1.Application of Intensity Modulated Radiation Therapy (IMRT) in Prostate Cancer.
Suk Won PARK ; Do Hoon OH ; Hoon Sik BAE ; Byung Chul CHO ; Jae Hong PARK ; Seung Hee HAN
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2002;20(1):68-72
This study was done to implement intensity-modulated radiation therapy (IMRT) for the treatment of primary prostate cancer and to compare this technique with conventional treatment methods. A 72-year- old male patient with prostate cancer stage T2a was treated with IMRT delivered with dynamic multi-leaf collimation. Treatment was designed using an inverse planning algorithm, which accepts dose and dose- volume constraints for targets and normal structures. The IMRT plan was compared with a three-dimensional (3D) plan using the same 6 fields technique. Lower normal tissue doses and improved target coverage were achieved using IMRT at current dose levels, and facilitate dose escalation to further enhance locoregional control and organ movement during radiotherapy is an important issue of IMRT in prostate cancer.
Humans
;
Male
;
Prostate*
;
Prostatic Neoplasms*
;
Radiotherapy
2.Radiotherapy for prostate cancer.
Journal of the Korean Medical Association 2015;58(1):21-29
Radiotherapy has an important role in the management of prostate cancer patients. It can be used as definitive treatment in place of surgery, postoperative adjuvant radiotherapy, or salvage treatment when recurrences develop after surgery. During definitive radiotherapy treatment, dose escalation can improve biochemical control but has not led to improved survival to date. Hypofractionated radiotherapy is applied for prostate cancer treatment, since prostate cancer has a low alpha/beta ratio. Contrary to theoretical expectations, hypofractionated treatment does not show improved therapeutic results and decreased toxicity, but it can reduce overall treatment time. Ongoing non-inferiority trials may assist in determining optimal hypofractionated treatment regimens. Adjuvant radiotherapy in patients with pathological T3 or positive resection margins can improve biochemical control and might increase overall survival. However, there is debate regarding the superiority of adjuvant radiotherapy over early salvage radiotherapy in high-risk patients after surgery. To address this issue, it will be necessary to wait for the results of current randomized trials.
Humans
;
Prostatic Neoplasms*
;
Proton Therapy
;
Radiotherapy*
;
Radiotherapy, Adjuvant
;
Recurrence
3.Current status and future perspectives of interstitial 125I seed implantation treatment for malignant tumors.
Chinese Journal of Oncology 2012;34(2):81-83
Brachytherapy
;
methods
;
Brain Neoplasms
;
radiotherapy
;
Glioma
;
radiotherapy
;
Humans
;
Iodine Radioisotopes
;
therapeutic use
;
Liver Neoplasms
;
radiotherapy
;
Lung Neoplasms
;
radiotherapy
;
Male
;
Mouth Neoplasms
;
radiotherapy
;
Neoplasms
;
radiotherapy
;
Pancreatic Neoplasms
;
radiotherapy
;
Prostatic Neoplasms
;
radiotherapy
;
Radiotherapy Dosage
;
Survival Rate
4.Stereotactic radiotherapy of the prostate: fractionation and utilization in the United States.
Joseph P WEINER ; David SCHWARTZ ; Meng SHAO ; Virginia OSBORN ; Kwang CHOI ; David SCHREIBER
Radiation Oncology Journal 2017;35(2):137-143
PURPOSE: To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. MATERIALS AND METHODS: Data was analyzed on men diagnosed with localized prostate cancer between 2004–2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. RESULTS: There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was 725 cGy × 5 fractions (49.6%) followed by 700 cGy × 5 fractions (21.3%). CONCLUSIONS: Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently 700-725 cGy × 5 fractions appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase.
Humans
;
Male
;
Prostate*
;
Prostatic Neoplasms
;
Radiosurgery
;
Radiotherapy*
;
United States*
5.Interfraction Prostate Movement in Bone Alignment After Rectal Enema for Radiotherapy.
Young Eun SEO ; Tae Hyo KIM ; Ki Soo LEE ; Won Yeol CHO ; Hyung Sik LEE ; Won Joo HUR ; Youngmin CHOI
Korean Journal of Urology 2014;55(1):23-28
PURPOSE: To assess the effect of a rectal enema on interfraction prostate movement in bone alignment (BA) for prostate radiotherapy (RT), we analyzed the spatial difference in prostates in a bone-matched setup. MATERIALS AND METHODS: We performed BA retrospectively with data from prostate cancer patients who underwent image-guided RT (IGRT). The prostate was identified with implanted fiducial markers. The setup for the IGRT was conducted with the matching of three fiducial markers on RT planning computed tomography images and those on two oblique kV x-ray images. Offline BA was performed at the same position. The coordinates of a virtual prostate in BA and a real prostate were obtained by use of the ExaxTrac/NovalisBody system, and the distance between them was calculated as the spatial difference. Interfraction prostate displacement was drawn from the comparison of the spatial differences. RESULTS: A total of 15 patients with localized prostate cancer treated with curative hypofractionated IGRT were enrolled. A total of 420 fractions were analyzed. The mean of the interfraction prostate displacements after BA was 3.12+/-2.00 mm (range, 0.20-10.53 mm). The directional difference was profound in the anterior-posterior and supero-inferior directions (2.14+/-1.73 mm and 1.97+/-1.44 mm, respectively) compared with the right-left direction (0.26+/-0.22 mm, p<0.05). The required margin around the clinical target volume was 4.97 mm with the formula of van Herk et al. CONCLUSIONS: The interfraction prostate displacement was less frequent when a rectal enema was performed before the procedure. A rectal enema can be used to reduce interfraction prostate displacement and resulting clinical target volume-to-planning target volume margin.
Enema*
;
Fiducial Markers
;
Humans
;
Prostate*
;
Prostatic Neoplasms
;
Radiotherapy*
;
Retrospective Studies
6.Multimodal therapy for locally advanced prostate cancer: the roles of radiotherapy, androgen deprivation therapy, and their combination.
Radiation Oncology Journal 2017;35(3):189-197
Locally advanced prostate cancer (LAPC) is defined as histologically proven T3–4 prostatic adenocarcinoma. In this review, we define the individual roles of radiotherapy (RT), short-term (ST-) and long-term (LT-) androgen deprivation therapy (ADT), and their combination in multimodal therapy for LAPC. Despite limitations in comparing the clinical outcomes among published papers, in the present study, a trend of 10-year clinical outcomes was roughly estimated by calculating the average rates weighted by the cohort number. With RT alone, the following rates were estimated: 87% biochemical failure, 34% local failure (LF), 48% distant metastasis (DM), 38% overall survival (OS), and 27% disease-specific mortality (DSM). Those associated with ADT alone were 74% BCF, 54% OS, and 25% DSM, which appeared to be better than those of RT alone. The addition of ADT to RT produced a notable local and systemic effect, regardless of ST- or LT-ADT. The LF rate decreased from 34% with RT alone to 21% with ST-ADT and further to 15% with LT-ADT. The DM and DSM rates also showed a similar trend among RT alone, RT+ST-ADT, and RT+LT-ADT. The combination of RT+LT-ADT resulted in the best long-term clinical outcomes, indicating that both RT and ADT are important parts of multimodal therapy.
Adenocarcinoma
;
Cohort Studies
;
Mortality
;
Neoplasm Metastasis
;
Prostate*
;
Prostatic Neoplasms*
;
Radiotherapy*
7.Multimodal therapy for locally advanced prostate cancer: the roles of radiotherapy, androgen deprivation therapy, and their combination.
Radiation Oncology Journal 2017;35(3):189-197
Locally advanced prostate cancer (LAPC) is defined as histologically proven T3–4 prostatic adenocarcinoma. In this review, we define the individual roles of radiotherapy (RT), short-term (ST-) and long-term (LT-) androgen deprivation therapy (ADT), and their combination in multimodal therapy for LAPC. Despite limitations in comparing the clinical outcomes among published papers, in the present study, a trend of 10-year clinical outcomes was roughly estimated by calculating the average rates weighted by the cohort number. With RT alone, the following rates were estimated: 87% biochemical failure, 34% local failure (LF), 48% distant metastasis (DM), 38% overall survival (OS), and 27% disease-specific mortality (DSM). Those associated with ADT alone were 74% BCF, 54% OS, and 25% DSM, which appeared to be better than those of RT alone. The addition of ADT to RT produced a notable local and systemic effect, regardless of ST- or LT-ADT. The LF rate decreased from 34% with RT alone to 21% with ST-ADT and further to 15% with LT-ADT. The DM and DSM rates also showed a similar trend among RT alone, RT+ST-ADT, and RT+LT-ADT. The combination of RT+LT-ADT resulted in the best long-term clinical outcomes, indicating that both RT and ADT are important parts of multimodal therapy.
Adenocarcinoma
;
Cohort Studies
;
Mortality
;
Neoplasm Metastasis
;
Prostate*
;
Prostatic Neoplasms*
;
Radiotherapy*
8.Development of an Automatic Seed Marker Registration Algorithm Using CT and kV X-ray Images.
Kwang Ho CHEONG ; Byung Chul CHO ; Sei Kwon KANG ; Kyoung Joo KIM ; Hoon Sik BAE ; Tae Suk SUH
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2007;25(1):54-61
PURPOSE: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on-board imager (OBI). MATERIALS AND METHODS: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed COMOBI with the reference COMCT. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. RESULTS: In the phantom study, the calculated COMCT and COMOBI agreed with COMactual within a millimeter. The algorithm also could localize each seed marker correctly and calculated COMCT and COMOBI for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of 0.1+/-2.7~1.8+/-6.6 mm in the AP direction, 0.8+/-1.6~2.0+/-2.7 mm in the SI direction and -0.9+/-1.5~2.8+/-3.0 mm in the lateral direction, even though the setup error was quite patient dependent. CONCLUSION: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.
Axis, Cervical Vertebra
;
Humans
;
Prostate
;
Prostatic Neoplasms
;
Radiotherapy
9.Choroidal Metastasis from Prostate Cancer.
Young LEE ; Yong Ho SHIN ; Young Bin KIM ; Dong Gi LEE ; Hyung Lae LEE
Korean Journal of Urological Oncology 2016;14(3):172-175
Metastasis of choroid from prostate cancer is not common and has not been reported before in Korea. We report a case of decreased vision in a patient with prostate cancer. After external beam radiotherapy, patient had complete response in the choroidal metastasis. Metastasis of choroid secondary to prostate is not common. There have been only 8 cases reported. In this case, we demonstrated that external beam radiotherapy showed a therapeutic effect.
Choroid*
;
Humans
;
Korea
;
Neoplasm Metastasis*
;
Prostate*
;
Prostatic Neoplasms*
;
Radiotherapy
10.Treatment strategies for locally advanced prostate cancer.
Chinese Medical Journal 2014;127(5):957-960