Oxaliplatin plus Capecitabine in the Perioperative Treatment of Locally Advanced Gastric Adenocarcinoma in Combination with D2 Gastrectomy: NEO-CLASSIC Study

LESSONS LEARNED

The NEO-CLASSIC study provided valuable insight for the clinical efficacy and tolerability profiles of perioperative chemotherapy with oxaliplatin and capecitabine, plus gastrectomy, in patients with localized resectable gastric cancer.The study was designed to explore the potential survival benefits of an eight-cycle, perioperative oxaliplatin and capecitabine (XELOX) schedule in the above-mentioned setting and to explore the feasibility of prolonging the cycles of preoperative chemotherapy. The projected endpoint was not met.

BACKGROUND

This multicenter, open-label study (NEO-CLASSIC) evaluated the efficacy and safety of oxaliplatin and capecitabine (XELOX), plus D2 gastrectomy, in localized resectable gastric cancer.

METHODS

Patients aged 18-75 years with histologically-confirmed gastric adenocarcinoma (stage T2-4a/N+M0) were given eight cycles of XELOX (four preoperatively, four postoperatively). Each 3-week cycle comprised capecitabine 1,000 mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1. Curative D2 gastrectomy was scheduled 2-4 weeks after the last preoperative cycle. The primary objective of the study was to determine the objective response rate (ORR) of XELOX in the preoperative setting. Sample size was calculated by assuming that a minimum of 47 cases would be required to increase the ORR by 15% (from 40% to 55%). With an estimated 10% dropout rate, 55 patients would have to be recruited.

RESULTS

Fifty-five patients were enrolled, and one was excluded because of screening failure. R0 resections were achieved in 45 of 54 intent-to-treat patients (83.3%), and four patients received R1 resections (Fig. 1). There were no complete responses, 27 (50.0%) partial responses, 22 cases (40.7%) of stable disease, and 4 (7.4%) of progressive disease. The objective response rate was 50.0%. Median follow-up was 52.97 months; 30 patients (55.6%) had disease progression (Table 1), and median progression-free survival was 20.10 (95% confidence interval: 4.31-35.89) months; median overall survival was 30.77 months (95% confidence interval was not yet available) (Fig. 2). Fifty-four patients completed 209 cycles of preoperative chemotherapy; 42 patients received 133 cycles of postoperative chemotherapy (Table 3). The rate of grade 3-4 adverse events was 8.5% (29/342 cycles); the most frequent events were neutropenia (9/342 cycles) and leukopenia (4/342 cycles).

CONCLUSION

These findings suggest that combination therapy with capecitabine and oxaliplatin as perioperative chemotherapy, followed by D2 gastrectomy, is effective and safe in late-stage, locally advanced gastric cancer. Although enrollment exceeded the 47 patients required to identify an increase in the ORR by 15% (from 40% to 55%), results did not meet the primary endpoint.

[Efficacy of reinforcement on duodenal stump using single purse-string suture during laparoscopic radical gastrectomy for gastric cancer]

Objective: To evaluate the efficacy of reinforcement on duodenal stump using single purse-string suture during laparoscopic radical gastrectomy for gastric cancer in preventing duodenal stump leakage. Methods: A descriptive cohort study was conducted to retrospectively collect clinical data of 211 patients with gastric adenocarcinoma who underwent laparoscopic radical gastrectomy with Roux-en-Y or Billroth Ⅱ reconstruction and reinforcement on duodenal stump using laparoscopic single purse-string suture in Zhongshan Hospital of Fudan University between January 2013 and December 2016. Of 211 patients, 136 were male and 75 were female with mean age of (57.5±11.1)(24 to 87) years. Tumors locating at gastric upper 1/3, middle 1/3 and low 1/3 were found in 62, 68 and 81 patients respectively. Eighty-three cases underwent total gastrectomy, 128 underwent distal subtotal gastrectomy, 107 underwent Roux-en-Y reconstruction and 104 underwent Billroth II reconstruction. The procedure of reinforcement on duodenal stump using single purse-string suture during laparoscopic radical gastrectomy was as follows: (1) after cutting the duodenal stump to about 2.0 cm in length, use a 3-0 single-strand absorbable suture to make a muscle layer purse at a distance of 1.0 to 1.5 cm from the duodenal stump; (2) use the purse line to make a slipknot; (3) push the duodenum stump into the purse with a needle holder or grasper; (4) tighten the knot of the purse string, and then make 4 to 5 knots for reinforcement. Postoperative complications were defined and graded according to the Clavien-Dindo grading criteria, and the incidence of early complications was recorded. Clinicopathologic features and postoperative outcomes were analyzed. Results: All patients completed operations successfully. The mean time of laparoscopic single purse-string suture was (5.1±1.6) (3.6 to 10.2) minutes. Postoperative early complication occurred in 31 cases (14.7%), of whom 27 cases developed surgery-related complications (12.8%), including 7 cases (3.3%) of peritoneal infection, 6 (2.8%) of pancreatic leakage, 4 (1.9%) of wound infection, 4 (1.9%) of gastroplegia, 2 (0.9%) of peritoneal hemorrhage, 2 (0.9%) of intestinal obstruction, 2 (0.9%) of lymphatic leakage, and no duodenal stump leakage; while 4 cases (1.9%) developed internal non-surgical complication, including 3 cases (1.4%) of pulmonary infection and 1 (0.5%) of cardiovascular event. The patient with peritoneal hemorrhage was healed after re-operation and all other patients were discharged uneventfully after conservative treatment. Four cases (1.9%) developed complications beyond grade III a of Clavien-Dindo criteria. Conclusion: Reinforcement on duodenal stump using laparoscopic single purse-string suture during laparoscopic radical gastrectomy with Roux-en-Y or Billroth II reconstruction is simple and effective, and can prevent the risk of development of duodenal stump leakage.

Effect of Laparoscopic vs Open Distal Gastrectomy on 3-Year Disease-Free Survival in Patients With Locally Advanced Gastric Cancer: The CLASS-01 Randomized Clinical Trial

IMPORTANCE

Laparoscopic distal gastrectomy is accepted as a more effective approach to conventional open distal gastrectomy for early-stage gastric cancer. However, efficacy for locally advanced gastric cancer remains uncertain.

OBJECTIVE

To compare 3-year disease-free survival for patients with locally advanced gastric cancer after laparoscopic distal gastrectomy or open distal gastrectomy.

DESIGN, SETTING, AND PATIENTS

The study was a noninferiority, open-label, randomized clinical trial at 14 centers in China. A total of 1056 eligible patients with clinical stage T2, T3, or T4a gastric cancer without bulky nodes or distant metastases were enrolled from September 2012 to December 2014. Final follow-up was on December 31, 2017.

INTERVENTIONS

Participants were randomized in a 1:1 ratio after stratification by site, age, cancer stage, and histology to undergo either laparoscopic distal gastrectomy (n = 528) or open distal gastrectomy (n = 528) with D2 lymphadenectomy.

MAIN OUTCOMES AND MEASURES

The primary end point was 3-year disease-free survival with a noninferiority margin of -10% to compare laparoscopic distal gastrectomy with open distal gastrectomy. Secondary end points of 3-year overall survival and recurrence patterns were tested for superiority.

RESULTS

Among 1056 patients, 1039 (98.4%; mean age, 56.2 years; 313 [30.1%] women) had surgery (laparoscopic distal gastrectomy [n=519] vs open distal gastrectomy [n=520]), and 999 (94.6%) completed the study. Three-year disease-free survival rate was 76.5% in the laparoscopic distal gastrectomy group and 77.8% in the open distal gastrectomy group, absolute difference of -1.3% and a 1-sided 97.5% CI of -6.5% to ∞, not crossing the prespecified noninferiority margin. Three-year overall survival rate (laparoscopic distal gastrectomy vs open distal gastrectomy: 83.1% vs 85.2%; adjusted hazard ratio, 1.19; 95% CI, 0.87 to 1.64; P = .28) and cumulative incidence of recurrence over the 3-year period (laparoscopic distal gastrectomy vs open distal gastrectomy: 18.8% vs 16.5%; subhazard ratio, 1.15; 95% CI, 0.86 to 1.54; P = .35) did not significantly differ between laparoscopic distal gastrectomy and open distal gastrectomy groups.

CONCLUSIONS AND RELEVANCE

Among patients with a preoperative clinical stage indicating locally advanced gastric cancer, laparoscopic distal gastrectomy, compared with open distal gastrectomy, did not result in inferior disease-free survival at 3 years.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01609309.

The role of oxaliplatin in the adjuvant setting of different Lauren's type of gastric adenocarcinoma after D2 gastrectomy: a real-world study

BACKGROUND

To compare the efficacy of oxaliplatin-based and oxaliplatin-free adjuvant chemotherapies in patients with different Lauren type gastric cancers after D2 gastrectomy.

METHODS

From our established gastric cancer database, patients with pathological stage II and III gastric cancer who received adjuvant chemotherapy after D2 gastrectomy at Zhongshan Hospital of Fudan University were analyzed. Patients who received different adjuvant chemotherapy regimens were divided into two subgroups: oxaliplatin-based and oxaliplatin-free subgroup. Clinical outcomes were analyzed according to pathological stage and different Lauren types.

RESULTS

From Jan 2010 to June 2017, a total of 580 patients met all the eligibility criteria and were enrolled. The median DFS for all the patients was 24.37 months and the median OS was 56.70 months. In patients with intestinal type gastric cancer, the median DFS of the oxaliplatin-based subgroup was significantly longer than that of oxaliplatin-free subgroup (48.73 vs. 18.33 months, P < 0.001). The median OS was not reached in the oxaliplatin-based subgroup and 54.33 months in the oxaliplatin-free subgroup (P = 0.006). In patients with diffuse type gastric cancer, neither DFS nor OS differed significantly between two subgroups. In multivariate analysis, oxaliplatin-based adjuvant chemotherapy was independent positive predictor of DFS (HR 0.40; 95% CI 0.28-0.59; P < 0.001) and OS (HR 0.35; 95% CI 0.20-0.62; P < 0.001) in patients with intestinal type gastric cancer.

CONCLUSIONS

The results of our study suggested that oxaliplatin-based adjuvant chemotherapy was more effective in patients with intestinal type gastric cancer after D2 gastrectomy but showed no more survival benefit in patients with diffuse type.

Non-Local Low-Rank Cube-Based Tensor Factorization for Spectral CT Reconstruction

Spectral computed tomography (CT) reconstructs material-dependent attenuation images from the projections of multiple narrow energy windows, which is meaningful for material identification and decomposition. Unfortunately, the multi-energy projection datasets usually have lower signal-noise ratios (SNR). Very recently, a spatial-spectral cube matching frame (SSCMF) was proposed to explore the non-local spatial-spectral similarities for spectral CT. This method constructs a group by clustering up a series of non-local spatial-spectral cubes. The small size of spatial patches for such a group makes the SSCMF fail to fully encode the sparsity and low-rank properties. The hard-thresholding and collaboration filtering in the SSCMF also cause difficulty in recovering the image features and spatial edges. While all the steps are operated on 4-D group, the huge computational cost and memory load might not be affordable in practice. To avoid the above limitations and further improve the image quality, we first formulate a non-local cube-based tensor instead of group to encode the sparsity and low-rank properties. Then, as a new regularizer, the Kronecker-basis-representation tensor factorization is employed into a basic spectral CT reconstruction model to enhance the capability of image feature extraction and spatial edge preservation, generating a non-local low-rank cube-based tensor factorization (NLCTF) method. Finally, the split-Bregman method is adopted to solve the NLCTF model. Both numerical simulations and preclinical mouse studies are performed to validate and evaluate the NLCTF algorithm. The results show that the NLCTF method outperforms the other state-of-the-art competing algorithms.

Image gradient L0-norm based PICCS for swinging multi-source CT reconstruction

Dynamic computed tomography (CT) is usually employed to image motion objects, such as beating heart, coronary artery and cerebral perfusion, etc. Recently, to further improve the temporal resolution for aperiodic industrial process imaging, the swinging multi-source CT (SMCT) systems and the corresponding swinging multi-source prior image constrained compressed sensing (SM-PICCS) method were developed. Since the SM-PICCS uses the L1-norm of image gradient, the edge structures in the reconstructed images are blurred and motion artifacts are still present. Inspired by the advantages in terms of image edge preservation and fine structure recovering, the L0-norm of image gradient is incorporated into the prior image constrained compressed sensing, leading to an L0-PICCS Algorithm 1Table 1The parameters of L0-PICCS (δ1,δ2,λ1*,λ2*) for numerical simulation.Sourceswδ1(10-2)δ2(10-2)λ1*(10-2)λ2*(10-8)Noise-free510522.001.525522.001.55035002.00471014.33332.00500025522.00500050222.005000Noise51062002.505002554502.501.55054502.901.571027.385.91.5810000258.285.91.5850050522.001.5. The experimental results confirm that the L0-PICCS outperforms the SM-PICCS in both visual inspection and quantitative analysis.

[The defination of tumor deposit and its clinical significance in the diagnosis and treatment of gastric cancer]

Tumor deposit (TD) is a common histopathological finding in gastric cancer. With the improved ability of lymphadenectomy and pathological examination, the positive rate and harvested number of TD are also increasing. The role of TD in staging and prognosis prediction for gastric cancer patients is getting more attention. However, due to the lack of standardization and unification, the denomination, definition and diagnostic criteria are still controversial. The previous studies on the definition and diagnostic criteria of TD were reviewed to standardize the items and improve the awareness. TD is an independent prognostic factor in gastric cancer. Each TD should be counted separately as a lymph node in the final pN determination according to TNM staging system of the Union for International Cancer Control (UICC) or American Joint Committee on Cancer(AJCC) or Japanese classification of gastric carcinoma. But this rule is just an experience-based practice, without support from high-level evidence. Several studies have tried to incorporate TD into TNM staging system to improve the accuracy and discriminative ability. With the wide use of the 8th TNM staging system, how to incorporate TD into the new staging system in an easy and reasonable way still needs more investigations.

Low-dose spectral CT reconstruction using image gradient ℓ 0-norm and tensor dictionary

Spectral computed tomography (CT) has a great superiority in lesion detection, tissue characterization and material decomposition. To further extend its potential clinical applications, in this work, we propose an improved tensor dictionary learning method for low-dose spectral CT reconstruction with a constraint of image gradient ℓ ₀-norm, which is named as ℓ ₀TDL. The ℓ ₀TDL method inherits the advantages of tensor dictionary learning (TDL) by employing the similarity of spectral CT images. On the other hand, by introducing the ℓ ₀-norm constraint in gradient image domain, the proposed method emphasizes the spatial sparsity to overcome the weakness of TDL on preserving edge information. The split-bregman method is employed to solve the proposed method. Both numerical simulations and real mouse studies are perform to evaluate the proposed method. The results show that the proposed ℓ ₀TDL method outperforms other competing methods, such as total variation (TV) minimization, TV with low rank (TV+LR), and TDL methods.

Study on safety of laparoscopic total gastrectomy for clinical stage I gastric cancer: the protocol of the CLASS02-01 multicenter randomized controlled clinical trial

BACKGROUND

The safety of laparoscopic total gastrectomy (LTG) for the treatment of gastric cancer remains lack of clinical evidence. The Chinese Laparoscopic Gastrointestinal Surgery Study (CLASS) Group recently launched a multicenter randomized clinical trial (CLASS02-01) to compare the safety of LTG for clinical stage I gastric cancer with the conventional open total gastrectomy (OTG).

METHODS

This CLASS02-01 trial is a prospective, multicenter, randomized, controlled, open, and non-inferiority trial. Two hundred patients who met the inclusion criteria and did not accord with the exclusion criteria will be randomly divided into LTG group (n = 100) and OTG group (n = 100). The primary purpose of this study is to evaluate the early operative morbidity and mortality of LTG compared with OTG for clinical stage I gastric adenocarcinoma. The second purpose is to evaluate the recovery course and compare the postoperative hospital stay of the patients enrolled in this study.

DISCUSSION

This CLASS02-01 trial is the first prospective randomized two-arm controlled study to determine the safety of LTG compared with OTG. Through this trial, we hope to show that experienced surgeons can safely perform LTG with lymphadenectomy for gastric cancer.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03007550 . December 30, 2016.

Spatial-Spectral Cube Matching Frame for Spectral CT Reconstruction

Spectral computed tomography (CT) reconstructs the same scanned object from projections of multiple narrow energy windows, and it can be used for material identification and decomposition. However, the multi-energy projection dataset has a lower signal-noise-ratio (SNR), resulting in poor reconstructed image quality. To address this thorny problem, we develop a spectral CT reconstruction method, namely spatial-spectral cube matching frame (SSCMF). This method is inspired by the following three facts: i) human body usually consists of two or three basic materials implying that the reconstructed spectral images have a strong sparsity; ii) the same basic material component in a single channel image has similar intensity and structures in local regions. Different material components within the same energy channel share similar structural information; iii) multi-energy projection datasets are collected from the subject by using different narrow energy windows, which means images reconstructed from different energy-channels share similar structures. To explore those information, we first establish a tensor cube matching frame (CMF) for a BM4D denoising procedure. Then, as a new regularizer, the CMF is introduced into a basic spectral CT reconstruction model, generating the SSCMF method. Because the SSCMF model contains an L0-norm minimization of 4D transform coefficients, an effective strategy is employed for optimization. Both numerical simulations and realistic preclinical mouse studies are performed. The results show that the SSCMF method outperforms the state-of-the-art algorithms, including the simultaneous algebraic reconstruction technique, total variation minimization, total variation plus low rank, and tensor dictionary learning.

Smart low molecular weight hydrogels with dynamic covalent skeletons

We report a new strategy for fabricating a smart low molecular weight hydrogel based on dynamic covalent chemistry from a bola-type supra-gelator, which was facilely fabricated in situ from two non-assembling building blocks, (3-(2-(4-formylphenoxy) ethyl)-1-methyl imidazolium bromide, MA) and (3,3'-dithiobis (propionohydrazide), DSPDZ), through dynamic acylhydrazone bonding. The obtained low molecular weight hydrogels exhibited redox-responsive and controllable self-healing properties. The role of dynamic covalent bonding in the formation of smart hydrogels is revealed in this study, which provides a simple and bottom-up method for constructing smart low molecular weight hydrogels.

Reversible fabrication and self-assembly of a gemini supra-amphiphile driven by dynamic covalent bonds

A smart gemini supra-amphiphile behaving with pH/CO2 dual-sensitive hierarchical self-assembly was fabricated under the effect of dynamic covalent bonds. In the presence of an amino-functionalized cation, water-insoluble terephthalaldehyde, and an amphiphilic anion, the benzoic imine bond can initiate the transformation from a single-tailed supra-amphiphile to a gemini supra-amphiphile with increasing pH, followed by the subsequent evolution from micelles to vesicles. Reversible self-assembly and disassembly of the gemini supra-amphiphile can be realized via CO2/N2 treatment, thus inducing the fission and reversion of vesicles. Interestingly, the flexible nature of supra-amphiphiles allows for the hierarchical assembly of vesicles, leading to the formation of aqueous two-phase systems. Multiple responsive supra-amphiphiles have useful applications in the fabrication of smart supra-molecular materials, including self-healing materials, nanocarriers and chemosensors.

Down-regulation of miR-214 inhibits proliferation and glycolysis in non-small-cell lung cancer cells via down-regulating the expression of hexokinase 2 and pyruvate kinase isozyme M2

Glycolysis is a metabolic pathway that is enhanced in cancer cells. miR-214 plays an important role in cancer development and can modulate glycolysis. However, whether miR-214 can regulate glycolysis in non-small-cell lung cancer (NSCLC) cells has not yet been investigated. The expression levels of miR-214 in 7 NSCLC cell lines were measured by qRT-PCR. MTT assay was performed to evaluate the cell proliferation. Glucose consumption and lactate production were measured to assess the level of glycolysis. The expression of hexokinase 2 (HK2) and pyruvate kinase isozyme M2 (PKM2) was measured by qRT-PCR and western blot analysis. Luciferase reporter assay was carried out to confirm the target gene of miR-214. The levels of PTEN, p-Akt, Akt, p-mTOR, mTOR, p-S6K, and S6K were assessed by western blot analysis. Results showed that miR-214 levels were significantly increased in the 7 NSCLC cell lines compared with those in the human bronchial epithelial cell line. Down-regulation of miR-214 inhibited cell proliferation, glucose consumption, lactate production, and expression of HK2 and PKM2 in NSCLC cells. We also confirmed that miR-214 directly targeted PTEN and regulated the PTEN/Akt/mTOR pathway. Inhibition of the PTEN/Akt/mTOR pathway attenuated the effect of miR-214 mimics on glucose consumption, lactate production, and expression of HK2 and PKM2 in NSCLC cells. These results demonstrated that miR-214 down-regulation inhibited cell proliferation and glycolysis by down-regulating the expression of HK2 and PKM2 via the PTEN/Akt/mTOR pathway in NSCLC cells. Hence, our findings suggested that miR-214 might serve as a novel therapeutic target for NSCLC.

O-GlcNAcylation of RACK1 promotes hepatocellular carcinogenesis

BACKGROUND & AIMS

Aberrant oncogenic mRNA translation and protein O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) are general features during tumorigenesis. Nevertheless, whether and how these two pathways are interlinked remain unknown. Our previous study indicated that ribosomal receptor for activated C-kinase 1 (RACK1) promoted chemoresistance and growth in hepatocellular carcinoma (HCC). The aim of this study is to examine the role of RACK1 O-GlcNAcylation in oncogene translation and HCC carcinogenesis.

METHODS

The site(s) of RACK1 for O-GlcNAcylation was mapped by mass spectrometry analysis. HCC cell lines were employed to examine the effects of RACK1 O-GlcNAcylation on the translation of oncogenic factors and behaviors of tumor cells in vitro. Transgenic knock-in mice were used to detect the role of RACK1 O-GlcNAcylation in modulating HCC tumorigenesis in vivo. The correlation of RACK1 O-GlcNAcylation with tumor progression and relapse were analyzed in clinical HCC samples.

RESULTS

We found that ribosomal RACK1 was highly modified by O-GlcNAc at Ser122. O-GlcNAcylation of RACK1 enhanced its protein stability, ribosome binding and interaction with PKCβII (PRKCB), leading to increased eukaryotic translation initiation factor 4E phosphorylation and translation of potent oncogenes in HCC cells. Genetic ablation of RACK1 O-GlcNAcylation at Ser122 dramatically suppressed tumorigenesis, angiogenesis, and metastasis in vitro and in diethylnitrosamine (DEN)-induced HCC mouse model. Increased RACK1 O-GlcNAcylation was also observed in HCC patient samples and correlated with tumor development and recurrence after chemotherapy.

CONCLUSIONS

These findings demonstrate that RACK1 acts as key mediator linking O-GlcNAc metabolism to cap-dependent translation during HCC tumorigenesis. Targeting RACK1 O-GlcNAcylation provides promising options for HCC treatment.

LAY SUMMARY

O-GlcNAcylation of ribosomal receptor for activated C-kinase 1 at the amino acid serine122 promotes its stability, ribosome localization and interaction with the protein kinase, PKCβII, thus driving the translation of oncogenes and tumorigenesis of hepatocellular carcinoma. Increased O-GlcNAcylation of ribosomal receptor for activated C-kinase 1 is positively correlated with tumor growth, metastasis and recurrence in patients with hepatocellular carcinoma.

[Clinical research status of laparoscopic total gastrectomy in China]

Many retrospective and cohort studies have shown that laparoscopic total gastrectomy(LTG) has advantages of less trauma, quicker recovery and better incision than open total gastrectomy, and is not inferior to laparotomy in safety and the short- and long-term outcomes, so it has been widely applied. However there is still a lack of high level evidence-based basis. At present, several prospective multicenter clinical studies are being carried out in China, Japan and South Korea which have high incidence of gastric cancer to demonstrate the safety and feasibility of LTG and evaluate its long-term outcomes as well. A multicenter randomized controlled clinical trial comparing the safety of laparoscopic and open radical gastrectomy(CLASS-02 Research) conducted by Professor Sun Yihong, Zhongshan Hospital of Fudan University, is under way. The subjects of this study were the patients with clinical stage I(, the lesion locating in the gastric body, gastric fundus, or the esophagogastric junction (not involving the cardia dentate line), who were expected to be treated with total gastrectomy. The primary outcome measures were early operative morbidity and mortality and the secondary outcome measures were early postoperative recovery course and postoperative hospital stay. It is believed that results of the study will provide a high level evidence-based basis for the safety of LTG. The ongoing JCOG-1401 study in Japan aims to assess the feasibility and safety of LTG and LAPG for the treatment of early gastric cancer. LTG (Roux-en-Y reconstruction) or LAPG (double-tract or jejunal interposition reconstruction) will be performed in patients with clinical stage I( gastric cancer in this study. The primary endpoint of the study is the incidence of anastomotic leakage, and the secondary endpoints are proportion of patients converted to open surgery, the time to the first flatus, analgesic requirement, postoperative body temperature, the overall survival and relapse-free survival. The follow-up time is at least 5 years, and the results will also effectively evaluate the long-term efficacy of LTG and LAPG in the treatment for early gastric cancer. No.10 lymph nodes dissection of D2 total gastrectomy is a major difficulty in LTG. Japanese JCOG-0110 study has showed that for proximal gastric cancer patients without involvement of the greater curvature of the stomach, routine splenectomy for No.10 lymph nodes dissection is not recommended. In this regard, Professor Huang Changming, Union Hospital of Fujian Medical University, led the ongoing CLASS-04 study to evaluate the safety, feasibility and clinical efficacy of laparoscopic No.10 lymph node dissection with spleen preservation for patients with locally advanced gastric cancer locating in the upper part of the stomach. The ongoing CLASS-02 and JCOG-1401 studies will answer whether LTG is suitable for the treatment of early gastric cancer. We believe that in the absence of high level evidence-based basis, LTG should be applied cautiously to advanced gastric cancer, and LTG for early gastric cancer patients should also be operated by experienced surgeons.

Theoretically exact backprojection filtration algorithm for multi-segment linear trajectory

A theoretically exact backprojection filtration algorithm is proved and implemented for image reconstruction from a multi-segment linear trajectory assuming fan-beam geometry. The reconstruction formula is based on a concept of linear PI-line (L-PI) proposed in our previous work. The proof is completed in two consecutive steps. In the first step, it is proved that theoretically exact image reconstruction can be obtained on an arbitrary L-PI line from an infinite straight-line trajectory. In the second step, it is shown that accurate image reconstruction can be achieved from a multi-segment line trajectory by introducing a weight function to deal with the data redundancy. Numerical implementation and simulation results validate the correctness of our theoretical results.

The small animal material discrimination study based on equivalent monochromatic energy projection decomposition method with dual-energy CT system

Material discrimination is an important application of dual-energy computed tomography (CT) techniques. Projection decomposition is a key problem for pre-reconstruction material discrimination. In this study, we focused on the pre-reconstruction space based on the photoelectric and Compton effect decomposition model to characterize different material components, and proposed an efficient method to calculate the projection decomposition coefficient. We converted the complex projection integral into a linear equation by calculating the equivalent monochromatic energy from the high and low energy spectrum. Meanwhile, we constructed a dual-energy CT system based on a photon-counting detector to take small animal scan and material discrimination analysis. Finally, the results of simulation and experimental study demonstrated the feasibility of our proposed new method, and explained the characteristics of photoelectric absorption and Compton scattering reconstruction images.