Node Ratio Research Articles

The additive diagnostic role of diffusion-weighted magnetic resonance and chemical shift imaging (CSI) in differentiation between malignant and benign cervical lymph nodes

BackgroundImaging with conventional MRI plays a pivotal role in differentiation between benign and malignant nodes, which is crucial for choice of therapeutic plan. The purpose of this study was to evaluate the role of diffusion-weighted imaging DWI MRI and chemical shift imaging (CSI) (in and out of phase) in differentiation between malignant and benign cervical lymph nodes.Patients and methodsWe prospectively reviewed MR images of 31 patients presented to ENT department by cervical adenopathy. Imaging parameters documented included: morphology, ADC values and in-phase to out-of-phase (Ip/Op) ratios and signal drop in out-of-phase images.ResultsADC values of the benign and malignant nodes were 1.06 ± 0.25 and 0.85 ± 0.24, respectively. A statistically significant difference was found between the two groups (p = 0.041). An ADC value of 0.9 × 10−3 mm2/s was concluded to be the best cutoff value for differentiating benign from malignant LNs. The mean values of in/out-of-phase ratios of benign and malignant lymph nodes were 0.75 ± 0.16 and 0.96 ± 0.06, respectively. A statistically significant difference was found between the two groups (p = 0.001). The mean in/out-of-phase ratio of the benign nodes was significantly lower than that of the malignant nodes.ConclusionsCSI can differentiate between malignant and benign lymph nodes with a cutoff value of in/out-phase ratio of 0.9. Also, adding the diffusion-ADC map can prefer the same value with a cutoff value of 0.9 × 10−3 cm2/s. Adding CSI sequence to conventional MRI in examining the nodal status in patients with head and neck primary can enhance diagnostic accuracy of the examination.

Lymph node level ratio as a predictor of survival in oral cavity squamous cell carcinoma

ObjectiveTo evaluate whether nodal yields and ratios based on level serves as prognostic indicators in patients with oral cavity squamous cell carcinoma undergoing neck dissection. Materials and MethodsA retrospective analysis of 342 patients with oral cavity squamous cell carcinoma treated surgically between 1998 and 2017 were included.Demographics and clinicopathologic data were collated. Disease specific survival and overall survival were analyzed via Kaplan-Meier method and log-rank test as well as univariable and multivariable Cox models. ResultsTotal nodal yield is associated with improved overall and disease specific survival (p < 0.01). Total positive nodal yield (p < 0.01), positive nodal ratio per level (p < 0.001), and identification of <4 lymph nodes/level (p < 0.001) are associated with worse disease specific survival and overall survival. A ratio of at least 4 lymph nodes/level dissected yields the maximal hazard ratio on for both disease specific and overall survival optimizes the Kaplan-Meier split between survival groups. After controlling for sex, age, margin status, disease stage, extranodal extension, perineural invasion, and lymphovascular invasion as fixed covariates in the Cox models, a nodal level ratio of 4 lymph nodes/level provides hazard ratio (95% CI) of 3.59 (1.69, 7.60); p < 0.0006) for disease free survival and 2.90 (1.54, 5.46; p < 0.001) for overall survival. ConclusionNodal level ratio of < 4 lymph nodes/level is associated with worse disease specific and overall survival in oral cavity squamous cell carcinoma. This level-specific metric may prove useful qualitatively and in predicting survival in oral cavity cancer with broader utility to address variations in levels of neck dissection performed.

Lymph node ratio and hematological parameters predict relapse-free survival in patients with high grade rectal neuroendocrine neoplasms after radical resection: a multicenter prognostic study

BackgroundThe prognostic nutritional index (PNI), alkaline phosphatase (ALP), and lymph node ratio (LNR) are reportedly related to prognosis. The aim of this study was to elucidate the clinical importance of the LNR and hematological parameters in patients with high grade rectal neuroendocrine neoplasms (HG-RNENs) who were undergoing radical resection.MethodsWe reviewed the medical records of patients with HG-RNENs from 17 large-scale medical centers in China (January 1, 2010–April 30, 2022). A nomogram was constructed by using a proportional hazard model. Bootstrap method was used to draw calibration plots to validate the reproducibility of the model. Concordance index (C-Index), decision curve analysis (DCA), and time-dependent area under the receiver operating characteristic curve (TD-AUC) analysis were used to compare the prognostic predictive power of the new model with American Joint Committee on Cancer (AJCC) TNM staging and European Neuroendocrine Tumor Society (ENETS) TNM staging.ResultsA total of 85 patients with HG-RNENs were enrolled in this study. In the 45 patients with HG-RNENs who underwent radical resection, PNI ≤ 49.13 (HR: 3.997, 95% CI: 1.379–11.581, P = 0.011), ALP > 100.0 U/L (HR: 3.051, 95% CI: 1.011–9.205, P = 0.048), and LNR > 0.40 (HR: 6.639, 95% CI: 2.224–19.817, P = 0.0007) were independent predictors of relapse-free survival. The calibration plots suggested that the nomogram constructed based on the three aforementioned factors had good reproducibility. The novel nomogram revealed a C-index superior to AJCC TNM staging (0.782 vs 0.712) and ENETS TNM staging (0.782 vs 0.657). Also, the new model performed better compared to AJCC TNM staging and ENETS TNM staging in DCA and TD-AUC analyses.ConclusionsLNR, ALP, and PNI were independent prognostic factors in patients with HG-RNENs after radical resection, and the combined indicator had better predictive efficacy compared with AJCC TNM staging and ENETS TNM staging.

Intracorporeal Vessel Ligation in Laparoscopic Right Colectomy for Cancer is Associated with Increased Lymph Node Yield.

This study aimed to compare intra- and extracorporeal division of the vascular pedicle in laparoscopic right colectomy regarding pathological outcomes, short-term morbidity, and local recurrence and distant metastases. Retrospective analysis of an IRB-approved database of all patients who underwent laparoscopic right colectomy for cancer between 01/2011 and 08/2021. Main outcome measures were number of harvested lymph nodes, length of resected colon, R1 rate, positive lymph node ratio, short-term post-operative morbidity, local recurrence, and distant metastases. Two-hundred seventy-one consecutive patients (136 males) patients underwent laparoscopic right hemicolectomy for cancer during the study period. Vessel ligation was intracorporeal in 171 (63%) and extracorporeal in 100 patients (37%); groups had similar baseline characteristics except for extent of resection as extended right hemicolectomy was significantly more often performed in the intracorporeal group. When the two groups were matched for theextent of resection (standard versus extended right hemicolectomy),the mean number of harvested lymph nodes (28.61 ± 12.04 versus25.37 ± 10.06, p = 0.04) and median length of theresected colon [26.00 (IQR:21.00, 32.00) versus 23.00 (IQR:19.00, 27.00)cm, p = 0.003] were significantly higher in the intracorporeal than in the extracorporeal group. The intracorporeal group required a significantly longer operative time than didthe extracorporeal group (168.94±57.9 vs. 139.7±41.3mins, p=0.001). No significant differences were noted between the groups in terms of ileus, hemorrhage, surgical site infection, re-operation rates, recurrence, or distant metastases. Intracorporeal vessel ligation in laparoscopic right hemicolectomy was associated with increased lymph node yield and longer specimens, although requiring longer operative times. Postoperative clinical outcomes were similar to outcomes in the extracorporeal ligation group.

Novel model based on ultrasound predict axillary lymph node metastasis in breast cancer

BackgroundWhether there is axillary lymph node metastasis is crucial for formulating the treatment plan for breast cancer. Currently, invasive methods are still used for preoperative evaluation of lymph nodes. If non-invasive preoperative evaluation can be achieved, it will effectively improve the treatment plan.ObjectiveConstructed a predict model based on ultrasound examination, which forest axillary lymph node metastasis in breast cancer, and validated this model.MethodPatients admitted to Xiamen First Hospital from April 2018 to August 2021 with complete case data were included in this study. Patients who had undergone breast cancer resection and axillary lymph node dissection or sentinel lymph node biopsy were divided into a training and validation cohort in a 7:3 ratio. In the training cohort, patients were divided into metastatic and non-metastatic groups based on whether axillary lymph nodes had metastasis. The parameters of the two groups were compared, and statistically significant parameters were included in multivariate analysis. Then, a Nomogram model was constructed, named Lymph metastasis predict model (LMPM). Calibration curves, receiver operating curve (ROC), and decision curve analysis (DCA) were plotted between the training and validation cohort, calculate the risk score of each patient, identify the optimal cutoff value, and test the predictive efficacy of LMPM.ResultTwo hundred seventy-three patients were enrolled in final study, the average age 49.7 ± 8.7, training cohort included 191 patients, the diameter of breast cancer, the lymph node peak systolic flow velocity (LNPS) and the cortex area hilum ratio (CH) of lymph node were exist significant difference in metastatic and non-metastatic group. Multivariate analysis showed cancer diameter, LNPS and CH included in LMPM, the cutoff value was 95, the calibration curve, ROC, DCA in training and validation cohort show satisfactory result.ConclusionThe predict model-LMPM, can predict axillary lymph node metastasis in breast cancer, which is useful for developing personalized treatment plans. However, further validation of the model is required by incorporating a larger number of patients.

Clinicopathological significance and the associated signaling pathway of p21-activated kinase 1 (PAK1) in colorectal cancer

The aim of this study was to evaluate the clinicopathological significance and associated signaling pathways of p21-activated kinase 1 (PAK1) in colorectal cancer (CRC). PAK1 immunohistochemical expression was investigated in 246 human CRC tissues to evaluate its clinicopathological significance and prognostic role. Correlations between PAK1 and the immunoscore, HIF-1α, and pFOXO1 were also evaluated. PAK1 was expressed in 169 of 246 CRC tissues (68.7%). PAK1 expression significantly correlated with the metastatic lymph node ratio (P = 0.023). However, PAK1 expression did not correlate with tumor size, tumor location, tumor differentiation, lymphovascular and perineural invasion, or distant metastasis. PAK1 expression was significantly higher in CRC with a low immunoscore than in CRC with a high immunoscore (P = 0.017). In addition, there were significant correlations between PAK1, HIF-1α, and pFOXO1 expression (P = 0.001 and P = 0.024, respectively). Patients with PAK1 expression had worse overall and recurrence-free survival than those without PAK1 expression (P 0.001 and P = 0.001, respectively). PAK1 expression was significantly correlated with worse prognosis in CRCs patients. In addition, PAK1 expression was significantly correlated with a low immunoscore and high expression of HIF-1α and pFOXO1 in CRCs.

Assessing the role of central lymph node ratio in predicting recurrence in N1a low-to-intermediate risk papillary thyroid carcinoma.

Lymph node metastasis in patients with papillary thyroid carcinoma (PTC) is associated with postoperative recurrence. Recently, most studies have focused on the evaluation of recurrence in patients with late-stage PTC, with limited data on those with early-stage PTC. We aimed to assess the relationship between lymph node ratio (LNR) and recurrence in low-to-intermediate-risk patients and validate its diagnostic efficiency in both structural (STR) and biochemical recurrence (BIR). Clinical data of patients with PTC diagnosed at the Affiliated Hospital of Jining Medical University were retrospectively collected. The optimal LNR cut-off values for disease-free survival (DFS) were determined using X-tile software. Predictors were validated using univariate and multivariate Cox regression analyses. LNR had a higher diagnostic effectiveness than metastatic lymph nodes in patients with low-to-intermediate recurrence risk N1a PTC. The optimal LNR cutoff values for STR and BIR were 0.75 and 0.80, respectively. Multivariate Cox regression analysis showed that LNR≥0.75 and LNR≥0.80 were independent factors for STR and BIR, respectively. The 5-year DFS was 90.5% in the high LNR (≥0.75) and 96.8% in low LNR (<0.75) groups for STR. Regarding BIR, the 5-year DFS was 75.7% in the high LNR (≥0.80) and 86.9% in low LNR (<0.80) groups. The high and low LNR survival curves exhibited significant differences on the log-rank test. LNR was associated with recurrence in patients with low-to-intermediate recurrence risk N1a PTC. We recommend those with LNR≥0.75 require a comprehensive evaluation of lateral neck lymphadenopathy and consideration for lateral neck dissection and RAI treatment.

Evaluation of the quality of neck dissection in patients with oral cavity squamous cell carcinoma

Oral cavity squamous cell carcinoma is one of the leading localizations in the structure of head and neck cancers in the Russian federation and in the world. Neck metastases are the key criterion which influence to survival, recurrence, and distant metastases in patients with oral squamous cell carcinoma. Neck dissection is a main step in the surgical treatment of oral squamous cell carcinoma. This literature review analyzes data on possible methods for assessing the quality of neck dissection in squamous cell carcinoma of the oral cavity. Evaluation criteria can be conditionally divided into prognostic (lymph node extracapsular extension, the size of the largest neck metastasis, lymph node yield, lymph node ratio, metastasis topography) and qualitative (lymph node yield, lymph node ratio). Nowadays, there are some prognostic factors of surgical specimen after neck dissection which we use in clinical practice except for lymph node yield, lymph node ratio. This paper analyzes the criteria for an objective assessment of the quality of the operation “neck dissection”. The clinical and prognostic significance of these parametrs is considered.

Lymph node ratio independently associated with postoperative thyroglobulin levels in papillary thyroid cancer

ObjectivesTo investigate the impact of the lymph node ratio (LNR) on postoperative thyroglobulin (Tg) levels in patients with papillary thyroid carcinoma (PTC). Patients and MethodsThis was a retrospective, cohort study. The association between clinicopathological variables and postoperative unstimulated Tg (uTg) levels, preablative-stimulated Tg (sTg) levels, and postablative unstimulated Tg levels was analysed. ResultsA total of 300 patients with PTC were identified. Multivariate logistic analysis showed that M classification (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.62–3.34), and postoperative thyroid-stimulating hormone levels (OR, 1.01; 95% CI, 1.01–1.02) were independently associated with postoperative uTg levels. One hundred and sixteen patients underwent radioactive iodine (RAI) therapy. Multivariate analysis showed that LNR in the central neck (OR, 1.24; 95% CI, 1.02–1.51), LNR in the lateral neck (OR, 1.73; 95% CI, 1.09–2.77), RAI dose (OR, 1.43; 95% CI, 1.21–1.69), and M classification (OR, 1.79; 95% CI, 1.22–2.61) were independently associated with preablative sTg levels. Tumour size (OR, 1.01; 95% CI, 1.00–1.01), LNR in the central neck (OR, 1.28; 95% CI, 1.08–1.51), LNR in the lateral neck (OR, 1.66; 95% CI, 1.10–2.49), RAI dose (OR, 1.54; 95% CI, 1.34–1.79), and M classification (OR, 1.56; 95% CI, 1.12–2.19) were also independently associated with postablative uTg levels. ConclusionLNR was independently associated with postoperative Tg levels in patients with PTC. Patients with high LNR were more likely to have incomplete biochemical responses after surgery.

Association Between Whole Blood Selenium Levels and Triglyceride-to-High-Density Lipoprotein Cholesterol Ratio Among the General Population.

Our study aimed to examine whether whole blood selenium (WBSe) levels are related to the triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio among the general population. A total of 13,470 adults were included and analyzed from the National Health and Nutrition Examination Survey (NHANES) 2011-2018. In multivariable analyses, LnWBSe levels were significantly related to Ln(TG/HDL-C) ratio in fully adjusted model (β = 0.35; 95% confidence interval (CI): 0.22, 0.48; P < 0.001). Furthermore, the highest quartile of LnWBSe levels was positively correlated with Ln(TG/HDL-C) ratio compared with the lowest quartile (β = 0.15; 95% CI: 0.10, 0.20; P for trend < 0.001). In the dose-response analyses, the correlation was non-linear. While LnWBSe levels < 1.10, LnWBSe levels were positively related to Ln(TG/HDL-C) ratio (β = 0.41; 95% CI: 0.31, 0.50; P < 0.001), whereas LnWBSe levels ≥ 1.10, the relationship was not significantly (β = - 0.20; 95% CI: - 0.54, 0.13; P = 0.228). The interaction test was significant for age, sex, total cholesterol (TC), and diastolic blood pressure (DBP) (all P for interaction < 0.05). Overall, WBSe levels were positively related to TG/HDL-C ratio, with a non-linear trend. Further research is required to determine these underlying mechanisms.

Lymph node ratio evaluation precisely predicts the benefit of postoperative radiotherapy in esophageal cancer: A retrospective cohort study.

The matter of postoperative radiotherapy (PORT) in esophageal cancer (ESCA) was far from conclusive. Some evidence indicated that lymph node status could affect treatment. We evaluated lymph node ratio (LNR) as an indicator that could be applied to predict PORT benefit. Retrospective cohort study collected the data of N1, N2, N3 stage ESCA patients from the Surveillance, Epidemiology, and End Results database (SEER) to analyze the association between LNR and prognosis from 2004 to 2015. Patients were categorized into two subsets based on the LNR cut-off value of 0.23 using receiver operating characteristic curve (ROC). Kaplan-Meier analysis was utilized to estimate the proportion of overall survival (OS) and esophagus cancer-specific survival (CSS) in two LNR groups. Cox regression analysis and competitive risk model was adopted to investigate the impacts of LNR on prognosis. Of 2,165 ESCA patients identified, 1,165 (53.8%) had LNR>0.23. The LNR was an independent prognostic factor and associated with better OS and CSS of LNR≤0.23 (P<0.001). In competitive risk model, a worse CSS was analyzed of LNR>0.23 (HR=1.71; 95% CI 1.53-1.91). Subgroup analyses indicated that PORT was associated with favorable OS and CSS. Furthermore, when stratified by Node stage, PORT was associated with a survival benefit only in N1 stage with higher LNR (LNR>0.23) after adjusting for other covariates. LNR exceeding 0.23 was negatively associated with prognosis in ESCA. The survival benefit from PORT in ESCA seems to be limited to LNR of 23% or more only in N1 stage. This study highlights the biomarker meaning of LNR on identifying PORT beneficiary in N1 stage.

The impact of lymph node ratio on disease recurrence in papillary thyroid microcarcinoma.

Lymph node (LN) metastases in papillary thyroid microcarcinomas (microPTCs) are common. The lymph node ratio (LNR) has been proposed as a risk factor for recurrence in papillary thyroid cancer. However, its relevance in microPTC is undetermined. Patients who underwent resection of their microPTC with concomitant LN clearance between 2005 and 2018 were identified. The LNR was calculated as the ratio of positive LNs to the total number of LNs. Data on 50 patients (36 female [72%]; median age 47 years [range: 19-84]) who underwent LN clearance (28 central [56%] vs 22 central + lateral [44%]) were analysed. Positive LNs were found in over two-thirds of the patients (n = 34; 68%). After a median follow-up of 61 months, 14 patients (28%) had developed recurrence. Positive LNs were not found to impact recurrence-free survival; extranodal extension and an LNR ≥ 0.26 were found to significantly increase the risk of recurrence on unadjusted analyses (p < 0.05). LN metastases are frequent among patients with microPTC. A higher LNR seems to be associated with recurrence. Additional studies are needed to further clarify these findings and to assess the possible role of LNR in treatment and surveillance.

Usefulness of attenuation value on computed tomography plain scan for diagnosing enlarged mediastinal lymph nodes metastases.

To evaluate the diagnostic value of computed tomography (CT) attenuation in mediastinal lymph node metastases of malignant tumors. A retrospective review was conducted of a Chinese institutional database of consecutive patients with a history of malignant tumors. Those who had enlarged, necrotic, or hypermetabolic lymph nodes detected in the mediastinum during routine CT examination or positron emission tomography (PET)/CT imaging from January 2019 to December 2021 were collected for investigation. All patients underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and were followed up for at least 6 months to diagnose lymph node metastases. One-to-one correlation was attempted between the CT images of the lymph nodes and EBUS-TBNA area of the same lymph node groups and similar size. Radiologists measured size, as well as plain CT and contrast-enhanced CT (CECT) attenuation values of mediastinal lymph nodes, and evaluated the effectiveness of these variables in diagnosing lymph node metastasis. A total of 135 lymph nodes of 114 patients were included in the study. In the univariate analysis, the long-axis diameter, short-axis diameter, short-axis/long-axis ratio, and plain CT attenuation values of lymph nodes were found to be statistically significantly different between the metastatic and non-metastatic lymph nodes. The areas under receiver operator characteristic (ROC) curves (AUCs) of long-axis diameter, short-axis diameter, short-axis/long-axis ratio, and plain CT attenuation value for diagnosing metastases were 0.711, 0.788, 0.671, and 0.827, respectively. The best value of the AUC for diagnosing lymph node metastases was 0.827 [95% confidence interval (CI): 0.749-0.890] using plain CT attenuation value ≤45 Hounsfield units (HU). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 92.8%, 69.2%, 86.5%, and 81.8%, respectively. Similar results were obtained from the 68 cases of lung cancer. Plain CT attenuation values reached the best AUC (0.860) for diagnosing lymph node metastases. Plain CT attenuation of lymph nodes is an effective method for diagnosing enlarged mediastinal lymph nodes with a history of multiple malignancies or lung cancer. Plain CT could be used as an additional test where there is no PET/CT available in cases of diagnostic dilemma.

Partitioning and speciation of lanthanides in the system magnetite (hematite) – hydrothermal solution at 450 oC and 100 MPa pressure

The initial results of the experimental study of a hydrothermal system including lanthanides (Ln) and Fe oxides (magnetite and hematite) are presented. Ln concentrations in solutions and crystals were determined by ICP-MS and LM-ICP-MS, accordingly. The Ln distribution and cocrystallization coefficients obtained are interpreted as the maximal estimates of “true” values corresponding to structurally bound admixture. It is shown that Ln (except for Eu) are the compatible elements in hydrothermal magnetite; heavy Ln (beginning with Tb) are compatible in hematite. The pronounced tendency of the elevation of both coefficients with the Ln atomic number beginning from Gd-Tb was established. This is significant for using the ratio of light and heavy Ln as a typochemical guide for localization of the source of ore elements. The high-Ln-containing phases in associations with magnetite and hematite were obtained. These phases have oxychloride (without Fe) and oxyhydroxide (with Fe) composition and demonstrate the example of co-locating light and heavy Ln in the common space of hydrothermal system due to mutual crystallization of the phases selectively accumulating light and heavy lanthanides.

Risk and prognostic factors in patients with colon cancer with liver metastasis.

The most common site of metastasis in patients with colon cancer is the liver. This study aimed to identify patients with colon cancer at high risk of developing liver metastasis and to explore their prognosis. The clinical characteristics, treatment methods and survival outcomes of patients diagnosed with colon cancer from 2010 to 2015 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Patients were divided into two groups according to the presence of liver metastasis, and multivariate logistic and Cox regression models were used to identify risk and prognostic factors. A total of 60,018 patients with colon cancer were selected from the SEER database. The incidence of liver metastasis was 9.2%. African American ethnicity, poor differentiation, higher tumor stage, higher lymph node ratio, and lung metastases were common factors associated with both liver metastasis risk and prognosis. Metastasectomy might improve survival among patients with colon cancer with resectable liver metastasis lesions and no other organ involvement.

Risk factors affecting oncological outcomes of surgical resections for middle and lower rectal cancer.

In our study, it was aimed to evaluate the factors affecting oncological outcomes in resections for rectal cancer. Between January 2010 and December 2014, patients with rectal tumors were analyzed retrospectively. Demographic and pathological data and oncological outcomes were analyzed as disease-free survival, overall survival, and local recurrence. A total of 158 patients' data were obtained. Median age was 60 (22-83). Fifty-three patients were older than 65 years of age (138). Ninety-five (60%) patients were males, and 63 (40%) were females. Eighty patients (50.4%) had middle rectal, and 78 (49.6) patients had lower rectal cancer. There was no effect of tumor localization on oncological outcomes. Univariate analyses revealed the effects of age (p= 0.003), operation type (p <0.001), nodal status (p <0.001), malignant lymph node ratio (p <0.001), stage of the disease (p <0.001), distal resection margin (p= 0.047), perineural invasion (p <0.001), lymphatic invasion (p <0.001), venous-vascular invasion (p= 0.025), local recurrence (p <0.001) and distant metastasis (p <0.001) on overall survival rates. Univariate analyses revealed the effects of nodal status (p= 0.007), malignant lymph node ratio (p= 0.005), stage of the disease (p= 0.008), perineural invasion (p= 0.004) and venous-vascular invasion (p <0.001) on disease-free survival rates. Univariate analyses revealed the effects of anastomotic leak (p= 0.015) and venous-vascular invasion (p= 0.001) on local recurrence rates. Older age, advanced nodal status, and distant metastasis were detected as independent risk factors for overall survival. Perineural and venous-vascular invasion were detected as independent risk factors for disease-free survival. Lastly, anastomotic leak and venous-vascular invasion were detected as independent risk factors for local recurrence.

Prediction of Response to 177Lu-PSMA Therapy Based on Tumor-to-Kidney Ratio on Pretherapeutic PSMA PET/CT and Posttherapeutic Tumor-Dose Evaluation in mCRPC.

The aim of this study was to analyze the absorbed dose of 177Lu-PSMA in osseous versus lymphatic metastases in patients with metastatic castration-resistant prostate cancer across therapy cycles and to relate those data to therapeutic success. In addition, pretherapeutic prostate-specific membrane antigen (PSMA) PET/CT was evaluated for its ability to predict response behavior. Methods: The study comprised 30 patients with metastatic castration-resistant prostate cancer, each receiving at least 3 cycles of 177Lu-PSMA therapy. Prostate-specific antigen (PSA) values between baseline and 6 wk after the third therapy cycle were used to classify the patients as responders (PSA decline ≥ 50%) or nonresponders (unchanged or increasing PSA level). Quantitative SPECT/CT images were acquired 24, 48, and 168 h after application of 177Lu-PSMA. The absorbed dose for tumor lesions was calculated with dosimetry software. From the pretherapeutic PET/CT scan, the tumor-to-kidney uptake ratio was determined for different SUVs. Results: Regardless of patient response, the kidneys received a mean dose of 0.55 ± 0.20 Gy/GBq per cycle. In the first therapy cycle, the lymph node lesions received a mean dose of 3.73 ± 1.65 Gy/GBq in responders and 1.86 ± 1.25 Gy/GBq in nonresponders (P < 0.01). For bone lesions, the respective mean doses were 3.47 ± 2.00 Gy/GBq and 1.48 ± 0.95 Gy/GBq (P < 0.01). When successive therapy cycles were compared, the mean dose was found to have been reduced from the first to the second cycle by 27% for lymph nodes and by 33% for bone lesions. A significant difference (P < 0.01) in the ratio of lymph node and bone lesion uptake to kidney uptake between responders and nonresponders could be deduced from the pretherapeutic PET/CT scan. Conclusion: Significantly higher doses were achieved for lymph node and bone lesions in responders. The highest absorbed dose, for both lymphatic and osseous lesions, was achieved in the first cycle, decreasing in the second therapy cycle thereafter despite unchanged therapy activities. It may be possible to estimate the response to therapy from the ratio of tumor uptake to kidney uptake obtained from the pretherapeutic PSMA PET/CT scans.

398 Histological Lymph Node Ratio and Long-Term Survival After Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma

Abstract Background Pancreatoduodenectomy (PD) is recommended in fit patients with a resectable pancreatic ductal adenocarcinoma (PDAC) of the pancreatic head. Early rates of recurrence are high and long-term survival is uncommon. This study aimed to investigate the association between histological lymph node ratio (LNR) and long-term survival. Method Data were extracted from the Recurrence After Whipple’s (RAW) study, a multicentre retrospective cohort study of outcomes of PD performed for pancreatic head malignancy (29 centres in 8 countries, n = 1484). Patients with histologically confirmed PDAC were identified, and five-year and overall survival rates were compared by LNR (number of positive resected nodes/total number of resected nodes). Analyses were performed using Fisher’s exact test, the Kaplan-Meier method, and the log-rank test. Results In total, 885 patients (59.6%) were found to have PDAC. Concerning LNR, 412 patients (48.3%) had a LNR &amp;lt;0.2 and 437 (51.5%) had a LNR ≥0.2 (unknown: 36 cases). Five-year survival was significantly higher in the former (34.0% vs 10.5%, p&amp;lt;0.0001). LNR was 0, &amp;gt;0.0-0.2 and &amp;gt;0.2 in 116 (17.5%), 261 (39.5%) and 284 (43.0%) patients, respectively (patients with missing data were excluded). Median survival was 646 (95% confidence interval: 526-766), 532 (483-581) and 438 (395-481) days, respectively (p&amp;lt;0.00001). Conclusions In our multicentre study of PD patients with confirmed PDAC, a histological LNR ≥0.2 was associated with reduced five-year survival. Patients with a LNR of &amp;gt;0.0-0.2 and &amp;gt;0.2 lived a median of 114 and 208 days less than those with a LNR of 0.0.

14. IMPACTS OF ADDITIONAL CYCLES OF NEOADJUVANT IMMUNOCHEMOTHERAPY ON ESOPHAGECTOMY IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background The aim of this study is to explore the pathological characteristics and safety of esophagectomy after different cycles of neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC). Methods We prospectively collected patients who underwent neoadjuvant immunochemotherapy combined with esophagectomy from two institutes between 2019 and 2022. The primary outcome was defined as pathological complete response (PCR), and the secondary outcomes were defined as the incidence of postoperative complications. Result The most commonly used checkpoint inhibitor was camrelizumab. A total of 152 enrolled patients underwent esophagectomy, with 9 of 119 patients (7.6%) in the 2-cycle group undergoing thoracotomy and 2 patients of 33 patients (6.1%) in the &amp;gt;2-cycle group converting to thoracotomy. Twenty-three patients in the 2-cycle group and 6 patients in the &amp;gt;2-cycle group achieved PCR, there was no statistically significant difference between the two groups (19.3% vs. 18.2%; P = 0.882). The N0 rate (57.1% vs. 51.5%; P = 0.565) and lymph node ratio (6% vs. 6%; P = 0.489) were similar between the two groups. The most common postoperative complication was pneumonia, there were no significant differences in postoperative complications between the two groups. Conclusion This study indicated that although additional cycles of neoadjuvant immunochemotherapy had no significant effect on the feasibility and safety of esophagectomy, 2-cycle of treatment is enough when considering pathological complete response rate.

795 Predictors and Timing of Recurrence After Surgical Resection of Pancreatic Adenocarcinoma

Abstract Aim To investigate the predictors and timing of recurrence after curative resection for pancreatic adenocarcinoma (PDAC). Method Consecutive patients who underwent curative resection for PDAC (2011-21) and consented to data and tissue collection, were followed up prospectively in a single institution. Clinico-pathological variables were analysed using the Cox proportional hazards model. Results 91 patients (median age 71 years (range 43 – 86)) had a median follow-up of 51 (95% CI 40–61) months. 66 (72.5%) patients experienced recurrence (12 locoregional, 11 liver, 5 lung, 3 peritoneal, 29 simultaneous locoregional and distant and 6 multi-focal distant). Median time to recurrence was 8.5 (95% CI 6.6-10.5) months and median survival after recurrence was 5.8 (95% CI 4.2-7.3) months. Stratification by recurrence location revealed no significant differences in time to recurrence (p = 0.24). Significant predictors for any recurrence were lymph node ratio ≥0.33 (p = 0.005, HR 2.8, 95% CI 1.4 – 5.8), adjuvant chemotherapy (p = 0.002, HR 0.4, 95% CI 0.2 – 0.7) and systemic inflammation score ≥500 (p = 0.01, HR 4.5, 95% CI 1.4 – 14.3). Conclusions Lymph node ratio, adjuvant chemotherapy and systemic inflammation score were significant predictors for recurrence after curative resection for PDAC: this needs validation in large national cohorts.