Neoadjuvant therapy for pancreatic cancer: Limitations and advances of response assessment (Review).

Neoadjuvant therapy (NAT) has been widely recommended for managing patients with borderline resectable pancreatic cancer and resectable tumors with high risk factors. Accurate evaluation of the response after NAT is crucial to decide surgery, which then improves the rate of R0 resection and avoids meaningless surgery. The response to NAT is currently evaluated by conventional radiological examination and changes of serum CA19­9 levels. However, these assessments cannot accurately reflect the response to NAT. This article describes the limitations and advances of NAT response evaluation in pancreatic cancer. The values of some traditional imaging techniques, including positron emission tomography, endoscopic ultrasound, and diffusion weighted magnetic resonance imaging, are discussed, as well as novel imaging modalities or biomarkers, such as radiomics, dual energy computed tomography and liquid biopsy.

Image-based laparoscopic tool detection and tracking using convolutional neural networks: a review of the literature.

Intraoperative detection and tracking of minimally invasive instruments is a prerequisite for computer- and robotic-assisted surgery. Since additional hardware, such as tracking systems or the robot encoders, are cumbersome and lack accuracy, surgical vision is evolving as a promising technique to detect and track the instruments using only endoscopic images. The present paper presents a review of the literature regarding image-based laparoscopic tool detection and tracking using convolutional neural networks (CNNs) and consists of four primary parts: (1) fundamentals of CNN; (2) public datasets; (3) CNN-based methods for the detection and tracking of laparoscopic instruments; and (4) discussion and conclusion. To help researchers quickly understand the various existing CNN-based algorithms, some basic information and a quantitative estimation of several performances are analyzed and compared from the perspective of 'partial CNN approaches' and 'full CNN approaches'. Moreover, we highlight the challenges related to research of CNN-based detection algorithms and provide possible future developmental directions.

Vacuum suction fixation versus staple fixation in TAPP laparoscopic hernia repair: introduction of a new technique for mesh fixation.

BACKGROUND: Proper mesh fixation is critical for successful TAPP laparoscopic hernia repair. Conventional mesh fixation may cause chronic neuralgia, groin paresthesia or other complications. This study aimed at introducing a new vacuum suction technique for mesh fixation and evaluating its efficacy and safety compared with traditional staple fixation way. METHODS: Clinical data of 242 patients undergoing TAPP from July 2011 to March 2014 were retrospectively analyzed. Patients were divided into vacuum suction fixation group and staple fixation group. The operation time, hospital stay, complications, recurrence, visual analogue scale pain score and cost were evaluated. RESULTS: All surgeries were successful. The operation time of staple group was (42.34 ± 10.15) min for unilateral hernia and (64.08 ± 16.01) min for bilateral hernias. The postoperative hospital stay was (2.76 ± 0.84) days. One recurrence was observed (0.90%). For vacuum group, the operation time was (42.66 ± 7.76) min and (63.92 ± 10.49) min, and hospital stay was (2.60 ± 0.74) days. No recurrence was observed. There was no significant difference in recurrence, operation time, postoperative pain and hospital stay between two groups (P > 0.05). Average cost were (11,714 ± 726) RMB for vacuum group which was lower than staple group (14,837 ± 1568) RMB (P < 0.05). The top three complications of staple group were scrotal emphysema (10.81%), scrotal seroma (6.31%) and temporary nerve paresthesia (4.50%) while for vacuum group, they were scrotal seroma (3.82%), temporary nerve paresthesia (3.05%), scrotal emphysema (1.53%) and uroschesis (1.53%). The incidence of scrotal emphysema was lower in vacuum group (P < 0.05). No significant difference was observed in other complications (P > 0.05). CONCLUSION: Both techniques for mesh fixation are safe and effective. There is no significant difference in recurrence, operation time, postoperative pain or hospital stay. The vacuum suction fixation technique is more economical with lower incidence of scrotal emphysema.

Radical lymph node dissection and assessment: Impact on gallbladder cancer prognosis.

AIM: To investigate the lymph node metastasis patterns of gallbladder cancer (GBC) and evaluate the optimal categorization of nodal status as a critical prognostic factor. METHODS: From May 1995 to December 2010, a total of 78 consecutive patients with GBC underwent a radical resection at Liaocheng People's Hospital. A radical resection was defined as removing both the primary tumor and the regional lymph nodes of the gallbladder. Demographic, operative and pathologic data were recorded. The lymph nodes retrieved were examined histologically for metastases routinely from each node. The positive lymph node count (PLNC) as well as the total lymph node count (TLNC) was recorded for each patient. Then the metastatic to examined lymph nodes ratio (LNR) was calculated. Disease-specific survival (DSS) and predictors of outcome were analyzed. RESULTS: With a median follow-up time of 26.50 mo (range, 2-132 mo), median DSS was 29.00 ± 3.92 mo (5-year survival rate, 20.51%). Nodal disease was found in 37 patients (47.44%). DSS of node-negative patients was significantly better than that of node-positive patients (median DSS, 40 mo vs 17 mo, χ² = 14.814, P < 0.001), while there was no significant difference between N1 patients and N2 patients (median DSS, 18 mo vs 13 mo, χ² = 0.741, P = 0.389). Optimal TLNC was determined to be four. When node-negative patients were divided according to TLNC, there was no difference in DSS between TLNC < 4 subgroup and TLNC ≥ 4 subgroup (median DSS, 37 mo vs 54 mo, χ² = 0.715, P = 0.398). For node-positive patients, DSS of TLNC < 4 subgroup was worse than that of TLNC ≥ 4 subgroup (median DSS, 13 mo vs 21 mo, χ² = 11.035, P < 0.001). Moreover, for node-positive patients, a new cut-off value of six nodes was identified for the number of TLNC that clearly stratified them into 2 separate survival groups (< 6 or ≥ 6, respectively; median DSS, 15 mo vs 33 mo, χ² = 11.820, P < 0.001). DSS progressively worsened with increasing PLNC and LNR, but no definite cut-off value could be identified. Multivariate analysis revealed histological grade, tumor node metastasis staging, TNLC and LNR to be independent predictors of DSS. Neither location of positive lymph nodes nor PNLC were identified as an independent variable by multivariate analysis. CONCLUSION: Both TLNC and LNR are strong predictors of outcome after curative resection for GBC. The retrieval and examination of at least 6 nodes can influence staging quality and DSS, especially in node-positive patients.