Shuichi Kawada

Biopsy Specimens Obtained 7 Days After Starting Chemoradiotherapy (CRT) Provide Reliable Predictors of Response to CRT for Rectal Cancer

PURPOSE Preoperative chemoradiation therapy (CRT) significantly decreases local recurrence in locally advanced rectal cancer. Various biomarkers in biopsy specimens obtained before CRT have been proposed as predictors of response. However, reliable biomarkers remain to be established. METHODS AND MATERIALS The study group comprised 101 consecutive patients with locally advanced rectal cancer who received preoperative CRT with oral uracil/tegafur (UFT) or S-1. We evaluated histologic findings on hematoxylin and eosin (H&E) staining and immunohistochemical expressions of Ki67, p53, p21, and apoptosis in biopsy specimens obtained before CRT and 7 days after starting CRT. These findings were contrasted with the histologic response and the degree of tumor shrinkage. RESULTS In biopsy specimens obtained before CRT, histologic marked regression according to the Japanese Classification of Colorectal Carcinoma (JCCC) criteria and the degree of tumor shrinkage on barium enema examination (BE) were significantly greater in patients with p21-positive tumors than in those with p21-negative tumors (P=.04 and P<.01, respectively). In biopsy specimens obtained 7 days after starting CRT, pathologic complete response, histologic marked regression according to both the tumor regression criteria and JCCC criteria, and T downstaging were significantly greater in patients with apoptosis-positive and p21-positive tumors than in those with apoptosis-negative (P<.01, P=.02, P=.01, and P<.01, respectively) or p21-negative tumors (P=.03, P<.01, P<.01, and P=.02, respectively). The degree of tumor shrinkage on both BE as well as MRI was significantly greater in patients with apoptosis-positive and with p21-positive tumors than in those with apoptosis-negative or p21-negative tumors, respectively. Histologic changes in H&E-stained biopsy specimens 7 days after starting CRT significantly correlated with pathologic complete response and marked regression on both JCCC and tumor regression criteria, as well as with tumor shrinkage on BE and MRI (P<.01, P<.01, P<.01, P<.01, and P=.03, respectively). CONCLUSIONS Immunohistochemical expressions of p21 and apoptosis together with histologic changes on H&E-stained biopsy specimens obtained 7 days after starting CRT are strong predictors of the response to CRT.

Phase II Study of Preoperative Concurrent Chemoradiotherapy with S-1 plus Bevacizumab for Locally Advanced Resectable Rectal Adenocarcinoma

Objective: A single-arm phase II clinical trial was conducted to evaluate the safety and efficacy of preoperative chemoradiotherapy (CRT) with concurrent S-1, bevacizumab, and radiation in patients with locally advanced rectal cancer (LARC). Methods: Fifty-two patients with LARC were enrolled. A total dose of 45 Gy was delivered in 25 fractions over 5 weeks, S-1 was administered orally twice a day on days 1-14 and 22-35, and bevacizumab was administered on days 1, 15, and 29. Surgical resection was scheduled 8 weeks (6-10 weeks) after completing the CRT. Results: All 52 patients underwent R0 radical surgery. Sphincter preservation was possible in 38 (73.1%) patients. A pathologic complete response was obtained in 10 (19.2%) patients, a pathologic downstaging was achieved in 37 (71.2%) patients, and the tumor shrinkage rate was 77.1%. The only grade 3 adverse events were leukopenia and rash in 1 (1.9%) patient. The rate of postoperative complications was 28.8%. Anastomotic leakage occurred in 9 (23.7%) of the 38 patients who underwent sphincter-preserving surgery. Perineal wound dehiscence developed in 2 (14.3%) of the 14 patients who received an abdominoperineal resection. Conclusions: Adding bevacizumab to S-1 clearly increased the incidence of wound-related complications, with no distinct enhancement of tumor response. i 2014 S. Karger AG, Basel

Visualization of the azygos arch valves on multidetector-row computed tomography

To evaluate the frequency and appearance of the azygos arch valves on chest examinations using multidetector-row computed tomography (MDCT), we retrospectively reviewed findings from 194 contrast-enhanced MDCT examinations of the chest. Rate of injection of 300 mgI/ml contrast materials was low (2.0 ml/s) and high (3.0 ml/s). Scanning delay was 80 s on examination on low-rate injection of contrast material and 20 s on high-rate injection of contrast material. The presence of residual contrast material in the azygos arch valves and reflux of contrast material into the azygos arch were recorded. The Cochran-Armitage trend test was used to compare the frequency of residual contrast material in the azygos arch valves and reflux of contrast material into the azygos arch in both groups. Of 92 examinations of high-rate injection of contrast material, 63 (68.5%) demonstrated residual contrast material in the azygos arch valves and 71 (77.2%) demonstrated reflux of contrast material into the azygos arch. A significantly higher frequency of reflux of contrast material into the azygos arch and residual contrast material in the azygos arch valves was seen in the high-rate injection group than in the low-rate injection group (P < 0.05). Residual contrast material in the azygos arch valves was demonstrated more frequently when contrast material was administered in the right side of the arm than in the left side of the arm (P < 0.05). Reflux of contrast material into the azygos arch was common in the high-injection-rate group and residual contrast material in the azygos arch valves was far more frequently seen in the high-injection-rate group than in the low-injection-rate group on MDCT.

Diffusion magnetic resonance imaging with gadofosveset trisodium as a negative contrast agent for lymph node metastases assessment.

PurposeThe aim of this study was to assess the feasibility of using intravenously administered gadofosveset trisodium as a negative contrast agent for lymph node (LN) assessment with diffusion-weighted imaging (DWI) using a VX2 tumor model in rabbits.Materials and methodsVX2 cells were injected in the right hind limb of five Japanese white rabbits to induce ipsilateral popliteal LN metastasis. DWI was performed before and every 7.5 min (until 1 h) after intravenous gadofosveset trisodium administration, at 1.5 T. Signal intensities (SIs) of right (metastatic) and left (nonmetastatic) popliteal LNs at each time point were measured and compared to each other using two-sided unpaired t-tests.ResultsThe SIs of metastatic lymph nodes were significantly higher (P < 0.05) than those of nonmetastatic LNs at each time point after intravenous gadofosveset trisodium administration. Although the SI of metastatic LNs was significantly higher (P = 0.0237) than that of nonmetastatic LNs before contrast injection, this difference became even more significant (P ≤ 0.0105) after gadofosveset trisodium administration.ConclusionThe SI of metastatic LNs at DWI is less suppressed than that of nonmetastatic LNs after the intravenous administration of gadofosveset trisodium. Therefore, intravenously administered gadofosveset trisodium shows promise for use as a negative contrast agent for discriminating metastatic from nonmetastatic LNs at DWI.

Relationship between histologic response and the degree of tumor shrinkage after chemoradiotherapy in patients with locally advanced rectal cancer

Preoperative chemoradiotherapy (CRT) significantly decreases local recurrence in advanced rectal cancer. We studied whether the degree of tumor shrinkage can be used as a predictor of histologic response.

Anomalous inferior vena cava associated with horseshoe kidney on multidetector computed tomography

We evaluated the prevalence of anomalous inferior vena cava (IVC) associated with 205 patients with horseshoe kidney (HSK) and 1990 patients without HSK on multidetector computed tomography and compared prevalence between both groups. We identified anatomical variations of the IVC in 8 patients (3.9%) with HSK (1 preisthmic IVC with retrocaval ureter, 4 double IVCs, 2 left IVCs, and 1 IVC with azygos continuation) and in 12 patients (0.6%) without HSK (8 double IVCs, 3 left IVCs, and 1 IVC with azygos continuation). Anomalous IVC was significantly more frequent in patients with HSK than those without it.

A case of right double inferior vena cava with circumcaval ureter

Congenital inferior vena cava (IVC) anomalies are silent and detected incidentally on imaging. Double IVC is the most common IVC anomaly and is usually characterized by the presence of an IVC on each side of the abdominal aorta. In contrast, right double IVC, which is defined as two post-renal IVCs positioned to the right of the abdominal aorta, is seldom recognized. We report a rare case of a complete right double IVC with a circumcaval ureter that was incidentally detected by CT and describe the embryological and clinical implications.

MR Imaging with Apparent Diffusion Coefficient Histogram Analysis: Evaluation of Locally Advanced Rectal Cancer after Chemotherapy and Radiation Therapy

Purpose To determine response to neoadjuvant chemotherapy and radiation therapy in patients with locally advanced rectal cancer (LARC) by using magnetic resonance (MR) apparent diffusion coefficient (ADC) histogram analysis. Materials and Methods Ninety-two patients with LARC underwent MR imaging with rectal barium before and after chemotherapy and radiation therapy (CRT). Rectal expansion with barium expanded the lumen, provided similar imaging geometry before and after CRT, and eliminated fecal matter, air, and residual fluid. T2-weighted images, the percentage change in ADC, and ADC histogram skewness and kurtosis were assessed. The histopathologic tumor regression grade (TRG) ranged from 1a (66%-99% residual tumor cells) to 3 (no residual cells). The Wilcoxon signed-rank test, the Spearman correlation test, multivariable linear regression, and one-way analysis of variance were used to determine post- and pretreatment differences and correlations between tumor size and ADC. Results Of the 92 patients, 16 (17.4%) had TRG 3, 27 (29.3%) had TRG 2b, 24 (26.1%) had TRG 2a, 14 (15.2%) had TRG 1b, and 11 (12%) had TRG 1a. Post-CRT skewness (regression coefficient = 10.9, P = .06) and percentage ADC change (regression coefficient = -0.18, P = .03) were associated with the percentage of residual tumor. Post-CRT skewness and percentage ADC change, respectively, showed negative and positive correlation with histopathologic TRG (post-CRT skewness: P = .024; percentage ADC change: P = .001). Conclusion In patients with LARC, post-CRT skewness of the ADC histogram and percentage change in ADC were useful for predicting a favorable response to neoadjuvant CRT.

Initial experience with computed tomographic colonography applied for noncolorectal cancerous conditions

PurposeThe aim of this study was to asses retrospectively the performance of computed tomography colonography (CTC) for noncolorectal cancerous conditions.Material and methodsA total of 44 patients with non-colorectal cancerous conditions underwent CTC. We researched the indications for CTC or present illness and evaluated the CTC imaging findings. We assessed whether diagnosis by CTC reduced conventional colonoscopic examinations.ResultsA total of 47 examinations were performed in 44 patients. The indications for CTC or a present illness were as follows: 15 patients with impossible or incomplete colonoscopy, 7 with diverticular disease, 6 with malignancy (noncolorectal cancer), 6 with Crohn’s disease, 4 suspected to have a submucosal tumor on colonoscopy, 2 with ischemic colitis, and 4 with various other diseases. Colonic findings were diagnosed on CTC in 36 examinations, and extracolonic findings were identified in 35 of 44 patients. In all, 17 patients had undergone colonoscopy previously, 9 (52.9%) of whom did not require further colonoscopy by CTC. Five patients underwent colonoscopy after CTC.ConclusionThe indications for CTC were varied for patients with noncolorectal cancerous conditions. CTC examinations could be performed safely. Unlike colonoscopy or CT without preparation, CTC revealed colonic and extracolonic findings and may reduce the indication of colonoscopy in patients with noncolorectal cancerous conditions.

Hooking intestine sign: a typical diagnostic CT finding of Petersen’s hernia

PurposeTo clarify typical diagnostic computed tomography (CT) findings of Petersen’s hernia for differentiation from other causes of internal hernia observed in patients having undergone gastrectomy with Roux-en-Y gastric bypass.MethodsWe retrospectively reviewed CT findings of internal hernia in patients who had undergone both gastrectomy and Roux-en-Y reconstruction and a second surgery for bowel obstruction. Thirteen patients with Petersen’s hernia and 6 with internal hernia other than Petersen’s hernia were investigated. Six CT findings, viz. whirl sign, mesenteric fat haziness, intestinal distension in the upper abdomen, herniated intestinal loop above the gastric level, middle/distal ileum courses downwards from the left hypochondrium, and hooking intestine sign, which means two or more intestines pass through the inner side of J-shaped vessels consisting of mesenteric vessels of the elevated jejunum, were scored and evaluated regarding their diagnostic performance.ResultsThe hooking intestine sign showed the highest sensitivity, specificity and accuracy (100%, 100% and 100%). We could detect J-shaped vessels in all Petersen’s hernia patients. Inside the J-shaped vessels there were two or more intestinal tracts passing through in the Petersen’s hernia group. There was only transverse colon inside the J-shaped vessels in the control group.ConclusionThe hooking intestine sign may be useful for diagnosing Petersen’s hernia on CT.