Cumulative incidence and risk factors for recurrence of upper tract urothelial carcinoma in patients undergoing radical cystectomy.

Objectives: This study aimed to evaluate the cumulative incidence of upper tract urothelial carcinoma (UTUC) recurrence and identify its risk factors in patients who underwent radical cystectomy (RC). Patients and methods: We performed RC on 385 patients between September 2002 and February 2020. After excluding 20 patients-13 with simultaneous nephroureterectomy, 6 with distal ureteral stump positivity and 1 with urachal cancer-365 patients were included in the analysis. To predict UTUC recurrence, we examined the cancer extension pattern in cystectomy specimens and categorized them into three types: cancer located only in the bladder (bladder-only type), cancer extending to the urethra or distal ureter (one-extension type) and cancer extending to both the urethra and distal ureter (both-extension type). We determined hazard ratios for UTUC recurrence for each covariate, including this cancer extension pattern. Results: Of the 365 patients, 60% had the bladder-only type, 30% had the one-extension type and 10% had the both-extension type. During a median follow-up period of 72 months for survivors, UTUC recurred in 25 of the 365 patients, with cumulative incidences of 3.7% at 5 years and 8.3% at 10 years. The median interval from cystectomy to recurrence was 65 months (interquartile range: 36-92 months). In the multivariate analysis, the extension pattern was a significant predictor of UTUC recurrence. The hazard ratios for UTUC recurrence were 3.12 (95% confidence interval [CI] = 1.15-8.43, p = 0.025) for the one-extension type and 5.96 (95% CI = 1.98-17.91, p = 0.001) for the both-extension type compared with the bladder-only type. Conclusions: The cancer extension pattern in cystectomy specimens is predictive of UTUC recurrence. A more extensive cancer extension in cystectomy specimens elevates the risk of subsequent UTUC recurrence. Intensive long-term monitoring is essential, particularly for patients with the both-extension type.

Clinicopathological Features of Buccal Squamous Cell Carcinoma with Focus on Patients Who Never Smoke and Never Drink.

Introduction Oral carcinoma has been reported at a substantial proportion in patients who never smoke and never drink. However, the proportion may vary by subsite and ethnicity. Objective We aimed to determine the clinicopathological features of buccal squamous cell carcinoma (SCC) in a Japanese population. Methods We retrospectively analyzed the records of patients diagnosed with buccal SCC at our institution from September 2002 to November 2015. We reviewed the gender, age, tumor status, treatment, smoking, alcohol drinking, multiple primary cancers, and prognosis of the patients. The overall and cause-specific survival rates were calculated, and the effects of clinicopathological variables were assessed by univariate analysis. Furthermore, the cause of death was evaluated. Results Among the 63 patients (men: 38; women: 25) included in the present study, 29 (46.0%) never smoked or drank. Women were almost 5 years older than men ( p = 0.014). The number of women in the group who never smoked or drank was disproportionately higher than that of those in the smoker or drinker groups ( p < 0.001). In total, 29 patients (46.0%) had 59 multiple primary cancers, including 26 oral cancers. Surgeries and radiotherapy were performed in 57 (90.5%) and 6 (9.5%) cases, respectively. The 5-year overall survival and disease-specific survival rates were 74.6 and 78.8%, respectively. Conclusion Our study confirms that buccal SCC may develop in older adult Japanese patients, especially in women who have never smoked or drank. These patients could be at risk for second primary malignancy.

Vascular resection for distal cholangiocarcinoma.

PURPOSE: Vascular resection (VR) is extended surgery to attain a negative radial margin (RM) for distal cholangiocarcinoma (DCC). The present study explored the significance of VR for DCC, focusing on VR, RM, and findings suggestive of vascular invasion on multidetector-row computed tomography (MDCT). METHODS: Patients with DCC who underwent resection between 2002 and 2019 were reviewed. RESULTS: Among 230 patients, 25 received VR. The overall survival (OS) in the VR group was significantly worse than in the non-VR group (16.7% vs. 50.7% at 5 years, P < 0.001). Patients who underwent VR with a negative RM failed to show a better OS than those who did not undergo VR with a positive RM (19.7% vs. 35.7% at 5 years, P = 0.178). Of the 30 patients who were suspected of having vascular invasion on MDCT, 11 did not receive VR because the vessels were freed from the tumor; these patients had a significantly better OS (57.9% at 5 years) than those who underwent VR. CONCLUSIONS: VR for DCC was associated with a poor prognosis, even if a negative RM was obtained. VR is not necessary for DCC when the vessels are detachable from the tumor.

Clinicopathological Features of Buccal Squamous Cell Carcinoma with Focus on Patients Who Never Smoke and Never Drink

Abstract Introduction Oral carcinoma has been reported at a substantial proportion in patients who never smoke and never drink. However, the proportion may vary by subsite and ethnicity. Objective We aimed to determine the clinicopathological features of buccal squamous cell carcinoma (SCC) in a Japanese population. Methods We retrospectively analyzed the records of patients diagnosed with buccal SCC at our institution from September 2002 to November 2015. We reviewed the gender, age, tumor status, treatment, smoking, alcohol drinking, multiple primary cancers, and prognosis of the patients. The overall and cause-specific survival rates were calculated, and the effects of clinicopathological variables were assessed by univariate analysis. Furthermore, the cause of death was evaluated. Results Among the 63 patients (men: 38; women: 25) included in the present study, 29 (46.0%) never smoked or drank. Women were almost 5 years older than men (p = 0.014). The number of women in the group who never smoked or drank was disproportionately higher than that of those in the smoker or drinker groups (p < 0.001). In total, 29 patients (46.0%) had 59 multiple primary cancers, including 26 oral cancers. Surgeries and radiotherapy were performed in 57 (90.5%) and 6 (9.5%) cases, respectively. The 5-year overall survival and disease-specific survival rates were 74.6 and 78.8%, respectively. Conclusion Our study confirms that buccal SCC may develop in older adult Japanese patients, especially in women who have never smoked or drank. These patients could be at risk for second primary malignancy.

Computed tomographic pulmonary angiography: Three cases of low-tube-voltage acquisition with a slow injection of contrast medium.

Acute pulmonary thromboembolism occurring during cancer treatment has been increasing with the number of cancer patients and chemotherapy cases. Computed tomographic pulmonary angiography (CTPA) for evaluating the pulmonary artery is generally performed using rapid injection of contrast medium. However, intravenous catheters for contrast medium injection might cause extravasation due to rapid injection. This case series describes three patients who underwent contrast-enhanced computed tomography combined with low-tube-voltage imaging and slow injection. Low-tube-voltage slow-injection CTPA can be an effective technique for obtaining high contrast enhancement while accommodating fragile veins and low injection rates.

Preoperative risk factors for early recurrence after resection of perihilar cholangiocarcinoma.

BACKGROUND: Early recurrence after curative resection of perihilar cholangiocarcinoma (PHCC) often occurs within a year of surgery. Preoperative predictors of early recurrence remain unclear. The aim of this study was to define reliable preoperative predictors of early recurrence. METHODS: Medical records and preoperative multidetector-row CT of patients with PHCC who underwent resection between 2002 and 2018 were reviewed. Clinical findings, tumour markers, and radiological appearances including a 'periductal enation sign' (PES) where there was evidence of soft tissue enhancement appearing to arise from the extrahepatic bile duct, were analysed. RESULTS: Among 261 patients who underwent resection for PHCC, 67 (25.7 per cent) developed early recurrence. Multivariable analysis identified four preoperative risk factors for early recurrence, namely carbohydrate antigen 19-9 (CA19-9) 37 U/ml or higher (OR 2.19, 95 per cent confidence interval (c.i.) 1.08 to 4.46), positive PES (OR 7.37, 95 per cent c.i. 2.46 to 22.10), mass-forming tumour (OR 4.46, 95 per cent c.i. 1.83 to 10.90), and luminal-occlusion tumour (OR 4.52, 95 per cent c.i. 2.11 to 9.68). The OR of preoperative risk factors were used to define four risk subgroups for early recurrence. The early recurrence rates in the low, moderate, high, and very-high risk groups were 0, 9.4 , 39.7, and 65.0 per cent respectively. CONCLUSION: CA19-9, PES, mass-forming tumour, and luminal-occlusion tumour identify patients at higher risk for early recurrence after resection of PHCC.

Biliary obstruction and pancreatitis after duodenal stent placement in the descending duodenum: a retrospective study.

BACKGROUND: Metallic stents placed in the descending duodenum can cause compression of the major duodenal papilla, resulting in biliary obstruction and pancreatitis. These are notable early adverse events of duodenal stent placement; however, they have been rarely examined. This study aimed to assess the incidence of and risk factors for biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum. METHODS: We retrospectively reviewed data of consecutive patients who underwent metallic stent placement in the descending duodenum for malignant gastric outlet obstruction at a tertiary referral cancer center between April 2014 and December 2019. Risk factors for biliary obstruction and/or pancreatitis were analyzed using a logistic regression model. RESULTS: Sixty-five patients were included. Biliary obstruction and/or pancreatitis occurred in 12 patients (18%): 8 with biliary obstruction, 2 with pancreatitis, and 2 with both biliary obstruction and pancreatitis. Multivariate analysis indicated that female sex (odds ratio: 9.2, 95% confidence interval: 1.4-58.6, P = 0.02), absence of biliary stents (odds ratio: 12.9, 95% confidence interval: 1.8-90.2, P = 0.01), and tumor invasion to the major duodenal papilla (odds ratio: 25.8, 95% confidence interval: 2.0-340.0, P = 0.01) were significant independent risk factors for biliary obstruction and/or pancreatitis. CONCLUSIONS: The incidence of biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum was non-negligible. Female sex, absence of biliary stents, and tumor invasion to the major duodenal papilla were the primary risk factors. Risk stratification can allow endoscopists to better identify patients at significant risk and permit detailed informed consent.

A novel method for predicting perineural invasion of distal cholangiocarcinoma on multidetector-row computed tomography.

PURPOSE: Excessive perineural invasion (PNI) is associated with a high risk of radial margin (RM) positivity and a poor prognosis for patients with distal cholangiocarcinoma (DCC). This study evaluates a new method of predicting the extent of PNI preoperatively. METHODS: The subjects of this retrospective study were 201 patients who underwent resection for DCC between 2002 and 2018. This study identified the 'periductal enation sign' (PES), defined as the surrounding soft tissue enhancement that appears as an enation from the circumference of the enhanced extrahepatic bile duct on multidetector-row computed tomography (MDCT) scans, as a predictor of PNI. We analyzed the outcomes of the patients in relation to the presence or absence of the PES on MDCT scans. RESULTS: The PES in the PNI-positive group was significantly longer than that in the PNI-negative group. As the length of the PES extended, the grade of PNI increased. A positive PES was defined as a PES length of ≥ 2.0 mm. Patients with a positive PES were more frequently positive for RM (23.7% vs. 2.1%) and locoregional recurrence (23.7% vs. 6.3%) and exhibited significantly poorer overall survival than those with a negative PES (30.2% vs. 54.6% at 5 years). CONCLUSIONS: The presence and extent of PNI can be predicted easily and effectively by the PES length. A positive PES was associated with poor local controllability and a poor prognosis.

New mimic of relapse or regional lymph node metastasis in a cancer survivor: a case of mRNA COVID-19 vaccine-induced lymphadenitis with high FDG uptake.

Western countries that were first to administer the COVID-19 vaccination report cases of vaccine-induced axillary lymphadenitis with high FDG uptake. However, no such findings have been reported from any Asian countries. We report here a confusing case of a 31-year-old female cancer survivor with high FDG uptake in her axillary lymph nodes, suggesting recurrence, following mRNA COVID-19 vaccination. Although the value of SUVmax was elevated (12.7), additional imaging revealed that her lymphatic lesions were benign, and they resolved spontaneously. This case of a strong immune reaction to COVID-19 vaccination in regional lymph nodes is the first reported in a Japanese patient. We should be aware of this new mimic and optimize diagnostic imaging methods accordingly in the era of COVID-19.

Incidence and location of perioperative deep vein thrombosis in patients with bladder cancer undergoing radical cystectomy.

OBJECTIVES: To determine the incidence and location of lower extremity deep vein thrombosis in patients undergoing radical cystectomy. METHODS: We performed radical cystectomy in 137 patients with bladder cancer between August 2014 and February 2020. Since 2014, we have had a policy to screen for deep vein thrombosis using lower extremity ultrasonography both before and after radical cystectomy. We determined the incidence and location of deep vein thrombosis and classified it as either proximal or distal type. Furthermore, we explored the incidence of pulmonary embolism within 3 months after radical cystectomy. RESULTS: After excluding six patients with a lack of ultrasonographic data, we evaluated 131 patients. Preoperative deep vein thrombosis (one proximal and 17 distal) was diagnosed in 18 patients (14%) with no symptoms. Postoperative deep vein thrombosis was diagnosed in 41 patients (31%; three proximal and 38 distal), of whom 26 (63%) had new-onset deep vein thrombosis after cystectomy. Three patients, two with proximal and one with distal type deep vein thrombosis, developed nonfatal pulmonary embolism postoperatively. Multivariate analysis showed that preoperative D-dimer levels (odds ratio 5.35, 95% confidence interval 1.74-16.50; P < 0.003), type of urinary diversion (ileal neobladder; odds ratio 11.15, 95% confidence interval 2.16-57.55; P = 0.004), and preoperative deep vein thrombosis (odds ratio 15.93, 95% confidence interval 3.82-66.30; P < 0.001) were significant risk factors for postoperative deep vein thrombosis. CONCLUSIONS: Pre- and post-radical cystectomy whole-leg ultrasonography can lead to an early perioperative diagnosis and immediate treatment of proximal deep vein thrombosis, thereby potentially preventing fatal pulmonary embolism.

FLAIR hyperintensity along the brainstem surface in leptomeningeal metastases: a case series and literature review.

BACKGROUND: The incidence of leptomeningeal metastasis (LM) is underestimated because of its non-specific signs and the low sensitivity of clinical diagnostic modalities. Cerebrospinal magnetic resonance (MR) imaging with and without contrast enhancement (CE) is a gold standard for the neuroradiological assessment of patients with suspected LM. Previous studies suggested that some LM cases show changes of the brainstem surface on non-contrast MR images without or before the appearance of abnormalities on CE images. We assessed the features of this non-contrast MR finding in a cohort of LM patients in this retrospective single-institution study. METHODS: We reviewed head MR images and clinical data of 142 consecutive patients in whom the final diagnosis was LM. RESULTS: We found that 11 of these 142 patients (7.7%) with LM had band-like hyperintensity on the brainstem surface on non-enhanced FLAIR images, which looked like bloomy rind on cheese. Three of seven patients who were examined using diffusion-weighted imaging showed restricted diffusion in the corresponding lesion site. The above-mentioned 11 patients included 10 women and 1 man, with a median age of 61 years. All 11 patients had primary lung adenocarcinoma. Seven patients had symptomatic hydrocephalus. Ten patients had EGFR-mutated and one had ALK-rearrangement adenocarcinomas. Before the diagnosis of LM, 10 patients had undergone systemic therapy with EGFR-TKI or pemetrexed, and 1 patient with ALK inhibitor and bevacizumab. CONCLUSIONS: We present a series of patients with bloomy rind sign that is non-enhancing LM reliably detected by FLAIR hyperintensity on the brainstem surface. This finding is rare, but may reflect the spread of cancer cells in both the leptomeningeal membrane and the surface of the brain parenchyma specifically in patients with lung adenocarcinomas. Further study is needed to determine the clinical significance of this sign, and the pathophysiological factors associated with it may be clarified by analyzing serial MR images in a larger cohort of patients treated for LM.

Molecular profile of a pleomorphic adenoma of the hard palate: A case report.

RATIONALE: Pleomorphic adenoma (PA) is the most common benign tumor of salivary glands. PAs have the potential for regional and distant metastases that preserve their benign phenotype; they also have the potential for malignant transformation. The molecular pathogenesis of malignant neoplasms has been studied extensively in recent years, unlike that of benign tumors, such as PA. PATIENT CONCERNS: In this case report, we identified the molecular signatures of a 57-year-old Japanese woman. Our patient presented with a swelling of the hard palate with an erosive appearance. DIAGNOSES: The patient was diagnosed with a right hard palate tumor suspected to be a malignant neoplasm. INTERVENTIONS: Partial maxillary resection and reconstruction were performed. OUTCOMES: There was no obstacle to swallowing or dysarthria after surgery. There was no sign of recurrent palatal tumor 4 years after the operation. Using next generation sequencing, 5 nonsynonymous mutations and CHCHD7-PLAG1 fusion genes were detected. Moreover, gene expression profiling indicated the possibility of the activation of several cancer-related signaling pathways. Although the PLAG1 gene is predicted to play a crucial role in PA tumorigenesis, its over-expression is reported to mediate multiple downstream factors. In this case, various up- and downregulated RNA signaling pathways, including MAP kinase signaling, PI3K/AKT1/MTOR signaling, JAK/STAT signaling, and PD-L1 signaling, were revealed. LESSONS: These molecular profiles of PA may elucidate the mechanism of metastasis, preserving its benign phenotype and carcinoma ex PA.

Intrahepatic Tumor Burden as a Novel Factor Influencing the Introduction of Second-line Chemotherapy for Hepatocellular Carcinoma.

BACKGROUND/AIM: To examine the factors influencing the introduction of the second-line chemotherapy and discuss the selection of first-line agent for hepatocellular carcinoma (HCC). PATIENTS AND METHODS: We retrospectively studied 154 patients with HCC who received sorafenib therapy. RESULTS: A total of 109 (70.8%) patients, maintained Child-Pugh grade A and Eastern Cooperative Oncology Group performance status (ECOG-PS) ≤1 upon sorafenib discontinuation. Multivariate analysis revealed that the up-to-seven criteria status in the hepatic lesion [p=0.019; odds ratio=OR, 2.685], albumin-bilirubin (ALBI) grade (p=0.002; OR=3.589), and macroscopic vascular invasion (MVI) (p=0.008; OR=2.972) were significant factors at sorafenib initiation that influenced the maintenance of Child-Pugh grade A and ECOG-PS ≤1 upon therapy discontinuation. CONCLUSION: Not only ALBI grade and MVI, but also up-to-seven criteria status in the hepatic lesion influence the introduction of second-line therapy, and could affect the selection of the first-line therapy.

Sorafenib versus Hepatic Arterial Infusion Chemotherapy as Initial Treatment for Hepatocellular Carcinoma with Advanced Portal Vein Tumor Thrombosis.

OBJECTIVE: To investigate the validity of hepatic arterial infusion chemotherapy with low-dose 5-fluorouracil and cisplatin (LFP) versus sorafenib as first-line treatment for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (Vp3, Vp4). PATIENTS AND METHODS: We retrospectively reviewed the cases of Child-Pugh A advanced HCC with Vp3 or Vp4 treated with LFP or sorafenib between October 2002 and December 2013. RESULTS: There were 32 patients in the LFP group and 14 patients in the sorafenib group. The objective response rate/disease control rate was 31.3/56.3% in the LFP group and 0/28.6% in the sorafenib group. The median survival time (MST) (309 vs. 120 days; p = 0.009) and the median time to treatment failure (109 vs. 37 days; p = 0.022) were significantly longer in the LFP group than in the sorafenib group. In the LFP group, a relatively favorable outcome (MST, 622 days) was obtained among the response cases. Among the nonresponse cases in the LFP group, at the time of cessation of LFP, 70.4% of cases were Child-Pugh A and 88.9% of cases maintained a score of ≤7 points; of the cases in whom Child-Pugh A was maintained, the survival period from the time of LFP discontinuation was significantly longer in the cases in whom sorafenib was introduced as a secondary treatment after LFP than in the cases treated with best supportive care (220 vs. 89 days; p = 0.002). The main adverse event with LFP was grade 3 or higher cytopenia, which was manageable, and adverse event-induced discontinuation was significantly lower as compared with sorafenib (p = 0.002). CONCLUSION: For the treatment of HCC with Vp3/Vp4, it is desirable to initially use LFP and then immediately change to sorafenib if no response is obtained.

"Direct MPR": A Useful Tool for Oblique CT Fluoroscopy-Assisted Puncture.

OBJECTIVE: Conventional multiplanar reconstruction (MPR) imaging can be used as a tool for planning oblique puncture procedures, but it takes a few minutes to reconstruct and is not appropriate for real-time CT fluoroscopy-assisted puncture. Recently, new MPR technology has been used that requires only 8 s and makes it possible to obtain a nearly real-time CT fluoroscopy-assisted oblique puncture. We refer to it as "direct MPR." This is the first clinical report of this technique. METHODS: Since February 2016, we have performed real-time, CT-guided oblique punctures with this new technology, "direct MPR," using an angio-CT system. We retrospectively reviewed all of our procedures with this new method between February 2016 and June 2016. RESULTS: We used this technique for 14 cases during the study period. Eight cases were radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), four were biopsies (lung and adrenal gland), and two were for percutaneous abscess drainage. Six of eight RFA cases were for HCC located immediately below the diaphragm. Both of the drainage cases were abscesses located immediately below the diaphragm. All procedures were successfully completed. The average length of the lesion in the RFA cases was 15.4 ± 3.2 mm. The average length of the lesions in all of the cases was 30.9 ± 31.9 mm. The average craniocaudal angle was 32.5° ± 14.0°. CONCLUSIONS: Direct MPR makes CT-guided oblique puncture for inaccessible targets, especially those located immediately below diaphragm, easier and safer. LEVEL OF EVIDENCE: Case series, Level IV.

Brain metastasis from hepatocellular carcinoma: The impact of radiotherapy on control of intracranial hemorrhage.

AIM: Brain metastasis from hepatocellular carcinoma (HCC) is rare and causes devastating outcomes with intracranial hemorrhage. We retrospectively analyzed the impact of radiotherapy in preventing hemorrhagic events among patients with brain metastasis from HCC. METHODS: Patients who underwent treatment for brain metastasis from HCC at our cancer center between January 2003 and December 2012 were identified from a prospectively compiled hospital database. Clinical characteristics were analyzed in patients with and without radiotherapy. RESULTS: Fifteen HCC patients with brain metastasis from HCC were classified into two groups: 11 patients underwent radiotherapy (group R) and four patients received best supportive care without radiotherapy (group N). Six patients (54.5%) in group R and four patients (100%) in group N showed intracranial hemorrhage at presentation of brain metastasis. No patients in group R experienced intracranial hemorrhage during follow up, although two patients in group N did. Median overall survival was 22.4 weeks (range, 5.42-69.1) in group R and 2.24 weeks (range, 1.0-15.4) in group N. CONCLUSION: For patients with brain metastasis from HCC, radiotherapy appears useful for controlling brain lesions, preventing intracranial hemorrhage and improving survival. Radiotherapy may contribute to control of intracranial tumor and prevention of intracranial hemorrhage for selected patients with brain metastasis from HCC.

Prospective evaluation of the optimal duration of bed rest after vascular interventions using a 3-French introducer sheath.

PURPOSE: To assess optimal bed-rest duration after vascular intervention by way of the common femoral artery using 3F introducer sheaths. MATERIALS AND METHODS: Eligibility criteria for this single-center, prospective study included clinically necessary angiography, no coagulopathy or anticoagulant therapy, no hypersensitivity to contrast medium, age >20 years, and written, informed consent. Enrolled patients were assigned to one of three groups (105/group) with the duration of bed rest deceased sequentially. A sheath was inserted by way of the common femoral artery using the Seldinger technique. The first group (level 1) received 3 h of bed rest after the vascular intervention. If no bleeding or hematomas developed, the next group (level 2) received 2.5 h of bed rest. If still no bleeding or hematomas developed, the final group (level 3) received 2 h of bed rest. If any patient had bleeding or hematomas after bed rest, the study was terminated, and the bed rest of the preceding level was considered the optimal duration. RESULTS: A total of 105 patients were enrolled at level 1 between November 2010 and September 2011. Eight patients were excluded from analysis because cessation of bed rest was delayed. None of the remaining subjects experienced postoperative bleeding; therefore, patient enrollment at level 2 began in September 2011. However, puncture site bleeding occurred in the 52nd patient immediately after cessation of bed rest, necessitating study termination. CONCLUSION: To prevent bleeding, at least 3 h of postoperative bed rest is recommended for patients undergoing angiography using 3F sheaths.

[Cancer treatment response evaluation based on imaging modalities, such as computed tomography, magnetic resonance imaging and FDG-PET].

RECIST, which is currently the standard evaluation criterion for clinical trials in cancer treatment, is widely extrapolated for use in clinical practice. However, the criteria depend on change in the size of tumors, and do not correspond to functional or metabolic change, or to changes in shape and texture such as tumor necrosis or cavitation due to molecular-targeted therapy. There will not be any changes that high-performance and high-resolution CT has been widely playing an important role in the future, in addition, so-called imaging biomarkers such as MRI and FDG-PET will have become used as diagnostic imaging modalities for the evaluation of cancer treatment and prognosis, because they can provide information concerning the morphological, functional and metabolic changes of tumors. Furthermore, in the current state where cancer treatment will be shifting towards individualized medicine by targeted therapies, we will need to evaluate these modalities to establish an adequate measurement method and timing, and the evaluation method. And the simplified and standardized criteria will be able to be achieved as future scientific cancer treatment evaluation.

[Content-based image-retrieval system - development, usefulness and perspectives of diagnostic assistant robot].

In recent years, diagnostic imaging modalities have proliferated from standard X-ray to CT, MRI and PET, and the working environments of radiologists have changed greatly with the popular spread of the PACS system. Radiologists are now facing enormous duties due to the dramatic increase in the volume of images from various modalities, and the shortage of radiologists in Japan has reached near-crisis levels. Furthermore, it is difficult to gain the knowledge needed to interpret diagnostic imaging and modalities under the growing, increasingly diverse and complex modalities and methods, for general physicians and trainees. On the other hand, there are some computer-aided diagnosis and detection systems that support radiologists. Here, we introduce a new diagnostic assistant robot that automatically retrieves cases on record that are similar to new cases, helps in making diagnoses, and can create CT reports semi-automatically, using an existing past CT database of pulmonary nodules with a structured report.