• Title, Summary, Keyword: stereotactic radiotherapy

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Maximum diameter versus volumetric assessment for the response evaluation of vestibular schwannomas receiving stereotactic radiotherapy

  • Choi, Youngmin;Kim, Sungmin;Kwak, Dong-Won;Lee, Hyung-Sik;Kang, Myung-Koo;Lee, Dong-Kun;Hur, Won-Joo
    • Radiation Oncology Journal
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    • v.36 no.2
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    • pp.114-121
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    • 2018
  • Purpose: To explore the feasibility of maximum diameter as a response assessment method for vestibular schwannomas (VS) after stereotactic radiosurgery or fractionated stereotactic radiotherapy (RT), we analyzed the concordance of RT responses between maximum diameters and volumetric measurements. Materials and Methods: Forty-two patients receiving curative stereotactic radiosurgery or fractionated stereotactic RT for VS were analyzed retrospectively. Twelve patients were excluded: 4 did not receive follow-up magnetic resonance imaging (MRI) scans and 8 had initial MRI scans with a slice thickness >3 mm. The maximum diameter, tumor volume (TV), and enhanced tumor volume (ETV) were measured in each MRI study. The percent change after RT was evaluated according to the measurement methods and their concordances were calculated with the Pearson correlation. The response classifications were determined by the assessment modalities, and their agreement was analyzed with Cohen kappa statistics. Results: Median follow-up was 31.0 months (range, 3.5 to 86.5 months), and 90 follow-up MRI studies were analyzed. The percent change of maximum diameter correlated strongly with TV and ETV (r(p) = 0.85, 0.63, p = 0.000, respectively). Concordance of responses between the Response Evaluation Criteria in Solid Tumors (RECIST) using the maximum diameters and either TV or ETV were moderate (kappa = 0.58; 95% confidence interval, 0.32-0.85) or fair (kappa = 0.32; 95% confidence interval, 0.05-0.59), respectively. Conclusions: The percent changes in maximum diameter and the responses in RECIST were significantly concordant with those in the volumetric measurements. Therefore, the maximum diameters can be used for the response evaluation of VS following stereotactic RT.

Successful Treatment of Infantile Fibrosarcoma Spinal Metastasis by Chemotherapy and Stereotactic Hypofractionated Radiotherapy

  • Lo, Cheng-Hsiang;Cheng, Shin-Nan;Lin, Kuen-Tze;Jen, Yee-Min
    • Journal of Korean Neurosurgical Society
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    • v.54 no.6
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    • pp.528-531
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    • 2013
  • We report a case of infantile fibrosarcoma in an 8-month-old boy manifested as a right-sided lower leg mass. Repeated local recurrence and distant metastasis were noted during the following three-year period. Whole body fluoro-deoxyglucose positron emission tomography scan revealed an asymptomatic metastasis involving the fourth lumbar vertebrae. The patient received chemotherapy (VAC regimen) with Cyberknife$^{(R)}$ stereotactic hypofractionated radiotherapy (26 Gy; 4 fractions). This treatment reduced tumor size by 23% without acute radiation toxicity even after 33 months. This case suggests that combining chemotherapy and this form of radiotherapy may be safe and effective against childhood spinal metastasis.

Utility Estimation of the Manufactured Stereotactic Body Radiotherapy Immobilization (자체 제작한 정위적체부방사선치료(Stereotactic Body Radiotherapy) 고정용구의 유용성 평가)

  • Lee, Dong-Hoon;Ahn, Jong-Ho;Seo, Jeong-Min;Shin, Eun-Hyeok;Choi, Byeong-Gi;Song, Gi-Won
    • The Journal of Korean Society for Radiation Therapy
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    • v.23 no.1
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    • pp.1-6
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    • 2011
  • Purpose: Immobilizations used in order to maintain the reproducibility of a patient set-up and the stable posture for a long period are important more than anything else for the accurate treatment when the stereotactic body radiotherapy is underway. So the purpose of this study is to adapt the optimum immobilizations for the stereotactic body radiotherapy by comparing two commercial immobilizations with the self-manufactured immobilizations. Materials and Methods: Five people were selected for the experiment and three different immobilizations (A: Wing-board, B: BodyFix system, C: Arm up holder with vac-lock) were used to each target. After deciding on the target's most stable respiratory cycles, the targets were asked to wear a goggle monitor and maintain their respiration regularly for thirty minutes to obtain the respiratory signals. To analyze the respiratory signal, the standard deviation and the variation value of the peak value and the valley value of the respiratory signal were separated by time zone with the self-developed program at the hospital and each tie-downs were compared for the estimation by calculating a comparative index using the above. Results: The stability of each immobilizations were measured in consideration of deviation changes studied in each respiratory time lapse. Comparative indexes of each immobilizations of each experimenter are shown to be A: 11.20, B: 4.87, C: 1.63 / A: 3.94, B: 0.67, C: 0.13 / A: 2.41, B: 0.29, C: 0.04 / A: 0.16, B: 0.19, C: 0.007 / A: 35.70, B: 2.37, C: 1.86. And when all five experimenters wore the immobilizations C, the test proved the most stable value while four people wearing A and one man wearing D expressed relatively the most unstable respiratory outcomes. Conclusion: The self-developed immobilizations, so called the arm up holder vac-lock for the stereotactic body radiotherapy is expected to improve the effect of the treatment by decreasing the intra-fraction organ motions because it keeps the respiration more stable than other two immobilizations. Particularly in case of the stereotactic body therapy which requires the maintenance of set-up state for a long time, the self-developed immobilizations is thought to more useful for stereotactic body radiotherapy rather than the rest two immobilizations with instable respiratory cycle as time passes.

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Minimally Invasive Stereotactical Radio-ablation of Adrenal Metastases as an Alternative to Surgery

  • Franzese, Ciro;Franceschini, Davide;Cozzi, Luca;D'Agostino, Giuseppe;Comito, Tiziana;De Rose, Fiorenza;Navarria, Pierina;Mancosu, Pietro;Tomatis, Stefano;Fogliata, Antonella;Scorsetti, Marta
    • Cancer Research and Treatment
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    • v.49 no.1
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    • pp.20-28
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    • 2017
  • Purpose The purpose of this study was to study the clinical outcome for patients with metastases of the adrenal gland treated with stereotactic body radiation therapy. Materials and Methods Forty-six patients were studied retrospectively. The dose prescription was 40 Gy in four fractions. Dosimetric analysis was performed using the dose volume histograms while clinical outcome was assessed using actuarial analysis with determination of the overall survival (OS) and local control (LC) rates. Results The planning objectives were met for all patients. With a median follow-up period of 7.6 months, at the last follow-up 42 patients (91.3%) were alive and four had died because of distant progression. The actuarial mean OS was $28.5{\pm}1.6months$, the median was not reached. One-year and 2-year OS were $87.6{\pm}6.1%$. None of the risk factors was significant in univariate analysis. Actuarial mean LC was $14.6{\pm}1.8months$ (95% confidence interval [CI], 11.0 to 18.2) and median LC was $14.5{\pm}2.0months$ (95% CI, 10.5 to 18.5). One-year and 2-year LC were $65.5{\pm}11.9%$ and $40.7{\pm}15.8%$, respectively. A mild profile of toxicity was observed in the cohort of patients. Forty patients (86.9%) showed no complication (grade 0); two patients reported asthenia, six patients (13.1%) reported either pain, nausea, or vomiting. Of these six patients, five patients (10.9%) were scored as grade 1 toxicity while one patient (2.2%) was scored as grade 2. Conclusion Stereotactic body radiation therapy treatment provided an adequate clinical response in the management of adrenal gland metastases.

Study on The Development of A New Whole Body Fame

  • Chung, Jin-Bum;Suh, Tae-Suk;Chung, Won-Kyun;Choe, Bo-Young;Lee, Hyoung-Koo
    • Proceedings of the Korean Society of Medical Physics Conference
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    • pp.136-137
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    • 2002
  • We have been researching upgrade version of a stereotactic whole body frame, used for evaluating daily setup accuracy of the patient positioning during fractionated extra-cranial stereotactic radiotherapy. Currently, we are focusing on the development of a new stereotactic whole body frame, and then will handle organ movement produced by breathing at the next stage. MeV-Green is chosen for the best immobilizer possible and the epoxy board is for the frame with the dimension of 110 em in length, 50 cm in width in order to maximize transmission rate of the beam from lateral or posterior direction and to fit CT and PET scanners with an aperture of 55 cm at least. The key point of an upgraded stereotactic whole body frame will be set on the collision-free rotation of the gantry with the frame, and the development of the checking structure for the daily patient repositioning regarding internal target.

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The Effectiveness of Volumetric Modulated arc Radiotherapy to Treat Patients with Metastatic Spinal Tumors

  • Park, Hyo-Kuk;Kim, Sungchul
    • International Journal of Contents
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    • v.13 no.4
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    • pp.12-15
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    • 2017
  • Among the possible stereotactic body radiation therapy (SBRT) modalities used to treat patients with metastatic spinal tumors, this study compared Cyberknife, tomotherapy, and volumetric modulated arc radiotherapy (VMAT). We established treatment plans for each of them modality and quantitatively analyzed the dose evaluation factors of the dose-volume histogram (DVH) for all spinal bones, focusing on the tumor and spinal cord, in order to examine the usefulness of VMAT. For the treatment planning dose, the mean dose ($D_{max}$) and $D_{5%}$ showed statistical differences in the target dose, but no difference was shown in the spinal cord dose. For the DVH indices, tomotherapy showed the best performance was the best in terms of uniformity index, while VMAT showed better performance was better than the other two modalities in terms of the conformity index and the dose gradient index. VMAT had a much shorter treatment time than Cyberknife and tomotherapy. These findings suggest that VMAT FFF is the most effective therapy for SBRT of patients with metastatic spinal tumors for whom a high dose of radiation is prescribed.

Whole Brain Radiotherapy Combined with Stereotactic Radiosurgery versus Stereotactic Radiosurgery Alone for Brain Metastases

  • Adas, Yasemin Guzle;Yazici, Omer;Kekilli, Esra;Akkas, Ebru Atasever;Karakaya, Ebru;Ucer, Ali Riza;Ertas, Gulcin;Calikoglu, Tamer;Elgin, Yesim;Inan, Gonca Altinisik;Kocer, Ali Mert;Guney, Yildiz
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7595-7597
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    • 2015
  • Background: The aim of this study was to evaluate the effect of whole brain radiotherapy (WBRT) combined with streotactic radiosurgery versus stereotactic radiosurgery (SRS) alone for patients with brain metastases. Materials and Methods: This was a retrospective study that evaluated the results of 46 patients treated for brain metastases at Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Radiation Oncology Department, between January 2012 and January 2015. Twenty-four patients were treated with WBRT+SRS while 22 patients were treated with only SRS. Results: Time to local recurrence was 9.7 months in the WBRT+SRS arm and 8.3 months in SRS arm, the difference not being statistically significant (p=0.7). Local recurrence rate was higher in the SRS alone arm but again without significance (p=0,06). Conclusions: In selected patient group with limited number (one to four) of brain metastases SRS alone can be considered as a treatment option and WBRT may be omitted in the initial treatment.

Survey of the Patterns of Using Stereotactic Ablative Radiotherapy for Early-Stage Non-small Cell Lung Cancer in Korea

  • Song, Sanghyuk;Chang, Ji Hyun;Kim, Hak Jae;Kim, Yeon Sil;Kim, Jin Hee;Ahn, Yong Chan;Kim, Jae-Sung;Song, Si Yeol;Moon, Sung Ho;Cho, Moon June;Youn, Seon Min
    • Cancer Research and Treatment
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    • v.49 no.3
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    • pp.688-694
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    • 2017
  • Purpose Stereotactic ablative radiotherapy (SABR) is an effective emerging technique for early-stage non-small cell lung cancer (NSCLC). We investigated the current practice of SABR for early-stage NSCLC in Korea. Materials and Methods We conducted a nationwide survey of SABR for NSCLC by sending e-mails to all board-certified members of the Korean Society for Radiation Oncology. The survey included 23 questions focusing on the technical aspects of SABR and 18 questions seeking the participants' opinions on specific clinical scenarios in the use of SABR for early-stage NSCLC. Overall, 79 radiation oncologists at 61/85 specialist hospitals in Korea (71.8%) responded to the survey. Results SABR was used at 33 institutions (54%) to treat NSCLC. Regarding technical aspects, the most common planning methods were the rotational intensity-modulated technique (59%) and the static intensity-modulated technique (49%). Respiratory motion was managed by gating (54%) or abdominal compression (51%), and 86% of the planning scans were obtained using 4-dimensional computed tomography. In the clinical scenarios, the most commonly chosen fractionation schedule for peripherally located T1 NSCLC was 60 Gy in four fractions. For centrally located tumors and T2 NSCLC, the oncologists tended to avoid SABR for radiotherapy, and extended the fractionation schedule. Conclusion The results of our survey indicated that SABR is increasingly being used to treat NSCLC in Korea. However, there were wide variations in the technical protocols and fractionation schedules of SABR for early-stage NSCLC among institutions. Standardization of SABR is necessary before implementing nationwide, multicenter, randomized studies.

A feasibility study evaluating the relationship between dose and focal liver reaction in stereotactic ablative radiotherapy for liver cancer based on intensity change of Gd-EOB-DTPA-enhanced magnetic resonance images

  • Jung, Sang Hoon;Yu, Jeong Il;Park, Hee Chul;Lim, Do Hoon;Han, Youngyih
    • Radiation Oncology Journal
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    • v.34 no.1
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    • pp.64-75
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    • 2016
  • Purpose: In order to evaluate the relationship between the dose to the liver parenchyma and focal liver reaction (FLR) after stereotactic ablative body radiotherapy (SABR), we suggest a novel method using a three-dimensional dose distribution and change in signal intensity of gadoxetate disodium-gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) hepatobiliary phase images. Materials and Methods: In our method, change of the signal intensity between the pretreatment and follow-up hepatobiliary phase images of Gd-EOB-DTPA-enhanced MRI was calculated and then threshold dose (TD) for developing FLR was obtained from correlation of dose with the change of the signal intensity. For validation of the method, TDs for six patients, who had been treated for liver cancer with SABR with 45-60 Gy in 3 fractions, were calculated using the method, and we evaluated concordance between volume enclosed by isodose of TD by the method and volume identified as FLR by a physician. Results: The dose to normal liver was correlated with change in signal intensity between pretreatment and follow-up MRI with a median $R^2$ of 0.935 (range, 0.748 to 0.985). The median TD by the method was 23.5 Gy (range, 18.3 to 39.4 Gy). The median value of concordance was 84.5% (range, 44.7% to 95.9%). Conclusion: Our method is capable of providing a quantitative evaluation of the relationship between dose and intensity changes on follow-up MRI, as well as determining individual TD for developing FLR. We expect our method to provide better information about the individual relationship between dose and FLR in radiotherapy for liver cancer.

Hypofractionated stereotactic body radiotherapy in low- and intermediate-risk prostate carcinoma

  • Kim, Hun Jung;Phak, Jeong Hoon;Kim, Woo Chul
    • Radiation Oncology Journal
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    • v.34 no.4
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    • pp.260-264
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    • 2016
  • Purpose: Stereotactic body radiotherapy (SBRT) takes advantage of low ${\alpha}/{\beta}$ ratio of prostate cancer to deliver a large dose in few fractions. We examined clinical outcomes of SBRT using CyberKnife for the treatment of low- and intermediate-risk prostate cancer. Materials and Methods: This study was based on a retrospective analysis of the 33 patients treated with SBRT using CyberKnife for localized prostate cancer (27.3% in low-risk and 72.7% in intermediate-risk). Total dose of 36.25 Gy in 5 fractions of 7.25 Gy were administered. The acute and late toxicities were recorded using the Radiation Therapy Oncology Group scale. Prostate-specific antigen (PSA) response was monitored. Results: Thirty-three patients with a median 51 months (range, 6 to 71 months) follow-up were analyzed. There was no biochemical failure. Median PSA nadir was 0.27 ng/mL at median 33 months and PSA bounce occurred in 30.3% (n = 10) of patients at median at median 10.5 months after SBRT. No grade 3 acute toxicity was noted. The 18.2% of the patients had acute grade 2 genitourinary (GU) toxicities and 21.2% had acute grade 2 gastrointestinal (GI) toxicities. After follow-up of 2 months, most complications had returned to baseline. There was no grade 3 late GU and GI toxicity. Conclusion: Our experience with SBRT using CyberKnife in low- and intermediate-risk prostate cancer demonstrates favorable efficacy and toxicity. Further studies with more patients and longer follow-up duration are required.