External beam radiotherapy combination is a risk factor for bladder cancer in patients with prostate cancer treated with brachytherapy.

PURPOSE: To investigate the risk of bladder cancer (BCa) in patients treated with brachytherapy for prostate cancer (PCa). METHODS: We retrospectively analyzed 583 patients with PCa who underwent brachytherapy with or without external beam radiotherapy (EBRT). We analyzed the disease-free survival (DFS) of BCa in patients with PCa who underwent brachytherapy with or without EBRT. We performed multivariate Cox regression analyses of DFS using age, EBRT, and Brinkman index (BI) score (number of cigarettes smoked per day × number of years smoking) ≥ 200 as variables for BCa after brachytherapy. RESULTS: Fourteen patients (2.4%) developed BCa after brachytherapy with or without EBRT. The percentage of high-grade urothelial carcinoma (UC) was 63.6%. A total of 85.7% of patients had non-muscle invasive BCa, and 14.3% of patients had muscle invasive BCa. DFS was longer in brachytherapy monotherapy than in combination therapy (brachytherapy + EBRT). Multivariate Cox regression analysis showed that a BI score ≥ 200 (Hazard Ratio (HR 8.61; 95% Confidence Interval (CI) 1.12-65.98) and EBRT combination (HR 3.29; 95% CI 1.03-10.52) were significantly associated with BCa development in patients with PCa treated with brachytherapy. Furthermore, patients with BI score ≥ 200 and EBRT combination had a significantly higher risk of BCa compared with patients with BI score < 200 (HR Log-rank test P = 0.010). CONCLUSION: Most cases of BCa after brachytherapy with or without EBRT are high grade and invasive. We hypothesized that the EBRT combination might be a risk factor for BCa in patients with PCa who underwent brachytherapy.

Definitive chemoradiotherapy for anal canal cancer: single-center experience.

BACKGROUND: Chemoradiotherapy (CRT) is a standard treatment for anal canal cancer although many patients with anal canal cancer undergo surgery in Japan. The efficacy of CRT for anal canal cancer was evaluated retrospectively. METHODS: Medical charts of 13 patients with anal canal cancer treated by definitive CRT from October 2004 to May 2016 were reviewed. Twelve patients had squamous cell carcinoma and one had adeno-squamous carcinoma. PET/CT simulation was performed in nine patients. The median total dose was 59.4 Gy (range 57.6-63.4 Gy) with fractions of 1.8-2.0 Gy. Ten patients received chemotherapy with mitomycin C (10 mg/m2) and fluorouracil (5-FU) (800 mg/m2 over 4 days) in weeks 1 and 5, while two patients were treated with cisplatin (40 mg) and 5-FU (750 mg over 5 days) in weeks 1 and 5. One elderly patient received radiotherapy (RT) alone. RESULTS: All 13 patients were alive after a median follow-up period of 102 months (range 16-121 months). Local failure only occurred in the patient with adeno-squamous cell carcinoma, while there was no loco-regional recurrence or distant metastasis in the other 12 patients. The 5-year loco-regional control rate (LRC) and 5-year overall survival rate (OS) were 92% and 100%, respectively. Acute toxicities of ≥ grade 3 were observed in six patients (46%), mainly being dermatitis around the anal verge, and late toxicity of ≥ grade 3 occurred in one patient. CONCLUSION: CRT for squamous cell carcinoma of the anal canal achieved good LRC and OS with acceptable toxicities.

Usefulness of direct-conversion flat-panel detector system as a quality assurance tool for high-dose-rate 192Ir source.

The routine quality assurance (QA) procedure for a high-dose-rate (HDR) 192Ir radioactive source is an important task to provide appropriate brachytherapy. Traditionally, it has been difficult to obtain good quality images using the 192Ir source due to irradiation from the high-energy gamma rays. However, a direct-conversion flat-panel detector (d-FPD) has made it possible to confirm the localization and configuration of the 192Ir source. The purpose of the present study was to evaluate positional and temporal accuracy of the 192Ir source using a d-FPD system, and the usefulness of d-FPD as a QA tool. As a weekly verification of source positional accuracy test, we obtained 192Ir core imaging by single-shot radiography for three different positions (1300/1400/1500 mm) of a check ruler. To acquire images for measurement of the 192Ir source movement distance with varying interval steps (2.5/5.0/10.0 mm) and temporal accuracy, we used the high-speed image acquisition technique and digital subtraction. For accuracy of the 192Ir source dwell time, sequential images were obtained using various dwell times ranging from 0.5 to 30.0 sec, and the acquired number of image frames was assessed. Analysis of the data was performed using the measurement analysis function of the d-FPD system. Although there were slight weekly variations in source positional accuracy, the measured positional errors were less than 1.0 mm. For source temporal accuracy, the temporal errors were less than 1.0%, and the correlation between acquired frames and programmed time showed excellent linearity (R2 = 1). All 192Ir core images were acquired clearly without image halation, and the data were obtained quantitatively. All data were successfully stored in the picture archiving and communication system (PACS) for time-series analysis. The d-FPD is considered useful as the QA tool for the 192Ir source.

A Phase I/II trial of radiotherapy concurrent with TS-1 plus cisplatin in patients with clinically resectable type 4 or large type 3 gastric cancer: Osaka Gastrointestinal Cancer Chemotherapy Study Group OGSG1205.

A Phase I/II trial of radiotherapy administered concurrently with TS-1 plus cisplatin has been initiated in Japanese patients with clinical resectable type 4 or large type 3 gastric cancer. The aim of this trial is to determine the recommended dose of TS-1 and cisplatin combined with radiotherapy at a fixed dose in the Phase I study, and to evaluate the efficacy and safety in the Phase II study. The primary endpoint for Phase II is the pathological complete response rate, assessed using surgically resected specimens. Secondary endpoints are the response rate, progression-free survival, overall survival, operation transitional rate, R0 resection rate, rate of treatment completion, rate of down-staging and rates of postoperative complications and adverse events. In Phase II, a total of 30 patients will be enrolled in the Osaka Gastrointestinal Cancer Chemotherapy Study Group trial over a period of 6 years.

Design of hemispherical radio frequency (RF) capacitive-type electrode free of edge effects for treatment of intracavitary tumors.

A new hemispherical electrode to heat oral cavity cancer is proposed. The electrode does not produce a hot spot around its edge, a feature that usually arises when using radio frequency (RF) capacitive-type heating. The hemispherical electrode was designed by computer simulation using a 3-D finite element method. To assess its practicality and effectiveness, we built a prototype hemispherical electrode and evaluated its heating characteristics by phantom experiments. The heating effects on the phantom were measured by thermography. The concave phantom surface in contact with the hemispherical electrode showed a uniform increase in temperature, with no obvious edge effect. The proposed electrode allows non-invasive RF capacitive-type heating for intracavity tumors that was not previously considered possible, and should contribute to the multidisciplinary treatment of intracavity tumors.

Mucinous carcinoma of the breast: MRI features of pure and mixed forms with histopathologic correlation.

OBJECTIVE: The purpose of this study was to describe the MRI features of the pure and mixed forms of mucinous carcinoma of the breast and the histopathologic correlation. MATERIALS AND METHODS: Seventeen pure and three mixed mucinous tumors of the breast were examined with T2-weighted MRI and triple-phase dynamic MRI. MR images were reviewed for evaluation of the signal intensity and enhancement patterns of tumors and for correlation with the histopathologic findings. RESULTS: The presence of very high signal intensity on T2-weighted images was a common feature of pure and mixed mucinous tumors. Fourteen pure tumors and one mixed tumor had very high signal intensity, and three pure and two mixed tumors had very high signal intensity and isointensity on T2-weighted images. The enhancement pattern during the early phase varied with the cellularity of pure tumors and with the distribution of nonmucinous components in mixed tumors. Hypocellular pure mucinous tumors had a typical pattern of gradual enhancement. CONCLUSION: Hypercellular pure mucinous tumors exhibit strong early enhancement and may be difficult to differentiate from mixed mucinous tumors. The distinction between the pure and mixed forms of mucinous carcinoma is important because mixed mucinous carcinoma more frequently undergoes lymph node metastasis and has a poorer prognosis than does pure mucinous carcinoma.

Two-step Intensity-modulated Radiation Therapy for Oropharyngeal Cancer: Initial Clinical Experience and Validation of Clinical Staging.

AIM: To evaluate the clinical results of two-step intensity-modulated radiation therapy (IMRT) for oropharyngeal cancer. PATIENTS AND METHODS: Eighty patients were treated with two-step IMRT between 2002 and 2014. Whole-neck radiotherapy (44.0-50.0 Gy/22-25 fractions) was delivered by IMRT, followed by boost IMRT to the high-risk clinical target volume (total dose of 70.0 Gy/35 fractions). Forty-seven patients received concurrent chemotherapy. Immunohistochemistry for human papillomavirus type 16 (HPV/p16) was performed for 64 patients. RESULTS: The 5-year overall survival and locoregional control rates for stage I, II, III, and IVA-B disease were 80.0%, 75.0%, 78.0%, and 64.0% and 100.0%, 75.0%, 92.0%, and 82.0%, respectively. Overall survival was significantly higher in HPV/p16-positive patients than in HPV/p16-negative patients (p=0.01). Xerostomia of grade 2 or more was noted in 10 patients. CONCLUSION: Favourable overall survival and locoregional control rates with excellent salivary preservation were obtained using the two-step IMRT method for oropharyngeal cancer.

Dosimetry advantages of intraoperatively built custom-linked seeds compared with loose seeds in permanent prostate brachytherapy.

PURPOSE: The aim of this study was to compare the implant quality between intraoperatively built custom-linked seeds (IBCL) and loose seeds (LS) retrospectively. MATERIAL AND METHODS: This study included 74 prostate cancer patients who were treated with permanent prostate brachytherapy (PPB) using IBCL (n = 37) or LS (n = 37) between July 2014 and June 2016. Dose-volume histogram (DVH) parameters, seed migration, and operation time were compared between the IBCL and LS groups. In addition to the standard target volume of the whole prostate gland, DVH parameters for prostate plus a 3 mm margin (CTV) were evaluated. RESULTS: In intraoperative planning, prostate V150 was lower (54.8% vs. 59.6%, p = 0.027), and CTV V100 (88.1% vs. 85.6%, p = 0.019) and D90 (98.5% vs. 92.6%, p = 0.0033) were higher in the IBCL group compared with in the LS group. In post-implant dosimetry, prostate V100 (96.9% vs. 95.2%, p = 0.020), CTV V100 (85.6% vs. 81.7%, p = 0.046), and CTV D90 (94.2% vs. 86.5%, p < 0.001) were higher, and prostate V150 (57.1% vs. 64.5%, p = 0.0051) and CTV V150 (31.5% vs. 35.7%, p = 0.046) were lower in the IBCL group compared with in the LS group. Regarding DVH changes between intraoperative planning and post-implant dosimetry, the decrease in prostate D90 was significantly lower in the IBCL group than in the LS group (-1.16% vs. -4.17%, p < 0.001). For the IBCL group, the operation time was slightly but significantly longer than that for the LS group (50.5 minutes vs. 43.7 minutes, p = 0.011). However, the seed migration rate was significantly lower in the IBCL group than in the LS group (5% vs. 41%, p < 0.001). CONCLUSIONS: Intraoperatively built custom-linked is more advantageous than LS in terms of dosimetric parameters and migration.

Multicentric granulocytic sarcoma of the breast: mammographic, sonographic, and MR findings.

A rare case of granulocytic sarcoma (GS) of the bilateral breasts after complete remission of acute myelogenous leukemia is reported. Mammogram showed multiple irregular high-density masses, and sonogram demonstrated multiple irregular low-echoic masses with a posterior shadow in the bilateral mammary glands. Contrast-enhanced MR images showed multiple irregular enhancing masses. None of those findings were pathognomonic of GS. However, MR image was useful to evaluate the response of the chemotherapy and detect the nonpalpable relapse tumor and determine the introduction of the radiation therapy early.

[Artifact of indicators equipped to stereotactic body frame scanned by 16-row MDCT can be resolved].

We found an artifact of the Stereotactic Body Frame's (SBF) indicators when we used diagnostic 16-row multi-detector computed tomography (MDCT) as a simulator. Stereotactic radiotherapy (SRT) requires the accuracy of each millimeter. However, a gap of 3 mm at the maximum along the Z axis was caused by this artifact. We assessed the characteristics and cause of this artifact and searched for an imaging parameter to reduce the artifact in SRT. It was considered that the artifact was formed mainly by a stair-step artifact and cone-beam artifact. We can acquired accuracy, 1 mm minimizing the beam width and pitch (10 mm/0.5625). However, exposure time was extended because minimum pitch was selected. The influence on dose calculation was negligible. We decided to use a default parameter for treatment planning, and this parameter for determining the isocenter. We found the MDCT parameters to get acceptable positional accuracy for SRT with SBF.