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.     

Prognostic significance of [(18)F]fluorodeoxyglucose uptake on positron emission tomography in patients with pathologic stage I lung adenocarcinoma

BACKGROUND: [(18)F]Fluoro-2-deoxyglucose uptake on positron emission tomography (FDG-PET) has been frequently used for diagnosis and staging of lung cancer. The prognostic significance of FDG uptake on PET was evaluated in patients with pathologic Stage I lung adenocarcinoma (tumor stages were based on the TNM classification of the International Union Against Cancer). METHODS: Disease-free survival of 98 patients with pathologic Stage I lung adenocarcinoma who were treated by curative resection was examined in relation to sex, age, histologic grade of differentiation, surgical procedure, tumor stage, and FDG uptake measured as the maximum standardized uptake value (SUV). RESULTS: Sixty-three patients were had Stage IA disease and 35 patients had Stage IB disease. Six patients each with Stage IA and Stage IB disease developed disease recurrence after a mean postsurgical follow-up period of 31 months. Ten (23%) of the 43 patients with SUV > or = 3.3 developed a recurrence compared with 2 (4%) of the 55 patients with SUV < 3.3 (P = .020). Ten (20%) of the 51 patients with moderately or poorly differentiated adenocarcinoma developed disease recurrence, compared with 2 (4%) of the 47 patients with well-differentiated adenocarcinoma (P = .056). Multivariate analysis demonstrated that histologic grade of differentiation was not correlated with the frequency of tumor recurrence (P = .286), whereas SUV was found to be marginally correlated (P = .079). CONCLUSIONS: FDG uptake appears to be predictive of disease-free survival in patients with Stage I lung adenocarcinoma. FDG uptake could yield important information for determining the likely value of postoperative adjuvant chemotherapy in such patients.     

The incremental effect of positron emission tomography on diagnostic accuracy in the initial staging of esophageal carcinoma

BACKGROUND: The purpose of the current study was to assess whether [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) provides incremental value (e.g., additional information on lymph node involvement or the presence of distant metastases) compared with computed tomography (CT) in patients with esophageal carcinoma. METHODS: The authors examined 149 consecutive patients with thoracic esophageal carcinoma. Eighty-one patients underwent radical esophagectomy without pretreatment, 17 received chemoradiotherapy followed by surgery, 3 underwent endoscopic mucosal resection, and the remaining 48 patients received definitive radiotherapy and chemotherapy. The diagnostic accuracy of FDG-PET and CT was evaluated at the time of diagnosis. RESULTS: The primary tumor was visualized using FDG-PET in 119 (80%) of 149 patients. Regarding lymph node metastases, FDG-PET had 32% sensitivity, 99% specificity, and 93% accuracy for individual lymph node group evaluation and 55% sensitivity, 90% specificity, and 72% accuracy for lymph node staging evaluation. PET exhibited incremental value over CT with regard to lymph node status in 14 of 98 patients who received surgery: 6 patients with negative CT findings were eventually shown to have lymph node metastases (i.e., they had positive PET findings and a positive reference standard [RS]); 6 patients with positive CT findings were shown not to have lymph node metastases (i.e., they had negative PET findings and a negative RS); and 2 patients were shown to have cervical lymph node metastases in addition to mediastinal or abdominal lymph node metastases. Among the remaining patients, PET showed incremental value over CT with regard to distant organ metastases in six patients. The overall incremental value of PET compared with CT with regard to staging accuracy was 14% (20 of 149 patients). CONCLUSIONS: FDG-PET provided incremental value over CT in the initial staging of esophageal carcinoma. At present, combined PET-CT may be the most effective method available for the preoperative staging of esophageal tumors.     

Japanese Gastric Cancer Association Task Force for Research Promotion: clinical utility of <Superscript>18</Superscript>F-fluoro-2-deoxyglucose positron emission tomography in gastric cancer. A systematic review of the literature

Since April 2010, the Japanese Public Health Insurance System has covered the costs incurred for performing ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) imaging for patients with advanced gastric cancer. The aim of this review was to evaluate the clinical impact of PET for patients with gastric cancer. A systematic literature search was performed in PubMed/MEDLINE using the keywords “gastric cancer” and “PET” to search for relevant articles published from January 2000 to September 2010. The clinical impact of selected articles was assessed by the authors to evaluate the following: (a) tumor staging, (b) diagnosis for recurrent disease, (c) evaluation of treatment response, and (d) screening for gastric cancer. FDG uptake increases in papillary adenocarcinoma, tubular adenocarcinoma, and solid-type poorly differentiated adenocarcinoma. This uptake is also associated with glucose transporter 1 expression. The sensitivity and specificity of FDG-PET for metastatic lymph node detection were 21–40% and 89–100%, respectively. The sensitivity and specificity for distant metastasis detection were 35–74% and 74–99%, respectively. Treatment response can be detectable at an earlier stage by PET than by computed tomography (CT), because FDG uptake by cancer cells decreases according to the treatment response. In summary, although PET has limitations such as frequent false-negative cases in signet-ring cell carcinoma and non-solid type poorly differentiated carcinoma, it can contribute to the selection of a more appropriate treatment modality by detecting distant metastases and treatment response.     

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.     

Role of fluorine-18 fluoro-deoxyglucose positron emission tomography scan in the evaluation and follow-up of patients with low-grade lymphomas

BACKGROUND: Fluorine-18 fluoro-deoxyglucose positron emission tomography (FDG-PET) scanning has excellent sensitivity and specificity for staging non-Hodgkin lymphomas, but to the authors' knowledge few studies to date have evaluated FDG-PET in low-grade lymphomas only. METHODS: A retrospective study was performed on patients with biopsy-proven nontransformed and transformed follicular lymphoma (FL), B-cell small-cell lymphocytic lymphoma (SLL/CLL), or marginal zone lymphoma (MZL) who underwent PET and computed tomography (CT) scans within 3 weeks. Standard uptake values (SUV) of all abnormal foci were measured. RESULTS: In FL, PET demonstrated 94% sensitivity and 100% specificity for staging. PET was more specific than CT for detecting recurrence or assessing therapeutic responses (91% vs. 50%). FDG avidity among patients with WHO Grades 1, 2, and 3 disease was not significantly different (analysis of variance [ANOVA]). For MZL staging, PET had moderate sensitivity (71%) and outperformed CT alone in the depiction of extranodal sites (85% vs. 57% sensitivity). In SLL/CLL, PET sensitivity was 53% and underestimated disease extent in 5 of 19 patients (26%) compared with CT. PET did not affect initial management but confirmed suspected recurrences in 75% of patients. Nontransformed FL had a higher SUV (ANOVA, P < .05) compared with MZL and SLL/CLL. SUV was higher in transformed than in nontransformed tumors (P < .001, Student t test). CONCLUSIONS: PET usefulness in staging low-grade lymphomas varies depending on histology. PET sensitivity is excellent in FL and moderate in MZL. PET is more specific than CT for follow-up in all types. PET has limited usefulness for SLL/CLL staging. However, a suggestive pattern of hazy and mild uptake was often noted in positive scans. In all low-grade lymphomas, the emergence of foci of intense uptake should raise suspicion of conversion to high-grade disease.     

FDG-PET has no definite role in preoperative imaging in gastric cancer

Background

Gastric cancer is fourth on the incidence list of cancers worldwide with a high disease-related mortality rate. Curation can only be achieved by a radical resection including an adequate lymphadenectomy. However, prognosis remains poor and cancer recurrence rates are high, also due to lymph node metastases. To improve outcome, (neo)adjuvant treatment strategies with chemo- and/or radiotherapy regimes are employed.

Aims

Accurate staging of gastric cancer at primary diagnosis is essential for adequate treatment. In this non-systematic review the role 18-F-Fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in preoperative staging is investigated. Furthermore, the results of neoadjuvant chemotherapy-induced tumour response monitoring by FDG-PET are discussed.

Results and conclusion

It is concluded that currently FDG-PET has no role in the primary detection of gastric cancer due to its low sensitivity. FDG-PET shows, however, slightly better results in the evaluation of lymph node metastases in gastric cancer compared to CT and could have therefore a role in the preoperative staging. Improvement in accuracy could be achieved by using PET/CT or other PET tracers than FDG, but these modalities need further investigation. FDG-PET, however, adequately detects therapy responders at an early stage following neoadjuvant chemotherapy.     

Repeat 18F-FDG PET for monitoring neoadjuvant chemotherapy in patients with stage III non-small cell lung cancer

PURPOSE: The relevance of (18)F-FDG PET for staging non-small cell lung cancer (NSCLC), in particular for the detection of lymph node or distant metastases, has been shown in several studies. The value of FDG-PET for therapy monitoring in NSCLC, in contrast, has not yet been sufficiently analysed. Aim of this study was to evaluate FDG-PET for monitoring treatment response during and after neoadjuvant radiochemotherapy (NARCT) in advanced NSCLC. METHODS: Sixty-five patients with histologically proven NSCLC stage III initially underwent three FDG-PET investigations, during NARCT prior to initiating radiation, and post-NARCT. Changes of FDG-uptake in the primary tumour at two time-points during NARCT were analysed concerning their impact on long-term survival. RESULTS: The mean maximum FDG uptake (standardized uptake value, SUVmax) of the whole group decreased significantly during NARCT (SUVmax PET 1: 14.9+/-4.0, SUVmax PET 3: 5.5+/-2.4, p=0.004). The difference between initial FDG uptake (PET 1) and uptake after induction chemotherapy (PET 2) was found to be highly predictive for long-term survival patients which had a greater than 60% decreases in their SUV change had a significantly longer survival than those below this threshold (5-year-survival 60% versus 15%, p=0.0007). Patients who had a lower than 25% decrease in their SUV change had a 5-years-survival lower than 5%. Furthermore, the difference between initial FDG uptake (PET 1) and uptake after completion of the whole NARCT (PET 3) was predictive for survival when 75% was applied as cut-off (p=0.02). However, the level of significance was considerably lower. CONCLUSION: FDG-PET is suitable for therapy monitoring in patients with stage III NSCLC. The decrease of FDG uptake during induction chemotherapy is highly predictive for patient outcome.     

Vinorelbine plus cisplatin versus cisplatin plus vindesine and mitomycin C in stage IIIB-IV non-small cell lung carcinoma: a prospective randomized study

This study was performed to investigate the utility of FDG-PET for: (1) initial staging, and (2) restaging of the primary and mediastinal nodal lesions 2 weeks after the completion of preoperative chemoradiotherapy in patients with stage III non-small cell lung cancer (NSCLC). Twenty-six patients with histologically confirmed stage III NSCLC were accrued to this study from April 1993 to July 1998. They included 21 with stage IIIA (N2) NSCLC who were enrolled into an institutional phase II study, and 5 patients with a highly selected subset of stage IIIB disease characterized by the presence of microscopic metastatic disease in contralateral mediastinal lymph nodes who were also treated with preoperative chemoradiotherapy; N3 lesions (n=3) and minimal T4 lesions. Demographic characteristics included median age 62 years (a range from 47 to 73) and gender ratio of male 15 to female 11. Histologic types of tumor consisted of squamous cell carcinoma 6, adenocarcinoma 11, large cell carcinoma 5, and non-small cell carcinoma 4. All patients had FDG-PET imaging of the chest before the initiation and 2 weeks after completion of preoperative therapy. The FDG-PET images were evaluated qualitatively for uptake at the primary tumor sites and mediastinal lymph nodes. Standard uptake values (SUVs) were also calculated for the primary tumors and all PET findings were correlated with surgical histopathologic data. Preoperative chemoradiotherapy resulted in complete pathologic response in 8 of 26 primary lesions. By qualitative analysis, 96% of these tumors showed level 3 or 4 uptake before preoperative chemoradiotherapy. After chemoradiotherapy, 57% (15/26) of patients showed at least a one level decrease in uptake, and the sensitivity and specificity of FDG-PET for differentiating residual tumor from pathologic complete response were 67% (12/18) and 63% (5/8). Mean SUV was 14.87+/-7.11 at baseline and decreased to 5.72+/-3.35 after chemoradiotherapy (n=21, P<0.00001). When a value of 3.0 was used as the SUV cut-off, sensitivity and specificity were 88 and 67%, respectively. The mean values of visual intensity were 3.87+/-0.35 and 3.8+/-0.51 for patients who achieved pathologic complete response (n=8) and for those who showed residual cancer after the preoperative therapy (n=18), respectively. The mean SUVs were 16.97+/-8.52 and 14.03+/-6.61 for patients who achieved pathologic complete response (n=6) and for those who showed residual cancer (n=15) after the preoperative therapy, respectively. Therefore, the degree of FDG uptake before preoperative chemoradiotherapy did not provide predictive value for subsequent tumor response. For mediastinal initial staging, the sensitivity and specificity of FDG-PET were 75 and 90.5%. The sensitivity and specificity of FDG-PET for mediastinal restaging were 58.0 and 93.0%. These results indicate that FDG-PET is useful for monitoring the therapeutic effect of neoadjuvant chemoradiotherapy in patients with stage III NSCLC. For the primary lesions, SUV based analysis has high sensitivity but limited specificity for detecting residual tumor. In contrast, for restaging of mediastinal lymph nodes, FDG-PET is highly specific, but has limited sensitivity.     

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.     

The standardized uptake value for F-18 fluorodeoxyglucose is a sensitive predictive biomarker for cervical cancer treatment response and survival

BACKGROUND: The objective of this study was to evaluate cervical tumor uptake of F-18 fluorodeoxyglucose (FDG) measured as the maximal standardized uptake value (SUV(max)) by positron emission tomography (PET) and its association with treatment response and prognosis in patients with cervical cancer. METHODS: The study population consisted of 287 patients with stage IA2 through IVB cervical cancer who underwent pretreatment FDG-PET studies. SUV(max), tumor volume, and sites of lymph node metastasis were recorded. Therapy included surgery, chemoradiation, or palliation. RESULTS: The mean SUV(max) was 11.4 (range, 1-50.4). The mean tumor volume by stage was 42.1 cm(3) for stage I tumors (using International Federation of Gynecology and Obstetrics [FIGO] staging criteria), 63.7 cm(3) for stage II tumors, 129.2 cm(3) for stage III tumors, and 166.2 cm(3) for stage IV tumors. There was no correlation between tumor volume and SUV(max) (correlation coefficient [R(2)] = 0.01). No significant difference in SUV(max) was observed between squamous histology (n = 247 patients) and nonsquamous histology (n = 40 patients; P = .089). Higher SUV(max) was associated with an increased risk of lymph node metastasis at diagnosis (P = .0009). A Cox proportional-hazards model for death from cervical cancer was used to evaluate tumor histology, lymph node metastasis, tumor volume, and SUV(max). The results indicated that SUV(max) was the only significant independent factor (P = .0027). Three prognostic groups were established using SUV(max). The overall survival rates at 5 years were 95% for an SUV(max) 5.2 and 13.3 (P < .0001). Increasing SUV(max) was associated with persistent abnormal FDG uptake in the cervix on 3-month FDG-PET studies in 238 patients who received curative chemoradiation (P = .04). CONCLUSIONS: The SUV(max) of the cervical tumor at diagnosis was a sensitive biomarker of treatment response and prognosis for patients with cervical cancer.     

Clinicopathologic Significance of False-Positive Lymph Node Status on FDG-PET in Lung Cancer

Introduction2-[¹⁸F] Fluoro-d-deoxyglucose (FDG) positron emission tomography (PET) is a relevant diagnostic procedure for staging lung cancer. However, accurate evaluation of lymph node metastases by PET is controversial because of false-positive FDG uptake.Patients and MethodsA total of 245 patients with lung cancer were retrospectively analyzed. Standardized maximum uptake values (SUV_max) of the primary tumor and lymph nodes were compared to pathologic lymph node metastases to correlate PET findings with clinicopathologic variables and patient outcomes.ResultsThe SUV_max values of metastatic lymph nodes were significantly higher than those of lymph nodes without metastases (P = .0036). When SUV_max ≥ 4 was defined as PET positive for metastasis, the sensitivity, specificity, and accuracy were 48.1%, 79.8%, and 73.1%, respectively. Multivariate logistic regression analysis showed that age > 75 years, bilateral hilar FDG uptake, and no lymph node swelling were significant factors related to false-positive lymph node metastases. Smoking status, FDG uptake in the primary tumor, and concurrent lung diseases were not significant factors.ConclusionMetastatic lymph nodes show higher FDG uptake than false-positive lymph nodes, and older patient age, bilateral hilar FDG uptake, and no swollen nodes are associated with no metastases. Patients with lymph node metastases have worse survival than those with false-positive FDG-PET findings. However, abnormal FDG uptake in the lymph node is an important prognostic factor.     

Axillary Lymph Node-to-Primary Tumor Standard Uptake Value Ratio on Preoperative 18F-FDG PET/CT: A Prognostic Factor for Invasive Ductal Breast Cancer

Purpose

This study assessed the axillary lymph node (ALN)-to-primary tumor maximum standard uptake value (SUV_max) ratio (ALN/T SUV ratio) in invasive ductal breast cancer (IDC) on preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to determine the effectiveness in predicting recurrence-free survival (RFS).

Methods

One hundred nineteen IDC patients (mean age, 50.5±10.5 years) with pathologically proven ALN involvement without distant metastasis and preoperative FDG PET/CT were enrolled in the study. SUV_max values of the ALN and primary tumor were obtained on FDG PET/CT, and ALN/T SUV ratio was calculated. Several factors were evaluated for their effectiveness in predicting RFS. These included several parameters on FDG PET/CT as well as several clinicopathological parameters: pathologic tumor/node stage; nuclear and histological grade; hormonal state; status with respect to human epidermal growth factor receptor 2, mindbomb E3 ubiquitin protein ligase 1 (MIB-1), and p53; primary tumor size; and ALN size.

Results

Among 119 patients with breast cancer, 17 patients (14.3%) experienced relapse during follow-up (mean follow-up, 28.4 months). The ALN/T SUV ratio of the group with disease recurrence was higher than that of the group without recurrence (0.97±1.60 and 0.45±0.40, respectively, p=0.005). Univariate analysis showed that the primary tumor SUV_max, ALN SUV_max, ALN/T SUV ratio, ALN status, nuclear and histological grade, estrogen receptor (ER) status, and MIB-1 status were predictors for RFS. Among these variables, ALN/T SUV ratio with hazard ratio of 4.20 (95% confidence interval [CI], 1.74-10.13) and ER status with hazard ratio of 4.33 (95% CI, 1.06-17.71) were predictors for RFS according to multivariate analysis (p=0.002 and p=0.042, respectively).

Conclusion

Our study demonstrated that ALN/T SUV ratio together with ER status was an independent factor for predicting relapse in IDC with metastatic ALN. ALN/T SUV ratio on preoperative FDG PET/CT may be a useful marker for selecting IDC patients that need adjunct treatment to prevent recurrence.     

Correlation of 18-F-fluorodeoxyglucose (FDG) accumulation with glucose transporter (Glut-1) expression in esophageal squamous cell carcinoma

BACKGROUND: We previously reported that positron emission tomography (PET) with 18-F-fluorodeoxyglucose (FDG) might be a useful tool for evaluating the stage of esophageal squamous cell carcinoma (SCC), and that FDG-PET shows greater accuracy in the diagnosis of lymph node metastasis than computed tomography. Further, we elucidated the relationships among FDG-PET performance, glucose transporter (Glut)-1 expression and serum levels of the tumor markers carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA) and squamous cell carcinoma antigen (SCC-Ag) in esophageal SCC. PATIENTS AND METHODS: We studied 44 patients with thoracic esophageal SCC who had undergone radical esophagectomy. Immunohistochemical analysis was used to detect the expression of Glut-1 in resected specimens and FDG accumulation was assessed by FDG-PET scan. RESULTS: FDG uptake in the primary tumor was found in 34 out of 44 (77.3%) patients. No significant correlation was observed between SUVs and the tumor markers CEA, CYFRA and SCC-Ag. The survival rate in patients with high FDG uptake (SUV > 3) was significantly lower than in cases with low FDG uptake (SUV < 3) (p < 0.01). A significant correlation was observed between SUV and Glut-1 expression (p < 0.05). The prognosis in patients with both low Glut-1 expression and low FDG uptake tended to be more favorable than in patients with high Glut-1 expression and/or high FDG uptake. CONCLUSION: Glut-1 expression was related to FDG uptake, and assessment of both FDG uptake and Glut-1 expression might be useful for providing prognostic information in patients with esophageal SCC.     

FDG-PET/CT imaging for staging and target volume delineation in preoperative conformal radiotherapy of rectal cancer

PURPOSE: To investigate the potential impact of using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on staging and target volume delineation for patients affected by rectal cancer and candidates for preoperative conformal radiotherapy. METHODS AND MATERIALS: Twenty-five patients diagnosed with rectal cancer T3-4 N0-1 M0-1 and candidates for preoperative radiotherapy underwent PET/CT simulation after injection of 5.18 MBq/kg of FDG. Clinical stage was reassessed on the basis of FDG-PET/CT findings. The gross tumor volume (GTV) and the clinical target volume (CTV) were delineated first on CT and then on PET/CT images. The PET/CT-GTV and PET/CT-CTV were analyzed and compared with CT-GTV and CT-CTV, respectively. RESULTS: In 4 of 25 cases (24%), PET/CT affected tumor staging or the treatment purpose. In 3 of 25 cases (12%) staged N0 M0, PET/CT showed FDG uptake in regional lymph nodes and in a case also in the liver. In a patient with a single liver metastasis PET/CT detected multiple lesions, changing the treatment intent from curative to palliative. The PET/CT-GTV and PET/CT-CTV were significantly greater than the CT-GTV (p = 0.00013) and CT-CTV (p = 0.00002), respectively. The mean difference between PET/CT-GTV and CT-GTV was 25.4% and between PET/CT-CTV and CT-CTV was 4.1%. CONCLUSIONS: Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively.     

Role of FDG-PET in the assessment of survival prognosis in melanoma

Positron-emission tomography (PET) employing fluorodeoxyglucose (FDG) has proven to be a highly sensitive and specific diagnostic method in the staging and restaging of various neoplasms, including melanoma, complementing morphologic imaging. FDG uptake has been correlated with proliferation rate, and thus, the degree of malignancy of a given tumor (i.e., grading). Consecutively, a relationship of survival prognosis and the extent of tumor burden as well as degree of FDG accumulation--determined by FDG-PET--has been suggested in various tumors. The aim of this study was to assess the potential of fluor-18-FDG-PET in order to evaluate the survival prognosis in melanoma. Patient data (n=95) were retrospectively analyzed, and the results of functional FDG-PET staging was correlated with survival data. Time of staging (diagnosis of primary versus recurrence) had no statistically significant effect on survival prognosis when patients were matched for pertaining node metastasis (NM) stages. Differences in survival were owing to the presence of metastatic disease rather than time of staging. Tumor (T)-stage (T1-T4) alone had no effect on survival prognosis when patients were matched for NM stages. Differences in survival were also due to higher rates of lymph node (LN) and organ metastases in higher T-stages. Detection of LN metastases (N1M0) had a statistically significant and predominant impact on 5-year survival (N0M0 80% versus N1M0 45%; p<0.01). Additional presence of distant metastases in LN-positive patients (N1M1) had only a statistically insignificant further impact on survival (5-year survival in N1M0 45% versus N1M1 29%; p>0.05). Exclusive presence of organ metastases (N0M1) showed a statistically significant drop of survival with a 5-year survival of 61% in N0M1 versus 80% in N0M0, respectively (p<0.03). Further, the combined presence of LN and distant metastases had the worst prognosis (5-year survival in N1M1 29% versus N0M1 61%; p<0.02). Based on a qualitative 4-point scoring system, patients with malignancy-typical FDG uptake showed an overall 5-year survival of 38%, as compared to patients with malignancy-suspicious lesions (71%; p 相似文献   

A prospective evaluation of the utility of 2‐deoxy‐2‐[18F]fluoro‐D‐glucose positron emission tomography and computed tomography in staging locally advanced gastric cancer

BACKGROUND:

The aim of this study was to examine prospectively the utility of adding preoperative [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG‐PET)/computed tomography (CT) to routine CT, endoscopic ultrasound (EUS), and laparoscopic staging of localized gastric cancer.

METHODS:

Patients with locally advanced gastric/gastroesophageal cancer were screened for 2 institutional review board–approved Memorial Sloan‐Kettering Cancer Center neoadjuvant chemotherapy protocols. Locally advanced disease was defined as T3 or T4, or lymph node–positive, based on EUS and high‐resolution CT scan. All patients underwent both standard FDG‐PET/CT and laparoscopy with cytological examination of washings. The sensitivity and specificity of FDG‐PET/CT for the identification of metastatic disease not seen on CT was determined. An economic model using Medicare/Medicaid reimbursement charges was developed to assess the cost‐effectiveness of these interventions.

RESULTS:

A total of 113 patients were enrolled from 2003 to 2010. All patients were assessed as having locally advanced disease by CT/EUS. FDG uptake in the primary tumor was associated with male sex, proximal tumors, and nondiffuse Lauren's subtype. 31 (27%) patients had occult metastatic disease detected by PET/CT (n = 11, 10%) and/or laparoscopy (n = 21, 19%), with a single overlap. Economic modeling suggests that the addition of FDG‐PET/CT to the standard staging evaluation of patients with locally advanced gastric cancer resulted in an estimated cost savings of ～US $13,000 per patient.

CONCLUSIONS:

FDG‐PET/CT identifies occult metastatic lesions in approximately 10% of patients with locally advanced gastric cancer. Because of reduced morbidity from fewer futile surgeries and lower patient care costs, PET/CT should be considered as a component of the standard staging algorithm for localized gastric cancer. Cancer 2012. © 2012 American Cancer Society.     

A case of primary lung cancer lesion demonstrated by F-18 FDG positron emission tomography/computed tomography (PET/CT) one year after the detection of metastatic brain tumor

Cancer of unknown primary origin (CUP) is an aggressive disease with a poor prognosis. Metastatic brain tumors occur in approximately 15% of all cancer patients. F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) contributes to the evaluation of cancer staging, although the benefits of PET/CT for detection of CUP origins has yet to be determined. In this study, we present a 37-year-old man with a brain tumor detected by magnetic resonance imaging. Surgical biopsy indicated a metastatic undifferentiated carcinoma, while clinical examination and a CT scan did not detect any abnormalities, with the exception of brain metastases. PET/CT did not reveal abnormal FDG uptake. PET/CT revealed abnormal intense FDG uptake in a small nodular lesion in the right lung 1 year following the detection of brain metastasis, and no other abnormal FDG uptake was observed elsewhere in the body. Right upper lobectomy and dissection of mediastinal lymph nodes were performed. The pathological diagnosis was poorly differentiated adenocarcinoma, which was similar to the brain metastatic lesion, and there was no lymph node metastasis. This case revealed an extremely rare lung cancer with primary lesions demonstrated by PET/CT 1 year after the detection of brain metastasis. This case reveals that F-18 FDG PET/CT imaging of CUP origin is capable of positively impacting on the identification of small primary tumor foci.     

18F-FDG PET/CT对肺腺癌EGFR突变状态的预测价值研究*

目的 :本研究旨在阐明18F-FDG PET/CT对于肺腺癌EGFR突变状态的预测价值。 方法: 选取2016年6月1日至2017年7月31日于天津医科大学肿瘤医院行术前PET/CT扫描及术后基因检测的肺腺癌患者117例。分析患者临床特征、肺内原发病灶SU? Vmax、SUVmean、SUVpeak及肺内原发病灶与纵隔血池SUVmax比值与EGFR突变状态间的关系。采用受试者工作特征曲线分析不同PET代谢参数对EGFR突变状态的预测能力。 结果: 117例患者中,EGFR突变型患者65例。未吸烟患者EGFR突变率高于吸烟患者（62.5% vs. 40.5%,P=0.026）。EGFR突变型肺内原发病灶SUVmax、SUVmean、SUVpeak及肺内原发病灶与纵隔血池SU? Vmax比值均明显低于野生型（SUVmax:8.02±3.96 vs. 10.31±5.80,P=0.017;SUVmean:4.97±2.51 vs. 6.45±3.68,P=0.015;SUVpeak:6.03±3.22 vs. 8.06±5.01,P=0.013;T/N:5.08±3.01 vs. 6.91±4.40,P=0.012）。不同诊断标准间诊断效能无明显差异。 结论: EGFR突变型患者肺内原发病灶FDG摄取值低于野生型患者,因此,18F-FDG PET/CT对肺腺癌患者EGFR突变状态的预测具有一定指导意义。      

The usefulness of MRI and PET imaging for the detection of parametrial involvement and lymph node metastasis in patients with cervical cancer

OBJECTIVE: The purpose of this study is to elucidate the usefulness of magnetic resonance imaging (MRI) and positron emission tomography (PET) for the detection of parametrial involvement and lymph node metastasis in patients with cervical cancer. METHODS: Thirty-six patients with cervical cancer were retrospectively enrolled. MRI and PET scans were performed for all patients within a week before radical surgery. The criterion for malignancy on MRI was >1 cm short axis diameter of the suspected lymph node. On PET, only fluorodeoxyglucose (FDG) uptake was significantly higher than the background and, if this FDG uptake showed on at least two consecutive axial slices, then the lesion was considered as a malignancy. We compared the extent of tumor on the surgical findings with the FIGO staging, MRI and PET scans. RESULTS: The accuracy of FIGO and MRI staging was 67 and 84.4%, respectively. The accuracy for detecting pelvic lymph node metastasis was better for PET than for MRI (78 versus 67%, respectively). All FDG uptake lymph nodes were confirmed as metastatic lymph nodes by pathological evaluation; this included five lymph nodes <1 cm in diameter. CONCLUSION: MRI provides an improved evaluation of local tumor extension, but PET is more useful for the evaluation of pelvic lymph nodes than MRI; however, PET still misses microscopic disease. Further studies are necessary to evaluate the usefulness of PET/computed tomography (CT) for the accuracy of the disease extension and the cost-effectiveness of MRI, PET or PET/CT in patients with cervical cancer.