• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3465-3468
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• 2016

Background: Fluorodeoxyglucose ($^{18}FDG$) PET/CT imaging has become an important component of the management paradigm in oncology. However, the significant imparted radiation exposure is a matter of growing concern especially in younger populations who have better odds of survival. The aim of this study was to estimate the effective dose received by patients having whole body $^{18}F$-FDG PET/CT scanning as per recent dose reducing guidelines at a tertiary care hospital. Materials and Methods: This prospective study covered 63 patients with different cancers who were referred for PET/CT study for various indications. Patients were prepared as per departmental protocol and 18FDG was injected at 3 MBq/Kg and a low dose, non-enhanced CT protocol (LD-NECT) was used. Diagnostic CT studies of specific regions were subsequently performed if required. Effective dose imparted by 18FDG (internal exposure) was calculated by using multiplying injected dose in MBq with coefficient $1.9{\times}10^{-2}mSv/MBq$ according to ICRP publication 106. Effective dose imparted by CT was calculated by multiplying DLP (mGy.cm) with ICRP conversion coefficient "k" 0.015 [mSv / (mG. cm)]. Results: Mean age of patients was $49{\pm}18$ years with a male to female ratio of 35:28 (56%:44%). Median dose of 18FDG given was 194 MBq (range: 139-293). Median CTDIvol was 3.25 (2.4-6.2) and median DLP was 334.95 (246.70 - 576.70). Estimated median effective dose imparted by $^{18}FDG$ was 3.69 mSv (range: 2.85-5.57). Similarly the estimated median effective dose by low dose (non-diagnostic) CT examination was 4.93 mSv (range: 2.14 -10.49). Median total effective dose by whole body 18FDG PET plus low dose non-diagnostic CT study was 8.85 mSv (range: 5.56-13.00). Conclusions: We conclude that the median effective dose from a whole body 18FDG PET/CT in our patients was significantly low. We suggest adhering to recently published dose reducing strategies, use of ToF scanner with CT dose reducing option to achieve the lower if not the lowest effective dose. This would certainly reduce the risk of second primary malignancy in younger patients with higher odds of cure from first primary cancer.

• Radiation Oncology Journal
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• v.31 no.2
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• pp.81-87
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• 2013

Purpose: To describe chronic rectal mucosal damage after pelvic radiotherapy (RT) for cervical cancer and correlate these findings with clinical symptoms and radiation dose. Materials and Methods: Thirty-two patients who underwent pelvic RT were diagnosed with radiation-induced proctitis based on endoscopy findings. The median follow-up period was 35 months after external beam radiotherapy (EBRT) and intracavitary radiotherapy (ICR). The Vienna Rectoscopy Score (VRS) was used to describe the endoscopic findings and compared to the European Organization for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) morbidity score and the dosimetric parameters of RT (the ratio of rectal dose calculated at the rectal point [RP] to the prescribed dose, biologically effective dose [BED] at the RP in the ICR and EBRT plans, ${\alpha}/{\beta}$ = 3). Results: Rectal symptoms were noted in 28 patients (rectal bleeding in 21 patients, bowel habit changes in 6, mucosal stools in 1), and 4 patients had no symptoms. Endoscopic findings included telangiectasia in 18 patients, congested mucosa in 20, ulceration in 5, and stricture in 1. The RP ratio, $BED_{ICR}$, $BED_{ICR+EBRT}$ was significantly associated with the VRS (RP ratio, median 76.5%; $BED_{ICR}$, median 37.1 $Gy_3$; $BED_{ICR+EBRT}$, median 102.5 $Gy_3$; p < 0.001). The VRS was significantly associated with the EORTC/RTOG score (p = 0.038). Conclusion: The most prevalent endoscopic findings of RT-induced proctitis were telangiectasia and congested mucosa. The VRS was significantly associated with the EORTC/RTOG score and RP radiation dose.

• Progress in Medical Physics
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• v.26 no.3
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• pp.137-142
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• 2015

We retrospectively analyzed the outcomes in patients who underwent reirradiation for brain metastasis. Twenty-three patients with brain metastases who were initially treated with palliative brain radiotherapy and were retreated with a second course of brain RT between June 2008 and December 2012. WBRT, 3DCRT and SRS were used for brain metastasis. The median dose of the first course of WBRT was 30 Gy (range, 23.4~30 Gy). The dose of the first course 3DCRT for lesion was 30 Gy in 3 Gy per fraction. The median dose of the first course of SRS was 16 Gy in 1 fraction (range, 12~24 Gy). The median dose of the second course of WBRT was 27.5 (range, 12~30 Gy). The median dose of the second course of 3DCRT for lesion was 30 Gy (range, 25~30 Gy). The dose of the second course of SRS was 16 Gy in 1 fraction. The second course of WBRT was administered on radiographic disease progression with symptom in all patients. With median follow-up of 25 months, overall symptom resolution rates were 47.8%. Rate of palliative efficacy was 82.6% including stable disease. The median survival time after initiation of reirradiation was 3.2 months. Median value of KPS prior to reirradiation was 30. Median value of KPS after reirradiation was 60. Reirradiation of brain metastasis maybe feasible and effective in select patients with a good performance status $KPS{\geq}60$ (: ECOG 0~2) prior to reirradiation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.785-789
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• 2016

A key drug for treatment of EGFR mutation-positive non-small cell lung cancer is epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). While the dosage of many general anti-tumor drugs is adjusted according to the patient body surface area, one uniform dose of most TKIs is recommended regardless of body size. In many cases, dose reduction or drug cessation is necessary due to adverse effects. Disease control, however, is frequently still effective, even after dose reduction. In this study, we retrospectively reviewed the characteristics of 26 patients at Fukuoka University Hospital between January 2004 and January 2015 in whom the EGFR-TKI dose was reduced with respect to progression free survival and overall survival. There were 10 and 16 patients in the gefitinib group and the erlotinib group, respectively. The median progression-free survival in the gefitinib group and the erlotinib group was 22.4 months and 14.1 months, respectively, and the median overall survival was 30.5 months and 32.4 months, respectively. After stratification of patients by body surface area, the overall median progression-free survival was significantly more prolonged in the low body surface area (<1.45 m2) group (25.6 months) compared to the high body surface area (>1.45 m2) group (9.7 months) (p=0.0131). These results indicate that low-dose EGFR-TKI may sufficiently control disease without side effects in lung cancer patients with a small body size.

• Journal of Radiation Protection and Research
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• v.16 no.1
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• pp.1-13
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• 1991

Effective dose equivalents resulting from inhalation of indoor radon-222 daughters at 12 residential areas in Korea were assessed by a simple mathematical lung dosimetry model based on the measurements of long-term averaged radon concentrations at 340 dwellings. The long-term averaged indoor radon-222 concentrations and corresponding eqilibrium equivalent radon $concentration(EEC_{Rn})$ measured by passive time-integrating CR-39 radon cups are in the range of $33.82{\sim}61.42Bq/m^3(median\;:\;48.90Bq/m^3)$ and of $13.53{\sim}24.57Bq/m^3(median\;:\;19.55Bq/m^3)$, respectively. The effective dose equvalent conversion factor for the exposure to unit $EEC_{Rn}$ derived in this study was estimated $1.07{\times}10^{-5}mSv/Bq\;h\;m^{-3}$ for a reference adult and agreed well with those recommended by the ICRP and UNSCEAR. The annual average dose equivalent to the lung $(H_{LUNG})$ from inhalation exposure to measured $EEC_{Rn}$ was estimated to be 20.90 mSv and resulting effective dose $equivalent(H_E)$ was to be 1.25 mSv, which is about 50% of the natural radiation exposure of 2.40 mSv/y to the public reported by the UNSCEAR.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.115-115
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• 2002

The anti-diarrhea and spasmolytic activities of Soonkijangquebo (SKJQB), a Korean herbal anti-diarrhea formulation, were subjected to pharmacological evaluation. SKJQB, at a dose of 50\ulcorner200 mg/kg, inhibited castor oil-induced diarrhea in mice. The median effective dose (ED50) of the anti-diarrhea effect was 93 mg/kg.(omitted)

• Archives of Pharmacal Research
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• v.3 no.2
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• pp.85-86
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• 1980

Dopaminergic influences on prolactin release from lactotrophs have been studied using the rat anterior pituitary cell culture. The prolactin inhibiting activity of hypothalamic extracts was examined in relation to dopamine. Dopamine inhibited prolactin secretion from the rat anterior pituitary cell culture in a dose dependent fashion. The median effective dose was $2{\times}10^{-7}$ / M and the maximal inhibition (70-90 % of the control value) was shown by 10$^{-5}$ / M dopamine. Further increase in dopamine concentration did not result in any further inhibition of prolactin secretion.nhibition of prolactin secretion.

• Journal of Radiation Protection and Research
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• v.45 no.2
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• pp.53-68
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• 2020

Background: International organizations such as the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported public exposure doses due to radionuclides released in the Fukushima nuclear accident a few years after the event. However, the reported doses were generally overestimated due to conservative assumptions such as a longer stay in deliberate areas designated for evacuation than the actual stay. After these reports had been published, more realistic dose values were reported by Japanese scientists. Materials and Methods: The present paper reviews those reports, including the most recently published articles; and summarizes estimated effective doses (external and internal) and issues related to their estimation. Results and Discussion: External dose estimation can be categorized as taking two approaches-estimation from ambient dose rate and peoples' behavior patterns-and measurements using personal dosimeters. The former approach was useful for estimating external doses in an early stage after the accident. The first 4-month doses were less than 2 mSv for most (94%) study subjects. Later on, individual doses came to be monitored by personal dosimeter measurements. On the basis of these measurements, the estimated median annual external dose was reported to be < 1 mSv in 2011 for 22 municipalities of Fukushima Prefecture. Internal dose estimation also can be categorized as taking two approaches: estimation from whole-body counting and estimation from monitoring of environmental samples such as radioactivity concentrations in food and drinking water. According to results by the former approach, committed effective dose due to ¹³⁴Cs and ¹³⁷Cs could be less than 0.1 mSv for most residents including those from evacuated areas. Conclusion: Realistic doses estimated by Japanese scientists indicated that the doses reported by WHO and UNSCEAR were generally overestimated. Average values for the first-year effective doses for residents in two affected areas (Namie Town and Iitate Village) were not likely to reach 10 mSv, the lower end of the doses estimated by WHO.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1463-1469
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• 2015

Background: To evaluate the safety and efficacy of combined chemoradiotherapy or radiotherapy alone in elderly patients with esophageal carcinoma to identify the best method of treatment. Materials and Methods: One hundred and sixteen patients with esophageal carcinoma aged 70 and older who received definitive radiotherapy or chemoradiotherapy entered the study. Overall survival (OS), disease-free survival (DFS) and treatment-related toxicities were assessed. Results: The median OS of the overall population was 17.9 months. For patients treated with cCRT, sCRT and radiotherapy alone, the median OS was 22.3 months, 18.0 months and 12.4 months respectively(P=0.044). Median OS for patients treated with radiotherapy dose ${\geq}60Gy$ and <60Gy was 20.2 months and 10.9 months respectively (p=0.017). By univariate analysis, Chemoradiotherapy (include cCRT and sCRT) and radiotherapy dose ${\geq}60Gy$ were found to achieve higher survival rates compared with radiotherapy alone and radiotherapy dose <60Gy (P=0.015, P=0.017). By multivariate analysis, chemoradiotherapy (HR=1.645, P=0.022) and radiotherapy dose ${\geq}60Gy$ (HR=1.642, P=0.025) were identified as independent prognostic factors of OS. Conclusions: Definitive concurrent chemoradiotherapy could be considered as a feasible and effective treatment in esophageal carcinoma patients aged 70 and older. Radiotherapy dose 60Gy is an effective treatment option compared with standard dose radiotherapy, while higher doses are not beneficial to improve survival.

• Radiation Oncology Journal
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• v.34 no.4
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• pp.290-296
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• 2016

Purpose: Radiotherapy (RT) is considered a mainstay of treatment in parameningeal rhabdomyosarcoma (PM-RMS). We aim to determine the treatment outcomes and prognostic factors for PM-RMS patients who treated with RT. In addition, we tried to evaluate the adequate dose and timing of RT. Materials and Methods: Twenty-two patients with PM-RMS from 1995 to 2013 were evaluated. Seven patients had intracranial extension (ICE) and 17 patients had skull base bony erosion (SBBE). Five patients showed distant metastases at the time of diagnosis. All patients underwent chemotherapy and RT. The median radiation dose was 50.4 Gy (range, 40.0 to 56.0 Gy). Results: The median follow-up was 28.7 months. Twelve patients (54.5%) experienced failure after treatment; 4 local, 2 regional, and 6 distant failures. The 5-year local control (LC) and overall survival (OS) were 77.7% and 38.5%, respectively. The 5-year OS rate was 50.8% for patients without distant metastases and 0% for patients with metastases (p < 0.001). Radiation dose (<50 Gy vs. ${\geq}50Gy$) did not compromise the LC (p = 0.645). However, LC was affected by ICE (p = 0.031). Delayed administration (>22 weeks) of RT was related to a higher rate of local failure (40.0%). Conclusion: RT resulted in a higher rate of local control in PM-RMS. However, it was not extended to survival outcome. A more effective treatment for PM-RMS is warranted.