Consistency mapping of 16 lymph node stations in gastric cancer by CT-based vessel-guided delineation of 255 patients

Risk factors for postoperative recurrence of pT2-3N0M0 esophageal squamous cell carcinoma and patterns of its recurrence

This study aimed to explore the patterns of postoperative recurrence in patients with pT2-3N0M0 esophageal squamous cell carcinoma (ESCC) and to identify the risk factors for the recurrence. Patients with pT2-3N0M0 ESCC who were treated at our hospital from January 2010 to August 2019 were divided into three categories: those with anastomotic recurrence, those with lymph node recurrence, and those with hematogenous metastasis. The sites of initial recurrence and metastasis were counted and potential risk factors were analyzed using univariate and multivariate Cox proportional hazard regression. Four hundred and eighty-five patients with pT2-3N0M0 ESCC were ultimately included, 176 (36.29%) of whom experienced tumor recurrence or metastasis. Cox multivariate analysis revealed that the postoperative T-stage, procedure, tumor location, and degree of differentiation were independent risk factors for postoperative recurrence (P < 0.05). The median time of recurrence was 38 months, and the most common site of recurrence was the lymph nodes in 126 patients (71.59%), followed by hematogenous metastasis in 73 patients (41.47%), and anastomotic recurrence in 21 patients (11.93%). 119 patients (67.61%) experienced recurrence within 36 months, with a probability of recurrence of 84.09% within 5 years, and recurrence remained relatively unchanged after 5 years. The proportion of postoperative lymph node recurrence and hematogenous metastasis in patients with pT3N0M0 ESCC was significantly higher than that in patients with pT2N0M0 ESCC (P < 0.05). At higher tumor locations in the body, the proportion of lymph node recurrence increased (P < 0.05). In conclusion, postoperative T-stage, procedure, tumor location, and degree of differentiation were independent risk factors for postoperative recurrence in pT2-3N0M0 ESCC, with regional lymph node recurrence being the most common pattern, emphasizing the importance of regional lymph nodes in this context.

Current and future strategies for radiation therapy in gastric cancer

Gastric cancers are heterogeneous. There are important differences between gastric and junctional tumors and a focus on evidence based on true gastric cancers is important to guide treatment decision and the design of innovative strategies. We present key evidence shaping the current use of radiotherapy, discuss technical radiotherapy considerations that are important to consider in multidisciplinary decision-making, and highlight selected research strategies including radiotherapeutic advances, theranostic approaches and key ongoing clinical trials to watch that will shape the role of radiotherapy in gastric cancers for the future.

ESTRO ACROP guidelines for the delineation of lymph nodal areas in upper gastrointestinal malignancies

The European SocieTy for Radiation and Oncology -Advisory Committee on Radiation Oncology Practice (ESTRO-ACROP) endorsed a project to provide guidelines (GL) for the identification and delineation of clinically negative lymph-nodal stations (LNs) involved in upper gastrointestinal clinical scenarios. The presented GL is focused on preoperative (or definitive) setting. The project aim is to improve the consistency of clinical target volume (CTV) delineation by providing: a description of the anatomical boundaries of the LNs; a radiological computed tomography-based atlas depicting the LNs areas; a free, web-based, interactive example case for independent training of radiation oncologists on LNs delineation according to the presented GL, by both qualitative and quantitative analysis (through the FALCON EduCase platform). This project was carried out with the intention to facilitate and improve uniformity of future upper gastrointestinal guidelines on nodal CTV delineation. We report methodology and results from the collaboration of a working group panel selected by the ESTRO-ACROP.

Performance of a machine learning-based decision model to help clinicians decide the extent of lymphadenectomy (D1 vs. D2) in gastric cancer before surgical resection

BACKGROUND

Controversy still exists on the optimal surgical resection for potentially curable gastric cancer (GC). Use of radiologic evaluation and machine learning algorithms might predict extent of lymphadenectomy to limit unnecessary surgical treatment. We purposed to design a machine learning-based clinical decision-support model for predicting extent of lymphadenectomy (D1 vs. D2) in local advanced GC.

METHODS

Clinicoradiologic features available from routine clinical assignments in 557 patients with GCs were retrospectively interpreted by an expert panel blinded to all histopathologic information. All patients underwent surgery using standard D2 resection. Decision models were developed with a logistic regression (LR), support vector machine (SVM) and auto-encoder (AE) algorithm in 371 training and tested in 186 test data, respectively. The primary end point was to measure diagnostic performance of decision model and a Japanese gastric cancer treatment guideline version 4th (JPN 4th) criteria for discriminate D1 (pT1 + pN0) versus D2 (≥ pT1 + ≥ pN1) lymphadenectomy.

RESULTS

The decision model with AE analysis produced highest area under ROC curve (train: 0.965, 95% confidence interval (CI) 0.948-0.978; test: 0.946, 95% CI 0.925-0.978), followed by SVM (train: 0.925, 95% CI 0.902-0.944; test: 0.942, 95% CI 0.922-0.973) and LR (train: 0.886, 95% CI 0.858-0.910; test: 0.891, 95% CI 0.891-0.952). By this improvement, overtreatment was reduced from 21.7% (121/557) by treat-all pattern, to 15.1% (84/557) by JPN 4th criteria, and to 0.7-0.9% (4-5/557) by the new approach.

CONCLUSIONS

The decision model with machine learning analysis demonstrates high accuracy for identifying patients who are candidates for D1 versus D2 resection. Its approximate 14-20% improvements in overtreatment compared to treat-all pattern and JPN 4th criteria potentially increase the number of patients with local advanced GCs who can safely avoid unnecessary lymphadenectomy.