Accuracy Of Positron Emission Tomography-computed Tomography Research Articles

Diagnosis of lymph node metastasis on rectal cancer by PET-CT computer imaging combined with MRI technology

To compare the diagnostic efficacy and clinical application value of Positron Emission Tomography-Computed Tomography (PET-CT) metabolic computer Imaging imaging and Magnetic Resonance Imaging (MRI) diffusion imaging technology for regional lymph node metastasis in rectal cancer, 41 patients with rectal cancer confirmed by colonoscopy were collected and underwent 3.0T pelvic MRI and PET-CT examination, respectively. PET-CT/MRI fusion software was used to fuse magnetic resonance images and PET-CT images and accurately locate the rectal cancer lesions and lymph nodes, and image-operation-pathology control method was used to identify the lymph nodes around the rectum. In addition, independent sample t-test or Mann-Whitney U test were used to compare the differences in the values of various parameters between the two groups of metastatic lymph nodes and non-metastatic lymph nodes, Spearman correlation was used to analyze the correlation between SUV value and ADC value of metastatic lymph node, and the diagnostic value of SUV value and ADC value was evaluated by drawing ROC curve. The results showed that when SUV took 2.0 as the diagnostic threshold, the accuracy of PET-CT in diagnosing metastatic lymph nodes was 90.1%; when the diagnostic threshold of ADC was 1.0×10−3mm2/s, the accuracy of DWI in diagnosing metastatic lymph nodes was 84.2%; the accuracy of the combination of the two methods for the diagnosis of metastatic lymph nodes was 94.4%. Therefore, it can be concluded that both PET-CT and MRI diffusion images were of high diagnostic value in the diagnosis of lymph node metastasis of rectal cancer, and their diagnostic results were highly consistent. When combined, the diagnostic accuracy can be further improved.

Accuracy of Response Assessment Positron Emission Tomography-Computed Tomography Following Definitive Radiotherapy Without Chemotherapy for Head and Neck Squamous Cell Carcinoma

AimThere are few data to inform on the use of response assessment 2-[fluorine-18]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography-computed tomography (PET-CT) following radical radiotherapy without chemotherapy for head and neck squamous cell carcinoma (HNSCC). This retrospective study evaluated the accuracy of PET-CT in HNSCC following radical radiotherapy. Materials and methodsIn total, 138 patients with HNSCC treated with radical radiotherapy without chemotherapy who underwent a baseline and response assessment FDG PET-CT were identified. FDG PET-CT outcomes were analysed with reference to clinicopathological outcomes. ResultsThe median follow-up was 26 months. FDG-avid disease at baseline was present for the primary site and lymph nodes in 118 and 86 patients, respectively. With regard to the primary tumour, the negative predictive value (NPV) of a complete metabolic response (CMR) was 95%; the positive predictive value (PPV) of equivocal uptake and a positive scan were 6% and 82%, respectively. The likelihood ratios for a CMR, equivocal and positive scans of the primary site were 0.19, 0.22, 14.8, respectively. With regard to lymph node disease, the NPV of a CMR was 91%, the PPV of equivocal uptake and a positive scan were 33% and 88%, respectively. Likelihood ratios for lymph node disease for CMR, equivocal and positive scans were 0.19, 0.97 and 15.1, respectively. ConclusionCompared with the accuracy reported in the literature following chemoradiotherapy, response assessment FDG PET-CT following radical radiotherapy without chemotherapy had a similarly high NPV, whereas the PPV following a positive scan was higher.

P2.01-64 Prognostic Value of PET-CT after Induction Chemoradiotherapy and Curative Surgery in IIIA-N2 NSCLC: A Multi-Institutional Analysis

We evaluate the correlation of clinical staging on positron emission tomography-computed tomography (PET-CT) and pathologic staging and the prognostic value of PET-CT after induction chemotherapy in patients with locally advanced Non-Small Cell Lung Cancer (NSCLC). We analyzed 42 cases of clinical stage IIIA-N2 NSCLC who receive 2 to 4 cycles of pre-operative chemotherapy with or without radiation followed by curative resection. The maximum standard uptake value (SUVmax) of the suspected lesion on PET-CT was recorded. PET-CT findings after induction chemotherapy were compared with those of initial PET-CT and pathology after surgery. The accuracy of PET-CT in restaging of the primary tumor after induction chemotherapy was 50.0%. 18 (42.8%) of 42 patients were underestimated ycT stage, and 3 (7.1%) of 42 patients was overestimated ycT stage by PET-CT scan. The accuracy of PET-CT in restaging of the nodal disease was 71.4%. 6 (14.3%) of 42 patients were underestimated ycN stage, and 6 (14.3%) of 42 patients were overestimated ycN stage as compared with pathologic staging. The 2-year overall survival (OS) and relapse-free survival (RFS) rate were 68.5% and 40.9%, respectively. Complete responders (ycT0N0M0) on PET-CT after induction chemotherapy had a significantly longer RFS time than did incomplete responders (28.3 months versus 9.1 months, P = 0.021). Complete response on PET-CT after induction chemotherapy with or without radiation was a good prognosticator for RFS in stage IIIA-N2 NSCLC patients who received surgery. However, response evaluation on PET-CT after induction chemotherapy should be interpreted with caution due to its unacceptable accuracy.

Mediastinal node staging by positron emission tomography-computed tomography and selective endoscopic ultrasound with fine needle aspiration for patients with upper gastrointestinal cancer: Results from a regional centre.

AIMTo investigate the impact of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and positron emission tomography-computed tomography (PET-CT) in the nodal staging of upper gastrointestinal (GI) cancer in a tertiary referral centre.METHODSWe performed a retrospective review of prospectively recorded data held on all patients with a diagnosis of upper GI cancer made between January 2009 and December 2015. Only those patients who had both a PET-CT and EUS with FNA sampling of a mediastinal node distant from the primary tumour were included. Using a positive EUS-FNA result as the gold standard for lymph node involvement, the sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy of PET-CT in the staging of mediastinal lymph nodes were calculated. The impact on therapeutic strategy of adding EUS-FNA to PET-CT was assessed.RESULTSOne hundred and twenty one patients were included. Sixty nine patients had a diagnosis of oesophageal adenocarcinoma (Thirty one of whom were junctional), forty eight had oesophageal squamous cell carcinoma and four had gastric adenocarcinoma. The FNA results were inadequate in eleven cases and the PET-CT findings were indeterminate in two cases, therefore thirteen patients (10.7%) were excluded from further analysis. There was concordance between PET-CT and EUS-FNA findings in seventy one of the remaining one hundred and eight patients (65.7%). The sensitivity, specificity, PPV and NPV values of PET-CT were 92.5%, 50%, 52.1% and 91.9% respectively. There was discordance between PET-CT and EUS-FNA findings in thirty seven out of one hundred and eight patients (34.3%). MDT discussion led to a radical treatment pathway in twenty seven of these cases, after the final tumour stage was altered as a direct consequence of the EUS-FNA findings. Of these patients, fourteen (51.9%) experienced clinical remission of a median of nine months (range three to forty two months).CONCLUSIONEUS-FNA leads to altered staging of upper GI cancer, resulting in more patients receiving radical treatment that would have been the case using PET-CT staging alone.

76P - Interpretation and prognostic value of PET-CT after induction chemotherapy with or without radiation in IIIA-N2 non-small cell lung cancer patients who receive curative surgery

Background: We evaluated the correlation of clinical staging on positron emission tomography-computed tomography (PET-CT) and pathologic staging and the prognostic value of PET-CT after induction chemotherapy in patients with locally advanced non-small cell lung cancer (NSCLC). Methods: We analyzed 42 cases of clinical stage IIIA-N2 NSCLC who received 2 to 4 cycles of pre-operative chemotherapy with or without radiation followed by curative resection. The maximum standard uptake value (SUVmax) of the suspected lesion on PET-CT was recorded. PET-CT findings after induction chemotherapy were compared with those of initial PET-CT and pathology after surgery. Results: The accuracy of PET-CT in restaging of the primary tumor after induction chemotherapy was 50.0%. 18 (42.8%) of 42 patients were underestimated ycT stage, and 3 (7.1%) of 42 patients was overestimated ycT stage by PET-CT scan. The accuracy of PET-CT in restaging of the nodal disease was 71.4%. 6 (14.3%) of 42 patients were underestimated ycN stage, and 6 (14.3%) of 42 patients were overestimated ycN stage as compared with pathologic staging. The 2-year overall survival (OS) and relapse-free survival (RFS) rate were 68.5% and 40.9%, respectively. Complete responders (ycT0N0M0) on PET-CT after induction chemotherapy had a significantly longer RFS time than did incomplete responders (28.3 months versus 9.1 months, P = 0.021). Conclusions: Complete response on PET-CT after induction chemotherapy with or without radiation was a good prognostic indicator for RFS in stage IIIA-N2 NSCLC patients who received surgery. However, response evaluation on PET-CT after induction chemotherapy should be interpreted with caution due to its unacceptable accuracy. Legal entity responsible for the study: Jong Hoon Lee Funding: None Disclosure: The author has declared no conflicts of interest.

The diagnostic accuracy of integrated positron emission tomography/computed tomography in the evaluation of pulmonary mass lesions in a tuberculosis-endemic area.

Integrated positron emission tomography/computed tomography (PET-CT) is a well-validated modality for assessing pulmonary mass lesions and specifically for estimating risk of malignancy. Tuberculosis (TB) is known to cause false-positive PET-CT findings. To investigate the utility of PET-CT in the evaluation of pulmonary mass lesions and nodules in a high TB prevalence setting. All patients referred for the evaluation of a solitary pulmonary nodule or mass and who underwent PET-CT scanning over a 3-year period were included. The PET-CT findings, including maximum standardised uptake value (SUVmax), were compared with the gold standard (tissue or microbiological diagnosis). The sensitivity, specificity, positive and negative predictive values and diagnostic accuracy for malignant disease were calculated according to the SUVmax cut-off of 2.5 and a proposed cut-off obtained from a receiver operating characteristic (ROC) curve. Forty-nine patients (mean (standard deviation) age 60.1 (10.2) years; 29 males) were included, of whom 30 had malignancy. Using an SUVmax cut-off of 2.5, PET-CT had a sensitivity, specificity, positive and negative predictive value and diagnostic accuracy for malignancy of 93.3%, 36.8%, 70.0%, 77.8% and 71.4%, respectively. After a ROC curve analysis, a suggested SUVmax cut-off of 5.0 improved the specificity to 78.9% and the diagnostic accuracy to 86.7%, with a small reduction in sensitivity to 90.0%. The diagnostic accuracy of PET-CT in the evaluation of pulmonary mass lesions using the conventional SUVmax cut-off of 2.5 was reduced in a TB-endemic area. An SUVmax cut-off of 5.0 has a higher specificity and diagnostic accuracy for malignancy, with a comparable sensitivity.

Interpretation and Prognostic Value of Positron Emission Tomography-Computed Tomography After Induction Chemotherapy With or Without Radiation in IIIA-N2 Non-small Cell Lung Cancer Patients Who Receive Curative Surgery.

We evaluate the correlation of clinical staging on positron emission tomography-computed tomography (PET-CT) and pathologic staging and the prognostic value of PET-CT after induction chemotherapy in patients with locally advanced nonsmall cell lung cancer (NSCLC).We analyzed 42 cases of clinical stage IIIA-N2 NSCLC who receive 2 to 4 cycles of preoperative chemotherapy with or without radiation followed by curative resection. The maximum standard uptake value (SUVmax) of the suspected lesion on PET-CT was recorded. PET-CT findings after induction chemotherapy were compared with those of initial PET-CT and pathology after surgery.The accuracy of PET-CT in restaging of the primary tumor after induction chemotherapy was 50.0%. Eighteen (42.8%) of 42 patients were underestimated ycT stage, and 3 (7.1%) of 42 patients was overestimated ycT stage by PET-CT scan. The accuracy of PET-CT in restaging of the nodal disease was 71.4%. Six (14.3%) of 42 patients were underestimated ycN stage, and 6 (14.3%) of 42 patients were overestimated ycN stage as compared with pathologic staging. The 2-year overall survival (OS) and relapse-free survival (RFS) rate were 68.5% and 40.9%, respectively. Complete responders (ycT0N0M0) on PET-CT after induction chemotherapy had a significantly longer RFS time than did incomplete responders (28.3 vs 9.1 months, P = 0.021).Complete response on PET-CT after induction chemotherapy with or without radiation was a good prognosticator for RFS in stage IIIA-N2 NSCLC patients who received surgery. However, response evaluation on PET-CT after induction chemotherapy should be interpreted with caution due to its unacceptable accuracy.

Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic area: A 5-year prospective observational study.

Integrated positron emission tomography/computed tomography (PET-CT) is a well-validated modality for assessing mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC), which determines management and predicts survival. Tuberculosis (TB) is known to lead to false-positive PET-CT findings. To assess the diagnostic accuracy of PET-CT in identifying mediastinal lymph node involvement of NSCLC in a high TB-endemic area. Patients who underwent both PET-CT and lymph node tissue sampling for the investigation of suspected NSCLC were prospectively included in this observational study. Results were analysed per patient and per lymph node stage. A post-hoc analysis was performed to test the validity of a maximum standardised uptake value (SUV-max) cut-off for lymph node positivity. PET-CT had a sensitivity of 92.6%, specificity of 48.6%, positive predictive value of 56.8% and negative predictive value (NPV) of 90.0% in the per-patient analysis. Diagnostic accuracy was 67.2%. Similar values were obtained in the per-lymph node stage analysis. TB was responsible for 21.1% of false-positive results. A SUVmax cut-off of 4.5 yielded an improvement in diagnostic accuracy from 64.0% to 84.7% compared with a cut-off of 2.5, but at the cost of decreasing the NPV from 90.6% to 83.5%. In a high TB-endemic area, PET-CT remains a valuable method for excluding mediastinal lymph node involvement in NSCLC. Patients with a negative PET-CT may proceed to definitive management without further invasive procedures. However, PET-CT-positive lymph nodes require pathological confirmation, and the possibility of TB must be considered.

PET-CT for assessing mediastinal lymph node involvement in patients with suspected resectable non-small cell lung cancer.

PET-CT for assessing mediastinal lymph node involvement in patients with suspected resectable non-small cell lung cancer.

Is There Any Role of Positron Emission Tomography Computed Tomography for Predicting Resectability of Gallbladder Cancer?

The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

PET–CT Evaluation of Solitary Pulmonary Nodules: Correlation with Maximum Standardized Uptake Value and Pathology

18-fluorine fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) has an established role for the characterization of solitary pulmonary nodules (SPN). Visual assessment of nodule morphology, together with maximum standardized uptake value (SUVmax), is used to estimate likelihood of malignancy. We correlated SUVmax value with pathology of SPN and assessed diagnostic accuracy in differentiating malignant from benign nodule, using 2.5 as threshold SUVmax. Retrospective review of PET-CT scans for SPN characterization between April 2008 and June 2011 was performed. Only cases with pathological verification were included. A total of 641 PET-CTs were performed for SPN characterization and staging; 186 patients (77 males, 109 females) with pathological confirmation were included, and 158 (85%) nodules were malignant: adenocarcinomas (n=66), squamous cell carcinomas (n=40), and metastases (n=20) were the commonest. 28 lesions (15%) were benign, including granuloma/chronic inflammation (n=8), infection (n=7), and hamartomas (n=5). Using cutoff SUVmax of 2.5, the accuracy of PET-CT in diagnosing malignant SPN is 81.2%, with sensitivity 86.7%, specificity 50%, PPV 90.7%, and NPV 40%. The likelihood of malignancy increases with SUVmax. Nevertheless, even with SUVmax <2.5, there is a 62% chance that a nodule is malignant. Although PET-CT is useful in diagnostic workup of SPN, it cannot replace "gold standard" tissue diagnosis.

Utility of 18F-FDG PET-CT in staging and restaging of patients with malignant salivary gland tumours

The aim of this study was to evaluate the clinical utility of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) in staging and restaging of patients with malignant primary salivary gland tumours. Data pertaining to 30 patients (age: 43.8±16.8 years; male/female: 20/10) with histopathologically proven malignant primary salivary gland tumours who underwent 36 F-FDG PET-CTs were retrospectively analysed. Ten PET-CTs were performed for staging and 26 for restaging. The primary site was the parotid gland in 22 patients, the submandibular gland in seven and the minor salivary gland in one patient. (18)F-FDG PET-CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local disease, nodal disease and distant metastasis. Results were compared with those of conventional imaging modalities [CIM (CT/ultrasound/bone scintigraphy)] when available (n=28). Clinical or imaging follow-up (minimum 6 months) data along with histopathological information (when available) were taken as the reference standard. Overall, 25 PET-CTs were positive and 11 were negative for disease. (18)F-FDG PET-CT showed local disease in 21 patients, nodal disease in 17 and distant metastasis in nine (lungs, four; liver, three; bones, four; and thyroid, one). Twenty-three PET-CTs were true positive, nine were true negative, two were false positive and two were false negative. The overall sensitivity of (18)F-FDG PET-CT was 92%, specificity was 82%, positive predictive value was 92%, negative predictive value was 82% and accuracy was 89%. No significant difference was seen in the accuracy of PET-CT between the staging and restaging groups (100 vs. 85%; P=0.468). In patients for whom comparable CIM data were available (n=28), PET-CT did not show any significant advantage over CIM (P=0.012) but was more specific (71 vs. 43%). (18)F-FDG PET-CT shows high accuracy in staging and restaging of patients with malignant primary salivary gland tumours. It is more specific than CIM for this purpose.

Comparative study between endoscopic ultrasonography and positron emission tomography-computed tomography in staging patients with esophageal squamous cell carcinoma

Treatment strategy of esophageal cancer mainly depends on accurate staging. At present, no single ideal staging modality is superior to another in preoperative tumor-node-metastasis (TNM) staging of patients with esophageal cancer. We aimed to investigate the efficacy of endoscopic ultrasonography (EUS) and positron emission tomography-computed tomography (PET-CT) for staging of esophageal cancer. We retrospectively studied 118 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy with or without neoadjuvant chemoradiotherapy (CRT) over a near 3-year period between January 2005 and November 2008 at a tertiary hospital in Taiwan. Patients were separated into two groups: without neoadjuvant CRT (group 1, n= 28) and with CRT (group 2, n= 90). Medical records of demographic data and reports of EUS and PET-CT of patients before surgery were reviewed. A database of clinical staging by EUS and PET-CT was compared with one of pathological staging. The accuracies of T staging by EUS in groups 1 and 2 were 85.2% and 34.9%. The accuracies of N staging by EUS in groups 1 and 2 were 55.6% and 39.8%. The accuracies of T and N staging by means of PET-CT scan were 100% and 54.5% in group 1, and were 69.4% and 86.1% in group 2, respectively. In group 2, 38 of 90 patients (42.2%) achieved pathologic complete remission. Among them, two of 34 (5.9%) and 12 of 17 (70.6%) patients were identified as tumor-free by post-CRT EUS and PET-CT, respectively. EUS is useful for initial staging of esophageal cancer. PET-CT is a more reliable modality for monitoring treatment response and restaging. Furthermore, the accuracy of PET-CT with regard to N staging is higher in patients who have undergone CRT than those who have not.

Role of Integrated PET-CT in Pelvic Lymph Node Staging of Cervical Cancer Before Radical Hysterectomy

Integrated positron emission tomography-computed tomography (PET-CT) with fluoro-2-deoxy-D-glucose (FDG) is a noninvasive technique that can depict different primary and metastatic tumor types on the basis of the increased glucose metabolism of malignant tissue. Some investigators believe that FDG PET is useful in detecting metastatic pelvic lymph nodes (LNs) especially in locally-advanced cervical cancer. The results of clinical studies, however, have been controversial, and the predictive value of PET-CT for the assessment of pelvic LNs in early-stage cervical cancer is unclear. This retrospective study examined the accuracy and feasibility of preoperative FDG PET-CT for primary pelvic LN staging in patients with operable cervical cancer. Between 2003 and 2007, the investigators identified through medical records 34 patients with invasive International Federation of Gynecology and Obstetrics (FIGO) stage IA2-IIB cervical cancer who underwent preoperative FDG PET-CT before type II or III radical hysterectomy and pelvic lymphadenectomy. The sensitivity, specificity, accuracy, and positive and negative predictive values for metastasis detection with PET-CT were calculated in relation to results of histological analysis following surgery. Seventeen of the 34 patients (50.0%) had pelvic LN metastases. The median number of harvested LNs was 29. Analysis of the accuracy of PET-CT scan in cervical cancer showed that overall region-specific sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET-CT were 36.4, 98.8, 85.7, 88.9, and 88.7%, respectively. The recurrence rates among patients with positive preoperative PET-CT scans were significantly higher than those with negative scans (3/8 versus 1/26, respectively, P = 0.03). These data show that preoperative integrated PET-CT has limited sensitivity, but high specificity in predicting pelvic LN metastasis in the staging of invasive cervical cancer, and may be useful for identifying patients at higher risk for cervical cancer recurrence.

Role of Integrated PET-CT in Pelvic Lymph Node Staging of Cervical Cancer before Radical Hysterectomy

Background: To investigate the feasibility of preoperative integrated positron emission tomography-computed tomography (PET-CT) with fluoro-2-deoxy-D-glucose (FDG) in primary pelvic lymph node (LN) staging before radical hysterectomy (RH) and pelvic lymphadenectomy (PLND) in cervical cancer. Methods: We reviewed medical records of all patients with FIGO stage IA2-IIB cervical cancer who underwent a preoperative FDG PET-CT and underwent type II or III RH and PLND between January 1, 2003, and July 31, 2007. Results: A total of 34 patients underwent preoperative PET-CT scans followed by RH and PLND during the study period. Of the 34 patients, 17 (50.0%) had pelvic LN metastases, and the median number of harvested LNs was 29 (range 13–57). The overall region-specific sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET-CT were 36.4, 98.8, 85.7, 88.9, and 88.7%, respectively. The patients with positive preoperative PET-CT scans showed higher recurrence rates (3/8) than those with negative scans (1/26); the difference was statistically significant (p = 0.031). Conclusion: Integrated PET-CT scan has limited sensitivity, but high specificity for predicting pelvic LN metastasis in preoperative staging of invasive cervical cancer. Furthermore, preoperative integrated PET-CT may be a useful tool for identifying patients with higher risk of cervical cancer recurrence.