Detection of the Highest-Grade Lesion in Multifocal Discordant Prostate Cancer by Multiparametric Magnetic Resonance Imaging.

PURPOSE: Prostate cancer generally occurs multifocally. The lesions of the largest size and highest-grade are often concordant, and defined as an index tumor. However, these factors sometimes do not coincide within one lesion. In such discordant cases, not the largest size lesion but the highest-grade lesion is known to determine the prognosis. We focused on the multiparametric magnetic resonance imaging (mpMRI) detectability of the highest-grade tumors in discordant cases. MATERIALS AND METHODS: We investigated the detectability of the highest-grade tumor using preoperative mpMRI in 50 discordant patients who underwent radical prostatectomy. The radiologist was informed of the tumor location on the pathological tumor map, and mpMRI interpretation for each tumor was performed. RESULTS: Prostate Imaging-Reporting and Data System (PI-RADS) scores of 1, 2, 3, 4, and 5 on preoperative mpMRI were assigned to 13, 1, 9, 16, and 11 of the largest tumors, respectively. On the other hand, scores of 1, 2, 3, 4, and 5 were assigned to 23, 0, 7, 19, and 1 of the highest-grade tumors, respectively. The difference between them was statistically significant (p=0.007). We also found that the largest anterior tumor frequently hid the ipsilateral posterior highest-grade tumor; the detection rate of the highest-grade tumor in this pattern was 42.1% (8 of 19 cases) CONCLUSION: We found that mpMRI detectability of the highest-grade tumor in discordant cases was inferior to that of the largest tumor with low malignant potential. Our results suggest that the risk of high-grade tumors which determine patient prognosis being overlooked.

Prediction of pathological up-staging after radical nephroureterectomy in patients with upper tract urothelial carcinoma.

PURPOSE: The diagnostic accuracy of computed tomography urography for upper tract urothelial carcinoma is high; however, difficulties are associated with precisely assessing the T stage. Preoperative tumor staging has an impact on treatment options for upper tract urothelial carcinoma. We herein attempted to identify preoperative factors that predict pathological tumor up-staging, which will facilitate the selection of treatment strategies. MATERIALS AND METHODS: We retrospectively identified 148 patients with upper tract urothelial carcinoma who underwent computed tomography urography preoperatively followed by radical nephroureterectomy without preoperative chemotherapy at our institution between 2000 and 2021. Preoperative factors associated with cT2 or lower to pT3 up-staging were examined using a multivariate logistic regression analysis. RESULTS: Ninety out of 148 patients were diagnosed with cT2 or lower, and 22 (24%) were up-staged to pT3. A multivariate analysis identified a positive voided urine cytology (HR 4.69, p = 0.023) and tumor length ≥ 3 cm (HR 6.33, p = 0.003) as independent predictors of pathological tumor up-staging. CONCLUSIONS: Patients diagnosed with cT2 or lower, but with preoperative positive voided urine cytology and/or tumor diameter ≥ 3 cm need to be considered for treatment as cT3.

What are the Factors That Induce Paradoxical Hypertrichosis After Laser Hair Removal?

BACKGROUND: Laser hair removal (LHR) is one of the most requested cosmetic procedures worldwide. A rare side effect is the appearance of excess hair around previously treated areas, known as paradoxical hypertrichosis. OBJECTIVES: The aim of this study was to retrospectively identify the cause of this side effect. METHODS: This study included all patients who underwent LHR at our center between November 2018 and November 2020. Alexandrite laser hair removal (HR) or diode laser super hair removal (SHR) was performed in 70% and 30% of cases, respectively. Clinical features and daily habits of patients with and without postlaser hypertrichosis were compared. RESULTS: Of the 7381 patients who received LHR, 25 patients (0.34%) demonstrated an increase in hair growth compared to baseline. Of these 25 patients, 24 had been treated with alexandrite laser HR (P < .01). The most common site was the upper arm, followed by the periareolar area. Daily sun protection was associated with a significantly lower incidence of hypertrichosis (P < .05), as was confirmed and shown to be independent of Fitzpatrick skin type by binary logistic regression analysis (odds ratio = 0.41, P < .05). CONCLUSIONS: In our clinic, we observed paradoxical hypertrichosis after laser hair removal in a small minority of cases, as described by others. We did not observe differences in incidence related to skin type, but daily sun protection and LHR with diode laser SHR were associated with significant reductions in incidence rates. In addition to previously reported common sites, we also identified the periareolar area as a high-risk region.

Universally Exhaustive Generation of Molecular Structures and Prediction of Their Electronic States Using Machine Learning for N-type Organic Transistor Materials.

We have proposed a new method for the exploration of organic functional molecules, using an exhaustive molecular generator combined without combinatorial explosion and electronic state predicted by machine learning and adapted for developing n-type organic semiconductor molecules for field-effect transistors. Our method first enumerates skeletal structures as much as possible and next generates fused ring structures using substitution operations for atomic nodes and bond edges. We have succeeded in generating more than 4.8 million molecules. We calculated the electron affinity (EA) of about 51 thousand molecules with DFT calculation and trained the graph neural networks to estimate EA values of generated molecules. Finally, we obtained the 727 thousand molecules as candidates that satisfy EA values over 3 eV. The number of these possible candidate molecules is far beyond what we have been able to propose based on our knowledge and experience in synthetic chemistry, indicating a wide diversity of organic molecules.

Synthetic magnetic resonance imaging for primary prostate cancer evaluation: Diagnostic potential of a non-contrast-enhanced bi-parametric approach enhanced with relaxometry measurements.

PURPOSE: Bi-parametric magnetic resonance imaging (bpMRI) with diffusion-weighted images has wide utility in diagnosing clinically significant prostate cancer (csPCa). However, bpMRI yields more false-negatives for PI-RADS category 3 lesions than multiparametric (mp)MRI with dynamic-contrast-enhanced (DCE)-MRI. We investigated the utility of synthetic MRI with relaxometry maps for bpMRI-based diagnosis of csPCa. METHODS: One hundred and five treatment-naïve patients who underwent mpMRI and synthetic MRI before prostate biopsy for suspected PCa between August 2019 and December 2020 were prospectively included. Three experts and three basic prostate radiologists evaluated the diagnostic performance of conventional bpMRI and synthetic bpMRI for csPCa. PI-RADS version 2.1 category 3 lesions were identified by consensus, and relaxometry measurements (T1-value, T2-value, and proton density [PD]) were performed. The diagnostic performance of relaxometry measurements for PI-RADS category 3 lesions in peripheral zone was compared with that of DCE-MRI. Histopathological evaluation results were used as the reference standard. Statistical analysis was performed using the areas under the receiver operating characteristic curve (AUC) and McNemar test. RESULTS: In 102 patients without significant MRI artefacts, the diagnostic performance of conventional bpMRI was not significantly different from that of synthetic bpMRI for all readers (p = 0.11-0.79). The AUCs of the combination of T1-value, T2-value, and PD (T1 + T2 + PD) for csPCa in peripheral zone for PI-RADS category 3 lesions were 0.85 for expert and 0.86 for basic radiologists, with no significant difference between T1 + T2 + PD and DCE-MRI for both expert and basic radiologists (p = 0.29-0.45). CONCLUSION: Synthetic MRI with relaxometry maps shows promise for contrast media-free evaluation of csPCa.

Does neoadjuvant chemotherapy have therapeutic benefit for node-positive upper tract urothelial carcinoma? Results of a multi-center cohort study.

OBJECTIVE: The indications of neoadjuvant chemotherapy (NAC) for lymph node-positive upper tract urothelial carcinoma (UTUC) have not been investigated regarding improved survival outcomes. Our specific aim was to compare the clinical outcomes of clinically node-positive UTUC patients who were treated by NAC followed by radical nephroureterectomy (RNU) or upfront RNU followed by adjuvant chemotherapy (AC). MATERIALS AND METHODS: Among 966 UTUC patients, we identified 89 with clinical nodal involvement who received either NAC before RNU nor AC after upfront RNU. Cox proportional hazard models were employed to evaluate the impact of chemotherapy modality on the oncological outcomes. RESULTS: Of the patient cohort, 36 (40.4%) received NAC followed by RNU, whereas 53 (59.6%) underwent RNU followed by AC. Multivariate analysis revealed that tumor size ≥3 cm, clinical T4, and gemcitabine and cisplatin regimen were independent risk factors for disease recurrence, whereas NAC followed by RNU was an independent factor for favorable RFS. Furthermore, regarding cancer-specific survival (CSS), NAC followed by RNU remained an independent factor for favorable CSS. According to Kaplan-Meier analysis, the 1-year and 2-year RFS were 67.9% and 47.0%, respectively, in the NAC+RNU group, which were significantly higher than those in the RNU+AC group (43.9% and 24.6%, respectively, P = 0.006). Moreover, the 1-year and 2-year CSS were 80.5% and 64.2%, respectively, in the NAC+RNU group, which were higher than those in the RNU+AC group (68.6% and 48.2%, respectively, P = 0.016). CONCLUSION: For node-positive UTUC patients, NAC followed by RNU was more clinically beneficial than RNU followed by AC.

Diagnostic performance of the vesical imaging-reporting and data system for detecting muscle-invasive bladder cancer in real clinical settings: Comparison with diagnostic cystoscopy.

PURPOSE: We herein compared the diagnostic performance of Vesical Imaging-Reporting and Data System (VI-RADS) scoring with diagnostic cystoscopy and evaluated diagnostic accuracies based on tumor locations. MATERIALS AND METHODS: Among 112 bladder cancer patients who underwent multiparametric magnetic resonance imaging and diagnostic cystoscopy preoperatively to detect bladder cancer, 61 were analyzed. VI-RADS was categorized into 5 stages by 2 radiologists (R1 and R2). Cut-off values ≥3 indicated muscle-invasive bladder cancer (MIBC). Muscle invasion (MI) was visually evaluated using diagnostic cystoscopy by 2 urologists (U1 and U2). The sensitivity and specificity of VI-RADS scores and diagnostic cystoscopy for diagnosing MI were compared. RESULTS: 16 patients (26.2%) were pathologically diagnosed with MIBC. Regarding MI diagnostic accuracy, the sensitivity/specificity of VI-RADS scores were 93.8/88.9% by R1 and 87.5/86.7% by R2, while those of diagnostic cystoscopy were 56.3/68.9% by U1 and 68.8/84.4% by U2. Therefore, the diagnostic accuracy of VI-RADS was significantly higher than that of cystoscopy, particularly for tumors located on the bladder neck, trigone, dome, and posterior and anterior walls. Over- and under-diagnosis rates were higher with VI-RADS than with diagnostic cystoscopy (25.9% vs. 14.8%) for tumors located on the lateral wall or ureteral orifice. CONCLUSION: VI-RADS had superior diagnostic performance for detecting MI, especially in tumors located at the bladder neck/trigone/dome/posterior and anterior wall. However, VI-RADS was inferior to cystoscopy in terms of MI detection for tumors located on the lateral wall or ureteral orifice. Therefore, a combination of diagnostic tools is recommended for the accurate staging of these tumors.

Deep Learning Algorithm for Fully Automated Detection of Small (≤4 cm) Renal Cell Carcinoma in Contrast-Enhanced Computed Tomography Using a Multicenter Database.

OBJECTIVES: Renal cell carcinoma (RCC) is often found incidentally in asymptomatic individuals undergoing abdominal computed tomography (CT) examinations. The purpose of our study is to develop a deep learning-based algorithm for fully automated detection of small (≤4 cm) RCCs in contrast-enhanced CT images using a multicenter database and to evaluate its performance. MATERIALS AND METHODS: For the algorithmic detection of RCC, we retrospectively selected contrast-enhanced CT images of patients with histologically confirmed single RCC with a tumor diameter of 4 cm or less between January 2005 and May 2020 from 7 centers in the Japan Medical Image Database. A total of 453 patients from 6 centers were selected as dataset A, and 132 patients from 1 center were selected as dataset B. Dataset A was used for training and internal validation. Dataset B was used only for external validation. Nephrogenic phase images of multiphase CT or single-phase postcontrast CT images were used. Our algorithm consisted of 2-step segmentation models, kidney segmentation and tumor segmentation. For internal validation with dataset A, 10-fold cross-validation was applied. For external validation, the models trained with dataset A were tested on dataset B. The detection performance of the models was evaluated using accuracy, sensitivity, specificity, and the area under the curve (AUC). RESULTS: The mean ± SD diameters of RCCs in dataset A and dataset B were 2.67 ± 0.77 cm and 2.64 ± 0.78 cm, respectively. Our algorithm yielded an accuracy, sensitivity, and specificity of 88.3%, 84.3%, and 92.3%, respectively, with dataset A and 87.5%, 84.8%, and 90.2%, respectively, with dataset B. The AUC of the algorithm with dataset A and dataset B was 0.930 and 0.933, respectively. CONCLUSIONS: The proposed deep learning-based algorithm achieved high accuracy, sensitivity, specificity, and AUC for the detection of small RCCs with both internal and external validations, suggesting that this algorithm could contribute to the early detection of small RCCs.

Diagnostic value of texture analysis of apparent diffusion coefficient maps for differentiating fat-poor angiomyolipoma from non-clear-cell renal cell carcinoma.

PURPOSE: To investigate the feasibility of texture analysis of apparent diffusion coefficient (ADC) maps for differentiating fat-poor angiomyolipomas (fpAMLs) from non-clear-cell renal cell carcinomas (non-ccRCCs). METHODS: In this bi-institutional study, we included two consecutive cohorts from different institutions with pathologically confirmed solid renal masses: 67 patients (fpAML = 46; non-ccRCC = 21) for model development and 39 (fpAML = 24; non-ccRCC = 15) for validation. Patients underwent preoperative magnetic resonance imaging (MRI), including diffusion-weighted imaging. We extracted 45 texture features using a software with volumes of interest on ADC maps. Receiver operating characteristic curve analysis was performed to compare the diagnostic performance between the random forest (RF) model (derived from extracted texture features) and conventional subjective evaluation using computed tomography and MRI by radiologists. RESULTS: RF analysis revealed that grey-level zone length matrix long-zone high grey-level emphasis was the dominant texture feature for diagnosing fpAML. The area under the curve (AUC) of the RF model to distinguish fpAMLs from non-ccRCCs was not significantly different between the validation and development cohorts (p = .19). In the validation cohort, the AUC of the RF model was similar to that of board-certified radiologists (p = .46) and significantly higher than that of radiology residents (p = .03). CONCLUSIONS: Texture analysis of ADC maps demonstrated similar diagnostic performance to that of board-certified radiologists for discriminating between fpAMLs and non-ccRCCs. Diagnostic performances in the development and validation cohorts were comparable despite using data from different imaging device manufacturers and institutions.

Clinical utility of the Vesical Imaging-Reporting and Data System for muscle-invasive bladder cancer between radiologists and urologists based on multiparametric MRI including 3D FSE T2-weighted acquisitions.

OBJECTIVES: To investigate the clinical utility of the Vesical Imaging-Reporting and Data System (VI-RADS) by comparing its diagnostic performance for muscle-invasive bladder cancer (MIBC) between radiologists and urologists based on multiparametric MRI, including three-dimensional (3D) fast spin-echo (FSE) T2-weighted acquisitions. METHODS: This study included 66 treatment-naïve patients (60 men, 6 women; mean age 74.0 years) with pathologically proven bladder cancer who underwent multiparametric MRI, including 3D FSE T2-weighted imaging, before transurethral bladder tumour resection between January 2010 and November 2018. The MRI scans were categorised according to the five-point VI-RADS score by four independent readers (two board-certified radiologists and board-certified urologists each), blinded to the histopathological findings. The VI-RADS scores were compared with the postoperative histopathological diagnosis. Interobserver agreement was assessed using weighted kappa coefficients. ROC analysis and generalised estimating equations were used to evaluate the diagnostic performance. RESULTS: Forty-nine (74.2%) and 17 (25.8%) tumours were confirmed to be non-MIBC and MIBC, respectively, based on pathological examination. The interobserver agreement was good-to-excellent between all pairs of readers (range, 0.73-0.91). The urologists' sensitivity/specificity values for DCE-MRI VI-RADS scores were significantly lower than those of radiologists. No significant differences were observed for the overall VI-RADS score. The AUC for the overall VI-RADS score was 0.94, 0.92, 0.89, and 0.87 for radiologists 1 and 2 and urologists 1 and 2, respectively. CONCLUSIONS: The VI-RADS score, based on multiparametric MRI including 3D FSE T2-weighted acquisitions, can be useful for radiologists and urologists to determine the bladder cancer muscle invasion status preoperatively. KEY POINTS: • VI-RADS (using multiparametric MRI including 3D FSE T2-weighted acquisitions) achieves good to excellent interobserver agreement and has similar diagnostic performance for detecting muscle invasion by both radiologists and urologists. • The diagnostic performance of the overall VI-RADS score is high for both radiologists and urologists, particularly due to the dominant effect of diffusion-weighted imaging on the overall VI-RADS score. • The sensitivity and specificity values of the T2WI VI-RADS scores for four readers in our study (using 3D FSE T2-weighted acquisitions) were similar (with slightly higher specificity values) to previously published results (using 2D FSE T2-weighted acquisitions).

Incidentally detected microcystic serous cystadenoma of the pancreas with splenic invasion: a case report and literature review.

Serous cystic neoplasms are relatively uncommon and rarely possess malignant potential. We report a rare case of pancreatic serous cystadenoma with splenic invasion in a female in her 60s. Dynamic contrast-enhanced CT revealed a 3 cm mass in the tail of the pancreas. The lesion showed marked enhancement in the arterial phase on dynamic CT, which extended into the spleen. No cystic components were detected in the pancreatic mass on either magnetic resonance cholangiopancreatography or T 2 weighted imaging. No metastasis or lymph node swelling was detected. Based on the hypervascularity of the tumour, the pre-operative diagnosis was pancreatic neuroendocrine tumour with splenic invasion. The patient underwent laparoscopic distal pancreatectomy with splenectomy. The pathological diagnosis was microcystic serous cystadenoma with locally aggressive features (infiltration into spleen, lymph nodes, and splenic vein). A few cases of pancreatic serous cystadenomas with splenic invasion have been reported; all were symptomatic, with diameters greater than approximately 9 cm. This is the first known case of incidentally detected serous cystadenoma with splenic invasion, reported with detailed imaging findings of dynamic CT and MRI.

A case of inguinal cellular angiofibroma.

INTRODUCTION: Cellular angiofibroma is a benign mesenchymal tumor that is rare and has a good prognosis. However, preoperative distinction of cellular angiofibroma from malignant tumors is difficult. CASE PRESENTATION: A 77-year-old man complained of a left inguinal mass, which was a solid, painless, mobile tumor measuring approximately 40 mm and contacted with the left spermatic cord. Based on his age, the location and imaging findings, a preoperative diagnosis of myxoid liposarcoma was made. The patient underwent left high inguinal orchiectomy with complete resection of the tumor. Histologically and immunohistochemically, the tumor had no feature of malignancy. A postoperative diagnosis of cellular angiofibroma was made. The patient remains free of disease recurrence 12 months after surgery. CONCLUSION: Cellular angiofibroma is a benign but rare tumor, which is sometimes difficult to distinguish from malignant neoplasms. Further studies are needed to accurately preoperatively diagnose this tumor.

Dual graph convolutional neural network for predicting chemical networks.

BACKGROUND: Predicting of chemical compounds is one of the fundamental tasks in bioinformatics and chemoinformatics, because it contributes to various applications in metabolic engineering and drug discovery. The recent rapid growth of the amount of available data has enabled applications of computational approaches such as statistical modeling and machine learning method. Both a set of chemical interactions and chemical compound structures are represented as graphs, and various graph-based approaches including graph convolutional neural networks have been successfully applied to chemical network prediction. However, there was no efficient method that can consider the two different types of graphs in an end-to-end manner. RESULTS: We give a new formulation of the chemical network prediction problem as a link prediction problem in a graph of graphs (GoG) which can represent the hierarchical structure consisting of compound graphs and an inter-compound graph. We propose a new graph convolutional neural network architecture called dual graph convolutional network that learns compound representations from both the compound graphs and the inter-compound network in an end-to-end manner. CONCLUSIONS: Experiments using four chemical networks with different sparsity levels and degree distributions shows that our dual graph convolution approach achieves high prediction performance in relatively dense networks, while the performance becomes inferior on extremely-sparse networks.

The efficacy of the TachoSil binding suturing technique in laparoscopic partial nephrectomy to prevent the development of pseudoaneurysm.

OBJECTIVE: Our specific aim was to introduce the TachoSil binding suturing technique for renal cell carcinoma (RCC) patients when closing the parenchymal defect after tumor excision during laparoscopic partial nephrectomy (LPN), which is a novel technique for reducing the risk of developing subsequent pseudoaneurysm (PA). METHODS: We identified 113 pT1aN0M0 RCC patients who underwent LPN at our institution. Eighty-one (72%) patients underwent the suturing procedure without binding TachoSil, whereas 32 (28%) patients underwent renorraphy with the renal defect closed together with TachoSil. The vascular complications were evaluated by computed tomography or magnetic resonance imaging with enhanced contrast material at the first visit after LPN. We conducted Fischer's exact test to determine risk factors for transcatheter arterial embolization (TAE). RESULTS: The median age was 55 (36-86) years old and the median follow-up time was 65 (12-147) months. In the overall population, there were 11 (11%) patients who underwent TAE because they developed PA. All 11 patients exhibited the imaging findings of PA, and were all from the conventional suturing group. In contrast, no patients for whom the TachoSil binding method was used had any significant findings on imaging (14% vs. 0%). Based on the analysis to determine risk factors for TAE due to PA development, the TachoSil binding suturing technique was one of the significant indicators for reducing the risk of developing PA. CONCLUSIONS: Our study demonstrated that the TachoSil binding suturing technique might reduce the development of PA after LPN. Prospective randomized study and comparison to the standard 2 or 3-layer renorrhaphy is needed to prove its actual value.

Usefulness of contrast-enhanced ultrasonography for diagnosis of renal cell carcinoma in dialysis patients: Comparison with computed tomography.

AIMS: To investigate the usefulness of contrast-enhanced ultrasonography for diagnosing renal cell carcinoma (RCC) in dialysis patients. MATERIAL AND METHODS: Of 1301 dialysis patients who underwent abdominal computed tomography (CT) between January 2012 and March 2017, 19 were suspected to have solid renal lesions; of these patients, 18 gave consent for and underwent contrast-enhanced ultrasonography with perflubutane in addition to CT; 13 underwent dynamic contrast-enhanced CT, and 5, who could not be administered iodinated contrast media, underwent unenhanced CT. The final diagnoses were based on histopathological findings or the presence/absence of enlargement of the lesion during follow-up. RESULTS: Of the 19 lesions in 18 patients, 14 were diagnosed as RCC and 5 as benign cysts. CT facilitated accurate diagnosis in 10/19 lesions (52.6%) with obvious enhancement (≥20 Hounsfield units [HU]), while definitive diagnosis by CT was difficult in 9 lesions: 2 lesions showed ambiguous enhancement (10-20 HU), 1 lesion was an inflammatory cyst with obvious enhancement, and 6 lesions were assessed by unenhanced CT. Compared with CT, contrast-enhanced ultrasonography allowed more accurate diagnosis (McNemar test, P = .02) in 17/19 lesions (89.5%, 14 RCC and 3 cysts; including all lesions assessed by unenhanced CT and 2 with ambiguous enhancement on CT), with 1 false-positive (inflammatory cyst with hyper-enhancement) and 1 false-negative result due to deep location of the lesion. CONCLUSIONS: Contrast-enhanced ultrasonography was useful for the diagnosis of RCC in dialysis patients with suspected solid renal lesions especially when contrast enhancement was not obvious on CT or contrast-enhanced CT could not be performed.

Preserved Kidney Volume, Body Mass Index, and Age Are Significant Preoperative Factors for Predicting Estimated Glomerular Filtration Rate in Living Kidney Donors at 1 Year After Donation.

BACKGROUND: Securing postdonation renal function in the lifetime of donors is a consequential subject for physicians, and precise prediction of postdonation renal function would be considerably beneficial when judging the feasibility of kidney donation. The aim of this study was to investigate the optimum model for predicting eGFR at 1 year after kidney donation. METHODS: We enrolled 101 living-related kidney donors for the development cohort and 44 for the external validation cohort. All patients in each cohort underwent thin-sliced (1 mm) enhanced computed tomography (CT) scans. We excluded individuals with diabetes, glucose intolerance, or albuminuria from this study. We evaluated preoperative factors including age, sex, hypertension, body mass index (BMI), serum uric acid, baseline eGFR, and body surface area (BSA)-adjusted preserved kidney volume (PKV) by using 3-dimensional reconstruction of thin-sliced enhanced CT images. To detect independent predictors, we performed multivariable regression analysis. RESULTS: The multivariable regression analysis revealed that age, BMI, predonation eGFR, and BSA-adjusted PKV were independent predictors of eGFR at 1 year after kidney donation (correlation coefficient: -0.15, -0.476, 0.521, 0.127, respectively). A strong correlation between predicted eGFR and observed eGFR was obtained in the development cohort (r = 0.839, P < .0001). The significance of this predictive model was also confirmed with the external validation cohort (r = 0.797, P < .0001). CONCLUSIONS: Age, BMI, predonation eGFR, and BSA-adjusted PKV may be useful for precisely predicting eGFR at 1 year after living kidney donation and be helpful to determine the feasibility of kidney donation from marginal donors.

Small intestinal perforation due to a huge gastrointestinal stromal tumor in a kidney transplant recipient: a case report and literature review.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) in transplant recipients are very rare and only a handful of cases have been reported to date. Here we present the first known case of a huge GIST in a kidney transplant recipient with perforation of small intestine. CASE PRESENTATION: A 64-year-old male presented at our hospital with right colic pain; he had received an ABO incompatible kidney transplant 6 years earlier and was treated with cyclosporine, mycophenolate mofetil, and methylprednisolone. Radiological evaluation revealed a huge (11 cm in diameter) solitary tumor at the small intestine without distant metastasis. The small intestinal wall at the tumor location was perforated one week after diagnosis and the patient underwent emergency surgery. The pathological findings were compatible with GIST and the tumor consisted of spindle cells with positive staining for KIT, CD34, and DOG1 and negative or weak staining for desmin and S-100 protein. A mutation in exon 11 of the c-kit gene was also detected. Cyclosporine was withdrawn and imatinib mesylate (400 mg daily) was introduced. However, thereafter, we needed to decrease the dose at 300 mg daily due to severe hyponatremia. Reduced imatinib treatment was well tolerated and recurrence was not observed for 18 months after surgery. CONCLUSIONS: The occurrence of GISTs in transplant patients is rare, and huge GISTs should be resected immediately after diagnosis because gastrointestinal tract at the tumor site could be perforated. Imatinib treatment is feasible in transplant recipients under immunosuppression, although immunosuppressive drugs metabolized by CYP3A4 should be used at a reduced dosage or withdrawn.

Prediction of extraprostatic extension by MRI tumor contact length: difference between anterior and posterior prostate cancer.

BACKGROUND: Tumor contact length (TCL) is defined as the extent of contact between prostate cancer and the prostatic capsule, and its predictive value for microscopic extraprostatic extension (EPE) has been reported. However, the impact of the zonal origin (anterior or posterior tumor) of the tumor on the diagnosis of EPE is controversial. METHODS: We retrospectively analyzed the records of 233 consecutive patients who underwent preoperative MRI and radical prostatectomy. We designated their tumors as anterior or posterior, and evaluated the correlation between the TCL measured by MRI and microscopic EPE in the radical prostatectomy specimen. Then, we created the predicted probability curves for EPE versus TCL for anterior and posterior prostate cancer. RESULTS: There were 109 patients (47%) with an anterior tumor and 124 patients (53%) with a posterior tumor. Postoperative pathological analysis confirmed pT3 in 18 patients (17%) with an anterior tumor and in 53 patients (43%) with a posterior tumor. Multivariate analysis demonstrated that the zonal origin of the tumor was an independent predictive factor for EPE. We developed separate probability curves of EPE versus TCL for anterior and posterior prostate cancer, which revealed that anterior tumors were less likely to invade the extraprostatic tissues. Among patients whose TCL was 10-20 mm, 9/32 patients (28%) with an anterior tumor had EPE compared with 24/45 patients (53%) with a posterior tumor (p = 0.036). The decision curve of this EPE predictive model had high clinical efficacy. CONCLUSIONS: Our results indicate that anterior tumors have more favorable pathological characteristics than posterior tumors with the same TCL measured by MRI. We constructed two separate predicted probability curves for EPE after discriminating anterior and posterior tumors, which will be useful for decision making in clinical practice.

Pre-donation BMI and preserved kidney volume can predict the cohort with unfavorable renal functional compensation at 1-year after kidney donation.

BACKGROUND: The magnitude of renal function recovery after kidney donation differs in donors with a heterogeneous background. Preoperative assessment of candidates with potentially unfavorable renal functional compensation is critical when baseline kidney function is marginal. We explored the significance of preserved kidney volume (PKV) and known preoperative risk factors for the prediction of unfavorable renal function compensation. METHODS: We enrolled 101 living donors for whom a 1-mm sliced enhanced computed tomography scan was performed preoperatively and clinical data could be collected up to 1 year after donation. The donors whose estimated glomerular filtration rate (eGFR) at 1 year after donation was 70% or higher of baseline eGFR were assigned to the "favorable renal compensation" group and the others to the "unfavorable renal compensation" group. RESULTS: Age, sex, and preoperative serum uric acid level were not significant predictors for "unfavorable renal compensation." Multivariable logistic regression analysis revealed that body mass index (BMI) and body surface area (BSA)-adjusted PKV were independent preoperative risk factors for "unfavorable renal compensation" (adjusted odds ratio, 1.342 and 0.929, respectively). Hypertension and preoperative eGFR were not independent predictors when adjusted with BMI and BSA-adjusted PKV. Receiver operative characteristic analysis revealed that the predictive equation with the two independent predictors yielded a good accuracy to detect donor candidates with unfavorable renal functional compensation (area under the curve = 0.803), and the optimal cut-off values were identified as 23.4 kg/m2 for BMI and 107.3 cm3/m2 for BSA-adjusted PKV. CONCLUSIONS: BMI and BSA-adjusted PKV may be useful to select candidates with potentially unfavorable renal function compensation before kidney donation.