The Effect of Probiotics for Preventing Radiation-Induced Morphological Changes in Intestinal Mucosa of Rats

기용간,김원택,조흥래,안기정,최영민,김동원 대한의학회 2014 Journal of Korean medical science Vol.29 No.10

Radiation therapy is an important treatment modality for abdominal or pelvic cancer, butthere is a common and serious complication such as radiation-induced enteritis. Probiotics isreported to have positive effects against radiation-induced enteropathy. In this study,morphological changes of bowel mucosa were analyzed in rats to presume the effect ofprobiotics on radiation-induced enteritis and its correlation with radiation dose. A total of48 adult male Sprague-Dawley rats were randomly assigned to two groups and received asolution containing 1.0×108 colony-forming units of Lactiobacillus acidophilus or wateronce daily for 10 days. Each of two groups was divided into three subgroups and abdominopelvicarea of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on theseventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and themucosal thickness and villus height of jejunum, ileum and colon were measured. Themorphological parameters of the small intestine represented significant differences betweentwo solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gysubgroup(P=0.065). There was no significant morphometric difference between twogroups irradiated with 20 Gy of radiation. Probiotics appear to be effective for themorphological shortening of small intestinal mucosa damaged by radiation less than orequal to 15 Gy.

Effect of Coenzyme Q10 on Radiation Nephropathy in Rats

기용간,김원택,김용호,김동현,배진숙,박달,전호상,이주혜,이자영,남지호 대한의학회 2017 Journal of Korean medical science Vol.32 No.5

The kidney is one of the most radiosensitive organs in the abdominal cavity and is the dose-limiting structure in cancer patients receiving abdominal or total body irradiation. In the present study, the effect of coenzyme Q10 (CoQ10) on radiation nephropathy was evaluated in rats. A total of 72 rats were equally randomized into 4 groups: Control, CoQ10, irradiation with 10 Gy (RT) + placebo, or RT + CoQ10. The 2 RT groups received single 10 Gy of abdominal irradiation. The 2 CoQ10 groups were supplemented daily with 1 mL of soybean oil containing 10 mg/kg of CoQ10. The RT + placebo and control groups received same dose of soybean oil. After 24 weeks, laboratory and histopathologic findings were compared. The 2 RT groups showed significant increases in blood urea nitrogen (BUN) and creatinine levels and significant pathologic changes such as glomerulosclerosis and tubulointerstitial fibrosis. CoQ10 supplementation resulted in significant reductions of BUN and creatinine levels compared with the RT + placebo group (P < 0.001 and P = 0.038, respectively). CoQ10 treatment significantly attenuated glomerular and tubular changes of irradiated kidney in semiquantitative analysis (P < 0.001 for both). Administration of CoQ10 can alleviate the radiation-induced nephropathy.

조기 성문암의 방사선치료에서 경동맥을 보호하기 위한 나선형 토모테라피의 적용 : Helical tomotherapy for minimizing carotid artery does in the radiohterapy of early glottic cancer

기용간 부산대학교 병원 암연구소 2014 부산대병원학술지 Vol.- No.36

노인 전립선암 환자에서 나선형 토모테라피의 적용

기용간,남지호,김원택,박달,김동현,이주혜,전호상,김동원 대한노인병학회 2013 Annals of geriatric medicine and research Vol.17 No.2

Background: Helical tomotherapy is a new form of image-guided intensity modulated radiation therapy that may improve local control and decrease radiation toxicity. The aim of this study was to evaluate if high-dose helical tomotherapy is tolerated by patients aged 75 years or older and if the side effects are comparable with those experienced by younger patients. Methods: Between January 2011 and August 2012, patients with prostate cancer who underwent helical tomotherapy without elective pelvic irradiation as definitive aim were reviewed and divided into two age groups: ≥75 years and <75 years. Acute genitourinary (GU) and lower gastrointestinal (GI) toxicities between the two groups were compared. Results: Twenty patients aged 75 years or older and 23 patients younger than 75 years were evaluated. Radiotherapy was administered to a total dose of 76−78Gy in 38−39 fractions or 70Gy in 28 fractions. There was no grade 3 or 4 acute toxicity and no grade 2 acute lower GI symptom, but the patients complained of grade 2 acute GU toxicity, 25.0% for the older group and 13.0% for the younger group. There was no significant difference in the rate of acute toxicity between the age groups. Hypofractionation showed a significant association with higher grade 2 acute GU toxicity (p=0.024) with the grade 2 acute GU toxicity having no significant correlation with T-stage, Gleason score, prostate specific antigen level, androgen deprivation therapy, and comorbidities. Conclusion: High-dose helical tomotherapy to the prostate without pelvic irradiation was well tolerated by elderly prostate cancer patients 75 years and older.

Structural Similarity Index 인자를 이용한 방사선 분할 조사간 환자 체위 변화의 자동화 검출능 평가: 초기 보고

윤한빈,전호상,이자영,이주혜,남지호,박달,김원택,기용간,김동현,Youn, Hanbean,Jeon, Hosang,Lee, Jayeong,Lee, Juhye,Nam, Jiho,Park, Dahl,Kim, Wontaek,Ki, Yongkan,Kim, Donghyun 한국의학물리학회 2015 의학물리 Vol.26 No.4

현대 방사선치료는 고선명 X선 투사영상을 이용하여 환자 및 종양의 위치를 확인하는 기술이 요구되지만, 3차원 영상 촬영을 위한 피폭량 및 영상정보의 급격한 증가는 환자에게 추가적인 부담이 될 수 있다. 본 연구에서는 영상의 구조 정보를 효과적으로 추출할 수 있는 Structural similarity (SSIM) 인자를 도입하여 매일 촬영하는 환자의 2차원 X선 영상간 차이를 자동 분석하여 환자의 위치 정확성의 검증 가능성을 제시하였다. 먼저 종양을 모사하기 위하여 구형 전산 팬텀의 크기와 위치를 변화시키면서 각각의 투사 영상을 시뮬레이션하고, SSIM 인자를 통해 영상 간 차이를 검출하여 분석하였다. 또한 12일간 매일 촬영한 방사선 치료 환자의 2차원 X선 영상들 간 차이를 동일한 방법으로 검출하였다. 그 결과 산출된 팬텀 변화에 따른 SSIM 값은 0.85~1 범위로, 관심영역(ROI)을 영상 전체가 아닌 팬텀으로 한정하였을 때는 0.006~1 범위로 나타나서 ROI 적용 시 민감도가 크게 상승하는 것을 확인하였다. 또한 임상 영상의 SSIM은 0.799~0.853 범위의 값을 나타냈으며 영상 간 차이가 SSIM 분포 상에 검출되는 것을 확인하였다. 본 연구결과는 소요 시간 및 피폭 등의 우려로 매일 사용하기 어려운 3차원 영상기법 대신 간단한 2차원 영상만을 이용하여 객관적이고 정량적인 환자 위치 정확성의 자동 평가 기법을 제공할 수 있을 것으로 기대된다. The modern radiotherapy technique which delivers a large amount of dose to patients asks to confirm the positions of patients or tumors more accurately by using X-ray projection images of high-definition. However, a rapid increase in patient's exposure and image information for CT image acquisition may be additional burden on the patient. In this study, by introducing structural similarity (SSIM) index that can effectively extract the structural information of the image, we analyze the differences between daily acquired x-ray images of a patient to verify the accuracy of patient positioning. First, for simulating a moving target, the spherical computational phantoms changing the sizes and positions were created to acquire projected images. Differences between the images were automatically detected and analyzed by extracting their SSIM values. In addition, as a clinical test, differences between daily acquired x-ray images of a patient for 12 days were detected in the same way. As a result, we confirmed that the SSIM index was changed in the range of 0.85~1 (0.006~1 when a region of interest (ROI) was applied) as the sizes or positions of the phantom changed. The SSIM was more sensitive to the change of the phantom when the ROI was limited to the phantom itself. In the clinical test, the daily change of patient positions was 0.799~0.853 in SSIM values, those well described differences among images. Therefore, we expect that SSIM index can provide an objective and quantitative technique to verify the patient position using simple x-ray images, instead of time and cost intensive three-dimensional x-ray images.

조기 성문암의 방사선치료에서 경동맥을 보호하기 위한 치료 계획

기용간(Yong Kan Ki),김원택(Won Taek Kim),남지호(Ji Ho Nam),김동현(Dong Hyun Kim),이주혜(Ju Hye Lee),박달(Dal Park),김동원(Dong Won Kim) 대한방사선종양학회 2011 Radiation Oncology Journal Vol.29 No.2

목적: 조기 성문암 환자에서 방사선치료의 만기 합병증인 뇌졸증을 예방하기 위해 경동맥을 보호하는 치료계획을 세우고 타당성을 알아보고자 연구를 계획하였다. 대상 및 방법: 2007년 1월부터 2010년 12월까지 원발성 조기 성문암으로 방사선치료를 받은 환자 중 전산화단층촬영모의치료를 받은 환자 31명의 모의치료 영상을 대상으로 하였다. 기존의 평행대항조사영역(parallel-opposing field, POF)과 조사영역의 빔방향상에서 동측의 경동맥을 제외하기 위해 빔각도를 조절한 조사영역(modified oblique field, MOF)으로 가상모의치료계획을 세우고 계획용표적체적, 경동맥과 척수의 선량분포, 평균선량과 V₃₅, V₄₀, V₅₀ 등을 기존 치료와 비교 분석하였다. 결과: 전체 31명 중 23명(74.2%)에서 25도, 8명(25.8%)에서 30도 전방으로 조절되었다. 두 군 사이에 선량에 따른 planning target volume의 체적백분율은 차이를 보이지 않았다(p=0.801). 경동맥의 선량에 따른 누적 체적백분율은 의미 있는 차이를 보였고(p<0.001), 26 ㏉ 이후에 MOF군에서 감소하기 시작했다. 경동맥의 평균선량은 POF군에서 38.5 ㏉, MOF군에서 26.3 ㏉였고(p=0.012), V₃₅, V₄₀, V₅₀ 모두에서 의미 있는 차이를 보였다. 결론: 이번 연구 결과로 조기 성문암 환자에서 빔각도를 전방으로 조절하여 경동맥의 조사선량을 감소시켰다. 이를 통해 경동맥 협착증을 예방하고 궁극적으로 뇌졸증을 줄일 수 있을 것으로 예상한다. Purpose: To examine the feasibility of the treatment planning for minimizing carotid artery dose in the radiotherapy of early glottic cancer. Materials and Methods: From 2007 to 2010, computed tomography simulation images of 31 patients treated by radiotherapy for early glottic cancer were analyzed. The virtual planning was used to compare the parallel-opposing fields (POF) with the modified oblique fields (MOF) placed at angles to exclude the ipsilateral carotid arteries. Planning target volume (PTV), irradiated volume, carotid artery, and spinal cord were analyzed at a mean dose, V₃₅, V₄₀, V₅₀ and with a percent dose-volume. Results: The beam angles were arranged 25 degrees anteriorly in 23 patients and 30 degrees anteriorly in 8 patients. The percent dose-volume of PTV shows no statistical difference. Conversely, the cumulative percent dose-volume of carotid artery shows the significant difference (p<0.001). The mean doses of carotid artery were 38.5 ㏉ for POF and 26.3 ㏉ for MOF and the difference was statistically significant (p=0.012). Similarly, V₃₅, V₄₀, and V₅₀ also showed significant differences between POF and MOF. Conclusion: The modified oblique field was respected to prevent a carotid artery stenosis and reduce the incidence of a stroke based on these results.

자궁내막암의 수술 후 방사선치료 결과에 영향을 미치는 예후인자

기용간(Yong Kan Ki),권병현(Byung Hyun Kwon),김원택(Won Taek Kim),남지호(Ji Ho Nam),윤만수(Man Su Yun),이형식(Hyung Sik Lee),김동원(Dong Won Kim) 대한방사선종양학회 2006 Radiation Oncology Journal Vol.24 No.2

목 적: 수술 후 보조적으로 방사선치료를 받은 자궁내막암 환자의 전체생존율, 무병생존율, 재발 부위 등을 분석하 여 이와 관련된 예후인자를 알아보고자 하였다. 대상 및 방법: 1992년 4월부터 2003년 5월까지 부산대학교병원에서 수술 후 방사선치료를 받은 자궁내막암 환자중 조직유형이 선암인 환자 54명을 대상으로 후향적 분석하였다. 전체 환자의 중앙 나이는 55세(35∼76세)였고, 병기 분포는 FIGO 병기 I군이 34명(63.0%), 병기 II군이 8명(14.8%), 병기 III군이 12명(22.2%)이었다. 모든 환자는 수술 및 외부 방사선조사(41.4∼54.0 Gy, 중앙값 50.4 Gy)를 받았고, 20명(전체 환자의 37.0%)의 환자에서 추가로 질내 근접치료(15.0∼24.0 Gy, 중앙값 15.0 Gy)를 받았다. 전체추적기간은 5∼115개월로 중앙추적기간은 35개월이었다. 분석 결과 유의인자로 나타난 조직분화도(histologic grade), 림프-혈관 침범 ymphovascular space invasion), 그리고 자궁근 침범 정도(myometrial invasion depth)를 점수화(GLM 점수)하여 생존분석을 시행하였다. 생존분석은 Kaplan-Meier 법을, 단변량 및 다변량 통계분석은 각각 log-rank 검정과 Cox 회귀분석을 사용했다. 결 과: 전체 자궁내막암 환자의 5년 생존율은 87.7%였고, 5년 무병생존율은 87.1%였다. 단변량 통계분석에서는 조 직분화도, 림프-혈관 침범, 그리고 자궁근 침범 정도가 전체생존율 및 무병생존율과 관련 있는 인자였고, 다변량 통계분석에서는 림프-혈관 침범이 무병생존율과 관련 있는 인자였다(p=0.0158). GLM 점수는 전체생존율 및 무병 생존율과 의미 있는 관계를 나타냈고(각각 p=0.0090, p=0.0073), 원격재발에도 유의한 예후인자로 나타났다(p=0.0132). 전체 환자 중 6명(11%)의 환자에서 재발을 보였고, 재발 부위는 대동맥 림프절 2명, 폐 2명, 쇄골상부림프절 1명, 질 1명이었다. 결 론: 수술 및 수술 후 방사선치료를 받은 자궁내막암 환자의 예후는 수술 후의 병리 소견과 밀접한 관계를 가지 고 있다. 더 많은 연구를 통해 자궁내막암 환자의 예후인자를 체계화한다면, 병의 진행양상을 예견하고 대처하는데 도움이 될 것이다. Purpose: This study was performed to determine the prognostic factors influencing relapse pattern, overall and disease-free survival in patients treated with postoperative radiotherapy for endometrial carcinoma. Materials and Methods: The records of 54 patients with endometrial adenocarcinoma treated postoperative radiotherapy at Pusan National University Hospital between April 1992 and May 2003 were reviewed retrospectively. Median age of the patients was 55 (range 35∼76). The distribution by surgical FIGO stages were 63.0% for 0Stage I, 14.8% for Stage II, 22.2% for Stage III. All patients received postoperative external radiotherapy up to 41.4∼54 Gy (median: 50.4 Gy). Additional intravaginal brachytherapy was applied to 20 patients (37.0% of all). Median follow-up time was 35 months (5∼115 months). Significant factors of this study: histologic grade, lymphovascular space invasion and myometrial invasion depth were scored (GLM score) and analyzed. Survival analysis was performed using Kaplan-Meier method. The log-rank test was used for univariate analysis and the Cox regression model for multivariate analysis. Results: 5-year overall and disease-free survival rates were 87.7% and 87.1%, respectively. Prognostic factors related with overall and disease-free survival were histologic grade, lymphovascular space invasion and myometrial invasion according to the univariate analysis. According to the multivariate analysis, lymphovascular space invasion was associated with decreased disease-free survival. GLM score was a meaningful factor affecting overall and disease-free survival (p=0.0090, p=0.0073, respectively) and distant recurrence (p=0.0132), which was the sum of points of histologic grade, lymphovascular space invasion and myometrial invasion. Total failure rate was 11% with 6 patients. Relapse sites were 2 para-aortic lymph nodes, 2 lungs, a supraclavicular lymph node and a vagina. Conclusion: The prognosis in patients with endometrial carcinoma treated by postoperative radiotherapy was closely related with surgical histopathology. If further explorations confirm the system of prognostic factors in endometrial carcinoma, it will help us to predict the progression pattern and to manage.

진행성 두경부 상피세포암 환자에서 소분할 방사선조사 후의 치료반응 평가

김원택(Won Taek Kim),기용간(Yong Kan Ki),남지호(Ji Ho Nam),김동현(Dong Hyun Kim),조규섭(Kyu Sup Cho),이진춘(Jin Choon Lee),이병주(Byung Joo Lee),김동원(Dong Won Kim) 대한방사선종양학회 2009 Radiation Oncology Journal Vol.27 No.2

목 적: 근치적 치료가 힘든 두경부 진행암 환자들을 대상으로 시행된 소분할 방사선조사의 치료반응 정도를 객관적 으로 평가해 보고, 이런 환자들에 대한 적절한 방사선치료 방법을 알아보고자 이 연구를 진행하였다. 대상 및 방법: 두경부에서 발생한 상피세포암종으로 진단되어 1998년부터 2008년까지 원발 병변 또는 림프절 병변에 대해 3 Gy 분할선량으로 고식적 소분할 방사선치료를 받았던 환자 31명을 대상으로 후향적 분석을 하였다. 대상 환자들의 방사선치료 전 컴퓨터단층촬영 영상자료를 통해 종양의 용적을 측정하였고, 이를 방사선치료 종료 후 2∼3개월째의 컴퓨터단층촬영 자료와 비교하여 치료반응을 평가하였다. 아울러 소분할 방사선치료로 인한 치료독성의 빈도와 정도를 확인하였고, 전체 생존율 및 무진행 생존율, 그리고 생존율이나 치료반응과 관련된 예후인자들 알아보고자 통계 분석 작업을 하였다. 결 과: 대상 환자들의 평균 연령은 70세였으며, 85%의 경우가 stage 4였다. 종양의 용적은 평균 128.4 cc였고, ECOG 활동점수 상 1점과 2점이 67.7%였다. 총방사선량은 24∼45 Gy (중간값 36 Gy)로 2명을 제외한 대부분의 환자가 30 Gy 이상 조사받았으며, 치료기간은 10∼25일이었다. 완전반응을 보인 경우가 4명(12.9%)이었고, 19명(61.3%)의 환자에서 부분반응을 보였다. 중간 생존기간은 8.9개월이었으며, 1년 무진행생존율은 12.9%였다. 치료반응 정도에 따른 생존율의 차이를 발견할 수 있었으며, 원발 부위, 병기, 종양의 용적, 방사선치료 범위, 총방사선량 등이 생존율이나 치료반응 정도와 유의한 관련이 있었다. 치료 기간 및 치료 종결 후 grade 4 이상의 치료독성은 없었다. 결 론: 소분할 방사선치료 결과 약 74%의 환자들에서 종양이 줄어드는 것을 객관적으로 확인할 수 있었다. 적절한 분할선량 및 추가 방사선치료가 필요한 환자들의 선별에 있어서는 추가적인 연구가 필요하겠다. Purpose: This study was performed to objectively evaluate the rate of tumor response to hypofractionated radiotherapy for advanced squamous cell carcinomas of the head and neck. Materials and Methods: Thirty-one patients with advanced squamous cell carcinoma of the head and neck, who were treated by hypofractionated radiotherapy with 3 Gy per fraction for palliative purpose between 1998 and 2008, were reviewed retrospectively. Every tumor-volume was measured and evaluated from CT (computed tomography) images obtained before and 2∼3 months after radiotherapy. The radiation toxicity was assessed during and after radiotherapy. A statistical analysis was performed to investigate overall survival, progressionfree survival, and the prognostic factors for survival and response. Results: The median age of the study patients was 70 years. In addition, 85% of the patients were in stage 4 cancer and 66.7% had an ECOG performance status of 1∼2. The mean tumor-volume was 128.4 cc. Radiotherapy was administered with a total dose of 24∼45 Gy (median: 36 Gy) over 10∼25 days. Twenty-nine patients were treated with 30 Gy or more. The observed complete response rate was 12.9% and the partial response rate was 61.3%. Median survival time was 8.9 months and the 1-year progression-free survival rate was 12.9%. The treatment response rate was confirmed as a prognostic factor in the rate of survival. The primary site, stage, tumor-volume, radiotherapy field and overall radiation-dose showed a significant relationship with survival and treatment response. No grade 4 toxicity was observed during and after radiotherapy. Conclusion: There was an objective tumor-regression in about 74% of patients treated by hypofractionated radiotherapy. Further evaluation is needed to select the appropriate fraction-size and patient who may require the additional radiotherapy.

유리선량계의 전처리 방법이 방사선 치료 선량 측정에 미치는 영향

전호상,남지호,박달,김용호,김원택,김동원,기용간,김동현,이주혜,Jeon, Hosang,Nam, Jiho,Park, Dahl,Kim, Yong Ho,Kim, Wontaek,Kim, Dongwon,Ki, Yongkan,Kim, Donghyun,Lee, Ju Hye 한국의학물리학회 2013 의학물리 Vol.24 No.2

여러 치료선량 측정기들 중 치료 현장에서의 사용이 간편한 형광물질 기반 측정기인 유리선량계(Glass Rod Dosimeter, GRD)는 방사선 조사 후 측정 소자의 안정화를 위한 전처리(Pre-processing) 과정이 필수적이며, 가열방식($70^{\circ}C$, 30분)과 대기방식($20^{\circ}C$, 24시간)의 두 가지의 전처리 방식이 사용되고 있다. 본 연구에서는 각각의 전처리 조건이 측정 결과에 미치는 영향을 분석하여 사용자들에게 유용한 참고자료를 제시하고자 한다. 20개의 GRD 소자들 모두에 같은 선량을 조사한 후, 10개씩 나누어 각각 다른 전처리 방식을 사용하여 판독함으로써 각 전처리 방식의 특징들을 상호 비교하였다. 가열방식의 경우 소자 간 판독 편차는 1.13%, 시간에 따른 평균 판독값의 편차는 최대 5.33%였다. 대기방식의 경우에는 소자 간 판독 편차가 0.49%, 시간에 따른 평균 판독값의 편차는 최대 1.28%로 나타났다. 또한 동일한 선량을 주었을 때 전처리 방식에 따라 판독 절대값은 4.1%의 차이를 보였다. 또한 251명의 환자들을 대상으로 한 임상 측정 평가 결과 부위에 따라 다르지만 평균적으로 5% 이내의 측정 오차를 보였으나, 대기 방식의 경우 판독 시점에 따른 영향이 상대적으로 크게 나타났다. 결론적으로 GRD는 치료 현장에서 사용하기에 적합하나 신속한 판독이 요구되지 않는다면 대기방식의 전처리가 보다 적합하며 정해진 판독 시점을 지켜야 한다. 또한 치료 부위 등 조사 조건의 변화에 관계없이 안정적인 정확성을 기대할 수 있는 측정 방법에 대한 연구가 향후 필요하다고 생각된다. The experimental verification of treatment planning on the treatment spot is the ultimate method to assure quality of radiotherapy, so in-vivo skin dose measurement is the essential procedure to confirm treatment dose. In this study, glass rod dosimeter (GRD), which is a kind of photo-luminescent based dosimeters, was studied to produce a guideline to use GRDs in vivo dosimetry for quality assurance of radiotherapy. The pre-processing procedure is essential to use GRDs. This is a heating operation for stabilization. Two kinds of pre-processing methods are recommended by manufacturer: a heating method (70 degree, 30 minutes) and a waiting method (room temperature, 24 hours). We equally irradiated 1.0 Gy to 20 GRD elements, and then different preprocessing were performed to 10 GRDs each. In heating method, reading deviation of GRDs at same time were relatively high, but the deviation was very low as time went on. In waiting method, the deviation among GRDs was low, but the deviation was relatively high as time went on. The meaningful difference was found between mean reading values of two pre-processing methods. Both methods present mean dose deviation under 5%, but the relatively high effect by reading time was observed in waiting method. Finally, GRD is best to perform in-vivo dosimetry in the viewpoint of accuracy and efficiency, and the understanding of how pre-processing affect the accuracy is asked to perform most accurate in-vivo dosimetry. The further study is asked to acquire more stable accuracy in spite of different irradiation conditions for GRD usage.

Prognostic value of the maximum standardized uptake value for the locoregional control in early glottic cancer

김동현,기용간,주지현,Jeon Hosang,Park Dahl,남지호,김원택 대한방사선종양학회 2021 Radiation Oncology Journal Vol.39 No.4

Purpose: To evaluate the prognostic value of the pretreatment maximum standardized uptake value (SUVmax) for locoregional control (LRC) of early glottic cancer treated with primary radiotherapy.Materials and Methods: We retrospectively reviewed the medical records of 101 patients with T1-T2N0 glottic cancer treated with helical tomotherapy between 2013 and 2016. The clinical T-stages were T1 in 87 (86.1%) and T2 in 14 (13.9%) patients. The median total dose was 63 Gy (63–67.5 Gy) in 2.25 Gy per fraction. The survival outcomes were plotted using Kaplan-Meier curves. Receiver operating characteristic curves were used to assess the optimal SUVmax cut-off value for predicting locoregional recurrence.Results: The median follow-up period was 58 months (range, 11 to 90 months). The 5-year overall survival (OS) and locoregional recurrence-free survival rates were 96.8% and 85.4%, respectively. The median pretreatment SUVmax of the primary tumor for all 101 patients was 2.3 (range, 1.1 to 9.1). The best cut-off value for SUVmax for predicting LRC was 3.3, with a sensitivity of 78.6% and specificity of 73.6%. Univariate analysis showed that T-stage, overall treatment time (≥43 days), and high SUVmax (≥3.3) were significant predictors of LRC. Multivariate analysis showed that LRC was independently affected by a high SUVmax (≥3.3) (hazard ratio = 5.505, p = 0.020).Conclusion: High pretreatment SUVmax (≥3.3) is a negative prognostic factor for LRC in early glottic cancer patients treated with primary radiotherapy.