An Investigation of Body Size Impact on Organ Doses for Neutron External Exposures Using the MRCP-based Phantom Library.

ABSTRACT: In a recent study, a comprehensive library composed of 212 phantoms with different body sizes was established by deforming the adult male and female mesh-type reference computational phantoms (MRCPs) of ICRP Publication 145 and the next-generation ICRP reference phantoms over the current voxel-type reference phantoms of ICRP Publication 110. In this study, as an application of the MRCP-based phantom library, we investigated dosimetric impacts due to the different body sizes for neutron external exposures. A comprehensive dataset of organ/tissue dose coefficients (DCs) for idealized external neutron beams with four phantoms for each sex representatively selected from the phantom library were produced by performing Monte Carlo simulations using the Geant4 code. The body size-dependent DCs produced in this study were systematically analyzed, observing that the variation of the body weights overall played a more important role in organ/tissue dose calculations than the variation of the body heights. We also observed that the reference body-size DCs based on the MRCPs indeed significantly under- or overestimated the DCs produced using the phantoms, especially for those much heavier (male: 175 cm and 140 kg; female: 165 cm and 140 kg) than the reference body sizes (male: 176 cm and 73 kg; female: 163 cm and 60 kg) by up to 1.6 or 3.3 times, respectively. We believe that the use of the body size-dependent DCs, together with the reference body-size DCs, should be beneficial for more reliable organ/tissue dose estimates of individuals considering their body sizes rather than the most common conventional approach, i.e., the sole use of the reference body size DCs.

Assessment of thyroid-specific quality of life in patients with benign symptomatic thyroid nodules treated with radiofrequency or ethanol ablation: a prospective multicenter study.

PURPOSE: Radiofrequency ablation (RFA) and ethanol ablation (EA) are effective and safe for benign symptomatic thyroid nodules (BSTNs). However, relatively little is known about the effects of these procedures on patients' quality of life (QoL). This prospective, multicenter study evaluated the effects of RFA and EA on changes in thyroid-specific QoL in patients with BSTNs and assessed the volume reduction and safety of these procedures. METHODS: Eighty-six consecutive patients with 86 BSTNs were prospectively included from two medical centers. RFA was performed for 55 BSTNs with solidity ≥50% and EA was performed for 31 BSTNs with solidity <50%. QoL was evaluated using an 11-scale, multiple-choice thyroid-specific QoL questionnaire. Nodule characteristics and QoL were evaluated at diagnosis and 1, 6, and 12 months after treatment. Overall QoL was rated from 0 (good) to 4 (poor). RESULTS: The mean longest size and volume of the index nodule were 4.2±1.5 cm and 21.6±22.1 mL, respectively. Patients received 1.1 treatments on average (range, 1 to 2). Significant post-treatment volume reductions were noted; however, the EA group showed a higher volume reduction than the RFA group at 1 (78.7%-16.1% vs. 49.1%-15.8%), 6 (86.3%-21.7% vs. 73.0%-14.5%), and 12 (90.9%-14.9% vs. 80.3%-12.4%) months. The score for each scale of the QoL questionnaire improved significantly during follow-up (all P<0.001). Overall QoL improved significantly, from 1.7±0.9 at diagnosis to 0.6±0.7 at the 12-month follow-up (P<0.001). There were no major complications. CONCLUSION: Both RFA and EA are safe and effective in reducing nodule volume and improving thyroid-specific QoL in patients with BSTNs.

Assessment of the image quality of extended depth-of-focus intraocular lens models in polychromatic light.

PURPOSE: The use of monochromatic light in the assessment of intraocular lenses (IOLs) has been criticized for not representing the real-world situation. This study aimed to measure and compare the image quality of 3 extended depth-of-focus (EDOF) IOL models in monochromatic and polychromatic light. SETTING: David J Apple Laboratory, Heidelberg, Germany. DESIGN: In vitro study. METHODS: An optical metrology instrument was used to study image quality metrics of diffractive IOLs with chromatic aberration correction (Symfony and AT Lara) and a refractive lens (Mini Well). The modulation transfer function (MTF) was measured in green and polychromatic light at a 2.0 mm, 3.0 mm, and 4.0 mm aperture. The EDOF IOL's tolerance to defocus was tested against a monofocal lens. RESULTS: The mean MTF of the EDOF IOL at far distance was decreased in polychromatic compared with monochromatic light. The largest effect was found in the refractive lens; however, at intermediate distance, only small differences occurred. In their tolerance to defocus, the EDOF IOLs were superior to the monofocal IOL. The diffractive IOL had higher MTFs than that of the refractive IOL at 2 primary foci, the refractive IOL's optical quality varied less with defocus at 3.0 mm. The refractive lens was the most susceptible to changes in aperture size. CONCLUSION: The diffractive EDOF IOL was more resistant to chromatic effects than the refractive IOL. The EDOF IOLs provided an extended through-focus performance compared with the monofocal IOL, but differences in optical design, particularly pupil dependency, should be considered when refining IOL selection for patients.

Validation of the Korean version of visual analogue scale for irritable bowel syndrome questionnaire for assessment of defecation pattern changes.

PURPOSE: Patients often complain of change of defecation pattern and it is necessary to quantify their symptoms. To quantify symptoms, use of questionnaire is ideal, so we adopted a simple and easily writable visual analogue scale for irritable bowel syndrome questionnaire (VAS-IBS). The aim of this study was to develop and validate the Korean version of VAS-IBS questionnaire (Korean VAS-IBS) that can adequately reflect the defecation pattern. METHODS: This study translated English VAS-IBS into Korean using the forward-and-back translation method. Korean VAS-IBS was performed on 30 patients, who visited the outpatient clinic and had no possibility of special defecation pattern. Detailed past medical history and Bristol stool chart was added to the questionnaire. The survey was conducted twice, and the median interval between the 2 surveys was 10 days (8-11 days). Cronbach α for internal consistency reliability and intraclass correlation coefficients for test-retest reliability were analyzed. RESULTS: Korean VAS-IBS achieved acceptable homogeneity with a Cronbach α coefficient of 0.66-0.79 showing adequate internal consistency reliability. In addition, intraclass correlation coefficients showed significant test-retest reliability with 0.46-0.80 except for the question assessing the "perception of psychological wellbeing." CONCLUSION: The Korean VAS-IBS is a valid and reliable questionnaire for the measurement of the symptoms of defecation pattern changes.

Assessment of Breast Cancer Patients' Knowledge and Decisional Conflict Regarding Tamoxifen Use.

Breast cancer is the most common type of female cancer. Tamoxifen, a selective estrogen receptor modulator, is widely used to decrease breast cancer recurrence and mortality among patients. However, it also increases the risk of endometrial cancer. This study aimed to assess knowledge and decisional conflict regarding tamoxifen use. Between June and October 2014, breast cancer patients using tamoxifen were consecutively screened and requested to complete a survey including the EQ-5D, Satisfaction with Decision Scale (SWD), Decisional Conflict Scale (DCS), and a self-developed, 15-item questionnaire measuring tamoxifen-related knowledge. The study sample comprised 299 patients. The mean total knowledge score was 63.4 of a possible 100.0 (range, 13.3-93.3). While 73.9% of the participants knew that tamoxifen reduces the risk of breast cancer recurrence, only 57.9% knew that the drug increases endometrial cancer risk. A higher education level (≥ college) was associated with a higher, total knowledge score (ß = 4.291; P = 0.017). A higher knowledge score was associated with a decreased DCS score (ß = -0.366; P < 0.001). A higher SWD score was also associated with decreased decisional conflict (ß = -0.178; P < 0.001). In conclusion, the breast cancer patients with higher levels of tamoxifen-related knowledge showed lower levels of decisional conflict regarding tamoxifen use. Clinicians should provide the exact information about tamoxifen treatment to patients, based on knowledge assessment results, so as to aid patients' decision-making with minimal conflict.

Impact of lower limb lymphedema on quality of life in gynecologic cancer survivors after pelvic lymph node dissection.

OBJECTIVE: To evaluate the impact of lower limb lymphedema (LLL) on quality of life (QOL) in cervical, ovarian, and endometrial cancer survivors after pelvic lymph node dissection. STUDY DESIGN: A cross-sectional case-control study was performed using the Korean version of the Gynecologic Cancer Lymphedema Questionnaire (GCLQ-K) and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30). In total, 25 women with LLL and 28 women without LLL completed both questionnaires. RESULTS: The GCLQ-K total symptom score and scores for swelling-general, swelling-limb, and heaviness were significantly higher in the LLL group than in the control group. In the EORTC QLQ-C30, the LLL group reported more financial difficulties compared to the control group (mean score, 16.0 vs. 6.0; P=0.035). Global health status was poorer in the LLL group with borderline statistical significance (mean score, 62.7 vs. 71.4; P=0.069). Spearman's correlations suggested that global health status in the EORTC QLQ-C30 correlated with the GCLQ-K total symptom score (in the LLL group, R=-0.64, P=0.001; in the control group, R=-0.42, P=0.027). CONCLUSIONS: QOL decreases due to LLL-related symptoms and financial difficulty in women with LLL. Well-designed prospective studies are required to confirm these findings.

Development and evaluation of Korean version of Quality of Sexual Function (QSF-K) in healthy Korean women.

This study was done to develop a Korean version of the Quality of Sexual Function (QSF-K) and evaluate the validity and reliability of the QSF-K. The participants were 220 women who visited the Center for Uterine Cancer at the National Cancer Center in Korea. Participants completed the scale once and then again at a two to four week interval. The QSF-K, Female Sexual Function Index (FSFI) and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ-C30) were used in this study. Receiver operating characteristics (ROC) curve, area under the ROC curve (AUC), intraclass correlation coefficients (ICC), and Cronbach's alpha were analyzed. In the analysis of the reliability, Cronbach's alpha was 0.83 and the ICC was 0.70. The validity measured with the AUC of the QSF-K comparing the FSFI and Global Health/QOL of the EORTC-QLQ-C30 was 0.717 and 0.728, respectively. Specifically, the AUC of the sexual activity level of the QSF-K was 0.838 in the FSFI comparison. The AUC of the psycho-somatic QOL of the QSF-K was 0.758 in the Global Health/QOL of the EORTC-QLQ-C30 comparison. Approximately half of the women (51.8%) had mild complaints/problems. The Korean version of the QSF was developed and validated.