Treatment Effectiveness and Recurrence of Extracranial Arteriovenous Malformations Following Surgical Operations: A 15-Year Retrospective Cohort Study.

BACKGROUND: At present, there is no golden standard for treatment of extracranial arteriovenous malformations (AVMs) and recurrence remains a major challenge with limited available evidence on the associated factors. This study aimed to evaluate the effectiveness of surgical treatment options, in terms of size reduction, symptoms, and early recurrence in patients treated surgically for AVMs. METHODS: A retrospective cohort study was conducted to evaluate patients with AVMs following surgical treatment in 2 centers from 2005 to 2020. Posttreatment lesion size and symptoms, as well as recurrence, were assessed. Multiple regression analysis was performed to identify factors associated with recurrence. RESULTS: Forty-four surgical treatment cases in 31 patients were assessed with a mean follow-up duration period of 67.9 ± 39.5 months. Treatment included total resection in 26 cases (59.1%) and partial resection 18 (40.9%), with free flap coverage used in 19 cases (43.2%). No acute exacerbation following treatment was observed in our cohort. Total resection significantly reduced posttreatment lesion size (P < 0.001), symptoms (P < 0.001), and recurrence (20.0%, P = 0.03). The recurrence rate was significantly higher after partial resection (73.7%, P = 0.03). Total resection was identified as an associated factor for significantly reduced AVM recurrence (odds ratio: 0.12; 95% confidence interval: 0.03, 0.52). However, the use of free flaps did not significantly reduce recurrence, post treatment size or improve AVM symptoms. CONCLUSIONS: Total resection is the optimal treatment for AVMs. Free flaps are useful in covering large defects but the regulative effect of free flap remains controversial.

Pre-first-line chemotherapy risk stratification for overall survival in advanced urothelial carcinoma in sequential therapy era.

PURPOSE: To explore pre-treatment risk factors for overall survival (OS) in advanced urothelial carcinoma (UC) patients treated with first-line (1L) chemotherapy in sequential therapy (ST) era. Additionally, to evaluate the proportion of patients who were not able to undergo subsequent immune checkpoint inhibitor (ICI) therapy according to the subgroups stratified by the risk factors. METHODS: A multicenter retrospective study was conducted. Metastatic or locally advanced UC patients treated between 2017 and 2022 were included. The Kaplan-Meier method with the log-rank test and multivariate Cox regression models were used to address OS. RESULTS: Three hundred and fourteen patients treated with 1L chemotherapy were included in the study and 57 (18.2%) patients were not able to proceed to subsequent ICI therapy. Pre-chemotherapy risk factors for OS in 314 patients were ECOG-PS 1 or more, having no primary site resection, C-reactive protein (CRP) level of 3 mg/dL or more, and non-cisplatin-based regimen. Patients having 3 or 4 risk factors had higher risk for not being able to receive ST (Mann-Whitney U test, P < 0.001). As risk factors for OS in 230 patients who were able to receive ST, having no primary site resection, a neutrophil to lymphocyte ratio of 3 or more, and the presence of liver metastasis were identified. CONCLUSION: We reported the risk factors for OS in advanced UC patients treated with 1L chemotherapy in ST era. Patients with high risk for OS may not be able to proceed to subsequent ICI therapy even in the ST era.

Utility of neutrophil-to-lymphocyte ratio as an indicator of tumor immune status in non-small cell lung cancer.

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic biomarker in non-small cell lung cancer (NSCLC); however, the underlying biological rationale remains unclear. The present study aimed to explore the potential utility of NLR as a surrogate biomarker for immune response to cancer and to elucidate the underlying mechanism. METHODS: This retrospective study included the medical records of 120 patients with NSCLC who underwent surgery at the study institution in 2012. NLR in peripheral blood was determined from blood test within 30 days before surgery. Tumor immune status was evaluated using immunohistochemical staining to identify CD3+, CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs), and the relationship of NLR, with clinicopathologic characteristics including 5-year overall survival (OS), and the tumor immune status was investigated. The median values of NLR and TIL count were used as cutoff points. RESULTS: The 5-year OS was significantly better in patients with low NLR (<2.2) than in those with high NLR (≥2.2) (70.1% vs. 56.8%, P = 0.042) and in patients with high CD3+ TIL count (≥242) than in those with low CD3+ TIL count (<242) (70% vs. 56.8%, P = 0.019). Additionally, the CD3+ TIL count was negatively correlated with preoperative NLR (P = 0.005). CONCLUSION: NLR might potentially reflect the immune status of tumor microenvironment, explaining its impact on prognosis of patients with NSCLC.

Effective division of the intersegmental plane using a robotic stapler in robotic pulmonary segmentectomy.

PURPOSES: Robot-assisted thoracoscopic (RATS) segmentectomy is becoming increasingly common because of the expanded indications for segmentectomy and the widespread adoption of robotic surgery. The precise division of the intersegmental plane is necessary to ensure oncologic margins from the tumor and to preserve the lung function. In this study, we present a strategy for accurately dividing the intersegmental plane using a robotic stapler and review the surgical outcomes. METHODS: RATS portal segmentectomy was performed using the Da Vinci Xi system and the intersegmental plane was dissected using a robotic stapler. We evaluated the perioperative outcomes in 92 patients who underwent RATS portal segmentectomy between May 2020 and January 2023. These results were compared with those of 82 patients who underwent complete video-assisted thoracoscopic surgery (CVATS) during the same period. RESULTS: The operative and console times were 162 and 97 min, respectively. No intraoperative complications occurred, and postoperative complications were observed in four cases (4.3%). The operative time, blood loss, postoperative complications, and maximum incision size were significantly lower in the RATS group than in the CVATS group. However, RATS requires a significantly higher number of staplers than CVATS. CONCLUSIONS: The division of the intersegmental plane using a robotic stapler in RATS portal segmentectomy was, therefore, found to be safe and effective.

Postoperative Complications in Living Donors for Lung Transplantation.

Background: Living donor lobar lung transplantation is a life-saving procedure for critically ill patients. This requires 2 healthy donors exposed to risks and without medical benefit. Therefore, the donor's safety and minimal postoperative complications are crucial. This study aimed to investigate the short-term outcomes and identify the risk factors affecting these outcomes. Methods: The data of 175 living donors enrolled between 1998 and 2022 were analyzed. Donors were divided into era 1 (1998-2009) and era 2 (2010-2022). Results: The overall incidence of postoperative complications was 39%, of which 7% were major complications. Donors who underwent surgery on the right side had a higher incidence of delayed pulmonary fistulae (P = 0.01) and elevated liver enzyme levels (P = 0.028). Living donor surgery on the right side (P = 0.01), era 2 (P = 0.01), and the need for plasty (P = 0.04) were predictors of postoperative complications. Conclusions: Updated data on complications and their correlation with postoperative quality of life from this study could aid in the selection of potential donors and facilitate informed consent.

Modified open-thoracotomy-view approach in robotic-assisted thoracoscopic lung resection.

Robotic-assisted thoracoscopic surgery (RATS) is widely performed in thoracic surgery. The open-thoracotomy-view approach (OTVA) is one approach in RATS lung resection. OTVA is a good surgical approach that provides the same field of view as that with open thoracotomy and allows active participation of the assistant. However, the OTVA has certain limitations compared with other approaches, such as difficulty placing a robotic arm in the lower intercostal space, the assistant port is positioned further from the hilum, and CO2 insufflation is required. We have made some modifications to the OTVA by placing one of the robotic arms in the lower intercostal space, which enhances the operability for the surgeon without the need for CO2 insufflation. Additionally, by positioning the assistant port between the robotic arms, the assistant is closer to the hilum, and there is no requirement for a closed port owing to the absence of CO2 insufflation, resulting in improved performance by the assistant. Therefore, for the assistant to perform well, it is necessary to make modifications to the OTVA to widen the typically narrow space between the robotic arms. We performed lung resection using our modified 4-port 3-arm OTVA method in 20 patients from June 2022 to July 2023. Although we have not used our modified OTVA in a large number of cases, we have not observed critical issues to date. In this report, we introduce our modified OTVA as an option in RATS for lung resection.

Intrinsic and extrinsic factors causing hyperplasia of the prostate.

Prostatic hyperplasia is very common in elderly men and is a typical disease that reduces quality of life. Histologically, hyperplasia of the prostate gland causes obstruction at the bladder outlet, resulting in symptoms such as a weak urine stream. Various factors have been considered to cause histological enlargement of the prostate, but the underlying cause is still unknown. The factors that cause prostate hyperplasia can be broadly classified into intrinsic and extrinsic ones. Extrinsic factors include things that we directly come into contact with such as bacteria and food. On the other hand, intrinsic factors are those that cause changes in functions originally provided in the body due to some cause, including extrinsic factors, such as chronic inflammation and an imbalance of sex hormones. A large number of reports have been made to date regarding the etiology of prostatic hyperplasia, although they have not yet clarified the fundamental cause(s). The various factors currently known should be outlined for future research. Should it be possible to prevent this highly prevalent prostatic hyperplasia which is mainly cause of dcreasing quality of life, there is no doubt that it would be a huge contribution to humanity.

[A Case of Neuropathic Lower Urinary Tract Dysfunction Due to Spina Bifida Occulta Discovered at the Age of 19 Years and Successfully Treated with Multidisciplinary Therapy].

A 19-year-old man had been aware of dysuria and urinary incontinence since childhood but did not seek medical attention. He was diagnosed with acute pyelonephritis due to lower urinary tract dysfunction associated with spina bifida occulta and tethered cord syndrome (TCS) due to spinal cord lipoma. After placement of a urethral catheter and antibacterial chemotherapy, the patient was cured of acute pyelonephritis. He was treated with solifenacin and started clean self-intermittent catheterization (CIC). Shortly after the start of CIC, the acute pyelonephritis flared up again, and he was managed with a reinserted urethral catheter until an untethering operation. Preoperative video urodynamics showed that the bladder morphology was Ogawa classification grade III with vesicoureteral reflux (VUR) at 92 ml infusion. With the combination of an untethering operation and additional mirabegron, the functional bladder capacity was increased to 353 ml and VUR improved, allowing for safe urinary management of the CIC. TCS can be diagnosed at any age and requires appropriate urinary management and therapeutic intervention as early as possible after diagnosis.

Impact of the neutrophil-to-lymphocyte ratio on patients with locally advanced non-small cell lung cancer who suffer radiation pneumonitis during the course of induction chemoradiotherapy followed by surgery.

PURPOSE: Radiation pneumonitis (RP) is an obstacle for patients after surgery following induction chemoradiotherapy for locally advanced non-small cell lung cancer (LA-NSCLC). We performed a comparative analysis of the association between clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and prognosis, in LA-NSCLC patients with or without RP during induction chemoradiotherapy followed by surgery. METHODS: The subjects of this analysis were 168 patients undergoing trimodality therapy for LA-NSCLC between January, 1999 and May, 2019. Patients were divided into two groups: the RP group (n = 41) and the non-RP group (n = 127). We compared the clinicopathological factors including the NLR between the groups and analyzed the association between the NLR and prognosis. RESULTS: The RP group had more patients with tumors located in the lower lobe, more bilobar resections, shorter operative times, no implementation of postoperative adjuvant chemotherapy, and a higher postoperative NLR than the non-RP group. There were no significant differences in serious postoperative complications and the prognosis. Patients with a low postoperative NLR had a significantly better prognosis in the non-RP group, and a trend toward a better prognosis even in the RP group. CONCLUSION: Postoperative NLR may be a useful prognostic factor, even for patients who suffer RP after trimodality therapy for LA-NSCLC.

Validation study on the 2 mm diameter cutoff in lymph node-positive cases following radical prostatectomy in accordance with the AJCC/UICC TNM 8th edition: Real-world data analysis from a Japanese cohort.

OBJECTIVES: The American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) 8th edition has proposed micrometastasis as a lymph node metastasis (LN+) of diameter ≤2 mm in prostate cancer. However, supporting evidence has not described. We evaluated LN+ patients' survival after radical prostatectomy (RP) based on the LN maximum tumor diameter (MTD). METHODS: Data from 561 LN+ patients after RP and pelvic LN dissection (PLND) treated between 2006 and 2019 at 33 institutions were retrospectively investigated. Patients were stratified by a LN+ MTD cutoff of 2 mm. Outcomes included castration resistance-free survival (CRFS), metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS). RESULTS: In total, 282 patients were divided into two groups (LN+ MTD >2 mm [n = 206] and ≤2 mm [n = 76]). Patients of LN+ status >2 mm exhibited significantly decreased CRFS and MFS, and poorer CSS and OS. No patients developed CRPC in the LN+ status ≤2 mm group when the PLND number was ≥14. Multivariate analysis showed the number of LN removed, RP Gleason pattern 5, and MTD in LN+ significantly predicted CRFS. CONCLUSIONS: Patients of LN+ status ≤2 mm showed better prognoses after RP. In all the patients in the ≤2-mm group, the progression to CRPC could be prevented with appropriate interventions, particularly when PLND is performed accurately. Our findings support the utility of the pN substaging proposed by the AJCC/UICC 8th edition; this will facilitate precision medicine for patients with advanced prostate cancer.

Comparison of Oncological Outcomes of Pembrolizumab as Second-line Therapy and Maintenance Avelumab Therapy in Advanced Urothelial Carcinoma After Platinum-based Chemotherapy.

BACKGROUND/AIM: Sequential therapy using chemotherapy and subsequent immune checkpoint inhibitor (ICI) treatment prolongs the survival of patients with advanced urothelial carcinoma (UC). However, no comparison data for oncological outcome between pembrolizumab and avelumab has been reported. Thus, we compared oncological outcomes between pembrolizumab as second-line therapy and maintenance avelumab therapy in patients with advanced UC. PATIENTS AND METHODS: We retrospectively evaluated patients with advanced UC treated with pembrolizumab or avelumab between January 2018 and February 2023. We compared oncological outcomes after adjusting for patient characteristics. Immune-related adverse events (AEs) in each group were evaluated using the Common Terminology Criteria for Adverse Events. RESULTS: There were 186 and 44 patients in the pembrolizumab- and avelumab-treated cohorts, respectively. After propensity score matching, 43 patients from each group were selected and analyzed. Median progression-free survival from the initiation of pembrolizumab and avelumab treatments was 126 and 139 days, respectively (log-rank test, p=0.625). Median overall survival in the pembrolizumab and avelumab cohorts were 658 days and not reached, respectively (log-rank test, p=0.249). Thirty-eight (20.4%) and 14 (31.8%) all-grade immune-related AEs were observed in 186 pembrolizumab- and 44 avelumab-treated patients, respectively (chi-squared test, p=0.112). Regarding endocrine-related AEs, 12 (6.5%) and none (0%) were observed in pembrolizumab- and avelumab-treated patients, respectively (Fisher's exact probability test, p=0.129). CONCLUSION: Pembrolizumab and maintenance avelumab therapy provide equivalent oncological outcomes in patients with advanced UC. Although no significant difference was observed, there might be a potential risk of higher endocrine-related AEs due to pembrolizumab compared to avelumab maintenance therapy.

Enzalutamide versus Abiraterone Plus Prednisolone for Nonmetastatic Castration-Resistant Prostate Cancer: A Sub-Analysis from the ENABLE Study for PCa.

Enzalutamide (ENZ) and abiraterone plus prednisolone (ABI) can improve the survival of patients with castration-resistant prostate cancer (CRPC). However, the agent that is more effective against nonmetastatic CRPC remains unclear. To evaluate the agent that can be used as the first-line treatment for CRPC, an investigator-initiated, multicenter, randomized controlled trial (ENABLE Study for PCa) including both metastatic and nonmetastatic CRPC was conducted in Japan. The prostate-specific antigen (PSA) response rate, overall survival, some essential survival endpoints, and safety of patients with nonmetastatic CRPC were also analyzed. In this subanalysis, 15 and 26 patients in the ENZ and ABI arms, respectively, presented with nonmetastatic CRPC. There was no significant difference in terms of the PSA response rate between the ENZ and ABI arms (80% and 64%, respectively; p = 0.3048). The overall survival did not significantly differ between the two arms (HR: 0.68; 95% CI: 0.22-2.14, p = 0.5260). No significant differences were observed in terms of radiographic progression-free survival and cancer-specific survival between the ENZ and ABI arms (HR: 0.81; 95% CI: 0.35-1.84; p = 0.6056 and HR: 0.72; 95% CI: 0.19-2.73; p = 0.6443, respectively). Only four and six patients in the ENZ and ABI arms, respectively, had ≥grade 3 adverse events. ABI and ENZ had similar efficacy and safety profiles in patients with nonmetastatic CRPC.

Prognostication in Lymph Node-Positive Prostate Cancer with No PSA Persistence After Radical Prostatectomy.

BACKGROUND: This study aimed to create a prognostic model to predict disease recurrence among patients with lymph node involvement but no prostate-specific antigen (PSA) persistence and to explore its clinical utility. METHODS: The study analyzed patients with lymph node involvement after pelvic lymph node dissection with radical prostatectomy in whom no PSA persistence was observed between 2006 and 2019 at 33 institutions. Prognostic factors for recurrence-free survival (RFS) were analyzed by the Cox proportional hazards model. RESULTS: Among 231 patients, 127 experienced disease recurrence. The factors prognostic for RFS were PSA level at diagnosis (≥ 20 vs. < 20 ng/mL: hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.09-2.52; P = 0.017), International Society of Urological Pathology grade group at radical prostatectomy (RP) specimen (group ≥ 4 vs. ≤ 3: HR, 1.63; 95% CI 1.12-2.37; P = 0.010), pathologic T-stage (pT3b/4 vs. pT2/3a: HR, 1.70; 95% CI 1.20-2.42; P = 0.0031), and surgical margin status (positive vs. negative: HR, 1.60; 95% CI 1.13-2.28; P = 0.0086). The prognostic model using four parameters were associated with RFS and metastasis-free survival. CONCLUSION: The prognostic model in combination with postoperative PSA value and number of lymph nodes is clinically useful for discussing treatment choice with patients.

Real-world sequential treatment patterns and clinical outcomes among patients with advanced urothelial carcinoma in Japan.

OBJECTIVES: Immune checkpoint inhibitors and enfortumab vedotin have opened new avenues for sequential treatment strategies for locally advanced/metastatic urothelial carcinoma (la/mUC). In the pre-enfortumab vedotin era, many patients could not receive third-line treatment owing to rapid disease progression and poor general status. This study aimed to analyze real-world sequential treatment practices for la/mUC in Japan, with a focus on patients who do not receive third-line treatment. METHODS: We analyzed data for 1023 la/mUC patients diagnosed between January 2020 and December 2021 at 54 institutions from a Japanese nationwide cohort. RESULTS: At the median follow-up of 28.5 months, the median overall survival from first-line initiation for 905 patients who received systemic anticancer treatment was 19.1 months. Among them, 81% and 32% received second- and third-line treatment. Notably, 52% had their treatment terminated before the opportunity for third-line treatment. Multivariate logistic regression analysis revealed that low performance status (≥1), elevated neutrophil-to-lymphocyte ratio (≥3), and low body mass index (<21 kg/m2) at the start of first-line treatment were independent risk factors for not proceeding to third-line treatment (p = 0.0024, 0.0069, and 0.0058, respectively). In this cohort, 33% had one of these factors, 36% had two, and 15% had all three. CONCLUSIONS: This study highlights the high frequency of factors associated with poor tolerance to anticancer treatment in la/mUC patients. The findings suggest the need to establish optimal sequential treatment strategies, maximizing efficacy within time and tolerance constraints, while concurrently providing strong supportive care, considering immunological and nutritional aspects.

Gap analysis between trainees' subjective competencies and the competencies expected by instructors in urology: A need assessment survey in Japan.

OBJECTIVE: According to the rapid progress in surgical techniques, a growing number of procedures should be learned during postgraduate training periods. This study aimed to clarify the current situation regarding urological surgical training and identify the perception gap between trainees' competency and the competency expected by instructors in Japan. METHODS: Regarding the 40 urological surgical procedures selected via the Delphi method, we collected data on previous caseloads, current subjective autonomy, and confidence for future skill acquisition from trainees (<15 post-graduate years [PGY]), and the competencies when trainees became attending doctors expected by instructors (>15 PGY), according to a 5-point Likert scale. In total, 174 urologists in Hokkaido Prefecture, Japan were enrolled in this study. RESULTS: The response rate was 96% (165/174). In a large proportion of the procedures, caseloads grew with accumulation of years of clinical practice. However, trainees had limited caseloads of robotic and reconstructive surgeries even after 15 PGY. Trainees showed low subjective competencies at present and low confidence for future skill acquisition in several procedures, such as open cystectomy, ureteroureterostomy, and ureterocystostomy, while instructors expected trainees to be able to perform these procedures independently when they became attending doctors. CONCLUSION: Trainees showed low subjective competencies and low confidence for future skill acquisition in several open and reconstructive procedures, while instructors considered that these procedures should be independently performable by attending doctors. We believe that knowledge of these perception gaps is helpful to develop a practical training program.

[Two Cases of Retroperitoneal Synovial Sarcoma].

We experienced two cases of renal primary synovial sarcoma. Case 1: A 29-year-old man underwent laparoscopic radical nephrectomy and was originally diagnosed with renal cell carcinoma. Case 2: A 25-year-old man was treated by open radical nephrectomy since radiographical findings indicated tumor invasion to the ureter causing hydronephrosis. Both cases were pathologically diagnosed as renal synovial sarcomas, and were followed using computed tomography. Recurrence was observed within a year in both cases.

Development and preliminary evaluation of a novel procedure for creation of an ileal conduit stoma aimed at preventing parastomal hernia.

OBJECTIVES: Our previous study suggested that the operative procedure is critical for the development of parastomal hernia. We developed a novel procedure for the creation of an ileal conduit stoma to prevent parastomal hernia. Herein we evaluate the efficacy and safety of the procedure. METHODS: A total of 113 Japanese patients underwent radical cystectomy and ileal conduit diversion for bladder cancer from January 2017 through December 2021 at our institution. After excluding those with incomplete data, 103 patients consisting of 46 (44.7%) with the conventional procedure and 57 (55.3%) with the novel procedure were consecutively enrolled. The main points of the novel procedure are as follows: (1) the passage of the ileal conduit is ≤2.4 cm in diameter in principle; (2) the posterior rectus sheath and peritoneum are vertically incised 2 cm laterally from the middle of the stoma site to make an oblique passage for the ileal conduit; and (3) the anterior rectus sheath and posterior rectus sheath with peritoneum are fixed to the ileal conduit separately. RESULTS: Radiography-based parastomal hernia was observed in 11 patients (10.7%) with a median follow-up of 22.0 months. The incidences of parastomal hernia were 3.5% and 19.6% in the novel and the conventional procedure groups, respectively (p = 0.011). The former had a significantly lower cumulative incidence of parastomal hernia (p = 0.008, log-rank test). No specific complications associated with the procedure were observed. CONCLUSIONS: The results of the preliminary cohort study suggest that the novel procedure is safe and effective for the prevention of parastomal hernia.

Restrictive allograft dysfunction rather than bronchiolitis obliterans syndrome had a major impact on the overall survival after living-donor lobar lung transplantation.

PURPOSE: Chronic lung allograft dysfunction (CLAD) is a known long-term fatal disorder after lung transplantation. In this study, we evaluated the CLAD classification of the International Society for Heart and Lung Transplantation (ISHLT) for living-donor lobar lung transplantation (LDLLT). METHODS: We conducted a single-center retrospective review of data from 73 patients who underwent bilateral LDLLT between 1998 and 2019. Factors related to opacity on computed tomography (CT) and restriction on pulmonary function tests (PFTs) were also analyzed. RESULTS: Overall, 26 (36%) patients were diagnosed with CLAD, including restrictive allograft syndrome (RAS), n = 10 (38.5%); bronchiolitis obliterans syndrome (BOS), n = 8 (30.8%); mixed, n = 1 (3.8%); undefined, n = 2 (7.7%); and unclassified, n = 5 (19.2%). The 5-year survival rate after the CLAD onset was 60.7%. The survival of patients with BOS was significantly better than that of patients with RAS (p = 0.012). In particular, patients with restriction on PFT had a significantly worse survival than those without restriction (p = 0.001). CONCLUSIONS: CLAD after bilateral LDLLT does not have a major impact on the recipient survival, especially in patients with BOS. Restriction on PFT may predict a particularly poor prognosis in patients with CLAD after bilateral LDLLT.

Prediction of Tumor PD-L1 Expression in Resectable Non-Small Cell Lung Cancer by Machine Learning Models Based on Clinical and Radiological Features: Performance Comparison With Preoperative Biopsy.

OBJECTIVE: We investigated if PD-L1 expression can be predicted by machine learning using clinical and imaging features. METHODS: We included 117 patients with c-stage I/II non-small cell lung cancer who underwent radical resection. A total of 3951 radiomic features were extracted by defining the tumor (within tumor contour), rim (contour ±3 mm) and exterior (contour +10 mm) on preoperative contrast computed tomography. After feature selection by Boruta algorithm, prediction models of tumor PD-L1 expression (22C3: ≥1%, <1%) of resected specimens were constructed using Random Forest: radiomics, clinical, and combined models. Their performance was evaluated by 5-fold cross-validation, and AUCs were compared using Delong test. Next, study groups were categorized as patients without biopsy (training set), and those with biopsy (test set). Predictive ability of biopsy was compared to each prediction model. RESULTS: Of 117 patients (66 ± 10 years old, 48% male), 33 (28.2%) had PD-L1≥1%. Mean AUC of PD-L1≥1% for the validation set in radiomics, clinical, and combined models were 0.80, 0.80, and 0.83 (P = .32 vs. clinical model), respectively. The diagnosis of malignancy was made in 22 of 38 (58%) patients with attempted biopsies, and PD-L1 was measurable in 19 of 38 (50%) patients. Diagnostic accuracies of PD-L1≥1% from 19 determinable biopsies and 38 all attempted biopsies were 0.68 and 0.34, respectively. These were out performed by machine learning: 0.71, 0.71, and 0.74 for radiomics, clinical, and combined models, respectively. CONCLUSIONS: Our machine learning could be an adjunctive tool in estimating PD-L1 expression prior to neoadjuvant treatment, particularly when PD-L1 is indeterminable with biopsy.