Adenocarcinoma of the Esophagus and the Esophagogastric Junction: Positron Emission Tomography Improves Staging and Prediction of Survival in Distant but Not in Locoregional Disease

In adenocarcinoma of the esophagus and esophagogastric junction for prognostication and treatment allocation, one prerequisite is accurate pretreatment staging. This staging, we hypothesized, would be improved by the use of positron emission tomography (PET). After 55 patients suitable for radical esophageal resection were staged with PET, spiral computed tomography (CT), and endoscopic ultrasonography (EUS), results were compared with histopathology and with survival. Accuracy in detecting locoregional lymph node metastasis did not differ significantly between EUS (72%), PET (60%), and CT (58%). Adding PET to standard staging failed to improve the accuracy of N staging (P = 0.250). In M staging, accuracy between CT (75%) and PET (76%) did not differ. The accuracy of combined studies of CT and PET and of EUS, CT, and PET were 87% (P = 0.016 versus CT) and 91% (P = 0.031 versus EUS and CT), respectively. Of the 55 patients, 19 (35%) had metastatic lesions. By combined use of CT and EUS and by combined use of CT, EUS, and PET, 8 and 14 (P = 0.031), respectively, could be detected. In nodal disease without distant metastases, PET did not improve the prediction of survival. However, positive PET for distant metastasis by either positive EUS or CT predicts well the poor survival of these patients. The staging value of PET by itself in adenocarcinoma of the esophagus is limited because of low accuracy for nodal and the lack of specificity for distant disease prognosis. Adding PET to standard staging does, however, improve detection of stage IV disease and its associated poor survival. 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).     

MDCT对胃食管交界区癌术前TN分期及分型的诊断价值

目的探讨多层螺旋CT(MDCT)对胃食管交界区癌术前TN分期及分型的诊断价值。方法回顾性分析四川大学华西医院2008年1月至2011年6月期间经手术及病理检查证实、术前完成MDCT扫描的149例胃食管交界区癌(adenocarcinoma of esophagogastric junction,AEG)患者的临床资料,将术前MDCT检查结果与术后结果对比分析。结果 MDCT能准确对AEG进行术前TN分期及分型,对T1、T2、T3及T4期分期诊断的准确性分别为97.3%、91.3%、84.5%和89.3%;对Ⅰ、Ⅱ、Ⅲ分型诊断的准确性分别为84.6%、63.8%和79.2%;对评价淋巴结是否转移的准确性为88.6%(132/149),转移淋巴结多以圆形和融合型、强化明显和显著以及环形强化和不均匀强化为特征,其病理转移率较高(P=0.000)。结论术前MDCT检查能准确判断AEG的TN分期、分型,有助于临床制定手术方式、决定手术路径。     

Improved Staging With Pretreatment Positron Emission Tomography/Computed Tomography in Low Rectal Cancer

Background ¹⁸F-Fluorodeoxyglucose (FDG)-positron emission tomography (PET) and computed tomography (CT) are widely accepted in the evaluation for metastatic or recurrent rectal cancer. Only spiral CT and transrectal ultrasonography (TRUS) are routinely used in the initial evaluation of primary rectal cancer. We wished to determine whether PET/CT could provide additional information in patients undergoing standard evaluation for primary rectal cancer. Methods Thirty-seven patients (mean age, 58 years; range, 26–90 years) with a previously untreated rectal cancer underwent TRUS or magnetic resonance imaging, spiral CT, and FDG-PET/CT. The tumor location (low, ≤6 cm; mid, 7–10 cm; or high, ≥10 cm) and carcinoembryonic antigen level were recorded. Discordant findings between spiral CT and FDG-PET/CT were confirmed by histological analysis or imaging follow-up. Results FDG-PET/CT identified discordant findings in 14 patients (38%), and this resulted in upstaging of 7 patients (50%) and downstaging of 3 patients (21%). Although node-positive disease on TRUS/magnetic resonance imaging was associated with discordant FDG-PET/CT findings, this was not statistically significant. Discordant PET/CT findings were significantly more common in patients with a low rectal cancer than in those with mid or high rectal cancer (13 vs. 1; P = .0027). The most common discordant finding was lymph node metastasis (n = 7; 50%). Histological confirmation of discordant FDG-PET/CT findings was performed in seven patients, and in no case did FDG-PET/CT prove to be inaccurate. Discordant PET/CT findings resulted in a deviation in the proposed treatment plan in 27% of patients (n = 10). Conclusions FDG-PET/CT frequently yields additional staging information in patients with low rectal cancer. Improved accuracy of pretreatment imaging with FDG-PET/CT will allow for more appropriate stage-specific therapy. Presented at the Annual Meeting of the Society of Surgical Oncology, Atlanta, Georgia, March 3–6, 2005.     

Is Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography Imaging Cost-effective in Prostate Cancer: An Analysis Informed by the proPSMA Trial

BackgroundBefore integrating prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) into routine care, it is important to assess if the benefits justify the differences in resource use.ObjectiveTo determine the cost-effectiveness of PSMA-PET/CT when compared with conventional imaging.Design, setting, and participantsA cost-effectiveness analysis was developed using data from the proPSMA study. proPSMA included patients with high-risk prostate cancer assigned to conventional imaging or ⁶⁸Ga-PSMA-11 PET/CT with planned health economics data collected. The cost-effectiveness analysis was conducted from an Australian societal perspective.Intervention⁶⁸Ga-PSMA-11 PET/CT compared with conventional imaging (CT and bone scan).Outcome measurements and statistical analysisThe primary outcome from proPSMA was diagnostic accuracy (nodal and distant metastases). This informed a decision tree analysis of the cost per accurate diagnosis.Results and limitationsThe estimated cost per scan for PSMA PET/CT was AUD$1203, which was less than the conventional imaging cost at AUD$1412. PSMA PET/CT was thus dominant, having both better accuracy and a lower cost. This resulted in a cost of AUD$959 saved per additional accurate detection of nodal disease, and AUD$1412 saved for additional accurate detection of distant metastases. The results were most sensitive to variations in the number of men scanned for each ⁶⁸Ga-PSMA-11 production run. Subsequent research is required to assess the long-term costs and benefits of PSMA PET/CT-directed care.ConclusionsPSMA PET/CT has lower direct comparative costs and greater accuracy compared to conventional imaging for initial staging of men with high-risk prostate cancer. This provides a compelling case for adopting PSMA PET/CT into clinical practice.Patient summaryThe proPSMA study demonstrated that prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) better detects disease that has spread beyond the prostate compared with conventional imaging. Our analysis shows that PSMA PET/CT is also less costly than conventional imaging for the detection of disease spread.This research was presented at the European Association of Nuclear Medicine Scientific Meeting in October 2020.     

Evaluation of Shoulder Disorders by 2-[F-18]-fluoro-2-deoxy-D-glucose Positron Emission Tomography and Computed Tomography

Background

Although flourine-18-flourodeoxyglucose (FDG) positron emission tomography (PET) has a limitation for localizing anatomical structures, combining it with computed tomography (CT) has made it more efficient for overcoming such limitations. This study aims to evaluate the efficacy of PET/CT for evaluating diseases of the shoulder.

Methods

Retrospective examination was performed on 25 patients who underwent FDG-PET/CT scanning. All the patients were over 60 years of age, and they were evaluated both clinically and radiologically for shoulder pain. The study period was from May, 2006 to May, 2008. One of the patients had metastatic lesion in a shoulder and this patient was excluded from the study, so the total number of subjects in the study was finally 24 patients.

Results

PET/CT showed 67% sensitivity, 73% specificity, a positive predictive value of 60%, a negative predictive value of 79%, 27% false positivity and 33% false negativity concerning shoulder pain. PET/CT showed negative finding in 4 cases that were successfully treated by operative treatment (rotator cuff tear [RCT], 3 cases; impingement syndrome, 1 case). Negative findings were also noted in 6 cases in which the pain subsided after conservative treatment (RCT, 1 case; suspected RCT, 2 cases; impingement syndrome, 3 cases). All the patients with osteoarthritis and rheumatoid arthritis had positive findings on PET/CT scanning.

Conclusions

PET/CT is a useful adjunct to the existing imaging modalities to assess functional and pathophysiologic processes and at a very early stage, and so PET/CT can help physicians make better preoperative and postoperative decisions on treatment.     

Pitfalls of Positive Findings in Staging Esophageal Cancer With F-18-Fluorodeoxyglucose Positron Emission Tomography

Background: 18-F-fluorodeoxyglucose positron emission tomography (FDG-PET) is valuable in staging of esophageal cancer. However, FDG-PET may falsely upstage patients leading to incorrect exclusion from surgical treatment. This study was performed to determine the false-positive rate and possible causes.Methods: The rate of false-positive lesions on FDG-PET was documented in 86 out of a group of 98 patients. Lesions were defined as false positive when pathological examination was negative or as absence of tumor activity within 6 months of follow-up. To evaluate the influence of a learning curve on the false-positive rate, the PET scans were revised recently.Results: False-positive lesions were found in 13 patients (13 of 86; 15%). FDG-PET incorrectly revealed only locoregional node metastases in 5 patients in whom surgery with curative intent was performed. Ten lesions in the other 8 patients were classified as distant organ or as nonregional node metastases (M1a/1b). Finally, 5 patients upstaged to M1a/1b underwent a curative resection. The number of false-positive lesions decreased from 16 to 5 (6%) after revision.Conclusions: Proper interpretation of FDG-PET in staging esophageal cancer is impeded by false-positive results. Even after completion of the learning curve, positive FDG-PET findings still have to be confirmed by additional investigations.     

[18F]-Fluorodeoxyglucose Positron Emission Tomography in the Diagnosis,Treatment Stratification,and Monitoring of Patients with Retroperitoneal Fibrosis: A Prospective Clinical Study

Background

The ability to distinguish malignant from benign retroperitoneal fibrosis (RPF) and to select patients who are likely to respond to steroid treatment using a noninvasive test would be a major step forward in the management of patients with RPF.

Lymphadenectomy for Adenocarcinoma of the Gastroesophageal Junction (GEJ): Impact of Adequate Staging on Outcome

Introduction Adequate staging of gastric cancer requires examination of at least 15 lymph nodes. Most resected patients are inadequately staged potentially confounding the interpretation of clinical data. The aim of this study was to determine whether adequate staging revealed different prognostic factors or improved survival compared with patients with <15 nodes examined after R0 resection for GEJ cancer. Methods A prospectively maintained database identified 366 patients with Siewert types II and III adenocarcinoma of the GEJ who underwent R0 resection without neoadjuvant therapy at a single institution. Patients were grouped into adequately (≥15 nodes examined) or inadequately staged (<15 nodes examined). Median follow up was 51 months. Results From 1985 through 2003, 250/366 (68%) patients were adequately staged and 116/366 (32%) were inadequately staged. There was no difference in operative mortality between adequately staged (5.2%) and inadequately staged patients (4.3%, P = NS). Adequately staged patients had more positive lymph nodes (median 2) compared with inadequately staged patients (median 1, P < 0.01). Multivariable analysis of adequately staged patients found the number of positive lymph nodes, T stage, and lymphovascular invasion to be independent prognostic factors for overall survival (OS). For inadequately staged patients only the number of positive lymph nodes and T stage were independent prognostic factors. Adequate staging was an independent prognostic factor for patients with advanced (T ≥ 2 Nany) tumors. For T1 tumors adequate staging was not associated with improved survival. Conclusions Patients with GEJ cancer should undergo adequate lymphadenectomy to permit examination of ≥15 lymph nodes allowing the accurate identification of prognostic variables. Removal of ≥15 lymph nodes is associated with more accurate survival estimates for patients with advanced disease.     

Use of Positron Emission Tomography in Surgery Follow-Up of Esophageal Cancer

Introduction  Although the prognosis of patients with esophageal cancer has been improved by extended dissection, the incidence of recurrence still remains high. In esophageal cancer, positron emission tomography (PET) using ¹⁸F-fluorodeoxyglucose (FDG) already demonstrated to be useful for initial staging and monitoring response to therapy. This prospective study compared the ability of FDG-PET and conventional imaging to detect early recurrence of esophageal cancer after initial surgery in asymptomatic patients. Materials and Methods  Between October 2003 and September 2006, 41 patients with esophageal cancer were included in a prospective study after initial radical esophagectomy. FDG-PET, thoracoabdominal computed tomography (CT), abdominal ultrasonography, and endoscopy were performed every 6 months after initial treatment. Results and Discussion  Twenty-three patients had recurrent disease (56%), mostly within the first 6 months after surgery (70%). Despite two false-positive scans due to postoperative changes, FDG-PET was more accurate than CT (91% vs. 81%, p = 0.02) for the detection of recurrence with a sensitivity of 100% (vs. 65%), a specificity of 85% (vs. 91%), and a negative predictive value of 100% on a patient-by-patient-based analysis. For the detection of locoregional recurrence, FDG-PET was more accurate than CT (96.2% vs. 88.9%). FDG-PET was also more accurate than CT for the detection of distant metastases (92.5% vs. 84.9%), especially when involving either bones (100%) or liver (98.1%). A lower sensitivity of FDG-PET (57%) for the early detection of small lung metastases did not affect patient management (accuracy = 92.5%). Conclusion  FDG-PET appears to be very useful for the systematic follow-up of asymptomatic patients after esophagectomy with an initial scan performed 6 months after surgery. Presented at the Forty-sixth Annual Meeting of The European Society of Nuclear Medicine, Athens, Greece, September 30–October 4, 2006 (oral presentation).     

Preclinical Imaging of Mammary Intraepithelial Neoplasia with Positron Emission Tomography

Small-animal imaging with positron emission tomography (PET) has become a valuable tool for evaluating preclinical models of breast cancer and other diseases. In this review, we examine a number of issues related to preclinical imaging studies with PET, using transgenic models of ductal carcinoma in situ and metastasis as specific examples. We discuss imaging components such as reconstruction, normalization, and extraction of quantitative parameters. We also analyze the effect of longitudinal correlations on cohort size and present some simple statistical techniques for determining cohort sizes that may be helpful in designing preclinical imaging studies. We describe studies that are greatly facilitated by access to non-invasive imaging data including a study involving multiple endpoints and another investigating metastasis. We conclude with a brief survey of emerging approaches in small-animal PET imaging.     

18F-FDG PET显像在大肠癌诊治中的应用

目的 介绍18F-氟代脱氧葡萄糖正电子发射型断层显像(18F-FDG PET)在大肠癌诊治中使用的最新进展。方法 对近几年来国外关于18F-FDG PET显像对大肠癌诊治研究进展进行分析和总结。结果 18F-FDGPET显像对早期诊断大肠癌复发、转移及大肠癌的分期均优于CT及MRI检查。结论 18F—FDG PET显像可以作为诊断大肠癌的一种重要检查手段，并有助于治疗方案的选择。     

In Vivo Distribution of Liposome-Encapsulated Hemoglobin Determined by Positron Emission Tomography

Positron emission tomography (PET) is a noninvasive imaging technology that enables the determination of biodistribution of positron emitter-labeled compounds. Lipidic nanoparticles are useful for drug delivery system (DDS), including the artificial oxygen carriers. However, there has been no appropriate method to label preformulated DDS drugs by positron emitters. We have developed a rapid and efficient labeling method for lipid nanoparticles and applied it to determine the movement of liposome-encapsulated hemoglobin (LEH). Distribution of LEH in the rat brain under ischemia was examined by a small animal PET with an enhanced resolution. While the blood flow was almost absent in the ischemic region observed by [¹⁵O]H₂O imaging, distribution of ¹⁸F-labeled LEH in the region was gradually increased during 60-min dynamic PET scanning. The results suggest that LEH deliver oxygen even into the ischemic brain from the periphery toward the core of ischemia. The real-time observation of flow pattern, deposition, and excretion of LEH in the ischemic rodent brain was possible by the new methods of positron emitter labeling and PET system with a high resolution.     

Evaluation of Fluorodeoxyglucose Positron Emission Tomography in the Detection of Axillary Lymph Node Metastases in Patients With Early-Stage Breast Cancer

Background: The aim of this study was to assess the capacity of positron emission tomography (PET) with fluorodeoxyglucose (FDG) to determine axillary lymph node status in patients with breast cancer undergoing sentinel node (SN) biopsy.Methods: Thirty-two patients with breast cancer and clinically negative axillary nodes were recruited. All patients underwent FDG-PET before SN biopsy. After SN biopsy, all patients underwent complete axillary lymph node (ALN) dissection.Results: The SNs were identified in all patients. Fourteen patients (43.8%) had metastatic SNs (macrometastatic in seven, micrometastatic in six, and isolated tumor cells in one). The false-negative rate of SN biopsy was 6.6% (1 in 15). FDG-PET identified lymph node metastases in 3 of the 14 patients with positive SNs. The overall sensitivity, specificity, and positive and negative predictive values of FDG-PET in the diagnosis of axillary metastasis were 20%, 100%, 100%, and 58.6%, respectively. No false-positive findings were obtained with FDG-PET.Conclusions: This study demonstrates the limitations of FDG-PET in the detection of ALN metastases in patients with early breast cancer. In contrast, FDG-PET seems to be a specific method for staging the axilla in breast cancer. SN biopsy can be avoided in patients with positive FDG-PET, in whom complete ALN dissection should be the primary procedure.     

Positron Emission Tomography (PET) has Limited Utility in the Staging of Pancreatic Adenocarcinoma

Background

Positron emission tomography (PET) as an adjunct to conventional imaging in the staging of pancreatic adenocarcinoma is controversial. Herein, we assess the utility of PET in identifying metastatic disease and evaluate the prognostic potential of standard uptake value (SUV).

Methods

Imaging and follow-up data for patients diagnosed with pancreatic adenocarcinoma were reviewed retrospectively. Resectability was assessed based on established criteria, and sensitivity, specificity, and accuracy of PET were compared to those of conventional imaging modalities.

Results

For 123 patients evaluated 2005–2011, PET and CT/MRI were concordant in 108 (88 %) cases; however, PET identified occult metastatic lesions in seven (5.6 %). False-positive PETs delayed surgery for three (8.3 %) patients. In a cohort free of metastatic disease in 78.9 % of cases, the sensitivity and specificity of PET for metastases were 89.3 and 85.1 %, respectively, compared with 62.5 and 93.5 % for CT and 61.5 and 100.0 % for MRI. Positive predictive value and negative predictive value of PET were 64.1 and 96.4 %, respectively, compared with 75.0 and 88.9 % for CT and 100.0 and 91.9 % for MRI. Average difference in maximum SUV of resectable and unresectable lesions was not statistically significant (5.65 vs. 6.5, p?=?0.224) nor was maximum SUV a statistically significant predictor of survival (p?=?0.18).

Conclusion

PET is more sensitive in identifying metastatic lesions than CT or MRI; however, it has a lower specificity, lower positive predictive value, and in some cases, can delay definitive surgical management. Therefore, PET has limited utility as an adjunctive modality in staging of pancreatic adenocarcinoma.     

A Prospective Evaluation of Positron Emission Tomography Scanning,Sentinel Lymph Node Biopsy,and Standard Axillary Dissection for Axillary Staging in Patients with Early Stage Breast Cancer

Background: Positron emission tomography (PET) is a noninvasive imaging modality that can detect malignant lymph nodes. This study determined the sensitivity, specificity, predictive values, and likelihood ratios of PET scanning compared with standard axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) in staging the axilla in women with early stage breast cancer.Methods: Women with clinical stage I or II breast cancer had whole body PET scanning before ALND and SLNB, in a prospective, blinded protocol. ALND were evaluated by standard hematoxylin and eosin (H&E) staining techniques, while sentinel nodes were also examined for micrometastatic disease.Results: A total of 98 patients were recruited. PET compared with ALND demonstrated sensitivity of 0.40 (95% CI, 0.16, 0.68), specificity 0.97 (CI, 0.90, 0.99), positive likelihood ratio 14.4 (CI, 3.21, 64.5), positive predictive value 0.75 (CI, 0.35, 0.97), and false–negative rate of 0.60 (CI, 0.32, 0.84). Test properties were similar for PET compared with sentinel nodes positive by H&E staining. A few false–positive scans (0.028, CI, 0.003, 0.097) were seen. Multiple logistic regression analysis found that PET accuracy was better in patients with high grade and larger tumors. Increased size and number of positive nodes were also associated with a positive PET scan.Conclusions: The sensitivity of PET compared with ALND and SLNB was low, whereas PET scanning had high specificity and positive predictive values. The study suggests that PET scanning cannot replace histologic staging in early stage breast cancer. The low rate of false–positive findings suggests that PET can identify women who can forego SLNB and require full axillary dissection.     

[11C]Metahydroxyephedrine and [18F]Fluorodeoxyglucose Positron Emission Tomography Improve Clinical Decision Making in Suspected Pheochromocytoma

Background Pheochromocytomas are rare tumors of chromaffin cells for which the optimal management is surgical resection. Precise diagnosis and localization may be elusive. We evaluated whether positron emission tomography (PET) scanning with the combination of [¹⁸F]fluorodeoxyglucose (FDG) and the norepinephrine analogue [¹¹C]metahydroxyephedrine (mHED) would allow more exact diagnosis and localization. Methods Fourteen patients with suspected pheochromocytoma were evaluated by anatomical imaging (computed tomography or magnetic resonance imaging) and [¹³¹I]metaiodobenzylguanidine (MIBG) planar imaging. PET imaging was performed by using mHED with dynamic adrenal imaging, followed by a torso survey and FDG with a torso survey. Images were evaluated qualitatively by an experienced observer. Results Eight patients had pathology-confirmed pheochromocytoma. Of the other six, two patients had normal adrenal tissue at adrenalectomy, and the other four had subsequent clinical courses inconsistent with a diagnosis of pheochromocytoma. In four of eight patients with pheochromocytoma, MIBG failed to detect one or more sites of pathology-confirmed disease. The mHED-PET detected all sites of confirmed disease, whereas FDG-PET detected all sites of adrenal and abdominal disease, but not bone metastases, in one patient. MIBG and FDG-PET results were all negative in the six patients without pheochromocytoma. One patient with adrenal medullary hyperplasia had a positive mHED-PET scan. PET scanning aided the decision not to operate in three of six patients. The resolution of PET functional imaging was superior to that of MIBG. Conclusions PET scanning for pheochromocytoma offers improved quality and resolution over current diagnostic approaches. PET may significantly influence the clinical management of patients with a suspicion of these tumors and warrants further investigation. Presented at the 58th Annual Meeting of the Society of Surgical Oncology, Atlanta, Georgia, March 2005.