Final Analysis of 3 Versus 6 Months of Adjuvant Oxaliplatin and Fluoropyrimidine-Based Therapy in Patients With Stage III Colon Cancer: The Randomized Phase III ACHIEVE Trial.

PURPOSE: The phase III ACHIEVE trial conducted in Japan was one of six prospective studies included in the International Duration Evaluation of Adjuvant Therapy collaboration, which explored whether 3 months of adjuvant fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) therapy would be noninferior to 6 months of treatment in patients with curatively resected stage III colon cancer. We report the final analyses of survival and long-term safety. PATIENTS AND METHODS: Eligible patients were randomly assigned (1:1) to either 3 or 6 months of adjuvant chemotherapy (modified [m]FOLFOX6 or CAPOX, as selected by the treating physician). Random assignment was stratified according to number of involved lymph nodes, center, regimen, primary site, and age. The primary end point was disease-free survival, assessed in the modified intention-to-treat population. Overall survival (OS) was a secondary end point. RESULTS: The modified intention-to-treat population comprised 1,291 patients: 641 in the 6-month treatment group and 650 in the 3-month treatment group. Median follow-up for this analysis was 74.7 months. Five-year OS rates were comparable: 87.0% in the 3-month treatment group and 86.4% in the 6-month treatment group (hazard ratio, 0.91; 95% CI, 0.69 to 1.20; P = .51). Subgroup analysis of OS did not reveal a significant interaction between baseline characteristics and treatment duration. Peripheral sensory neuropathy lasting longer than 5 years was more common in the 6- compared with 3-month treatment group (16% v 8%, respectively), and in those receiving mFOLFOX6 compared with CAPOX (14% v 11%, respectively). CONCLUSION: In Asian patients, shortening adjuvant therapy duration from 6 to 3 months did not compromise efficacy and reduced the rate of long-lasting peripheral sensory neuropathy. In this setting, 3 months of CAPOX therapy is an appropriate adjuvant treatment option.

Artificial accommodating intraocular lens powered by an ion polymer-metal composite actuator.

The current method of controlling the focus of an accommodating intraocular lens is based on ciliary muscle contraction and cannot be used in older patients with presbyopia. We aimed to develop a dynamically accommodating intraocular lens powered by a membrane-shaped ion polymer metal composite actuator that is thin enough to be inserted in the eye. This study addresses two key problems identified in our previous accommodating intraocular lens prototype: the lack of repeatability due to the use of swine lenses instead of artificial lenses and the occurrence of a sixth order aberration. Thus, we present a new accommodating intraocular lens design and a method to transfer energy to actuators. To accommodate lens deformation and depth of focus, we used a membrane-shaped ion polymer metal composite actuator, thin enough to be inserted in the eye, and used an artificial silicone lens. To prevent the sixth order aberration, we included a ring between the ion polymer metal composite actuator and the lens. Different voltage patterns were applied to the IPMC actuator and changes in focus were observed. We were able to obtain repeatability and prevent the sixth order aberration. The dioptric power changed to ±0.23 D when ±1.5 V was used; however, at >1.5 V, a large accommodating range occurred, in addition to astigmatic vision. Thus, we have developed a novel prototype that is completely artificial, allowing reproducible and repeatable results. Visual accommodative demands were successfully met; however, although astigmatic vision was lessened, it was not completely eradicated.

Intraoperative maneuvers may affect the development of early postoperative small bowel obstruction after laparoscopic colorectal cancer surgery: Multicenter prospective cohort study.

BACKGROUND: Early postoperative small bowel obstruction (EPSBO) is one of the most common complications after colorectal cancer (CRC) surgery, and clarification of its causes is desired. Several reports have demonstrated the risks of EPSBO, but few have focused on laparoscopic surgery for CRC and intraoperative maneuvers. We therefore prospectively examined the risk factors for EPSBO after laparoscopic CRC resection. METHODS: We prospectively enrolled 706 patients with CRC that underwent laparoscopic CRC resection in our hospital and affiliated hospitals. We analyzed several factors concerning EPSBO including intraoperative procedures. RESULTS: EPSBO developed in 43 of the 706 cases (6.1%). Univariate analysis showed that risk factors for EPSBO were male sex, increased operative time, repositioning of the small intestine before wound closure and anastomotic leakage. Risk factors for EPSBO according to multivariate analysis were increased operative time (odds ratio (OR) 2.41; P = 0.032), repositioning of the small intestine before wound closure (OR 3.58; P = 0.005) and anastomotic leakage (OR 3.91; P = 0.006). CONCLUSION: To reduce EPSBO after laparoscopic CRC surgery, the operation should be finished as soon as possible without performing optional maneuvers. To avoid development to EPSBO, particular care is required in cases where the risk of anastomotic leakage is predicted to be high.

Laparoscopic anterior resection with or without transanal tube for rectal cancer patients - A multicenter randomized controlled trial.

BACKGROUND: In rectal cancer surgery, insertion of transanal tube has been shown to have efficacy to prevent anastomotic leakage. This randomized controlled study aims to clarify the incidence of anastomotic leakage with or without transanal tube in patients with rectal cancer. METHODS: Patients who underwent elective low anterior resection were randomly allocated to either have transanal tube insertion or not for five days after surgery. We examined the incidence of anastomotic leakage, postoperative 30-day morbidity and mortality. RESULTS: 157 patients were randomized to the transanal tube group or the no-transanal tube group. Symptomatic anastomotic leakage occurred in six patients (7.6%) of the former group and eight patients (10.3%) in the latter group, without significant difference (p = 0.559). There was also no significant difference in morbidity between groups (p = 0.633) and no mortality was detected. CONCLUSIONS: Transanal tube insertion had no significant benefit towards prevention of anastomotic leakage in rectal cancer surgery.

Pathological assessment of the lymph node biopsies for lymphadenopathy in rheumatoid arthritis.

Objectives: To assess the incidence of reactive lymph node hyperplasia (RLH) and the diagnostic characteristics that can help differentiate it from lymphoproliferative disorders (LPD) in patients with rheumatoid arthritis (RA).Methods: Data on patient characteristic from 32 consecutive RA patients with lymphadenopathy at a single medical center over a 6-year period were collected and analyzed to determine whether any of these characteristics can differentiated RLH from LPD.Results: LPD including methotrexate (MTX) - associated LPD (MTX-LPD) and RLH were diagnosed in 19 and 10 patients, respectively. Conclusive diagnosis was not reached in the remaining three cases and they were regarded as grey-zone cases. Age, levels of lactate dehydrogenase (LDH) and soluble interleukin-2 receptor (sIL-2R), as well as maximum standardized uptake value (SUVmax), were significantly higher in LPD than in RLH patients. The diagnosis cut-off values for these parameters were 66 year, 169 U/L, 899 U/mL and 8.18, respectively, based on the receiver operating characteristics curve analysis for both RLH and LPD.Conclusions: About one-third of patients with RA who presented with lymphadenopathy had reactive lymph node enlargement. Older age and higher levels of LDH, sIL-2R, and SUVmax are more associated with LPD than should be considered when deciding to perform a biopsy.

The efficacy and safety of tazobactam/ceftolozane in combination with metronidazole in Japanese patients with complicated intra-abdominal infections.

Tazobactam/ceftolozane, a novel antimicrobial therapy, is active against Pseudomonas aeruginosa and most extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae. We report the results of the efficacy and safety of tazobactam/ceftolozane in Japanese patients with complicated intra-abdominal infections (cIAI). A multicenter, open-label, noncomparative study (MK-7625A Protocol 013, ClinicalTrials.gov Identifier: NCT02739997) to investigate the efficacy and safety of tazobactam/ceftolozane used in combination with metronidazole in Japanese patients with cIAI was conducted. One hundred Japanese patients with cIAI received tazobactam/ceftolozane 1.5 g (tazobactam 0.5 g/ceftolozane 1 g) plus metronidazole 500 mg intravenously every 8 h for 60 min for 4-14 days. The clinical response rate at the Test-of-Cure visit (TOC; Day 28 ± 2 days) was 92.0% (81/88 subjects). By disease type, the clinical response rates were 92.3% (24/26) for cholecystitis, 100% (6/6) for liver abscess, 93.5% (58/62) for intra-abdominal abscess and 90.2% (55/61) for peritonitis. The per-subject microbiological response rate at the TOC was 90.2% (55/61). Per-pathogen microbiological response rates in the most common baseline pathogens were Escherichia coli 90.2% (37/41), Kebsiella pneumoniae 91.7% (11/12), Streptococcus anginosus 100% (11/11), Streptococcus constellatus 90.0% (9/10) and Bacteroides fragilis 95.2% (20/21). The most common drug-related AEs were aspartate aminotransferase increased (11.0%) and alanine aminotransferase increased (9.0%). No serious drug-related AE was reported during the study. The favorable effect of tazobactam/ceftolozane in the treatment of cIAI suggests that the agent will be useful in clinical practice in Japan.

[A Case of Long-Term Survival in Gastric Cancer with Multiple Liver Metastases Successfully Treated by Conversion Surgery after S-1 plus Cisplatin Combination Therapy].

A 49-year-old man was diagnosed with advanced gastric cancer, with a chief complaint of epigastric discomfort. Computed tomography revealed multiple liver metastases. S-1 plus cisplatin therapy was administered as first-line chemotherapy, and after 4courses, the liver metastases markedly reduced. Total gastrectomy with D2 lymphadenectomy and a needle biopsy of segment 2 of the liver were performed. Histopathological examination revealed no viable cancer cells in the resected stomach, lymph nodes, or liver tissue. The primary tumor was defined as Grade 3 by histopathological examination. Adjuvant chemotherapy with S-1 was administered for 1 year. The patient is alive without recurrence more than 6 years after surgery.

Lateral lymph node metastasis in a patient with T1 upper rectal cancer treated by lateral lymph node dissection: a case report and brief literature review.

BACKGROUND: Lateral lymph node (LLN) metastasis may occur in patients with advanced rectal cancers of which the lower margins are located at or below the peritoneal reflection. However, LLN metastasis from a T1 rectal cancer is rare. Here, we report a case of LLN metastasis from a T1 upper rectal cancer that was successfully treated by sequential LLN dissection. CASE PRESENTATION: A 56-year-old man was referred to our hospital for the treatment of a T1 upper rectal cancer. We performed a laparoscopic low anterior resection. Histological examination showed a moderately differentiated adenocarcinoma with submucosal layer invasion; the invasion depth was classified as head invasion, without vessel or lymph duct invasion. Tumor budding was classified as grade 1. A total of six lymph nodes were harvested, and no lymph node metastases were detected. The postoperative course was uneventful. At 6 months after surgery, however, the serum carcinoembryonic antigen levels were elevated, and abdominal computed tomography (CT) revealed swollen lymph nodes in the right internal and common iliac artery area. Positron emission tomography with CT revealed hot spots in the same lesions. A retrospective re-evaluation of the preoperative CT images revealed no apparent swollen lymph nodes; however, an unusual soft tissue area was detected around the right internal iliac artery. A right LLN dissection was performed. Fifteen lymph nodes were resected, and histologically, metastases of adenocarcinoma were identified in 3 nodes. The postoperative course was again uneventful. The patient was given 12 cycles of adjuvant chemotherapy with FOLFOX (fluorouracil, leucovorin, and oxaliplatin). The patient remains healthy and with no signs of recurrence at 30 months after the second surgery. CONCLUSIONS: LLN metastasis occurs very rarely in patients with T1 upper rectal cancer and no risk factors for lymph node metastasis; however, a careful perioperative examination of the LLN should be performed. In cases involving LLN metastasis, a LLN dissection may be a therapeutic option if performed with curative intent.

Long-term irreversible trastuzumab-induced cardiotoxicity for metastatic breast cancer in a patient without cardiac risk factors.

Trastuzumab improves clinical outcomes in patients with human epidermal growth factor receptor-2-positive breast cancer. However, cardiotoxicity is a potentially important concern, and the long-term cardiac effects of trastuzumab therapy remain unclear. Although reduction of cardiac function by trastuzumab is mostly reversible, some patients, especially those with cardiac risk factors, may rarely experience chronic heart failure or prolonged left ventricular ejection fraction reduction. There have been no detailed published analyses of patients with such unfavorable clinical courses. We report the rare case of a metastatic breast cancer in a woman without cardiac risk factors who experienced long-term irreversible cardiotoxicity after discontinuation of trastuzumab therapy.

Ultra-Low-Dose Fetal CT With Model-Based Iterative Reconstruction: A Prospective Pilot Study.

OBJECTIVE: Prenatal diagnosis of skeletal dysplasia by means of 3D skeletal CT examination is highly accurate. However, it carries a risk of fetal exposure to radiation. Model-based iterative reconstruction (MBIR) technology can reduce radiation exposure; however, to our knowledge, the lower limit of an optimal dose is currently unknown. The objectives of this study are to establish ultra-low-dose fetal CT as a method for prenatal diagnosis of skeletal dysplasia and to evaluate the appropriate radiation dose for ultra-low-dose fetal CT. SUBJECTS AND METHODS: Relationships between tube current and image noise in adaptive statistical iterative reconstruction and MBIR were examined using a 32-cm CT dose index (CTDI) phantom. On the basis of the results of this examination and the recommended methods for the MBIR option and the known relationship between noise and tube current for filtered back projection, as represented by the expression SD = (milliamperes)-0.5, the lower limit of the optimal dose in ultra-low-dose fetal CT with MBIR was set. The diagnostic power of the CT images obtained using the aforementioned scanning conditions was evaluated, and the radiation exposure associated with ultra-low-dose fetal CT was compared with that noted in previous reports. RESULTS: Noise increased in nearly inverse proportion to the square root of the dose in adaptive statistical iterative reconstruction and in inverse proportion to the fourth root of the dose in MBIR. Ultra-low-dose fetal CT was found to have a volume CTDI of 0.5 mGy. Prenatal diagnosis was accurately performed on the basis of ultra-low-dose fetal CT images that were obtained using this protocol. The level of fetal exposure to radiation was 0.7 mSv. CONCLUSION: The use of ultra-low-dose fetal CT with MBIR led to a substantial reduction in radiation exposure, compared with the CT imaging method currently used at our institution, but it still enabled diagnosis of skeletal dysplasia without reducing diagnostic power.

Hyperacute peripheral neuropathy is a predictor of oxaliplatin-induced persistent peripheral neuropathy.

PURPOSE: Chronic peripheral neuropathy is a major adverse response to oxaliplatin-containing chemotherapy regimens, but there are no established risk factors pertaining to it. We investigated the efficacy of hyperacute peripheral neuropathy (HAPN) as a predictor of oxaliplatin-induced persistent peripheral neuropathy (PPN). METHODS: Forty-seven cases of stage III colorectal cancer who received adjuvant chemotherapy with oxaliplatin after curative surgery between January 2010 and August 2014 were retrospectively reviewed. HAPN was defined as acute peripheral neuropathy (APN) occurring on day 1 (≤24 h after oxaliplatin infusion) of the first cycle. PPN was defined as neuropathy lasting >1 year after oxaliplatin discontinuation. RESULTS: The average total dose of oxaliplatin was 625.8 mg/m2, and the average relative dose intensity was 66.7%. Twenty-two of the 47 patients (46.8%) had PPN and 13 (27.7%) had HAPN. Male sex, treatment for neuropathy, HAPN, and APN were significantly more frequent in patients with PPN (p = 0.013, 0.02, <0.001, and 0.023, respectively). There was no significant difference in the total oxaliplatin dose between patients with and without PPN (p = 0.061). Multivariate analyses revealed total dose of oxaliplatin and HAPN as independent predictors of PPN [p = 0.015; odds ratio (OR) = 1.005, 95% confidence interval (CI), 1.001-1.009 and p = 0.001; OR = 75.307, 5.3-1070.123, respectively]. The total dose of oxaliplatin was relatively lower in patients with HAPN than that in those without HAPN in the PPN-positive group (not significant, p = 0.068). CONCLUSION: HAPN was found to be a predictor of oxaliplatin-induced PPN.

[A Case with Solitary Brain Metastatic Tumor from Colon Cancer].

We report a rare long-surviving case of solitary brain metastasis from colon cancer. The patient was a 64-year-old female. She had undergone laparoscopic right hemicolectomy for ascending colon cancer in October 2012(pStage III b). She was discharged from the hospitalin a satisfactory state, but 26 days after the operation, she was transported to the emergency department for systemic tonic-clonic convulsions. Magnetic resonance imaging revealed solitary metastatic tumor in the brain, but there were no metastatic lesions in other organs. Metastatic lesion was small and complete removal was considered to be difficult. Thus, we planned stereotactic radiosurgery for the metastases, and then regimen of mFOLFOX6 plus Bmab, tegafur-uracil plus Leucovorin were administered. As a means of evaluating recurrence of brain metastasis, methionine positron emission tomography(methionine PET)was also performed, and the patient has survived for 54 months since the surgery, to date, without recurrence. Cases with brain metastasis of colorectal cancer often have metastases involving other organs and are considered to have a poor prognosis. For solitary brain metastasis, long-term survival can be obtained with multidisciplinary treatments, and methionine PET is considered to be usefulfor recurrence evaluation after radiation treatment.

Voltage-controlled accommodating IOL system using an ion polymer metal composite actuator.

Surgeons treat cataracts by replacing the clouded lens with an intraocular lens (IOL), but patients are required to wear reading glasses for tasks requiring near vision. We suggest a new voltage-controlled accommodating IOL made of an ionic polymer metal composite (IPMC) actuator to change focus. An in vitro experiment was conducted where an actuator was placed inside the eye and moved with applied voltage. The lens attached to the actuator was deformed by its movement to change the patient's focus. The results showed that this system can accommodate a change of approximately 0.8 diopters under an applied voltage of ± 1.3 V.

Influence of Ambient Humidity on the Voltage Response of Ionic Polymer-Metal Composite Sensor.

Electrical potential based on ion migration exists not only in natural systems but also in ionic polymer materials. In order to investigate the influence of ambient humidity on voltage response, classical Au-Nafion IPMC was chosen as the reference sample. Voltage response under a bending deformation was measured in two ways: first, continuous measurement of voltage response in the process of absorption and desorption of water to study the tendency of voltage variation at all water states; second, measurements at multiple fixed ambient humidity levels to characterize the process of voltage response quantitatively. Ambient humidity influences the voltage response mainly by varying water content in ionic polymer. Under a step bending, the amplitude of initial voltage peak first increases and then decreases as the ambient humidity and the inherent water content decrease. This tendency is explained semiquantitatively by mass storage capacity related to the stretchable state of the Nafion polymer network. Following the initial peak, the voltage shows a slow decay to a steady state, which is first characterized in this paper. The relative voltage decay during the steady state always decreases as the ambient humidity is lowered. It is ascribed to progressive increase of the ratio between the water molecules in the cation hydration shell to the free water. Under sinusoidal mechanical bending excitation in the range of 0.1-10 Hz, the voltage magnitude increases with frequency at high ambient humidity but decreases with frequency at low ambient humidity. The relationship is mainly controlled by the voltage decay effect and the response speed.

Local diagnostic reference level based on size-specific dose estimates: assessment of pediatric abdominal/pelvic computed tomography at a Japanese national children's hospital.

BACKGROUND: A child's body size is not accurately reflected by volume CT dose index (CTDIvol) and dose-length product (DLP). Size-specific dose estimation (SSDE) was introduced recently as a new index of radiation dose. However, it has not yet been established as a diagnostic reference level (DRL). OBJECTIVE: To calculate the SSDE of abdominal/pelvic CT and compare the SSDE with CTDIvol. To calculate the DRLs of CTDIvol and SSDE. Our hypotheses are: SSDE values will be greater than CTDIvol, and our DRL will be smaller than the known DRLs of other countries. MATERIALS AND METHODS: The CTDIvol and DLP of 117 children who underwent abdominal/pelvic CT were collected retrospectively. The SSDE was calculated from the sum of the lateral and anteroposterior diameters. The relationships between body weight and effective diameter and between effective diameter and CTDIvol/SSDE were compared. Further, the local DRL was compared with the DRLs of other countries. RESULTS: Body weight and effective diameter and effective diameter and SSDE were positively correlated. In children ages 1, 5 and 10 years, the SSDE is closer to the exposure dose of CTDIvol for the 16-cm phantom, while in children ages 15 years, the SSDE falls between CTDIvol for the 16-cm phantom and that for the 32-cm phantom. The local DRL was lower than those of other countries. CONCLUSION: With SSDE, the radiation dose increased with increasing body weight. Since SSDE takes body size into account, it proved to be a useful indicator for estimating the exposure dose.

Nationwide radiation dose survey of computed tomography for fetal skeletal dysplasias.

BACKGROUND: Recently, computed tomography (CT) has been used to diagnose fetal skeletal dysplasia. However, no surveys have been conducted to determine the radiation exposure dose and the diagnostic reference level (DRL). OBJECTIVE: To collect CT dose index volume (CTDIvol) and dose length product (DLP) data from domestic hospitals implementing fetal skeletal 3-D CT and to establish DRLs for Japan. MATERIALS AND METHODS: Scan data of 125 cases of 20 protocols from 16 hospitals were analyzed. The minimum, first-quartile, median, third-quartile and maximum values of CTDIvol and DLP were determined. The time-dependent change in radiation dose setting in hospitals with three or more cases with scans was also examined. RESULTS: The minimum, first-quartile, median, third-quartile and maximum CTDIvol values were 2.1, 3.7, 7.7, 11.3 and 23.1 mGy, respectively, and these values for DLP were 69.0, 122.3, 276.8, 382.6 and 1025.6 mGy·cm, respectively. Six of the 12 institutions reduced the dose setting during the implementation period. CONCLUSIONS: The DRLs of CTDIvol and DLP for fetal CT were 11.3 mGy and 382.6 mGy·cm, respectively. Institutions implementing fetal CT should use these established DRLs as the standard and make an effort to reduce radiation exposure by voluntarily decreasing the dose.

Monitoring of peripheral vascular condition using a log-linearized arterial viscoelastic index during endoscopic thoracic sympathectomy.

This paper proposes a novel technique to support the monitoring of peripheral vascular conditions using biological signals such as electrocardiograms, arterial pressure values and pulse oximetry plethysmographic waveforms. In this approach, a second-order log-linearized model (referred to here as a log-linearized peripheral arterial viscoelastic model) is used to describe the non-linear viscoelastic relationship between blood pressure waveforms and photo-plethysmographic waveforms. The proposed index enables estimation of peripheral arterial wall stiffness changes induced by sympathetic nerve activity. The validity of the method is discussed here based on the results of peripheral vascular condition monitoring conducted during endoscopic thoracic sympathectomy (ETS). The results of ETS monitoring showed significant changes in stiffness variations between the periods before and during the procedures observed (p < 0.01) as well as during and after them (p < 0.01), so that it was confirmed that sympathetic nerve activity is drastically decreased in the area around the monitoring site after the thoracic sympathetic nerve trunk on the monitoring side is successfully blocked. In addition, no change was observed in the values of the proposed index during the ETS procedure on the side opposite that of the monitoring site. The experimental results obtained clearly show the proposed method can be used to assess changes in sympathetic nerve activity during ETS.

A log-linearized arterial viscoelastic model for evaluation of the carotid artery.

This paper proposes a method for qualitatively estimating the mechanical properties of arterial walls on a beat-to-beat basis through noninvasive measurement of continuous arterial pressure and arterial diameter using an ultrasonic device. First, in order to describe the nonlinear relationships linking arterial pressure waveforms and arterial diameter waveforms as well as the viscoelastic characteristics of arteries, we developed a second-order nonlinear model (called the log-linearized arterial viscoelastic model) to allow estimation of arterial wall viscoelasticity. Next, to verify the validity of the proposed method, the viscoelastic indices of the carotid artery were estimated. The results showed that the proposed model can be used to accurately approximate the mechanical properties of arterial walls. It was therefore deemed suitable for qualitative evaluation of arterial viscoelastic properties based on noninvasive measurement of arterial pressure and arterial diameter.

Development of DICOM image-based CT low dose simulator using fan-beam transform.

BACKGROUND: Projection-data based method is established as an accurate simulation of low-dose CT, but cooperation of the CT manufacturer is required. Image-based method is awaited for independent and efficient research. OBJECTIVE: To develop and verify image-based method for adding noise to DICOM images. METHODS: This technique reproduces projection data by fan-beam transform of the DICOM image data and by creating and reconstructing noise projections into a noise image that can be added to the original image. A cylindrical test phantom and anthropomorphic phantom were used to verify the simulation method for both standard and adaptive iterative reconstruction methods. RESULTS: The simulated images compared favorably with actual images. Standard deviation difference of the simulated images were 1.27% ± 0.81% (cylindrical phantom) and ranged from 1.61% ± 0.81% (head), to 5.41% ± 1.57% (hepatic portal region) (anthropomorphic phantom). The standard deviation difference of the cylindrical phantom with the adaptive iterative technique were 3.41% ± 1.76% at 50% ASIR and 3.85% ± 1.82% at 100% ASIR. The simulated noise power spectra of both types of images were comparable to the actual images. CONCLUSION: We developed and validated a DICOM image-based low-dose simulation that allows researchers to perform dose reduction research independently and efficiently.

Laparoscopic colectomy for a patient with congenital renal agenesis.

We present a very rare case of laparoscopic colectomy for a patient with ascending colon cancer and an agenetic right kidney. A 57-year-old man visited our institute for further evaluation for a positive fecal occult blood test. Approximately, 20 years earlier, the right kidney of the patient was found to be congenitally absent. A physical examination indicated no anatomical anomalies in his genitourinary system, and the renal function was within the normal range. Total colonoscopy revealed a cancer of the ascending colon and laparoscopic colectomy was performed. The right colon was mobilized by lateral-to-medial extension of a retroperitoneal dissection between the fusion fascia and the anterior renal fascia. The right testicular vessels were preserved without injury to the anterior renal fascia; however, the right ureter could not be detected. The operation was performed safely. Thus, we believe that in patients with congenital unilateral renal agenesis, the anterior renal fascia is present, and laparoscopic ipsilateral colectomy can be safely performed in such patients.