis before retropubic radical prostatectomy (RRP) with extended pelvic LN dissection (PLND).

Design, setting, and participants

From February 2008 to August 2009, 36 patients with histologically proven PCa and no pelvic LN involvement on contrast-enhanced CT with a risk ≥10% but ≤35% at LN metastasis according to the Partin tables were enrolled in this study.

Intervention

Patients preoperatively underwent ¹¹C-choline PET-CT and DWI. Subsequently all patients underwent a wide RRP and an extended PLND.

Measurements

Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for LN status of ¹¹C-choline PET-CT and DWI were calculated with the final histopathology of the LNs as comparator.

Results and limitations

Seventeen patients (47%) had a pN1 stage, and 38 positive LNs were identified. On a LN region-based analysis, sensitivity, specificity, PPV, NPV, and the number of correctly recognised cases at ¹¹C-choline PET-CT were 9.4%, 99.7%, 75.0%, 91.0%, and 7.9%, respectively, and at DWI these numbers were 18.8%, 97.6%, 46.2%, 91.7%, and 15.8%, respectively. Twelve LN regions containing macrometastases, of which 2 had capsular penetration, were not detected by ¹¹C-choline PET-CT; 11 LNs, of which 2 had capsular penetration, were not detected by DWI. This is a small study with 36 patients, but we intend to recruit more patients.

Conclusions

From this prospective histopathology-based evaluation of ¹¹C-choline PET-CT and DWI for LN staging in high-risk PCa patients, it is concluded that these techniques cannot be recommended at present to detect occult LN metastases before initial treatment.     

Combined 18F‐fluorocholine and 18F‐fluoride positron emission tomography/computed tomography imaging for staging of high‐risk prostate cancer

Study Type – Diagnosis (cohort) Level of Evidence 2a What's known on the subject? and What does the study add? Positron emission tomography/computed tomography (PET/CT) with choline and fluoride for the detection of metastases in patients with prostate cancer have each been evaluated, with mixed results. Choline PET/CT has been evaluated against pelvic lymphadenectomy, generally with a low sensitivity but a high specificity; however, the study populations have been heterogenous. Fluoride PET/CT has been evaluated against other imaging methods, such as bone scan, single photon emission CT and MRI, and has been shown to have high specificity as well as sensitivity for bone metastases, but there are no studies with biopsy verification. This is the first study that evaluates the clinical use of both choline and fluoride PET/CT on the same patients in a well‐defined population of patients with high‐risk prostate cancer.

OBJECTIVE

• ? To investigate how often positron emission tomography/computed tomography (PET/CT) scans, with both ¹⁸F‐fluorocholine and ¹⁸F‐fluoride as markers, add clinically relevant information for patients with prostate cancer who have high‐risk tumours and a normal or inconclusive planar bone scan.

PATIENTS AND METHODS

• ? Patients with prostate cancer with prostate specific antigen (PSA) levels between 20 and 99 ng/mL and/or Gleason score 8–10 tumours, planned for treatment with curative intent based on routine staging with a negative or inconclusive bone scan, were further investigated with a ¹⁸F‐fluorocholine and a ¹⁸F‐fluoride PET/CT.
• ? None of the patients received hormonal therapy before the staging procedures were completed.

RESULTS

• ? For 50 of the 90 included patients (56%) one or both PET/CT scans indicated metastases.
• ? ¹⁸F‐fluorocholine PET/CT indicated lymph node metastases and/or bone metastases in 35 patients (39%).
• ? ¹⁸F‐fluoride PET/CT was suggestive for bone metastases in 37 patients (41%).
• ? In 18 patients (20%) the PET/CT scans indicated widespread metastases, leading to a change in therapy intent from curative to non‐curative.
• ? Of the patients with positive scans, 74% had Gleason score 8–10 tumours. Of the patients with Gleason score 8–10 tumours, 64% had positive scans.

CONCLUSIONS

• ? PET/CT scans with ¹⁸F‐fluorocholine and ¹⁸F‐fluoride commonly detect metastases in patients with high‐risk prostate cancer and a negative or inconclusive bone scan.
• ? For 20% of the patients the results of the PET/CT scans changed the treatment plan.

     

11C-acetate and 18F-fluorodeoxyglucose positron emission tomography of pulmonary adenocarcinoma

Positron emission tomography (PET) with 11C-acetate has been recently reported in detection of slow-growing tumors, such as well-differentiated adenocarcinomas of the lung, which are often negative with 18F-fluorodeoxyglucose (FDG) PET. Here we present findings of acetate-PET and FDG-PET in a case of adenocarcinoma that was comprised of peripheral ground glass opacity and solid central components, and was histologically comprised of both a well-differentiated and a moderately-differentiated adenocarcinoma, respectively. Acetate-PET was positive in both components, whereas FDG-PET was only positive in the solid central component. The present case demonstrates the figurative findings of acetate-PET and FDG-PET in lung adenocarcinoma.     

Comparison of magnetic resonance imaging and computed tomography in the preoperative staging of rectal cancer

Nineteen patients with middle and lower rectal carcinomas were operated on, with abdominoperineal resection in 10 patients, lower anterior resection with coloanal anastomosis in 6 patients, and colorectal anastomosis in 3 patients. The distance of the lower margin of the tumor to insertion of the levator ani on the rectal wall was correctly evaluated by computed tomography in 12 (63%) of 19 patients and by magnetic resonance imaging in 13 (68%) of 19 patients, while digital examination correctly assessed the distance in 15 (79%) of 19 patients. Computed tomography and magnetic resonance imaging were unable to assess extension through the rectal wall. No significant difference was observed between computed tomography and magnetic resonance imaging in assessing extension to the perivesical fat, adjacent organs, pelvic side wall, or lymph nodes. According to the TNM classification, magnetic resonance imaging correctly staged 74% (14/19) of carcinomas, while computed tomography correctly staged 68% (13/19).     

Congenital dacryocystocele with intranasal extension: correlation of computed tomography and magnetic resonance imaging

A case of dacryocystocele with intranasal extension is described by magnetic resonance imaging (MRI) characteristics, which are correlated with the appearance on computed tomography (CT) scans. Computed tomography and MRI are equally sensitive in detecting dacryocystocele. Magnetic resonance imaging has the advantages of characterizing the cyst contents, allowing multiplanar imaging without the need for manipulation of the patient, and the absence of radiation exposure. Computed tomography has the advantage of detecting bone changes involving the bony nasolacrimal canal. Clinically, these abnormalities usually resolve spontaneously and only rarely require surgical intervention.     

Usefulness of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography in diagnosis and treatment of pelvic recurrence of bladder cancer after radical cystectomy: a case report

A 58-year-old woman visited our hospital with complaints of serious edematous change in the left lower extremity, eleven months after she received total cystectomy and ileal conduit. Although enhanced pelvic computerized tomography (CT) and magnetic resonance imaging (MRI) were repeatedly performed, the pelvic recurrence was not detected. To investigate the presence or absence of pelvic recurrence further, we performed 18F-fluorodeoxyglucose positron emission/computerized tomography (18F-FDG-PET/CT). 18F-FDG-PET/CT clearly demonstrated high uptake by the pelvic lymph node recurrence. We selected radiochemotherapy using a limited irradiation field for the treatment of lymph node recurrence to cure the edema. One month after the treatment, the edema in the left lower extremity was greatly improved. Four months later, 18F-FDG-PET/CT was performed again to evaluate the efficacy of the treatment and reduced uptake of the irradiation field was observed.     

Multimodal metabolic imaging of cerebral gliomas: positron emission tomography with [18F]fluoroethyl-L-tyrosine and magnetic resonance spectroscopy

OBJECT: The purpose of this study was to determine the predictive value of [18F]fluoroethyl-L-tyrosine (FET)-positron emission tomography (PET) and magnetic resonance (MR) spectroscopy for tumor diagnosis in patients with suspected gliomas. METHODS: Both FET-PET and MR spectroscopy analyses were performed in 50 consecutive patients with newly diagnosed intracerebral lesions supposed to be diffuse gliomas on contrast-enhanced MR imaging. Lesion/brain ratios of FET uptake greater than 1.6 were considered positive, that is, indicative of tumor. Results of MR spectroscopy were considered positive when N-acetylaspartate (NAA) was decreased in conjunction with an absolute increase of choline (Cho) and an NAA/Cho ratio of 0.7 or less. An FET lesion/brain ratio, an NAA/Cho ratio, and signal abnormalities on MR images were compared with histological findings in neuronavigated biopsy specimens. The FET lesion/brain ratio and the NAA/Cho ratio were identified as significant independent predictors for the histological identification of tumor tissue. The accuracy in distinguishing neoplastic from nonneoplastic tissue could be increased from 68% with the use of MR imaging alone to 97% with MR imaging in conjunction with FET-PET and MR spectroscopy. Sensitivity and specificity for tumor detection were 100 and 81% for MR spectroscopy and 88 and 88% for FET-PET, respectively. Results of histological studies did not reveal tumor tissue in any of the lesions that were negative on FET-PET and MR spectroscopy. In contrast, a tumor diagnosis was made in 97% of the lesions that were positive with both methods. CONCLUSIONS: In patients with intracerebral lesions supposed to be diffuse gliomas on MR imaging, FET-PET and MR spectroscopy analyses markedly improved the diagnostic efficacy of targeted biopsies.     

Evaluation of fluorine-18-fluorodeoxyglucose whole body positron emission tomography imaging in the staging of lung cancer

BACKGROUND: Surgical resection of lung cancer remains the treatment of choice in appropriately staged disease, but conventional imaging techniques have limitations. Positron emission tomography (PET) may improve staging accuracy. METHODS: We studied whole body and localized thoracic PET in staging lung cancer. Standardized uptake value was calculated for the primary lesion. Ninety-seven patients under consideration for surgical resection were included. PET, computed tomography, and clinical staging were compared to stage at operation, biopsy, or final outcome. Mean follow up was 17.5 months. RESULTS: PET detected all primary lung cancers with two false-positive primary sites. Sensitivity and specificity for N2 and N3 mediastinal disease was 20% and 89.9% for computed tomography and 70.6% and 97% for PET. PET correctly altered stage in 26.8%, nodal stage in 13.4%, and detected distant metastases in 16.5%. PET missed 7 of 10 cerebral metastases. PET altered management in 37% of patients. PET staging (p<0.0001) and standardized uptake value (p<0.001) were the best predictors of time to death apart from operative staging. CONCLUSIONS: PET provides significant staging and prognostic information in lung cancer patients considered operable by standard criteria. Routine use of PET will prevent unnecessary operation and may be cost effective.     

正电子发射型断层成像技术对胃癌术前的诊断价值及临床意义

目的评估正电子发射型断层成像(PET)技术在胃癌患者术前的诊断价值及临床意义。方法对21例胃癌患者术前进行PET全身显像分期和手术探查分期及病理分期对照,采用国际抗癌联盟(IUCC)公布的TNM分期标准,并进行χ2检验。结果PET对胃癌原发灶的显示率为100%,PET对淋巴结(N)分期的准确率为85.7%(18/21),术中探查对N分期准确率为75%(15/20),两组间经χ2检验差异无显著性意义(P>0.05)。PET图像显示了全部4例患者的远处组织器官转移病灶。结论PET对胃癌原发灶及其远处转移病灶的检测准确、敏感,能对胃癌诊断、手术方法和治疗原则的选择提供有价值的参考依据。