18F-脱氧葡萄糖正电子发射计算机断层显像CT检查在前列腺癌诊断和分期中的应用价值

目的 评价18F-脱氧葡萄糖(18F-FDG)正电子发射计算机断层显像CT检查(PET/CT)在前列腺癌诊断和分期中的应用价值.方法 经手术或穿刺活检病理证实为前列腺癌患者40例,年龄52 ～ 78岁,平均67岁.其中T24例,T316例,T420例.行18F-FDG PET/CT及99Tcm-MDPECT骨显像检查,统计PET/CT显像对前列腺癌原发灶、淋巴结转移及骨转移诊断的敏感性,对比分析PET/CT显像及99Tcm-MDPECT骨显像对骨转移的诊断效果.结果 40例患者中,18F-FDG PET/CT检查显示前列腺局部结节状放射性浓聚17例,对原发灶诊断敏感性为43％.17例淋巴结转移患者中CT检查发现8例,18F-FDG PET/CT检查发现15例,诊断敏感性为88％,其中5例患者因PET/CT检查改变了临床分期以及治疗方案.18F-FDG PET/CT对骨转移诊断的敏感性与99Tcm-MDP骨显像相近,但特异性(95％)和准确率(96％)均明显高于99Tcm-MDP骨显像,其中6例患者因PET/CT检查改变了临床分期,2例改变了治疗方案.结论 18F-FDG PET/CT对前列腺癌淋巴结转移和骨转移有较高诊断价值,对前列腺的分期具有特殊优势,可为临床医生制定治疗方案提供可靠依据.     

Positron emission tomography for urological tumours

For urological tumours, positron emission tomography (PET) is currently most useful in testicular cancer. In patients with residual masses or raised marker levels after treatment, PET is both sensitive and specific for detecting recurrent disease, at suspected and unsuspected sites. Although fewer studies are available it also appears to be useful for staging at diagnosis, although this requires further investigation. Prostate cancer imaging has been more variable, with studies showing that PET cannot reliably differentiate between tumour and hypertrophy. It is not as good as a bone scan for defining bone metastases. In renal cancer, PET can be used to define the primary tumour, providing better staging of local recurrence than computed tomography (CT), and to define metastatic disease. There are few studies in bladder cancer, and despite excretion of the tracer via the bladder in early studies, it has better results than CT or magnetic resonance imaging for local staging; again it can detect metastases. Overall, the place of PET in urological tumours is developing, with the strongest areas undoubtedly being testicular and renal cancer. Tracers other than fluorodeoxyglucose are being examined and are providing further information.     

Clinical value of 18FDG PET/MRI in muscle-invasive,locally advanced,and metastatic bladder cancer

ObjectiveMetastatic bladder cancer is an aggressive disease that can often be difficult to diagnose and stage with conventional cross-sectional imaging. The primary objective of this study was to determine the clinical value of fluorine-18 2-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) PET/MRI for surveillance and restaging of patients with muscle-invasive, locally advanced, and metastatic bladder cancer compared to conventional imaging methods.Materials and MethodsThis retrospective study enrolled patients with muscle-invasive, locally advanced and metastatic bladder cancer in a single institute evaluated with ¹⁸F-FDG PET/MRI. All patients also underwent conventional imaging with CT. Additional imaging may also have included ¹⁸F-FDG PET/CT (¹⁸F-FDG PET), or sodium fluoride (NaF) PET/CT in some patients. Images were reviewed by a diagnostic radiologist/nuclear medicine physician. Number of lesions and sites of disease were captured and compared between ¹⁸F-FDG PET/MRI and conventional imaging. Lesions were confirmed by sequential imaging or lesion biopsy. All patients were followed for survival.ResultsFifteen patients (4 for surveillance; 11 for restaging) underwent 34 ¹⁸F-FDG PET/MRI scans. Each patient received a corresponding conventional CT around the time of the ¹⁸F-FDG PET/MRI (median 6 days). The 15 patients (11 male; 4 female) had a median age of 61.5 years (range 37–73) and histologies of urothelial carcinoma (n = 13) and small-cell carcinoma of the bladder (n = 2) diagnosed as stage 4 (n = 13), stage 3 (n = 1), or stage 2 (n = 1). ¹⁸F-FDG PET/MRI detected 82 metastatic malignant lesions involving lymph nodes (n = 22), liver (n = 10), lung (n = 34), soft tissue (n = 12), adrenal glands (n = 1), prostate (n = 1), and bone (n = 2) with a resultant advantage of 36% for lesion visibility in comparison with CT. Serial imaging or biopsy confirmed these lesions as malignant.Conclusion¹⁸F-FDG PET/MRI can detect metastatic lesions which cannot be identified on conventional CT, and this can allow for better treatment planning and improved disease monitoring during therapy.     

Role of positron emission tomography in urological oncology

??Positron emission tomography (PET) is a diagnostic tool using radiotracers to show changes in metabolic activities in tissues. We analysed the role of PET and PET/computed tomography (CT) in the diagnosis, staging, and follow-up of urological tumours. ??A critical, non-structured review of the literature of the role of PET and PET/CT in urological oncology was conducted. ??PET and PET/CT can play a role in the management of urological malignancies. For prostate cancer, the advances in radiotracers seems promising, with novel radiotracers yielding better diagnostic and staging results than 18F-fluorodeoxyglucose (18F-FDG). In kidney cancer, PET and PET/CT allow a proper diagnosis before the pathological examination of the surgical specimen. For testis cancer, PET and PET/CT have been shown to be useful in the management of seminoma tumours. In bladder cancer, these scans allow a better initial diagnosis for invasive cancer, while detecting occult metastases. ??PET and its combined modality PET/CT have shown their potential in the diagnosis of urological malignancies. However, further studies are needed to establish the role of PET in the management of these diseases. Future applications of PET may involve fusion techniques such as magnetic resonance imaging with PET.     

Significance of PET/CT in determining actual TNM staging for patients with various lung cancers

We investigated the difference in TNM stage of lung cancer provided by PET/CT (combining positron emission tomography and computed tomography) as compared with TNM stage obtained with conventional imaging studies (CI) with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) with iron contrast media. Sixty-seven cases of lung cancer were included in this study. Overall, the rate of correction of TNM staging was 70.1% after PET/CT. The correction rate for each factor was 32.8% in T, 37.3% in N, and 37.3% in M. High rates of correction were observed in small cell lung cancer (SCLC), with 75% (6/8 cases) obtained by PET/CT. When SCLCs were divided into limited disease (n = 6) involving 1 hemithorax, including mediastinal and contralateral hilar lymph nodes, and others (extensive disease, n = 2), the correction rate was as high as 80% for limited disease. In conclusion, PET/CT can provide actual TNM staging and recognition for oncologists in staging, which would not mislead to selection of inadequate subsequent treatment.     

Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET)

BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease.     

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。     

Positron emission tomography/computed tomography influences on the management of resectable pancreatic cancer and its cost-effectiveness

OBJECTIVE: We sought to determine the impact of positron emission tomography/computed tomography (PET/CT) on the management of presumed resectable pancreatic cancer and to assess the cost of this new staging procedure. SUMMARY BACKGROUND DATA: PET using 18F-fluorodeoxyglucose (FDG) is increasingly used for the staging of pancreatic cancer, but anatomic information is limited. Integrated PET/CT enables optimal anatomic delineation of PET findings and identification of FDG-negative lesions on computed tomography (CT) images and might improve preoperative staging. MATERIAL AND METHODS: Patients with suspected pancreatic cancer who had a PET/CT between June 2001 to April 2004 were entered into a prospective database. Routine staging included abdominal CT, chest x-ray, and CA 19-9 measurement. FDG-PET/CT was conducted according to a standardized protocol, and findings were confirmed by histology. Cost benefit analysis was performed based on charged cost of PET/CT and pancreatic resection and included the time frame of staging and surgery. RESULTS: Fifty-nine patients with a median age of 61 years (range, 40-80 years) were included in this analysis. Fifty-one patients had lesions in the head and 8 in the tail of the pancreas. The positive and negative predictive values for pancreatic cancer were 91% and 64%, respectively. PET/CT detected additional distant metastases in 5 and synchronous rectal cancer in 2 patients. PET/CT findings changed the management in 16% of patients with pancreatic cancer deemed resectable after routine staging (P = 0.031) and was cost saving. CONCLUSIONS: PET/CT represents an important staging procedure prior to pancreatic resection for cancer, since it significantly improves patient selection and is cost-effective.     

Fluorodeoxyglucose positron emission tomography integrated with computed tomography to determine resectability of primary lung cancer

PURPOSE: Fluorodeoxyglucose positron emission tomography integrated with computed tomography (FDGPET/CT) was evaluated as a routine staging technique for primary lung cancer. MATERIALS AND METHODS: We prospectively compared FDG-PET/CT in determining clinical stage and surgical indication with conventional staging not including positron emission tomography (PET). A total of 50 consecutive patients diagnosed with primary lung cancer by cytological or histological examination were studied; 20 of them underwent surgery. RESULTS: Discrepancies between the two staging methods were observed in 14 patients (28%). The stage assigned by PET increased in 12 cases (24%) and decreased in 2 (4%). PET staging was accurate in eight cases with otherwise undetected distant metastases (M1) but was incorrect in six cases, including five where it overdiagnosed nodal metastases (N). Two clinical N3 patients (4%) would have missed a chance of surgery if the surgical indication had been determined by PET staging alone. According to our criteria for surgery, other patients were assigned correctly to surgery by PET staging. The maximum standard uptake value (maxSUV) of all primary lesions ranged from 0 to 23.0 (mean +/- SD, 8.0 +/- 4.4). The mean maxSUV among surgical cases (5.8 +/- 3.6) was significantly smaller than among nonsurgical cases (9.5 +/- 4.2) (P < 0.05). CONCLUSION: Staging examination including FDG-PET/CT and brain magnetic resonance imaging ordinarily can determine the clinical stage and resectability of primary lung cancer. False-positive findings in regional lymph nodes, possibly reflecting past infectious disease, are the most important remaining problem.     

Advantages of positron emission tomography over computed tomography in mediastinal staging of non-small cell lung cancer

BACKGROUND: New treatment algorithms in early stage non-small cell lung cancer (NSCLC) involving preoperative chemotherapy require accurate clinical staging of the mediastinum. This study compares the accuracy of 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) scanning with that of computed tomography (CT) scanning in the clinical staging of non-small cell lung cancer. MATERIALS AND METHODS: A retrospective review was performed on 52 patients with NSCLC who were evaluated with both CT and PET scans. All patients had their mediastinal lymph nodes sampled by mediastinoscopy or at the time of thoracotomy for pulmonary resection. Each imaging study was evaluated separately and correlated with histopathologic results. RESULTS: For detecting mediastinal metastases the sensitivities of PET and CT scans were 67 and 50%, respectively; specificities were 91 and 65%, respectively; accuracies were 88 and 63%, respectively; positive predictive values were 50 and 16%, respectively; negative predictive values were 95 and 88%, respectively. PET scans were significantly better than CT scans at detecting mediastinal metastases (PET, 4/8; CT, 3/19) (P = 0.01). CONCLUSIONS: PET scanning is superior to CT scanning for clinical staging of the mediastinum in NSCLC. A more confident decision regarding stratification of patients into current treatment algorithms can be made when the decision is based on PET scanning rather than the current "gold standard" of CT scanning.     

Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer

OBJECTIVE: To determine the sensitivity, specificity, and accuracy of positron emission tomography with 2-fluorine-18-fluorodeoxyglucose (PET-FDG) in the preoperative staging (N and M staging) of patients with lung cancer. The authors wanted to compare the efficacy of PET scanning with currently used computed tomography (CT) scanning. MATERIALS AND METHODS: Results of whole-body PET-FDG imaging and CT scans were compared with histologic findings for the presence or absence of lymph node disease or metastatic sites. Sampling of mediastinal lymph nodes was performed using mediastinoscopy or thoracotomy. RESULTS: PET-FDG imaging was significantly more sensitive, specific, and accurate for detecting N disease than CT. PET changed N staging in 35% and M staging in 11% of patients. CT scans helped in accurate anatomic localization of 6/57 PET lymph node abnormalities. CONCLUSION: PET-FDG is a reliable method for preoperative staging of patients with lung cancer and would help to optimize management of these patients. Accurate lymph node staging of lung cancer may be ideally performed by simultaneous review of PET and CT scans.     

Diagnostic efficacy of [11C]choline positron emission tomography/computed tomography compared with conventional computed tomography in lymph node staging of patients with bladder cancer prior to radical cystectomy

Background

Current imaging techniques are of limited value for lymph node (LN) staging in bladder cancer (BCa) patients scheduled for radical cystectomy (RC).

Objective

Evaluate the diagnostic efficacy of [11C]choline positron emission tomography in combination with computed tomography (PET/CT) for LN staging of patients with BCa scheduled for RC and compare that efficacy with the diagnostic efficacy of CT and the gold standard of histopathologic evaluation.

Design, setting, and participants

From June 2004 to May 2007, 44 patients with localized BCa were staged with [11C]choline PET with low-dose CT for attenuation correction and simultaneous intravenous and rectal contrast-enhanced diagnostic CT before RC and pelvic lymph node dissection (PLND). LNs were dissected from the internal and external iliac arteries up to the origin of the inferior mesentery artery according to a template with 14 predefined anatomic fields.

Intervention

Diagnostic [11C]choline PET/CT before RC and regional LN dissection.

Measurements

Histopathologic findings of resected LN were correlated with the results of [11C]choline PET/CT and CT alone in a patient- and field-based manner. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [11C]choline PET/CT and CT were assessed.

Results and limitations

LN metastases were found in 12 of 44 patients (27%). On patient-based analysis, sensitivity, specificity, PPV, NPV, and accuracy for [11C]choline PET/CT were calculated as 58%, 66%, 39%, 81%, and 64%, respectively; and for CT the calculated percentages were 75%, 56%, 39%, 86%, and 61%, respectively. Twenty-five of 471 dissected LN fields (5%) showed metastases. On field-based analysis, sensitivity, specificity, PPV, NPV, and accuracy for [11C]choline PET/CT were 28%, 95%, 21%, 96%, and 91%, respectively; for CT, the calculated percentages were 39%, 92%, 20%, 96%, and 90%, respectively. Limitations of this study are small patient number and the fact that not all patients underwent extensive PLND.

Conclusions

In patients with BCa who were scheduled for RC, preoperative LN staging with [11C]choline PET/CT was not able to improve diagnostic efficacy compared with conventional CT alone.     

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.     

Positron emission tomography with F-18-fluorodeoxyglucose in a combined staging strategy of esophageal cancer prevents unnecessary surgical explorations

Distant metastases or local invasion are frequently found during the explorative phase of surgery for esophageal cancer. This study was performed to determine the rate of patients with incurable disease encountered during exploration and to examine the impact of preoperative staging, including positron emission tomography (PET), on the number of unnecessary explorations. The records of 203 patients with esophageal cancer who were eligible for curative resection were retrospectively reviewed. The surgical reports were analyzed to obtain the reasons for abandoning resection. Furthermore, the different staging modalities according to the related time interval were reviewed for each patient to analyze the influence of them on the number of explorations. After exploratory surgery, resection was abandoned in 78 of the 203 patients (38%) because of distant metastases (n = 59; 29%), metastatic spread and local irresectability (n = 5; 2%), and local irresectability (n = 14; 7%). In a logistic regression model with all preoperative staging modalities and the year of examination as independent variables, F-18-fluorodeoxyglucose (FDG)-PET) was the only modality that predicts intended curative resection in these patients (P < 0.001). In patients with esophageal cancer who are suitable for potentially curative surgery, resection was abandoned mainly because of distant metastases encountered during exploration. The addition of FDG-PET may have reduced the rate of unnecessary surgery in this group of patients. Presented at the Forty-Fifth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, Louisiana, May 15–19, 2004 (poster presentation).     

18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is accurate for high-grade prostate cancer bone staging when compared to bone scintigraphy

IntroductionIn this study, we compared ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-positron emission tomography/computed tomography (PET/CT) and bone scintigraphy accuracies for the detection of bone metastases for primary staging in high-grade prostate cancer (PCa) patients to determine if ¹⁸F-FDG-PET/CT could be used alone as a staging modality.MethodsMen with localized high-grade PCa (n=256, Gleason 8–10, International Society of Urological Pathology [ISUP] grades 4 or 5) were imaged with bone scintigraphy and ¹⁸F-FDG-PET/CT. We compared, on a per-patient basis, the accuracy of the two imaging modalities, taking inter-modality agreement as the standard of truth (SOT).Results¹⁸F-FDG-PET/CT detected at least one bone metastasis in 33 patients compared to only 26 with bone scan. Of the seven false-negative bone scintigraphies, four (57.1%) were solitary metastases (monometastatic), three (42.9%) were oligometastatic (2–4 lesions), and none were plurimetastatic (>4 lesions). Compared to SOT, ¹⁸F-FDG-PET/CT showed higher sensitivity and accuracy than bone scintigraphy (100% vs. 78.8%, and 98.7% vs. 98.2%) for the detection of skeletal lesions.Conclusions¹⁸F-FDG-PET/CT appears similar or better than conventional bone scans to assess for bone metastases in patients newly diagnosed with high-grade PCa. Since intraprostatic FDG uptake is also a biomarker for failure of radical prostatectomy and that FDG-PET/CT has been shown to be accurate in detecting PCa lymph node metastasis, FDG-PET/CT has the potential to be used as the sole preoperative staging modality in high-grade PCa.     

Funktionelle Bildgebung beim Harnblasenkarzinom

Computed tomography (CT) represents the current standard imaging modality in muscle invasive bladder cancer; however, local tumor and lymph node staging is often impaired. Magnetic resonance imaging (MRI) with diffusion-weighted sequences, determination of apparent diffusion coefficient (ADC) values or utilization of supraparamagnetic iron nanoparticles potentially exhibits advantages in the assessment of local tumor and lymph node involvement and therefore might play a role in the staging of bladder tumor in the future. Likewise, positron emission tomography (PET) with the currently used tracers ¹⁸F fluorodeoxyglucose (¹⁸F-FDG), ¹¹C-choline and ¹¹C-acetate is being investigated in bladder cancer patients, mostly in combination with diagnostic CT. Although promising results could be obtained for PET/CT investigations to some extent, the true value cannot be determined at present.     

Dual-Time <Superscript>18</Superscript>F-FDG PET/CT Imaging in Initial Locoregional Staging of Breast Carcinoma: Comparison with Conventional Imaging and Pathological Prognostic Factors

The aims of this retrospective study were to consider the diagnostic role of dual-time ¹⁸F-fluorodeoxyglucose positron emission tomography and computed tomography (¹⁸F-FDG PET/CT) in detection of breast carcinoma and axillary lymph node (ALN) status and to evaluate the primary tumor ¹⁸F-FDG uptake pattern. Preoperative staging was performed by ¹⁸F-FDG PET/CT in 78 female patients with breast carcinoma. Conventional imaging results were evaluated by breast magnetic resonance imaging (MRI) of 79 lesions in 78 patients, bilateral mammography (MMG) of 40 lesions in 40 patients, and breast ultrasonography (USG) of 47 lesions in 46 patients. The primary tumor detection rate using ¹⁸F-FDG PET/CT was higher than those using MRI, USG, and MMG. The sensitivity and specificity of ¹⁸F-FDG PET/CT scans for detecting multifocality were higher than those of MRI. The specificity of ALN metastasis detection with MRI was higher than that with ¹⁸F-FDG PET/CT, but ¹⁸F-FDG PET/CT had higher sensitivity. Higher ¹⁸F-FDG uptake levels were detected in patients with ALN metastasis, histologic grade 3, estrogen–progesterone-negative receptor status, lymphatic invasion, and moderate to poor prognostic groups. There was no statistical difference for the retention index in categorical pathological parameters except for progesterone-negative status. In conclusion, ¹⁸F-FDG PET/CT scans may be a valuable imaging technique for evaluating primary tumor and axillary status in staging breast carcinoma and ¹⁸F-FDG uptake may be a prognostic factor that indicates aggressive tumor biology and poor prognosis. Dual-time imaging in breast carcinoma staging may not be used for predicting pathological criteria and the aggressiveness of primary lesions.     

Positron‐emission tomography/computed tomography (PET/CT) in the initial staging of primary rectal cancer

Objective The aim of this study was to assess the role of ¹⁸flourodeoxyglucose positron‐emission tomography/computed tomography (PET/CT) in the initial staging of primary rectal adenocarcinoma. Method A total of 20 patients with adenocarcinoma of the rectum were assessed with both PET/CT and conventional staging (CT chest/abdomen/pelvis, MRI rectum). Discordance with conventional imaging and incidental findings on PET were recorded and the patients presented to a colorectal cancer multidisciplinary team to assess management changes. Patients were followed up so that discordant or incidental findings could be verified by intra‐operative examination, imaging or histology where possible. Results Positron‐emission tomography/computed tomography correctly identified the primary tumour in all 20 patients. Comparing PET/CT with conventional staging modalities, there were 11 discordant or incidental findings in nine patients (45%). This resulted in a potential change in stage in 30% (four patients downstaged and two upstaged). PET/CT suggested additional neoplastic pathology in three patients and excluded the same in two patients. The incidental neoplastic findings were of minor clinical significance and one was eventually deemed false positive. While PET/CT resulted in potential management changes in five patients (25%), no changes in surgical management occurred. When tumours were grouped according to conventional stage, PET/CT resulted in fewer changes in stage in stage I (0%), compared with stages II to IV (43%) (P = 0.08). Conclusion Positron‐emission tomography/computed tomography provides additional information to conventional staging in primary rectal cancer. This information produced minor management changes in this study and did not effect surgical management. PET/CT may be most appropriately used selectively in more advanced stages and where indeterminate findings exist with conventional staging.     

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.

     

Molecular positron emission tomography and PET/CT imaging in urological malignancies

OBJECTIVES: Positron emission tomography (PET) provides unique insights into molecular pathways of diseases. PET using [F-18]-fluorodeoxyglucose (FDG) has gained increasing acceptance for the diagnosis, staging, and treatment monitoring of various tumour types. The aim of this review is to provide an update on the current status of molecular PET and PET/CT imaging in urological malignancies. METHODS: The current literature on PET and PET/CT imaging was reviewed and summarized for prostate cancer, bladder cancer, renal cell carcinoma, and germ cell tumours. RESULTS: Depending on the radiotracer used, PET offers diagnostic information based on glucose, choline or amino acid metabolism and has also been applied to imaging tumour cell proliferation and tissue hypoxia in urological malignancies. The diagnostic performance of FDG-PET is hampered by the renal excretion of FDG and by the low metabolic activity often seen in tumours such as prostate cancer. However, new PET tracers including radiolabelled choline and acetate may offer an alternative approach. There is consistent evidence that FDG-PET provides important diagnostic information in detecting metastatic and recurrent germ cell tumours and it might offer additional information in the staging and restaging of bladder and renal cancer. CONCLUSIONS: Although PET imaging has been shown to be a clinically useful tool, its application in urological malignancies still needs to be fully determined by larger prospective trials. The introduction of novel PET radiopharmaceuticals along with the new technology of PET/CT will likely change the future role of molecular imaging in urological malignancies.