The additional value of integrated PET/CT over PET in initial lymph node staging of esophageal cancer

The purpose of the present study was to assess the contribution of simultaneous functional/anatomical imaging using integrated 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), compared with PET alone for the evaluation of initial lymph node staging in esophageal cancer. We studied 167 consecutive patients with thoracic esophageal squamous cell carcinoma (SCC) who had radical esophagectomy performed between January 1999 and April 2007. For individual nodal group evaluation, PET/CT showed 46.0% sensitivity (p<0.05 vs. PET), 99.4% specificity, 95.1% accuracy (p<0.05 vs. PET), 87.0% positive and 95.5% negative predictive values. PET showed 32.9% sensitivity, 98.9% specificity, 93.1% accuracy, 74.7% positive predictive value and 93.9% negative predictive value. Thus, the sensitivity and accuracy of PET/CT were significantly higher than those of PET. Comparisons between CT, PET and PET/CT in detecting lymph node metastasis by each region showed that PET/CT had a higher sensitivity in lower thoracic regions than PET and CT (p<0.05 vs. CT and PET). Lymph node staging (N0 vs. N1) was not significantly different, but staging per lymph nodal group was significantly better with PET/CT. Integrated PET/CT imaging with co-registration of anatomic and functional imaging data is useful in the initial lymph node staging of patients with operable esophageal cancer compared with PET alone.     

Comparison between positron emission tomography and computed tomography in the use of the assessment of esophageal carcinoma

BACKGROUND: The role and potential value of positron emission tomography (PET) scanning in certain tumors has been widely investigated in recent years. The authors retrospectively assessed the performance of 18-F-fluorodeoxyglucose (FDG)-PET in the assessment of esophageal squamous cell carcinoma (SCC). METHODS: The results using PET were compared with those using computed tomography (CT), and these were correlated with the pathologic findings. The authors studied 32 patients with thoracic esophageal SCC who had undergone radical esophagectomy. RESULTS: Uptake of FDG in the primary tumor was found in 25 of the 32 (78.1%) cases. Comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between the FDG uptake and each of the depth of tumor invasion (P < 0.05), occurrence of lymph node metastasis (P < 0.01), and lymphatic invasion (P < 0.01). The survival rate in cases with high FDG uptake (standardized uptake value [SUV], >3) was significantly lower than that in cases with low FDG uptake (SUV, < 3; P < 0.05). In the evaluation of lymph node staging by the detection of lymph node metastasis, FDG-PET showed 77.8% sensitivity, 92.9% specificity, and 84.4% accuracy, and CT scanning showed 61.1% sensitivity, 71.4% specificity, and 65.6% accuracy. Positron emission tomography scanning showed a high degree of accuracy in the neck, upper thoracic, and abdominal regions. However, in the mid- and lower thoracic regions, the sensitivity was very low. The smallest lymph node metastasis that was detected by FDG-PET imaging was 6 mm. The average size of lymph node metastasis that was undetected by FDG-PET scanning was 7.3 mm (range, 1-17 mm). CONCLUSIONS: In conclusion, FDG-PET may be used as a noninvasive diagnostic technique in assessing the aggressiveness of the tumor and the prognosis in patients with esophageal SCC. During the preoperative diagnostic procedures, the sensitivity, specificity, and accuracy of lymph node staging is higher with FDG-PET than with CT imaging. In view of the high specificity of FDG-PET, it also gives useful information to guide the choice of treatment of esophageal carcinoma.     

Positron emission tomography of esophageal carcinoma using (11)C-choline and (18)F-fluorodeoxyglucose: a novel method of preoperative lymph node staging.

BACKGROUND: Accurate preoperative staging is an important but difficult problem in determining therapy for patients with esophageal carcinoma. Positron emission tomography (PET) is used with [methyl-(11)C]choline ((11)C-choline) and 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) to detect a variety of malignancies. The authors used PET with both of these agents to detect lymph node metastases in patients with esophageal carcinoma. METHODS: Lymph node metastases in 33 patients with biopsy-proven esophageal carcinoma (16 patients with tumors classified as T1 and 17 patients with tumors classified as T2-4) was examined by PET using (11)C-choline and (18)F-FDG, and the accuracy of the results was correlated with pathology findings after surgery. RESULTS: (11)C-choline PET was more effective than (18)F-FDG PET and computed tomography (CT) in detecting very small metastases localized in the mediastinum. It was ineffective, however, in detecting metastases localized in the upper abdomen, because of the normal uptake of (11)C-choline in the liver. (18)F-FDG PET was superior to CT in detecting metastases in the mediastinum and the upper abdomen, whereas (11)C-choline PET was superior to (18)F-FDG PET in detecting metastases in the mediastinum. When (11)C-choline PET and (18)F-FDG PET were used in combination, they were very effective in evaluating the lymph node status in both the mediastinum and the upper abdomen, and detected 85% of the metastatic lymph nodes (n = 46). CONCLUSIONS: In this study, the combination of (11)C-choline PET and (18)F-FDG PET was very effective in evaluating the lymph node status of patients with esophageal carcinoma preoperatively.     

Is there a role for FGD-PET in radiotherapy planning in esophageal carcinoma?

BACKGROUND AND PURPOSE: To determine the additional value of FDG-positron emission tomography (PET) to optimize delineation of the clinical target volume (CTV) in patients with advanced esophageal carcinoma. METHODS AND MATERIALS: The imaging and radiotherapy data from 30 patients with an advanced esophageal carcinoma were analysed. The lymph node classification for esophageal cancer was modified and translated into anatomical volumes on computed tomography (CT). The so defined 14 different regions were scored individually for lymph node involvement on CT, endoscopic ultrasound (EUS) and FDG-PET. The influence of discordant findings between conventional and functional imaging on the decision as to what should be irradiated was assessed. RESULTS: In 14 of the 30 patients (47%) discordances were found in detection of the pathological lymph nodes between CT/EUS and FDG-PET. In 8 patients, 9 lymph node regions were found with pathologic nodes on conventional imaging only. In three of these patients the influence of FDG-PET findings would have led to a decrease of the irradiated volume. In 6 patients, 8 lymph node regions were found with a normal CT/EUS and pathologic nodes on FDG-PET. In three of these patients (10%) the influence of the FDG-PET would have led to enlargement of the irradiated volume. CONCLUSIONS: The chance of a false negative result on FGD-PET is not negligible; therefore, the irradiated volume should not be reduced based on a negative FDG-PET in a region with suspect nodes on other investigations. However, due to the high specificity of FDG-PET enlarging the irradiated volume based on a positive FDG-PET in a region without suspected lymph nodes on CT and/or EUS should be considered. This indicates a role for FDG-PET in radiotherapy planning for esophageal cancer.     

Metastatic incidence of (PET)CT positive lung hilar and retroperitoneal lymph nodes in esophageal cancer patients

BackgroundExtra-regional lymph node metastases strongly determine treatment options in patients with esophageal cancer. Staging modalities such as (FDG-PET) CT scanning frequently show activity in retroperitoneal and lung hilar lymph nodes. This study evaluated the incidence of histologically confirmed metastases, treatment approach and recurrence patterns in patients with (FDG-PET) CT positivity in these regions.MethodsAll patients with (FDG-PET-) CT positive hilar and/or retroperitoneal lymph nodes at primary staging or restaging discussed at a multidisciplinary tumor board meeting for staging of esophageal cancer between January 2012–December 2017 were included. Biopsies and follow-up were evaluated to determine the presence of metastases and progression rates.ResultsFrom 2012 to 2017, 65 of 857 patients (7.6%) were selected with positive retroperitoneal and/or hilar lymph nodes. A total of 47/65 (72.3%) patients had positive retroperitoneal lymph nodes, which contained metastases in 19 (29.2%). When no biopsy was performed and curative treatment was given (n = 14), 9 patients had progression or locoregional and distant recurrence. Positive hilar lymph nodes were identified in 21 (32.3%) patients; 4 were biopsied and none contained metastases. In these patients no recurrence of disease was seen during follow-up.ConclusionsThe majority of biopsied (PET)CT-positive retroperitoneal lymph nodes at staging contained metastases, while biopsied (PET)CT-positive hilar nodes did not. Histological evaluation of (PET)CT -positive retroperitoneal lymph nodes at staging imaging is recommended, while based on this small series, (PET)CT-positive hilar lymph nodes most likely represent reactive lymphadenopathy.     

Improvement in preoperative staging of gastric adenocarcinoma with positron emission tomography

BACKGROUND: Positron emission tomography (PET) with 18- fluorodeoxyglucose (FDG) has been used to both detect and stage a variety of malignancies. The current study examined the value of PET for preoperative staging of gastric adenocarcinoma. METHODS: Sixty-eight patients (49 males and 19 females) with gastric adenocarcinoma, who were referred for preoperative FDG-PET scans, were enrolled in this study. The patients underwent spiral-computed tomography (CT) within 1 week of referral. The final diagnosis in all patients was made by histologic and surgical findings. For quantitative PET analysis, the regional tumor FDG uptake was measured by the standardized uptake value (SUV). RESULTS: For the primary tumor of a gastric adenocarcinoma, PET demonstrated an increased uptake in 64 of 68 patients (sensitivity, 94%), with a mean SUV of 7.0 (range, 0.9-27.7). A comparison of FDG uptake and clinicopathologic features showed significant association between FDG uptake and macroscopic type, tumor size, lymph node metastasis, histologic type, and TNM stage. The PET scan had a similar accuracy with that of CT for diagnosing local and distant lymph node metastases as well as peritoneal status. In assessing local lymph node status, however, PET had a higher specificity than CT (92% vs. 62%, P = 0.000). Moreover, PET had additional diagnostic value in 10 (15%) of 68 patients by upstaging 4 (6%) and downstaging 6 (9%) patients. PET combined with CT was more accurate for preoperative staging than either modality alone (66% vs. 51%, 66% vs. 47%, respectively; P = 0.002). CONCLUSIONS: FDG-PET improves the preoperative TNM staging of gastric adenocarcinoma. Based on its superior specificity, FDG-PET can facilitate the selection of patients for a curative resection by confirming a nodal status identified by CT.     

Lymph node staging by positron emission tomography in patients with carcinoma of the cervix.

PURPOSE: The aim of this study was to compare the results of computed tomography (CT) and positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG) for lymph node staging in patients with carcinoma of the cervix and to evaluate the relationship of the imaging findings to prognosis. PATIENTS AND METHODS: We retrospectively compared the results of CT lymph node staging and whole-body FDG-PET in 101 consecutive patients with carcinoma of the cervix. Patients were treated with standard irradiation and chemotherapy (as clinically indicated) and observed at 3-month intervals for a median of 15.4 months (range, 2.5 to 30 months). Progression-free survival was evaluated by the Kaplan-Meier method. RESULTS: CT demonstrated abnormally enlarged pelvic lymph nodes in 20 (20%) and para-aortic lymph nodes in seven (7%) of the 101 patients. PET demonstrated abnormal FDG uptake in pelvic lymph nodes in 67 (67%), in para-aortic lymph nodes in 21 (21%), and in supraclavicular lymph node in eight (8%). The 2-year progression-free survival, based solely on para-aortic lymph node status, was 64% in CT-negative and PET-negative patients, 18% in CT-negative and PET-positive patients, and 14% in CT-positive and PET-positive patients (P <.0001). A multivariate analysis demonstrated that the most significant prognostic factor for progression-free survival was the presence of positive para-aortic lymph nodes as detected by PET imaging (P =.025). CONCLUSION: This study demonstrates that FDG-PET detects abnormal lymph node regions more often than does CT and that the findings on PET are a better predictor of survival than those of CT in patients with carcinoma of the cervix.     

Maximum standardized uptake value on PET/CT in preoperative assessment of lymph node metastasis from thoracic esophageal squamous cell carcinoma

The presence of lymph node metastasis is an important prognostic factor for patients with esophageal cancer. Accurate assessment of lymph nodes in thoracic esophageal carcinoma is essential for selecting appropriate treatment and forecasting disease progression. Positron emission tomography combined with computed tomography （PET/CT） is becoming an important tool in the workup of esophageal carcinoma. Here, we evaluated the effectiveness of the maximum standardized uptake value （SUVmax） in assessing lymph node metastasis in esophageal squamous cell carcinoma （ESCC） prior to surgery. Fifty-nine surgical patients with pathologically confirmed thoracic ESCC were retrospectively studied. These patients underwent radical esophagectomy with pathologic evaluation of lymph nodes. They all had 18F-FDG PET/CT scans in their preoperative staging procedures. None had a prior history of cancer. The pathologic status and PET/CT SUVmax of lymph nodes were collected to calculate the receiver operating characteristic （ROC） curve and to determine the best cutoff value of the PET/CT SUVmax to distinguish benign from malignant lymph nodes. Lymph node data from 27 others were used for the validation. A total of 323 lymph nodes including 39 metastatic lymph nodes were evaluated in the training cohort, and 117 lymph nodes including 32 metastatic lymph nodes were evaluated in the validation cohort. The cutoff point of the SUVmax for lymph nodes was 4.1, as calculated by ROC curve （sensitivity, 80%; specificity, 92%; accuracy, 90%）. When this cutoff value was applied to the validation cohort, a sensitivity, a specificity, and an accuracy of 81%, 88%, and 86%, respectively, were obtained. These results suggest that the SUVmax of lymph nodes predicts malignancy. Indeed, when an SUVmax of 4.1 was used instead of 2.5, FDG-PET/ CT was more accurate in assessing nodal metastasis.     

FDG-PET in staging lung cancer: how does it change the algorithm?

BACKGROUND: In patients with lung cancer, positron emission tomography (PET) using fluor-18-fluorodesoxyglucose (FDG) may be used both to detect extrathoracic metastases (ETM) and for mediastinal lymph node staging (MLS), potentially reducing the need for mediastinoscopy. We assessed the added value of FDG-PET in detecting ETM and focused on the reliability of FDG-PET and mediastinoscopy for MLS. PATIENTS AND METHODS: In 72 consecutive patients with non-small cell lung cancer, the impact of adding FDG-PET to full conventional clinical staging was prospectively analyzed. The predictive value of FDG-PET findings and tumor location for pathologic mediastinal lymph node status were assessed in a logistic regression analysis. RESULTS: Unexpected extrathoracic metastases were detected by FDG-PET in 15% of patients. In MLS overall negative and positive predictive values were 71 and 83% for FDG-PET, and 92 and 100% for mediastinoscopy. However, the negative predictive value of FDG-PET was only 17% in case of FDG-PET positive N1 nodes and/or a centrally located primary tumor, whereas it was 96% in case of FDG-PET negative N1 nodes and a non-centrally located primary tumor. CONCLUSION: By incorporating FDG-PET in clinical staging, 15% of patients with lung cancer are upstaged due to unexpected extrathoracic metastases. In case of a negative mediastinal FDG-PET, mediastinoscopy can only be omitted in the presence of a non-centrally located primary tumor and without FDG-PET positive N1 nodes.     

Inefficacy of F-18 fluorodeoxy-D-glucose-positron emission tomography scans for initial evaluation in early-stage cutaneous melanoma

BACKGROUND: The purpose of the current study was to determine the sensitivity and specificity of initial F-18 fluorodeoxy-D-glucose-positron emission tomography (FDG-PET) scanning for detection of occult lymph node and distant metastases in patients with early-stage cutaneous melanoma. METHODS: The authors conducted a prospective nonrandomized clinical trial. Inclusion criteria were patients with cutaneous melanoma tumors > 1.0 mm Breslow thickness, local disease recurrence, or solitary intransit metastases without regional lymph or distant metastases by standard clinical evaluation. All patients underwent whole-body FDG-PET scanning before surgical therapy. Abnormal PET findings were studied by targeted conventional imaging and/or biopsy. FDG-PET scans were interpreted in a blinded fashion. Regional lymph node basins were staged by sentinel lymph node biopsy (SLNB). PET scan findings in regional lymph nodes were compared with histology of SLNB specimens. Abnormal distant PET scan findings were studied with repeat conventional scan imaging at 3-6 months and were correlated with the first site(s) of clinical disease recurrence. Blinded PET scan findings were correlated with all information to determine sensitivity and specificity. RESULTS: There were 144 assessable patients with a mean tumor depth of 2.8 mm. The median follow-up for these patients was 41.4 months. Blinded interpretations of FDG-PET scan images showed that 31 patients (21%) had signs of metastatic disease, 13 patients had probable regional lymph node metastases, and 18 patients had 23 sites of possible distant metastases. SLNB and/or follow-up demonstrated regional lymph node metastases in 43 of 184 lymph node basins in 40 patients (27.8%). Compared with all clinical information, FDG-PET scan sensitivity for detection of regional lymph node metastases was 0.21 (95% confidence [CI], 0.10-0.36) and specificity was 0.97 (95% CI, 0.93-0.99). No distant sites were confirmed to be true positive by targeted conventional imaging/biopsy at the time of presentation. Thirty-four patients (23.6%) presented with 54 foci of metastatic disease at initial disease recurrence. FDG-PET scan sensitivity for prediction of the first site(s) of clinical disease recurrence was 0.11 (95% CI, 0.04-0.23). Excluding patients with brain metastases, FDG-PET scan sensitivity for detection of occult Stage IV disease in patients was 0.04 (95% CI, 0.001-0.20) and specificity was 0.86 (95% CI, 0.79-0.92). CONCLUSIONS: FDG-PET scanning did not impact the care of patients with early-stage melanoma already staged by standard techniques. Routine FDG-PET scanning was not recommended for the initial staging evaluation in this population.     

PET for Staging of Esophageal Cancer

FDG-PET is of clinical value especially for detection of distant metastases or recurrentesophageal cancer.For the staging of primary tumor or locoregional lymph node metastasis PET is cur-rently not suitable.     

18FDG-PET对大肠癌分期、再分期诊断的价值

目的:评价18FDG-PET(18氟标记脱氧葡萄糖-正电子发射断层扫描)对大肠癌分期及术后再分期的价值。方法:对24例经肠镜检查初步诊断为直肠、结肠癌的患者行全身18FDG-PET检查,并在1～2W内完成手术及病理诊断。大肠癌术后18FDG-PET随访56例。结果:24例病理证实为大肠癌,23例局部18FDG摄取增高,SUVmax=7.09±3.26,2.98～12.2(SUV,Standarduptakevalue)。18FDG-PET对于肿瘤原发病灶诊断准确率为95%(23/24)。假阴性1例。单纯局部(主要为第1站)淋巴结转移8例(灵敏度8/16,50%),远处转移8例。改变33%(8/24)的患者治疗方案。56例随访病例中30例PET显示阴性,其中5例随访2年后复发,准确率83.4%。26例发现局部和/或多发转移,其中颈部淋巴结转移8例;肺及纵隔转移4例;肝转移7例;腹腔淋巴结转移11例;吻合口局部复发12例,骨转移11例。结论:18FDG-PET对大肠癌的分期和术后的再分期诊断有较高价值。     

PET在食管癌分期中的作用

FDG-PET is of clinical value especially for detection of distant metastases or recurrent esophageal cancer. For the staging of primary tumor or locoregional lymph node metastasis PET is currently not suitable.     

食管癌IMRT前FDG PET-CT显像对治疗决策的影响

目的 探讨食管癌初治患者IMRT前PET-CT显像对其治疗方案的影响。方法 回顾分析60例经食管镜检证实的食管癌患者,患者均为初次治疗,经常规影像检查后拟行IMRT。放疗前行PET-CT显像,观察是否有分期和治疗方案改变。结果 与常规影像比,PET-CT显像使12例患者分期发生改变(2例T期上调、6例N期上调、2例N期下调、2例M期上调)。3例患者由于新发现较多的远处转移,治疗方案由放疗改为化疗。PET-CT检查导致20例患者靶区改变,其中16例因发现更多转移淋巴结使靶体积增大,4例则排除了淋巴结转移使靶区缩小。结论 PET-CT对食管癌区域淋巴结和远处转移诊断有一定优势,有助提高分期准确性,改变了部分患者治疗决策方案。     

The Diagnostic Value of FDG-PET/CT for Urachal Cancer

Background: Urachal carcinoma (UrC) is a rare malignancy that often presents at an advanced stage with metastases in up to a quarter of patients. There is no consensus on the optimal form of staging for patients with UrC. In the present study, we evaluated the diagnostic value of ¹⁸F-fluorodeoxyglucose–positron emitted tomography/computed tomography (FDG-PET/CT) for UrC.Patients and Methods: We evaluated 40 consecutive patients who were staged for urachal cancer between 2010 and 2020. They underwent a total of 62 FDG-PET/CTs (40 for primary staging, and 22 during follow-up), which were compared with standard-of-care contrast-enhanced CT (CECT). The metabolic detection of primary tumors, lymph node metastases (LNMs), peritoneal metastases (PMs), distant metastases (DMs), and local recurrence by FDG-PET/CT was evaluated. Sensitivity and specificity were calculated compared with CECT. Histopathology or follow-up imaging was the reference standard.Results: Of all 40 patients, 33 patients (83%) had urachal adenocarcinoma—26 (65%) with a mucinous component and 7 (17%) with invasive urothelial carcinoma. All local UrC tumors could be visualized on CT, and 80% showed increased FDG uptake. At initial staging, FDG-PET/CT detected FDG-avid LNMs, PMs, and DMs in 50%, 17%, and 25% of patients, respectively. These metastases were also visualized on CECT. During follow up, FDG-PET/CT revealed FDG-avid local recurrences that were not seen on CT in two out of eight patients (25%).Conclusion: The present study demonstrates that most UrC can be visualized on FDG-PET/CT. At initial diagnosis, FDG-PET/CT does not seem to yield additional information compared with CECT; however, FDG-PET/CT may be helpful during follow-up. This is a small study, and the findings should be corroborated with larger series.     

FDG-PET and detection of distant metastases and simultaneous tumors in head and neck squamous cell carcinoma: a comparison with chest radiography and chest CT

Detection of distant metastases and second primary tumors in patients with head and neck squamous cell carcinoma (HNSCC) is of importance because of the impact on treatment and prognosis. The aim of this study was to assess the value of whole-body fluorodeoxyglucose-positron emission tomography (FDG-PET) in detecting distant metastases and second primary tumors below clavicular level in HNSCC compared to chest CT and chest radiography (CXR). Patient records of 149 consecutive patients with a primary HNSCC in whom a whole-body FDG-PET for initial staging was performed were reviewed. FDG-PET showed a sensitivity and specificity for detecting distant disease of 92% and 93%, respectively. Chest CT (n=82) showed a sensitivity and a specificity of 74% and 61% respectively. CXR (n=106) showed a sensitivity and a specificity of 41% and 91%, respectively. FDG-PET was shown to be able to detect distant metastases and second primary tumors in HNSCC with a high sensitivity and specificity. The higher sensitivity of PET compared to chest CT is mainly due to the detection of extrapulmonary malignancy. Sensitivity of PET and CT were similar in detecting intrapulmonary malignancy, but PET specificity was significantly higher. FDG-PET helps to determine the nature of pulmonary lesions and might be considered as a first diagnostic modality for detecting distant disease in advanced HNSCC.     

Prospective study of fluorodeoxyglucose-positron emission tomography imaging of lymph node basins in melanoma patients undergoing sentinel node biopsy.

PURPOSE: To prospectively compare positron emission tomography (PET) imaging of regional lymph node basins to sentinel node biopsy (SNB) in patients with American Joint Committee on Cancer (AJCC) stage I, II, and III melanoma localized to the skin. METHODS: Patients with cutaneous melanoma with Breslow's depth greater than 1 mm (AJCC T2-4N0M0) or localized regional cutaneous recurrence (TxN2bM0) underwent whole-body imaging of glucose metabolism with fluorodeoxyglucose (FDG) PET followed by SNB. PET scans were interpreted in a blinded fashion and compared with histologic analyses of SNB specimens and clinical follow-up examination. Nodal tumor volumes were estimated. RESULTS: Eighty-nine lymph node basins were evaluated by FDG-PET and SNB in 70 assessable patients. Eighteen patients (25.7%) had lymph node metastases at the time of FDG-PET imaging: 17 proved by SNB (24.3%) and one by follow-up examination (1.4%). Median tumor volume in positive sentinel node basins was 4.3 mm3 (range, 0.07 to 523 mm3). Sensitivity of SNB for detection of occult regional lymph node metastases was 94.4%, specificity was 100%, positive predictive value (PPV) was 100%, and negative predictive value (NPV) was 98.6%. Sensitivity of FDG-PET was 16.7%, specificity was 95.8%, PPV was 50%, and NPV was 81.9%. At a median follow-up duration of 16.6 months, seven patients (10%) developed recurrent disease. PET predicted one recurrence (14.3%) in a node basin missed by SNB. CONCLUSION: FDG-PET is an insensitive indicator of occult regional lymph node metastases in patients with melanoma because of the minute tumor volumes in this population. FDG-PET does not have a primary role for staging regional nodes in patients with clinically localized melanoma.     

The role of surgical staging in esophageal carcinoma

Given the overall poor prognosis of patients with esophageal carcinoma and considering the new therapeutic options, surgeons should accurately stage patients preoperatively to appropriately tailor their treatment. CT, MRI, PET and EUS are still inaccurate in evaluating local surgical resectability and in detecting abdominal and thoracic lymph node metastases. Minimally invasive surgical staging is a promising adjunct to esophageal cancer staging. The thoracoscopic and laparoscopic staging provide more accurate information for evaluating local invasion, lymph node and distant metastasis. The greater accuracy afforded by minimally invasive staging is essential for patients who should undergo radical surgical or multimodal treatment. According to data reported by many authors, it seems most useful to combine nonoperative staging procedures as CT/MRI and EUS with minimally invasive staging techniques.     

Accuracy of positron emission tomography in mediastinal node assessment in coal workers with lung cancer

The purpose of this study was to explore the accuracy of ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) in the assessment of mediastinal lymph node in coal workers who had non-small cell lung cancer. We retrospectively reviewed 42 retired coal workers who had lung cancer without distant metastasis, between May 2007 and May 2010. Regarding the mediastinal lymph nodes, when the standard uptake value was greater than 2.5, it was considered “malignancy positive.” After histological examination of the mediastinal lymph nodes, anthracotic and metastatic ones were detected. The results of PET/CT were analyzed to determine its accuracy. Of these 42 patients, PET/CT detected 47 positive mediastinal lymph nodes in 24 patients with a mean SUV maximum of 6.2 (2.6–13.8). One hundred and thirty-one mediastinal lymph node foci were dissected. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-PET/CT in detecting nodal metastases were 84% (16/19), 65% (15/23), 66% (16/24), 83% (15/18), and 74% (31/42) on a per-patient basis, respectively. Mediastinal node staging with FDG-PET/CT in coal workers is insufficient due to the high false-positive rates due to the presence of pneumoconiosis. In these patients, an invasive technique such as mediastinoscopy seems mandatory for confirmation of ipsilateral or contralateral mediastinal lymph node metastasis.     

Comparison of the accuracy of magnetic resonance imaging and positron emission tomography/computed tomography in the presurgical detection of lymph node metastases in patients with uterine cervical carcinoma: a prospective study

BACKGROUND: The objective of the current study was to determine the accuracy of magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) for detecting lymph node metastases in patients with uterine cervical carcinoma compared with thin-section histopathologic results from systemic lymphadenectomy. METHODS: Twenty-two patients with International Federation of Obstetrics and Gynecology (FIGO) Stage IB-IVA cervical carcinoma who underwent both MRI and PET/CT before lymphadenectomy were included in this study. Lymphadenectomy involved removing all visible lymph nodes in the surgical fields. To enable region-specific comparisons, paraaortic and pelvic lymph nodes were divided into seven regions: the paraaortic area, both common iliac areas, both external iliac areas, and both internal iliac/obturator areas. Histopathologic evaluation of lymph nodes was the diagnostic standard. Chi-square analysis was used to compare the accuracy of MRI and PET/CT for the detection of metastatic lymph nodes. A P value < or = 0.05 was considered statistically significant. RESULTS: With MRI, the sensitivity, specificity, and accuracy rates for detecting metastatic lymph nodes in each lymph node group were 30.3% (10 of 33 lymph node groups), 92.6% (112 of 121 lymph node groups), and 72.7% (122 of 154 lymph node groups), respectively; with PET/CT, those rates were 57.6% (19 of 33 lymph node groups), 92.6% (112 of 121 lymph node groups), and 85.1% (131 of 154 lymph node groups), respectively. Statistical analysis showed that PET/CT was more sensitive than MRI (P = 0.026) but that there were no statistical differences noted with regard to specificity (P = 1.000) or accuracy (P = 0.180). Power analysis demonstrated that a sample size of 685 lymph node groups (98 patients) would be necessary to demonstrate that PET/CT was more accurate than MRI (alpha = 0.05; beta = 0.80). CONCLUSIONS: PET/CT was more sensitive than MRI for detecting lymph node metastases in patients with uterine cervical carcinoma.