Preoperative PET-CT Research Articles

Significance of SUV Max for Predicting Occult Lymph Node Metastasis and Prognosis in Early-Stage Tongue Squamous Cell Carcinoma.

Objective Our goal was to clarify the significance of SUV max for predicting occult lymph node metastasis and prognosis in early-stage tongue squamous cell carcinoma (SCC). Methods cT1-2N0 tongue SCC patients who underwent a preoperative PET-CT examination were prospectively enrolled. The association between SUV max and occult lymph node metastasis was analyzed. The main study endpoint was locoregional control (LRC). The Cox model was used to determine the independent factors. Results A total of 120 patients were included for analysis, and the median SUV max was 9.7. In 60 patients with an SUV max ≤9.7, 5 patients had occult metastasis; in 60 patients with an SUV max >9.7, 13 patients had occult metastasis, and the difference was significant (p=0.041). In patients with an SUV max ≤9.7, the 5-year LRC rate was 93%; in patients with an SUV max >9.7, the 5-year LRC rate was 81%, and the difference was significant (p=0.045). Conclusion An SUV max >9.7 was a marker for occult lymph node metastasis and could decrease LRC in patients with cT1-2N0 tongue SCC.

Impact of skeletal muscle mass on postoperative delirium in patients undergoing free flap repair after oral cancer resection

Postoperative delirium (POD) is a major risk factor for an extended hospital stay and higher costs, and is associated with increased mortality. The incidence of POD is high in free flap procedures, and POD may also be a risk factor for flap loss and complications. Sarcopenia is a condition characterized by skeletal muscle mass (SMM) depletion and a decrease in muscle power or physical activity. The aim of this study was to investigate risk factors for postoperative delirium (POD), including SMM, in 122 patients undergoing free flap repair after oral cancer resection. All patients underwent preoperative abdominal-lumbar CT or PET-CT. Cross-sectional areas (cm2) of skeletal muscles at the third lumbar vertebra were measured on preoperative CT, normalized for height, and defined as the skeletal muscle index (SMI, cm2/m2). Risk factors for POD were investigated, including the value of SMI and taking the type of POD into consideration. POD occurred in 45 patients (36.9%), and was hyperactive in 28 (62.2%), mixed in 13 (28.9%), and hypoactive in 4 (8.9%). In multivariate analysis, high preoperative albumin (p = 0.046, adjusted odds ratio [OR] = 3.69) and postoperative insomnia (p < 0.001, OR = 6.79) were significant risk factors for POD. In a sub-analysis evaluating risk factors restricted to POD including the hypoactive type, lower SMI (p = 0.035, OR = 2.52 per 10-unit decrease) and postoperative insomnia (p = 0.003, OR = 6.37) were significant. We conclude that lower SMM increases the hypoactive and mixed types of POD. Increasing SMM by exercise and nutritional therapy preoperatively may prevent such POD in free flap repair for oral cancer.

The relationship between SUVmax on preoperative 68Ga-PSMA PET-CT and the clinicopahtological characteristics in patients treated with radical prostatectomy

Objective To investigate the relationship between SUVmax on preoperative 68Ga-PSMA PET-CT and the clinicopathological characteristics of patients treated with radical prostatectomy. Methods The clinicopahtological data of patients evaluated with 68Ga-PSMA PET-CT preoperatively and treated with radical prostatectomy between May 2016 and August 2019 were retrospectively reviewed. 31 patients with a mean age (63.1±4.9) and baseline PSA (72.71±173.15)ng/ml were enrolled. Their BMI mean (24.6±3.0)kg/m2. Baseline testosterone of 14 patients was (4.72±1.64)ng/ml.Based on the Gleason scores related ISUP classification, all patients were classified into grade one in 5 cases, grade 2in 7 cases, grade 3 in 4 cases, grade 4 in 10 cases and grade 5 in 5 cases. The clinical classification included 6 cases in T2a stage, 2 cases in T2b stage, 17 cases in T2c stage, 1 case in T3a stage, 4 cases in T3b stage and 1 case in T4 stage. SUVmax was accessed by two independent professional nuclear medicine physicians. SUVmax was 12.49±9.38. SPSS 16.0 software was used to do statistic analysis. Results The post-operative pathological results showed the surgical margin positive in 19 cases, negative in 12 cases, vascular positive in 5 cases, negative in 20 case, positive nerve invasion in 20 cases and negative in 11 cases. 2 patients were low risk, 7 patients were medium risk and 22 patients were high risk according to D′Amico classification. Based on the basis of PSA(≤10 or>10) and Gleason score(≤6 or>6), 6 patients were in group with low PSA and low Gleason score, 5 patients were low PSA and high Gleason score, 9 patients were high PSA and low Gleason score, 11 patients were high PSA and high Gleason score. SUVmax had a significant positive relationship with pathological ISUP(r=0.434, P=0.015) and SUVmax in patients with positive intravascular tumor emboli was significantly higher than those with negative intravascular tumor emboli(14.78±10.68 vs. 8.17±2.81, P=0.005). No significant correlation was found between SUVmax and baseline PSA, testosterone, pathologic T stage, surgical margin, nerve invasion, pelvic lymph node status as well as risk stratification. SUVmax could distinguish pathologic ISUP grade 5 with a maximum AUC 0.747 (P=0.033) and the sensitivity was 88.9%. The specificity was 77.3% when SUVmax≥11.34. SUVmax in patients with upgrading ISUP was significantly higher than that in patients with downgrading ISUP (16.01±5.40 vs. 4.98±2.11, P=0.007). Conclusions SUVmax measured on preoperative 68Ga-PSMA PET-CT may have a clinical significance in predicting unfavorable pathological factors for patients treated with radical prostatectomy. Key words: Prostatic neoplasms; Prostate cancer; Prostate-specific membrane antigen(PSMA); 68Ga; Positron-emission tomography(PET-CT); Maximum standardized uptake value(SUVmax); Gleason score

Preoperative PET-CT is useful for predicting recurrent extrahepatic metastasis of hepatocellular carcinoma after resection

PurposeIn recent years, it has been reported that use of 18F-FDG PET-CT can reveal the degree of hepatocellular carcinoma malignancy. We evaluate the ability of a preoperative 18F-FDG PET-CT to predict the recurrence of extrahepatic metastasis of HCC after surgery. MethodsWe retrospectively examined 67 patients who received 18F-FDG PET-CT prior to curative hepatic resection for HCC between April 2010 and March 2016. Multivariate Cox regression analysis was performed to identify the factors associated with recurrence of extrahepatic metastasis of HCC after surgery. We also evaluated the sensitivity, specifity, positive predictive value, negative predictive value and accuracy of diagnosis of 18F-FDG PET-CT for recurrent extrahepatic metastasis of HCC after surgery. ResultsThe multivariate analysis identified a tumor-to-normal liver standardized uptake value ratio (TNR) ≥ 1.53 (hazard ratio [HR], 0.037; P = 0.003), multiple tumor nodules (HR, 0.121; P = 0.007), and presence of microvascular invasion (HR, 0.094; P = 0.003) as independent predictors of distant metastasis recurrence. A TNR ≥ 1.53 showed a sensitivity of 91.7 %, specificity of 76.4 %, positive predictive value of 45.8 %, negative predictive value of 97.7 %, and accuracy of 79.1 % for diagnosing distant metastasis recurrence of HCC. In a binomial logistic regression analysis of tumor factors associated with a TNR ≥ 1.53, poor tumor differentiation and large tumor size were significant factors. Conclusion18F-FDG PET-CT and microvascular invasion may be useful for predicting the recurrence of extrahepatic metastasis of HCC after surgery.

Effect of waiting time to surgery on pancreatic cancer survival: A nationwide population-based cohort study

Background: Because of the aggressive nature of pancreatic cancer, timely surgery is considered to be important. However, little is known on the actual impact of waiting time to surgery on survival in pancreatic cancer patients. Materials & Methods: A nationwide population-based cohort study of all patients undergoing surgery for pancreatic cancer (resection or a palliative procedure) registered in the Danish Pancreatic Cancer Database during May 2011 to May 2016. We defined waiting time to surgery in two ways: 1) from the date of entry into the National Cancer Pathway to the date of surgery and 2) from the date of the last preoperative computed tomography (CT) or positron emission tomography (PET-CT) scan to the date of surgery. Waiting time was grouped into three groups: <28 days (<4 weeks), 28-55 days (4-8 weeks), and ≥56 days (≥8 weeks). We calculated median survival with associated 95% confidence intervals (CIs) for patients undergoing resection and for patients undergoing a palliative procedure. Results: We included 873 patients. Mean age was 67 years (range: 35-86 years). Resection was performed in 701 patients (80%); the remaining 172 patients (20%) underwent an explorative laparotomy or palliative surgery. 652 patients (75%) had a registration in the National Cancer Pathway (median waiting time: 31 days, and 818 patients (94%) had a registration of a preoperative CT or PET-CT scan (median waiting time: 32 days). We saw similar resection rates (∼80%) and median survival (∼22 months) in all thee groups. Conclusion: Waiting time to surgery did not affect survival in patients undergoing surgery for pancreatic cancer. Tabled 1Caption 1: Resection and survival rates following pancreatic cancer surgery according to pre-surgical waiting time.

Methastatic N2 in T1 Non-small cell lug cancer: Should we go back to invasive staging?

Aim: T1 patients who were operated due to non-small cell lung cancer (NSCLC)were evaluated retrospectively. The objective of this study was to evaluate metastatic lymph node status in T1 tumors and to discuss staging approaches in these tumors.Material and Methods: A total of 217 patients who met specified criteria between May 2012 and May 2019 were included in the study. Patients operated due to NSCLC who have a tumor size 3 cm were evaluated in terms of age, gender, preoperative diagnostic methods, thorax CT and PET-CT examinations, size, anatomic localization and histopathologic type of tumors, excised mediastinal lymph nodes and pathology results.Results: Of total 292 lymph node stations sampled in patients with adenocarcinoma, 257 (89.73%) were reported as benign and 30 (10.27) as malignant according to pathologic results. Of total 316 lymph node stations sampled in patients with squamous cell carcinoma, 298 (94.3%) were benign and 18 (5.7%) were malignant.N2 positivity was found in 40 (18.43%) of the 217 patients.Conclusion: Mediastinoscopy should be performed for staging in the presence of a tumor size above 2 cm, histopathological type of adenocarcinoma, high mass SUVmax values, lymph node with radiological growth and pathological involvement.

1879 Comparison of MRI, PET-CT, and Frozen Biopsy in The Evaluation of Lymph Node Status Before Fertility-Sparing Robotic or Laparoscopic Radical Trachelectomy in Early Stage Cervical Cancer

Study Objective To compare the accuracy of MRI, PET-CT, and frozen biopsy before fertility-sparing radical trachelectomy in early stage cervical cancer. Design This was a retrospective study on 134 young women with early stage cervical cancer who tried fertility-sparing laparoscopic or robotic radical trachelectomy. All patients underwent preoperative MRI and PET-CT. Comprehensive lymph node dissection was performed during surgery. Retrieved lymph nodes were sent for frozen biopsy before undertaking radical trachelectomy. The diagnostic accuracy of MRI, PET-CT, and frozen biopsy was compared using McNemar test and logistic regression using generalized estimating equations. The final pathologic report on lymph nodes was the gold standard for diagnosis. Setting University hospital. Patients or Participants 134 patients with early stage cervical cancer. Interventions Fertility-sparing, robotic or laparoscopic radical trachelectomy. Measurements and Main Results The retrieved lymph nodes totaled 3362 and mean of retrieved lymph nodes was 25 (range 7- 96). Twenty patients (14.9%) showed positive lymph node areas and 39 out of 986 (4.0%) lymph nodes areas were positive. There was no significant difference in sensitivity (22.6% versus 31.0%, p>0.99), specificity (94.3% versus 95.3%, p=0.83), and accuracy (90.8% versus 92.3%, p=0.5) between MRI and PET-CT in station-by-station analysis. There was significant difference in sensitivity, specificity, accuracy between MRI and frozen biopsy in station-by-station analysis. There was also a significant difference between PET-CT and frozen biopsy. Conclusion When comparing patients with patients, frozen biopsy approach is significantly better than MRI and PET-CT to evaluate sensitivity, specificity, and accuracy. Frozen biopsy of all lymph nodes retrieved during surgery is still the best method to evaluate lymph node status before fertility-sparing radical trachelectomy.

Potential value of FDG PET-CT in predicting occult lymph node metastasis in clinical stage ⅠA lung adenocarcinoma

Objective: To investigate the predictive value of (18)F-FDG PET-CT scan for occult lymph node metastasis in patients with stage ⅠA lung adenocarcinoma. Methods: The image and pathological data of 272 patients with stage ⅠA lung adenocarcinoma from October 2006 to September 2015 were retrospectively analyzed. All patients underwent preoperative (18)F-FDG PET-CT scan followed by lobectomy and systematic lymph node dissection. The correlation between occult lymph node metastasis and the maximum standardized uptake value (SUV(max)) of primary tumor as well as other clinicopathological factors was analyzed to screen the risk factors of occult lymph node metastasis in stage ⅠA lung adenocarcinoma. Results: Occult lymph node metastasis was detected in 50 patients (18.4%), with 24 (8.8%) patients of pN1 involvement and 26 (9.6%) of pN2 involvement. Among the 272 patients enrolled, 39 had pure ground glass nodule, 59 had part-solid nodule and 174 had solid nodule. All patients with pure ground glass nodule or nodule≤1 cm were pN0. For the 233 patients with part-solid and solid nodule, no lymph node metastasis was found in T1a stage (tumor length ≤1 cm). Primary tumor SUV(max) (Z=-5.663, P<0.001), nodule type (χ(2)=21.586, P<0.001), tumor location (χ(2)= 12.790, P< 0.001), histological grade (χ(2)= 22.784, P< 0.001) and visceral pleural invasion (χ(2)=5.357, P=0.021) showed significant differences between occult lymph node metastasis group (pN+ ) and non-lymph node metastasis group (pN0). With SUV(max)=2.405 as cut-off value, the sensitivity and specificity for predicting occult lymph node metastasis were 90.0% and 61.7%, the area under curve was 0.761(95%CI=0.700~0.823), and the negative predictive value was 95.8%. Multivariate analysis revealed that SUV(max) >2.405 (P<0.001), central location (P=0.030) and higher histological grade (P=0.024) were independent predictors of occult lymph node metastasis. Conclusions: For clinical stage ⅠA adenocarcinoma, primary tumor SUV(max) > 2.405, central location and higher histological grade were independent risk factors for occult lymph node metastasis. Systematic lymph node dissection may be avoided in lung adenocarcinoma with pure ground glass density, tumor length ≤1 cm or SUV(max) ≤ 2.405, due to the very low probability of nodal involvement.

Waiting time to surgery and pancreatic cancer survival: A nationwide population-based cohort study

IntroductionThe effect of waiting time to surgery on survival in pancreatic cancer patients is unclear. We examined this association in a nationwide population-based cohort study. Materials and methodsA nationwide population-based cohort study of all patients undergoing surgery for pancreatic cancer (resection or a palliative procedure) registered in the Danish Pancreatic Cancer Database from May 2011 to May 2016. We defined waiting time to surgery in two ways: 1) from the date of entry into the National Cancer Pathway to the date of surgery and 2) from the date of the last preoperative computed tomography (CT) or positron emission tomography (PET-CT) scan to the date of surgery. Waiting time was grouped into three groups: <28 days (<4 weeks), 28–55 days (4–8 weeks), and ≥56 days (≥8 weeks). We calculated median survival with associated 95% confidence intervals (CIs) for patients undergoing resection and for patients undergoing a palliative procedure. ResultsWe included 873 patients. Mean age was 67 years (range: 35–86 years). Resection was performed in 701 patients (80%); the remaining 172 patients (20%) underwent an explorative laparotomy or palliative surgery. 652 patients (75%) had a registration in the National Cancer Pathway (median waiting time: 31 days, and 818 patients (94%) had registration of a preoperative CT or PET-CT scan (median waiting time: 32 days). We saw similar resection rates (∼80%) and median survival (∼22 months) in all thee groups. ConclusionIn this study, waiting time to surgery did not affect survival in patients undergoing surgery for pancreatic cancer.

PS01.214: METASTATIC YIELD OF SUPERIOR MEDIASTINAL LYMPHADENECTOMY AND ASSOCIATION WITH PET IN INTRATHORACIC OESOPHAGEAL CARCINOMA TREATED WITH MINIMALLY INVASIVE OESOPHAGECTOMY

Abstract Background Lymph node status in oesophageal carcinoma is an important prognostic factor and predictor of survival. However, specific metastatic distribution patterns, especially for superior mediastinal lymph nodes, are not defined; they may be dependent on tumour location, histology and use of neoadjuvant treatment. Consensus for an optimal surgical strategy with regards to superior mediastinal lymphadenectomy (SML) has therefore not been formed. We aim to assess the metastatic yield of superior mediastinal nodes in intra-thoracic oesophageal cancer while correlating results with preoperative PET-CT. Methods Data from 39 consecutive 2-stage and 3-stage fully Minimally Invasive Oesophagectomies (MIO) performed by a single surgical team for intra-thoracic oesophageal or gastro-oesophageal junction carcinoma (Siewert I/II) between September 2016 and December 2017 were analysed. In n = 7 (18%), SML was performed. Of these n = 1 was for mid-oesophageal adenocarcinoma (ACA) and n = 6 were for squamous cell carcinoma (SCC) (5 for mid-oesophageal and 1 for distal oesophageal, which had a 2-stage procedure). Histological superior mediastinal nodal analysis was correlated with pre-operative PET-CT. Results Median total lymph node count was 45 (IQR, 37–68), with median SML count of 8 (IQR, 5–22). Of 7 SML’s, n = 1 (14.2%) revealed metastasis in 1/5 right paratracheal nodes. The patient had 3-stage MIO with no neo-adjuvant treatment for mid-oesophageal SCC. Final staging was pT3N2(6/45)M0. Preoperative PET-CT showed low avidity in right paratracheal nodes. Of the rest, 5 had negative PET-CT and 1 showed PET-positive paratracheal nodes, not confirmed histologically. The latter patient had neoadjuvant chemoradiotherapy for distal oesophageal ACA. Conclusion Although a small sample-sized study it demonstrates that PET-CT has a role in identifying metastatic superior mediastinal nodes. It can aid in the decision of resecting avid nodes but it should be born in mind that PET could have false positive results due to surrounding inflammation not uncommonly found in the lungs. False positivity (not confirmed histologically) may be also attributed to complete pathological lymph node response post neo-adjuvant treatment. SML’s role is not as clear in distal oesophageal/GOJ cancer compared to mid-oesophageal, but PET-CT seems a useful adjunct. In the West, SML shows a low metastatic yield for intra-thoracic oesophageal cancer. Disclosure All authors have declared no conflicts of interest.

Utilization of preoperative PET-CT and pelvic MRI reduces multimodality therapy in the care of women with early-stage cervical carcinoma

Utilization of preoperative PET-CT and pelvic MRI reduces multimodality therapy in the care of women with early-stage cervical carcinoma

The role of preoperative (18)F-FDG PET-CT in lymphatic metastasis diagnosis of cutaneous malignant melanoma on extremities and trunk

Objective: To evaluate the clinical value of preoperative (18)F-Fludeoxyglucose ((18)F-FDG PET-CT) in lymphatic metastasis diagnosis of cutaneous melanoma on extremities and trunk. Methods: 112 patients with cutaneous melanoma pathologically of extremities and trunk from January 2006 to December 2016, who received (18)F-FDG PET-CT examination preoperatively, were retrospectively reviewed. The correlations between the maximal diameters of lymph nodes, the maximal standard uptake value (SUV) and the diagnostic impression grades of PET-CT examination, and the final pathological diagnosis were analyzed. The correlations between Breslow thickness of primary lesions and the diagnostic impression of PET-CT examination were also analyzed. All the above were analyzed with Receiver Operating Characteristic (ROC) curve to get the cut-off value. Based on the final results of pathological diagnosis of lymph nodes as the golden standard, the statistically significant indicators of ROC curve analysis were used to evaluate the diagnostic effect, as well as to calculate the sensitivity, specificity and accuracy. With gender, age, maximal diameter of lymph nodes, maximal SUV, diagnosis impressions, and Breslow thickness as the independent variables and pathological diagnosis results of lymph nodes as the dependent variable, two-class stepwise Logistic regression analysis was used to determine the independence of diagnostic indicators. ROC curve analysis and log rank test were used to analyze the relationship between Breslow thickness and patient survival. Results: To evaluate melanoma patients' lymph node status, the results of ROC curve analysis showed that the area under the curve of lymph node maximal diameter, maximal SUV, diagnosis impression of PET-CT examinations were 0.789, 0.786 and 0.816, respectively (all P<0.05). The cut-off values were 0.85 cm, 1.45 and 2.5, respectively. The sensitivity of the cut-off values to determine the status of lymph nodes in melanoma patients were 71.4%, 64.9% and 72.1% respectively, and the specificities were 85.2%, 88.7% and 87.0% respectively. Multivariate Logistic regression analysis showed that PET-CT diagnosis impressions had independent diagnostic significance for the lymph node status of melanoma patients (OR=11.296, 95%CI: 2.550~50.033). The area under the curve of Breslow thickness evaluating PET-CT diagnostic impression is 0.664 (P=0.042) and the cut-off value was 4.25 mm. The survival rate of the patients with Breslow thickness ≥ 4.25 mm was lower than that in the group <4.25 mm (P=0.006). Conclusions: (18)F-FDG PET-CT can help to evaluate metastases and make treatment decisions for cutaneous melanoma of extremities and trunk, especially for patients whose primary lesion's Breslow thickness has reached more than 4.25 mm. For the patients whose maximal SUV of regional lymph node is higher than 1.45 and short diameter of the largest lymph node is larger than 0.85cm, the possibility of metastases should be considered.

Effect of PET-CT on disease recurrence and its management in patients with potentially resectable colorectal cancer liver metastases. The long-term results of a randomized controlled trial (PET-CT Imaging prior to liver resection for colorectal adenocarcinoma metastases).

3527Background: The PETCAM randomized trial evaluated the effect of preoperative PET-CT (vs. no PET-CT) on surgical management in patients with colorectal cancer liver metastases. This trial result...

Robotic video endoscopic inguinal lymphadenectomy (R-VEIL) for vulvar cancer with sentinel node mapping using indocyanine green and near-infrared fluorescence imaging technology

Video endoscopy inguinal lymphadenectomy (VEIL) has emerged as the new frontier for the surgical staging of vulvar cancer (VC) [1, 2]. In this surgical film we show a step-by-step video presentation of a Robotic SLNmapping using ICG (Canadian Task Force classification III). Although the therapeutic benefit of SLN remains controversial in clinical N0 (cN0) with VC N 4 cm [3], it provides prognostic information that can guide further adjuvant treatment. Robotic sentinel lymphnode (SLN) mapping using indocyanine green (ICG) appears to be a suitable and attractive alternative to provide reliable staging with respect to other tracers [3, 4]. A 75-year-old severely obesewoman (BMI:47.8 kg/m2) with squamous VC grading 3, clinical stage II (cT = 5 cm, cN0, cM0) and with a pre-operative PET-CT scan negative for metastatic localizations, was admitted for surgery. Surgical staging was performed including radical vulvectomy with macroscopic resection margins larger than 2 cm., SLN mapping with ICG followed by systematic inguinal lymphadenectomy. Da Vinci Xi System® was used to perform it. The operation was performed successfully with no intraoperative or postoperative complication. Operative time was 310 min overall. Twenty-five inguinal lymph nodes were removed (11 on the left, 14 on the right). The pathology report came back positive for SLN removed. The patient was discharged on day #4 and 20 days later started adjuvant radiochemotherapy. SLN with ICG is robotically feasible. However, we notice that further prospective trials are needed to compare ICG with other colorimetric and/or radioactive tracers in this subset of patients.

Utility of PET-CT in detecting nodal metastasis in cN0 early stage oral cavity squamous cell carcinoma

BackgroundManagement of the clinically node-negative neck (cN0) in patients with early stage oral cavity squamous cell carcinoma (OCSCC) is challenging. Accurate imaging alternatives to elective neck dissections would help reduce surgical morbidity. While pooled studies suggest that imaging modalities have similar accuracy in predicting occult nodal disease, no study has examined the utility of PET-CT in this specific population of low-volume, clinically T1 and T2 OCSCC patients. MethodsA retrospective review of patients in the Alberta Cancer Registry who were diagnosed with cT1 or T2N0M0 OCSCC who underwent elective unilateral or bilateral neck dissections was performed. Pre-operative PET-CT and CT necks were reviewed for number of radiographically suspicious lymph nodes. Surgical pathology reports were reviewed to obtain the total number of nodes sampled and number of malignant nodes. ResultsBetween 2009 and 2013, 148 patients were diagnosed with cT1 or T2N0M0 OCSCC. Of these, 96 patients underwent elective neck dissections. All patients underwent preoperative CT of the neck with 32 patients having undergone additional preoperative PET-CT. Based on finally surgical pathology, the overall rate of occult metastasis was 13.5% (13/96). The overall sensitivity and specificity of PET-CT in this cohort was 21.4% and 98.4%, respectively with a negative predictive value of 99.1%. Although sensitivity improved in patients with tumors ≥2 cm and depth ≥4 mm, specificity remained unchanged. ConclusionIn patients with cT1 and T2N0 OCSCC, PET-CT has high negative predictive value. These patients can be considered for treatment with single modality surgical resection and elective neck dissection.

Effect of PET-CT on disease recurrence and its management in patients with potentially resectable colorectal cancer liver metastases: The long-term results of a randomized control trial.

562 Background: The PETCAM randomized trial evaluated the effect of preoperative PET-CT (vs. no PET-CT) on surgical management in patients with colorectal cancer liver metastases. In this study, 8% of patients had a change in surgical management, including a higher proportion of major liver resections in the PET-CT arm. The current study compares the intervention groups for 5-year disease free (DFS) and overall survival (OS), and evaluated their long-term clinical course, i.e. sites of recurrence and management of disease recurrence. Methods: Recruitment to the trial occurred between 2005-2010, with last follow-up in 2013. Data on recurrence, management of recurrence and mortality from 2013-2017 was collected from patient’s charts. Recurrences according to site and management were described. Cox proportional Hazard Models were used to calculate the risk for recurrence and death. OS was calculated with Kaplan-Meir method and compared with log-rank test. Results: At 5 years, 157 of 404 (39%) patients were still alive and 19 patients were lost to follow-up. Median follow-up is 4.2 years. There were no differences in DFS (HR: 1.12, 95%CI: 0.88-1.42) or OS (HR: 0.97, 95%CI: 0.74-1.28) between groups. The median DFS for the 372 patients who had surgery was 17 months, 95%CI: 14.7-19.4. Risks factors for recurrence were: extrahepatic disease, liver tumour size, and nodal stage. The median OS for all patients was 50 months, 95%CI: 43.5-64.3. Risks factors for death also included age and prior use of chemotherapy. During the follow-up period, 287/404, 71% patients recurred (mostly liver and lung); 137 (48%) were treated solely with chemotherapy and 35% were treated with surgery with curative intent. Of these, the majority recurred (109/116, 94%). The median OS following first recurrence was 27.5 months, 95%CI: 23-30. Conclusions: PET-CT did not improve DFS or OS. Survival following liver resection is similar to previous reports, however most patients experience disease recurrence. A substantial proportion of patients who recur undergo surgery, however it is likely that they will recur again.

Role of FDG PET/CT scan in preoperative pancreatic cancer staging.

511 Background: Guidelines do not recommend routine FDG PET/CT (PET) as preoperative staging for pancreatic cancer, although many single center series have demonstrated that PET can lead to changes in management in a sizable minority of patients. We performed a retrospective analysis of patients undergoing PET for potentially resectable pancreatic adenocarcinoma at our institution to help define the utility of PET in this setting. Methods: We reviewed patients with pancreatic adenocarcinoma diagnosed at our center from June 2010 to May 2017 and included patients with pancreatic adenocarcinoma felt to be potentially resectable following standard staging studies [computed tomography (CT), magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS)] who also underwent preoperative PET. Data collected and analyzed included: demographics, pre-PET staging, CA19-9 levels, PET results and surgical outcomes. Results: Forty eight patients with pancreatic adenocarcinoma felt to be surgically resectable underwent PET. PET changed management in 4/48 (8.3%) of these patients. In all 4 of these patients, hepatic metastatic disease was detected on PET and planned surgery was canceled; metastatic disease was confirmed by biopsy in 1 of these patients. 1/48 (2.1%) of patients had a false positive PET scan, where a focus of suspected metastatic disease on PET was biopsied and found to be benign, allowing the patient to proceed to surgery. 3/48 (6.3%) of patients had a false negative PET; 2 patients had hepatic metastatic disease and one had peritoneal disease discovered during surgery. Mean time from negative PET to surgery in these 3 patients was 31 days (range 21-45). Degree of CA19-9 elevation and primary tumor FDG avidity did not correlate with detection of metastatic disease on PET. Conclusions: PET changed management in a smaller number of patients in this cohort than in many previously reported series with a nearly equal number of patients with false negative PET results proceeding to unnecessary surgery. These results are consistent with the currently uncertain role of PET in preoperative staging for pancreatic cancer and further work must be undertaken to optimize presurgical staging in this population.

Clinical value of preoperative 18F-FDG PET-CT imaging in staging of colorectal cancer

Objective To discuss the value of preoperative 18F-FDG PET-CT imaging in the staging of colorectal cancer. Methods Eighty-three patients with colorectal cancer were studied who underwent 18F-FDG PET-CT examinations without any previous treatment and subsequent operations within one week. The results of PET-CT and pathology were analyzed with chi-square test and Kappa consistency test. Results The diagnostic accuracy of primary colorectal lesions was 100%, the average of maximum standardized uptake value (SUVmax) was 14.54±8.10 (4.43-48.19). The diagnostic accuracy of local infiltration depth, lymph node metastasis, distant metastasis and TNM staging before operation were 73.49% (61/83), 90.36% (75/83), 97.59% (81/83) and 85.54% (71/83), respectively, and the Kappa values were 0.481, 0.797, 0.950, 0.788 (P < 0.05). The diagnostic sensibility of staging with T1-2, T3 and T4 were 30.00% (3/10), 68.42% (13/19) and 83.33% (45/54), respectively, the diagnostic accuracy of staging with T1-2, T3 and T4 were 91.57% (76/83), 74.70% (62/83) and 80.72% (67/83). Conclusion Preoperative 18F-FDG PET-CT imaging is an effective staging method for colorectal cancer, and has high accuracy in the detection of primary colorectal lesions, lymph node metastasis, distant metastasis and T4 stage lesions, but it is difficult for diagnosing of the T1-2 and T3 lesions. Key words: Colorectal neoplasms; Neoplasm staging; Positron-emission tomography; Fluorodeoxyglucose F18

Endoscopic surgery for early-stage nasopharyngeal carcinoma: a justified initial option

Objectives: To assess the prognosis of initial endoscopic surgery in T1N0M0 and T2N0M0 staged NPC patients.Materials and methods: Between 2002 and 2016, 10 previously untreated patients with T1N0M0 or T2N0M0 staged NPC volunteered to receive endoscopic surgery followed by four courses of TPF chemotherapy. EORTC QLQ-C30 and QLQ-H&N35 were used to evaluate the QOL after treatment.Results: With the median follow-up of 30 months (range, 9 months to 128 months), the 24-month survival rate was 100% (6/6), 90% (9/10) patients were still alive and well, 20% (2/10) patients reported tumor recurrence. One died of the disease at 128 months with nasopharyngeal recurrence. Another patient who refused preoperative PET-CT had a cervical recurrence at nine months, accepted nasopharynx and neck radiation two months later and was still alive and well at 50 months. In the post-treatment questionnaires, several NPC-specific (pain, swallowing, speech, social eating, opening mouth, dry mouth, sticky saliva) QOL domains were better preserved compared with radiotherapy alone or combined chemoradiotherapy in other surveys.Conclusions: Initial endoscopic surgery combined with chemotherapy maybe justified in the hands of highly experienced surgeon in selected early-stage NPC cases and can improve their QOL. In addition, preoperative PET-CT should be included in case of possible minimal metastases.

Clinical Significance and Phenotype of MTA1 Expression in Esophageal Squamous Cell Carcinoma.

Metastasis-associated gene 1 (MTA1) is considered a potential prognostic factor in esophageal cancer. We investigated the clinical relationship between MTA1, LAT1, and tumor metabolism, as evaluated by positron emission tomography (PET) in esophageal squamous cell carcinoma. We analyzed 142 esophageal squamous cell carcinoma patients who underwent curative resection without preoperative treatment. MTA1 expression was assessed by immuno-zahistochemistry, and tested against standardized uptake values from preoperative PET-CT. The association among MTA1, LAT1, and 18FAMT PET results were analyzed. MTA1 staining was observed in 82 of 142 cancer tissues. Five-year overall survival was 69.9 % in the absence of MTA1, but 50.7% otherwise (p=0.021), while disease-free survival was 66.5% and 49.0% (p=0.071), respectively. Abnormal 18FAMT accumulation was noted in 13 patients without MTA1 and in 18 patients with MTA1 (p=0.079), with maximum standardized uptake value 1.6±1.6 and 2.7±1.6, respectively (p=0.036). MTA1 expression was positively correlated with LAT1 (p=0.013) and CD34 (p=0.034) expression, but not with Ki-67 (p=0.078). MTA1 shows promise as a diagnostic and prognostic marker in esophageal cancer, and we anticipate that the gene will also prove to be a good therapeutic target.