Mass, Spectroscopy, and Two-Neutron Decay of

The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for the first time, with energies of 0.84(3) and 2.15(5) MeV above the two-neutron decay threshold and widths of 0.32(8) and 0.95(15) MeV, respectively. These were assigned to be the ground (J^{π}=0^{+}) and first excited (2^{+}) state, with E_{x}=1.31(6) MeV. The mass excess of ^{16}Be was thus deduced to be 56.93(13) MeV, some 0.5 MeV more bound than the only previous measurement. Both states were observed to decay by direct two-neutron emission. Calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component, while the 2^{+} level presents a far more diffuse neutron-neutron distribution.

Relationship between the housing coldness/warmth evaluation by CASBEE Housing Health Checklist and psychological distress based on TMM Community-Based Cohort Study: a cross-sectional analysis.

OBJECTIVES: Previous studies have reported the relationship between housing environment and health, although due to cost and effort, it was difficult to conduct housing condition surveys on a large scale. The CASBEE Housing Health Checklist (the Checklist) made it possible to easily evaluate the housing condition from the resident's perspective. This study examined the relationship between housing coldness/warmth evaluation using the Checklist and psychological distress in a large-scale general Japanese population. STUDY DESIGN: A cross-sectional study. METHODS: We analysed data from 29,380 people aged ≥20 years who lived in Miyagi Prefecture, Japan. As an assessment of housing coldness/warmth, we used the Checklist. We classified participants' total scores on the Checklist related to coldness/warmth into quartiles. The Kessler 6 scale was used as an indicator of psychological distress. Multivariable logistic regression models were used to estimate the adjusted odds ratio (OR) and 95% confidence intervals (CIs). Adjusted OR and P-values for linear trends were calculated using the quartiles of the Checklists' score. RESULTS: Among participants in Q1 (i.e., poorer subjective house condition), the percentage of people with psychological distress was high. Compared to the highest quartile, Q1 showed poorer evaluation of housing coldness/warmth, and higher OR for psychological distress. The OR (95% CI) of psychological distress for Q3, Q2, and Q1 compared with Q4 were 1.93 (1.74-2.14), 2.82 (2.55-3.12), and 5.78 (5.25-6.35), respectively. CONCLUSIONS: Housing coldness/warmth evaluation was significantly related to psychological distress. This finding suggests that maintaining a comfortable thermal environment at home could be important for residents' mental health.

Contour prognostic model for predicting survival after resection of colorectal liver metastases: development and multicentre validation study using largest diameter and number of metastases with RAS mutation status.

BACKGROUND: Most current models for predicting survival after resection of colorectal liver metastasis include largest diameter and number of colorectal liver metastases as dichotomous variables, resulting in underestimation of the extent of risk variation and substantial loss of statistical power. The aim of this study was to develop and validate a new prognostic model for patients undergoing liver resection including largest diameter and number of colorectal liver metastases as continuous variables. METHODS: A prognostic model was developed using data from patients who underwent liver resection for colorectal liver metastases at MD Anderson Cancer Center and had RAS mutational data. A Cox proportional hazards model analysis was used to develop a model based on largest colorectal liver metastasis diameter and number of metastases as continuous variables. The model results were shown using contour plots, and validated externally in an international multi-institutional cohort. RESULTS: A total of 810 patients met the inclusion criteria. Largest colorectal liver metastasis diameter (hazard ratio (HR) 1.11, 95 per cent confidence interval 1.06 to 1.16; P < 0.001), number of colorectal liver metastases (HR 1.06, 1.03 to 1.09; P < 0.001), and RAS mutation status (HR 1.76, 1.42 to 2.18; P < 0.001) were significantly associated with overall survival, together with age, primary lymph node metastasis, and prehepatectomy chemotherapy. The model performed well in the external validation cohort, with predicted overall survival values almost lying within 10 per cent of observed values. Wild-type RAS was associated with better overall survival than RAS mutation even when liver resection was performed for larger and/or multiple colorectal liver metastases. CONCLUSION: The contour prognostic model, based on diameter and number of lesions considered as continuous variables along with RAS mutation, predicts overall survival after resection of colorectal liver metastasis.

Prognostic grade for resecting hepatocellular carcinoma: multicentre retrospective study.

BACKGROUND: Surgical treatment for hepatocellular carcinoma (HCC) is advancing, but a robust prediction model for survival after resection is not available. The aim of this study was to propose a prognostic grading system for resection of HCC. METHODS: This was a retrospective, multicentre study of patients who underwent first resection of HCC with curative intent between 2000 and 2007. Patients were divided randomly by a cross-validation method into training and validation sets. Prognostic factors were identified using a Cox proportional hazards model. The predictive model was built by decision-tree analysis to define the resection grades, and subsequently validated. RESULTS: A total of 16 931 patients from 795 hospitals were included. In the training set (8465 patients), four surgical grades were classified based on prognosis: grade A1 (1236 patients, 14.6 per cent; single tumour 3 cm or smaller and anatomical R0 resection); grade A2 (3614, 42.7 per cent; single tumour larger than 3 cm, or non-anatomical R0 resection); grade B (2277, 26.9 per cent; multiple tumours, or vascular invasion, and R0 resection); and grade C (1338, 15.8 per cent; multiple tumours with vascular invasion and R0 resection, or R1 resection). Five-year survival rates were 73.9 per cent (hazard ratio (HR) 1.00), 64.7 per cent (HR 1.51, 95 per cent c.i. 1.29 to 1.78), 50.6 per cent (HR 2.53, 2.15 to 2.98), and 34.8 per cent (HR 4.60, 3.90 to 5.42) for grades A1, A2, B, and C respectively. In the validation set (8466 patients), the grades had equivalent reproducibility for both overall and recurrence-free survival (all P < 0.001). CONCLUSION: This grade is used to predict prognosis of patients undergoing resection of HCC.

Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

Maturation of nasal microbiota and antibiotic exposures during early childhood: a population-based cohort study.

OBJECTIVES: Little is known about maturation of the airway microbiota during early childhood and the consequences of early-life antibiotic exposure. METHODS: In a population-based birth cohort of 902 healthy Finnish children, we applied deep neural network models to investigate the relationship between the nasal microbiota (measured by 16S rRNA gene sequencing at up to three time points) and child age during the first 24 months. We also performed stratified analyses according to antibiotic exposure during the age period 0-2 months. RESULTS: The dense deep neural network analysis successfully modelled the relationship between 232 bacterial genera and child age with a mean absolute error of 4.3 (95%CI 4.0-4.7) months. Similarly, the recurrent neural network analysis also successfully modelled the relationship between 215 genera and child age with a mean absolute error of 0.45 (95%CI 0.42-0.47) months. Among the genera, Staphylococcus spp. and members of the Corynebacteriaceae decreased with age, while Dolosigranulum and Moraxella increased with age in the first 2 years of life (all false discovery rate (FDR) = 0.001). In children without early-life antibiotic exposure, Dolosigranulum increased with age (FDR = 0.001). By contrast, in those with early-life antibiotic exposure, Haemophilus increased with age (FDR = 0.002). CONCLUSIONS: In this prospective birth cohort of healthy children, we demonstrated the development of the nasal microbiota, with shifts in specific genera constituting maturation, in the first 2 years of life. Antibiotic exposures during early infancy were related to different age-discriminatory bacteria.

Surface Localization of the Dineutron in

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246 MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6 fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

Performance of a modified three-level classification in stratifying open liver resection procedures in terms of complexity and postoperative morbidity.

BACKGROUND: Traditional classifications for open liver resection are not always associated with surgical complexity and postoperative morbidity. The aim of this study was to test whether a three-level classification for stratifying surgical complexity based on surgical and postoperative outcomes, originally devised for laparoscopic liver resection, is superior to classifications based on a previously reported survey for stratifying surgical complexity of open liver resections, minor/major nomenclature or number of resected segments. METHODS: Patients undergoing a first open liver resection without simultaneous procedures at MD Anderson Cancer Center (Houston cohort) or the University of Tokyo (Tokyo cohort) were studied. Surgical and postoperative outcomes were compared among three grades: I (wedge resection for anterolateral or posterosuperior segment and left lateral sectionectomy); II (anterolateral segmentectomy and left hepatectomy); III (posterosuperior segmentectomy, right posterior sectionectomy, right hepatectomy, central hepatectomy and extended left/right hepatectomy). RESULTS: In both the Houston (1878 patients) and Tokyo (1202) cohorts, duration of operation, estimated blood loss and comprehensive complication index score differed between the three grades (all P < 0·050) and increased in stepwise fashion from grades I to III (all P < 0·001). Left hepatectomy was associated with better surgical and postoperative outcomes than right hepatectomy, extended right hepatectomy and right posterior sectionectomy, although these four procedures were categorized as being of medium complexity in the survey-based classification. Surgical outcomes of minor open liver resections also differed between the three grades (all P < 0·050). For duration of operation and blood loss, the area under the curve was higher for the three-level classification than for the minor/major or segment-based classification. CONCLUSION: The three-level classification may be useful in studies analysing open liver resection at Western and Eastern centres.

ANTECEDENTES: Las clasificaciones tradicionales de la resección hepática abierta (open liver resection, OLR) por número de segmentos resecados, no siempre se asocian con la complejidad quirúrgica y la morbilidad postoperatoria. El objetivo de este estudio fue comprobar si una clasificación de 3 niveles para estratificar la complejidad quirúrgica en función de los resultados quirúrgicos y postoperatorios, ideada originalmente para la resección hepática laparoscópica, es superior a las clasificaciones basadas en una encuesta descrita previamente para estratificar la complejidad quirúrgica de los procedimientos de OLR, nomenclatura menor/mayor, o número de segmentos resecados. MÉTODOS: Se estudiaron pacientes sometidos a una primera OLR sin otros procedimientos quirúrgicos concomitantes en el hospital MD Anderson (cohorte de Houston) o en la Universidad de Tokio (cohorte de Tokio). Se compararon los resultados quirúrgicos y postoperatorios entre 3 grados: I (resección limitada para el segmento anterolateral o posterosuperior y seccionectomía izquierda); II (segmentectomía anterolateral y hepatectomía izquierda); III (segmentectomía posterosuperior, seccionectomía posterior derecha, hepatectomía derecha, hepatectomía central y hepatectomía ampliada izquierda/derecha). RESULTADOS: En ambas cohortes de Houston (n = 1.878) y Tokio (n = 1.202), el tiempo operatorio, las pérdidas estimadas de sangre, y el índice de complejidad integral (comprehensive complication index) variaba en los 3 grados (todos P < 0,05) y aumentaba paso a paso desde los grados I a III (todos P < 0,05). La hepatectomía izquierda se asociaba con mejores resultados quirúrgicos y postoperatorios que la hepatectomía derecha, hepatectomía derecha ampliada, y seccionectomía posterior derecha, aunque estos cuatro procedimientos fueron categorizados como de complejidad intermedia en la clasificación basada en la encuesta. Los resultados quirúrgicos de las OLRs menores también variaron en los 3 grados (todos P < 0,05). Para el tiempo operatorio y la pérdida sanguínea, el área bajo la curva fue mayor para la clasificación de 3 niveles en el estudio actual, que para la clasificación menor/mayor o la clasificación basada en los segmentos. CONCLUSIÓN: La clasificación en 3 niveles puede ser útil en estudios que analizan las resecciones hepáticas abiertas en centros occidentales y orientales.

Significance of the surgical hepatic resection margin in patients with a single hepatocellular carcinoma.

BACKGROUND: The impact of a wide surgical margin on the outcome of patients with hepatocellular carcinoma (HCC) has not been evaluated in relation to the type of liver resection performed, anatomical or non-anatomical. The aim of this study was to evaluate the impact of surgical margin status on outcomes in patients undergoing anatomical or non-anatomical resection for solitary HCC. METHODS: Data from patients with solitary HCC who had undergone non-anatomical partial resection (Hr0 group) or anatomical resection of one Couinaud segment (HrS group) between 2000 and 2007 were extracted from a nationwide survey database in Japan. Overall and recurrence-free survival associated with the surgical margin status and width were evaluated in the two groups. RESULTS: A total of 4457 patients were included in the Hr0 group and 3507 in the HrS group. A microscopically positive surgical margin was associated with poor overall survival in both groups. A negative but 0-mm surgical margin was associated with poorer overall and recurrence-free survival than a wider margin only in the Hr0 group. In the HrS group, the width of the surgical margin was not associated with patient outcome. CONCLUSION: Anatomical resection with a negative 0-mm surgical margin may be acceptable. Non-anatomical resection with a negative 0-mm margin was associated with a less favourable survival outcome.

ANTECEDENTES: El impacto de un margen quirúrgico (surgical margin, SM) amplio en el resultado de pacientes con carcinoma hepatocelular (hepatocellular carcinoma, HCC) no ha sido evaluado en relación con el tipo de resección hepática realizada: anatómica o no anatómica. El objetivo del presente estudio fue evaluar el impacto del estado del SM en los resultados en pacientes sometidos a resección anatómica o no anatómica por un HCC solitario. MÉTODOS: Los datos de pacientes con un HCC solitario sometidos a resección parcial no anatómica (grupo Hr0) o resección anatómica de un segmento de Couinaud (grupo HrS) entre 2000 y 2007 se obtuvieron a partir de una base de datos nacional de Japón. En los grupos Hr0 y HrS se evaluaron la supervivencia global y la supervivencia libre de recidiva asociadas al estado microscópico del SM y a la amplitud del SM. RESULTADOS: Se incluyeron un total de 4.457 pacientes en el grupo Hr0 y 3.507 en el grupo HrS. Un SM microscópico positivo se asoció con una pobre supervivencia global en ambos grupos. Un SM negativo, pero a una distancia de 0 mm se asoció con una peor supervivencia global y libre de recidiva en comparación con aquellos asociados a un SM más amplio, solo en el grupo Hr0. En el grupo HrS, la amplitud del SM no se asoció con los resultados del paciente. CONCLUSIÓN: La resección anatómica con un SM negativo a una distancia de 0 mm puede ser aceptable. La resección no anatómica con un SM negativo a una distancia de 0 mm se asoció con resultados de supervivencia menos favorables.

Multicentre study of perioperative versus adjuvant chemotherapy for resectable colorectal liver metastases.

Background: It is not known whether perioperative chemotherapy, compared with adjuvant chemotherapy alone, improves disease-free survival (DFS) in patients with upfront resectable colorectal liver metastases (CLM). The aim of this study was to estimate the impact of neoadjuvant 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX) on DFS in patients with upfront resectable CLM. Methods: Consecutive patients who presented with up to five resectable CLM at two Japanese and two French centres in 2008-2015 were included in the study. Both French institutions favoured perioperative FOLFOX, whereas the two Japanese groups systematically preferred upfront surgery plus adjuvant chemotherapy. Inverse probability of treatment weighting (IPTW) and Cox regression multivariable models were used to adjust for confounding. The primary outcome was DFS. Results: Some 300 patients were included: 151 received perioperative chemotherapy and 149 had upfront surgery plus adjuvant chemotherapy. The weighted 3-year DFS rate was 33·5 per cent after perioperative chemotherapy compared with 27·1 per cent after upfront surgery plus adjuvant chemotherapy (hazard ratio (HR) 0·85, 95 per cent c.i. 0·62 to 1·16; P = 0·318). For the subgroup of 165 patients who received adjuvant FOLFOX successfully (for at least 3 months), the adjusted effect of neoadjuvant chemotherapy was not significant (HR 1·19, 0·74 to 1·90; P = 0·476). No significant effect of neoadjuvant chemotherapy was observed in multivariable regression analysis. Conclusion: Compared with adjuvant chemotherapy, perioperative FOLFOX does not improve DFS in patients with resectable CLM, provided adjuvant chemotherapy is given successfully.

Antecedentes: Se desconoce si la quimioterapia perioperatoria en comparación con la quimioterapia adyuvante sola mejora la supervivencia libre de enfermedad (disease­free survival, DFS) en pacientes con metástasis hepáticas de origen colorrectal (colorectal liver metastases, CLM) resecables de inicio. El objetivo de este estudio fue estimar el impacto de la neoadyuvancia con 5­fluorouracilo, leucovorina y oxaliplatino (FOLFOX) sobre la DFS en pacientes con CLM resecables desde el principio. Métodos: Se incluyeron pacientes consecutivos que presentaban hasta cinco CLM resecables en dos centros japoneses y dos centros franceses entre 2008 a 2015. Ambas instituciones francesas favorecían FOLFOX perioperatorio, mientras que los dos grupos japoneses utilizaban sistemáticamente la cirugía de entrada y quimioterapia adyuvante. Se utilizaron la probabilidad inversa del tratamiento ponderado (Inverse Probability of Treatment Weighting, IPTW) y el modelo multivariable de regresión de Cox para ajustar por factores de confusión. El resultado primario fue la DFS. Resultados: Se incluyeron 300 pacientes (grupo de quimioterapia perioperatoria n = 151 y grupo de cirugía de entrada más quimioterapia adyuvante n = 149). La DFS a los 3 años ponderada fue del 33% después de quimioterapia perioperatoria versus 27% tras cirugía de entrada (cociente de riesgos instantáneos, hazard ratio HR: 0,85; i.c. del 95% (0,62­1,16); P = 0,32). Cuando se consideró el subgrupo de pacientes que (n = 165) de manera efectiva (al menos 3 meses) recibieron FOLFOX adyuvante, el efecto ajustado de la quimioterapia neoadyuvante no fue significativo (HR: 1,19 (0,74­1,90); P = 0,48). No se observó un efecto significativo de la quimioterapia neoadyuvante en el análisis de regresión multivariable. Conclusión: En comparación con la quimioterapia adyuvante, el FOLFOX perioperatorio no mejora la DFS en CLM resecables siempre y cuando la quimioterapia adyuvante se administre de forma efectiva.

Comparative effectiveness of gastric bypass versus gastric banding on acute care use for cardiovascular disease in adults with obesity.

BACKGROUND AND AIMS: Gastric bypass is known to have larger effects on weight and metabolism than gastric banding. However, scarce data exist as to whether the differences are translated into differential risks of cardiovascular disease (CVD)-related morbidities. The objective was to examine whether adults with obesity and CVD who underwent gastric bypass have a lower rate of acute care use (emergency department [ED] visit or unplanned hospitalization) for CVD than those with gastric banding. METHODS AND RESULTS: We performed a comparative effectiveness study of gastric bypass versus banding among adults with obesity and CVD who underwent either surgery, using population-based [ED] and inpatient samples in California, Florida, and Nebraska from 2005 through 2011. The primary outcome was acute care use for CVD during a two-year postoperative period. We constructed negative binomial regression models to compare the event rate during sequential 6-month periods, using gastric banding group as the reference. We identified 11,229 adults with obesity and CVD who underwent gastric bypass and 3896 adults who had gastric banding. Patients with gastric bypass had significantly lower rate of the outcome compared to those with banding in the 7-12 months postoperative period (adjusted rate ratio [aRR] 0.77; 95% confidence interval [CI], 0.61-0.98; P = 0.03). The significant reduction in the rate persisted during 13-18 months (aRR 0.71; 95% CI, 0.57-0.90; P = 0.005) and 19-24 months (aRR 0.66; 95% CI, 0.52-0.82; P < 0.001) after bariatric surgery. CONCLUSION: In this population-based comparative effectiveness study of adults with obesity and CVD, the rate of acute care use for CVD was lower after gastric bypass compared to gastric banding.

Hepatectomy for hepatocellular carcinoma after perioperative management of portal hypertension.

BACKGROUND: Indications for hepatectomy in patients with hepatocellular carcinoma (HCC) who have portal hypertension (PH) have been controversial. Some studies have concluded that PH is a contraindication to hepatectomy, whereas others have suggested that perioperative prophylactic management (PPM) can help overcome complications after hepatectomy associated with PH. The objective of this retrospective study was to assess the short- and long-term outcomes after hepatectomy for HCC in patients with PH, with or without PPM. METHODS: Records were reviewed of consecutive patients who underwent hepatectomy for HCC, with or without PPM of PH, in a single institution from 1994 to 2015. Patients were divided into three groups: those who received PPM for PH (PPM group), patients who had PH but did not receive PPM (no-PPM group) and those without PH (no-PH group). RESULTS: A total of 1259 patients were enrolled, including 123 in the PPM group, 181 in the no-PPM group and 955 in the no-PH group. Three- and 5-year overall survival rates were 74·3 and 53·1 per cent respectively in the PPM group, 69·2 and 54·9 per cent in the no-PPM group, and 78·1 and 64·2 per cent in the no-PH group (P = 0·520 for PPM versus no PPM, P = 0·027 for PPM versus no PH, and P < 0·001 for no PPM versus no PH). Postoperative morbidity and mortality rates were 26·0 and 0·8 per cent respectively in the PPM group, 29·8 and 1·1 per cent in the no-PPM group, and 20·3 and 0 per cent in the no-PH group. CONCLUSION: The present study has demonstrated acceptable outcomes among patients with HCC who received appropriate management for PH in an Asian population. Enhancement of the safety of hepatic resection through use of PPM may provide a rationale for expansion of indications for hepatectomy in patients with PH.

Split-mouth evaluation of connective tissue graft with or without enamel matrix derivative for the treatment of isolated gingival recession defects in dogs.

OBJECTIVES: The potential additive effect of an enamel matrix derivative (EMD) to a subepithelial connective tissue graft (CTG) for recession coverage is still controversially discussed. Therefore, the aim of this study was to histologically evaluate the healing of gingival recessions treated with coronally advanced flap (CAF) and CTG with or without EMD in dogs. MATERIALS AND METHODS: Gingival recession defects (5 mm wide and 7 mm deep) were surgically created on the labial side of bilateral maxillary canines in 7 dogs. After 8 weeks of plaque accumulation and subsequent 2 weeks of chemical plaque control, the 14 chronic defects were randomized to receive either CAF with CTG (CAF/CTG) or CAF with CTG and EMD (CAF/CTG/EMD). The animals were sacrificed 10 weeks after reconstructive surgery for histologic evaluation. RESULTS: Treatment with CAF/CTG/EMD demonstrated statistically significantly better results in terms of probing pocket depth reduction (P < 0.05) and clinical attachment level gain (P < 0.001). The length of the epithelium was statistically significantly shorter in the CAF/CTG/EMD group than in the CAF/CTG group (1.00 ± 0.75 mm vs. 2.38 ± 1.48 mm, respectively, P < 0.01). Cementum formation was statistically significantly greater in the CAF/CTG/EMD group than following treatment with the CAF/CTG group (3.20 ± 0.89 mm vs. 1.88 ± 1.58 mm, respectively, P < 0.01). The CAF/CTG/EMD group showed statistically significantly greater complete periodontal regeneration (i.e., new cementum, new periodontal ligament, and new bone) than treatment with CAF/CTG (0.54 ± 0.73 mm vs. 0.07 ± 0.27 mm, respectively, P < 0.05). CONCLUSION: Within their limits, the present findings indicate that the additional use of EMD in conjunction with CAF + CTG favors periodontal regeneration in gingival recession defects. CLINICAL RELEVANCE: The present findings support the use of EMD combined with CTG and CAF for promoting periodontal regeneration in isolated gingival recession defects.

Predicting prognosis of resected hepatocellular carcinoma by radiomics analysis with random survival forest.

RATIONALE AND OBJECTIVES: To investigate the impact of random survival forest (RSF) classifier trained by radiomics features over the prediction of the overall survival of patients with resectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The dynamic computed tomography data of 127 patients (97 men, 30 women; mean age, 68 years) newly diagnosed with resectable HCC were retrospectively analyzed. After manually setting the region of interest to include the tumor within the slice at its maximum diameter, texture analyses were performed with or without a Laplacian of Gaussian filter. Using the extracted 96 histogram based texture features, RSFs were trained using 5-fold cross-validation to predict the individual risk for each patient on disease free survival (DFS) and overall survival (OS). The associations between individual risk and DFS or OS were evaluated using Kaplan-Meier analysis. The effects of the predicted individual risk and clinical variables upon OS were analyzed using a multivariate Cox proportional hazards model. RESULTS: Among the 96 histogram based texture features, RSF extracted 8 of high importance for DFS and 15 for OS. The RSF trained by these features distinguished two patient groups with high and low predicted individual risk (P=1.1×10-4 for DFS, 4.8×10-7 for OS). Based on the multivariate Cox proportional hazards model, high predicted individual risk (hazard ratio=1.06 per 1% increase, P=8.4×10-8) and vascular invasion (hazard ratio=1.74, P=0.039) were the only unfavorable prognostic factors. CONCLUSIONS: The combination of radiomics analysis and RSF might be useful in predicting the prognosis of patients with resectable HCC.