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BACKGROUND To summarize outcomes of reirradiation with intensity-modulated radiotherapy (IMRT) for recurrent or secondary head and neck cancer (HNC). METHODS Primary endpoints were 2-year local control (LC) and overall survival (OS). Studies involving only recurrent nasopharyngeal patients with cancer were excluded. RESULTS A total of 17 studies involving 1635 patients were included. Fourteen (82%) of those were retrospective, and 15 (88%) were from single institution. Reirradiation with IMRT produced pooled 2-year LC and OS rates of 52% (95% confidence interval [CI], 46%-57%) and 46% (95% CI, 41%-50%), respectively. In subgroup analyses, the rate of salvage surgery (

Objective: The effectiveness of adjuvant treatments for resected gallbladder carcinoma (GBC) has remained unclear due to lack of randomized controlled trials; thus, the aim of present study was to evaluate the role of adjuvant treatments, including chemoradiotherapy (CRT) and/or chemotherapy (CTx), in patients with resected GBC. Methods: A total of 733 GBC patients who received curative-intent surgical resection were identified in a multi-institutional database. Of 733 patients, 372 (50.8%) did not receive adjuvant treatment, whereas 215 (29.3%) and 146 (19.9%) received adjuvant CTx and CRT, respectively. The locoregional recurrence-free survival (LRFS), recurrence-free survival (RFS), and overall survival (OS) of the adjuvant treatment groups were compared according to tumor stage (stage II vs. stage III–IV). Results: In stage II disease (n = 381), the 5-year LRFS, RFS, and OS were not significantly different among the no-adjuvant therapy, CTx, and CRT groups, and positive resection margin, presence of perineural invasion, and Nx classification were consistently associated with worse LRFS, RFS, and OS in the multivariate analysis (P < 0.05). For stage III–IV (n = 352), the CRT group had significantly higher 5-year LRFS, RFS, and OS than the no-adjuvant therapy and CTx groups (67.8%, 45.2%, and 56.9%; 37.9%, 28.8%, and 35.4%; and 45.0%, 30.0%, and 45.7%, respectively) (P < 0.05). Conclusions: CRT has value as adjuvant treatment for resected GBC with stage III–IV disease. Further study is needed for stage II disease with high-risk features.

Background Radiation-induced rib fracture (RIRF) is one of the adverse effects of conventional radiotherapy on breast cancer. This study aimed to investigate the effects of tumor-rib distance and dose-dependent rib volume on RIRFs in patients with breast cancer. Methods We retrospectively included 510 women with breast cancer who underwent curative surgical resection with subsequent adjuvant radiotherapy and were followed up using bone scintigraphy. Adjuvant radiotherapy was administered to the whole breast at 50 Gy in 25 fractions for 5 weeks and to the tumor bed at 10–16 Gy in 5–8 fractions. The tumor-rib distance was measured using preoperative computed tomography (CT) images. Postoperative chest wall thickness and dose-dependent rib volumes, which are absolute rib volumes receiving >20 Gy (V20), 30 Gy (V30), 40 Gy (V40), 45 Gy (V45), and 50 Gy (V50), were measured from the stimulation CT images for radiation treatment planning. RIRFs were identified using follow-up bone scintigraphy images. We assessed the relationship of RIRF with tumor-rib distance, postoperative chest wall thickness, and dose-dependent rib volumes. Results The median follow-up duration was 58.8 months, and 92 patients (18.0%) experienced RIRF. Univariate analysis revealed that osteoporosis, surgery type, radiation field, tumor-rib distance, postoperative chest wall thickness, V20, V30, V40, V45, and V50 were risk factors for RIRF (p

BACKGROUND Although several prospective studies have reported the efficacy of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC), treatment-related toxicity varies and has not been determined. Therefore, the authors evaluated the safety and efficacy of SBRT for patients with HCC in a hepatitis B virus-endemic area. METHODS This multicenter phase 2 trial enrolled patients with unresectable HCC. Patients received SBRT with 45 to 60 Gy in 3 fractions. To evaluate gastroduodenal toxicity, esophagogastroduodenoscopy (EGD) was performed before and 2 months after SBRT. The primary endpoint was treatment-related severe toxicity at 1 year after SBRT. The secondary endpoints were the 2-year local control, progression-free survival, and overall survival rates. RESULTS In total, 74 patients were enrolled between January 2012 and April 2015, and 65 eligible patients were analyzed. One patient experienced radiation-induced liver disease with acute grade ≥3 toxicity 1 month after SBRT. In addition, 1 patient had a grade 3 esophageal ulcer with stenosis 5 months after SBRT. The actuarial rate of treatment-related severe toxicity at 1 year was 3%. The pre-SBRT and post-SBRT EGD findings were not significantly different among the 57 evaluable patients who underwent EGD. The 2-year and 3-year local control rates were 97% and 95%, respectively. The progression-free and overall survival rates were 48% and 84% at 2 years, respectively, and 36% and 76% at 3 years, respectively. CONCLUSIONS With a median follow-up of 41 months, this prospective multicenter study demonstrated that SBRT for patients with HCC is well tolerated and is an effective treatment modality.

The Korean Radiation Oncology Group (KROG) assessed the value of Deauville score (DS) on 18F-fluorodeoxyglucose Positron emission tomography-computed tomography (FDG PET/CT) as a predictor of recurrence and survival after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy in diffuse large B-cell lymphoma (DLBCL). A total of 512 patients with stage I–III DLBCL who received six cycles of R-CHOP with or without radiation therapy (RT) and obtained treatment responses according to PET-CT imagings after R-CHOP ± RT were included. Patients were sorted into two arms; DS 4–5 arm (n = 24) was matched at a 1:2 ratio with DS 1–3 arm (n = 48) using propensity score matching method. After a median follow-up time of 37.2 months, the recurrence-free survival rate (86.6% vs. 66.8%, P = 0.041) and overall survival rate (86.9% vs. 62.2%, P = 0.009) at 5 years were significantly different between the DS 1–3 and DS 4–5 arms. DS 4–5 arm showed higher 5-years locoregional recurrence-free survival (88.8% vs. 74.3%, P = 0.155) and distant failure-free survival (91.1% vs. 84.3%, P = 0.333) than DS 1–3 arm. In the multivariate analysis, DS was still a significant factor for recurrence-free survival [hazard ratio (HR), 3.840 and confidence interval (CI), 1.068–13.806; P = 0.039] and overall survival rates (HR 4.453 and CI 1.274–15.562; P = 0.019). This study showed and validated that Deauville score of 4–5 of PET-CT imaging taken after full-course of R-CHOP chemotherapy with or without RT could predict recurrence-free survival and overall survival in DLBCL patients.

We compared treatment outcomes between rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy alone with R-CHOP followed by consolidative radiation therapy (RT) in diffuse large B-cell lymphoma (DLBCL). We analyzed 404 patients with Stage I–II DLBCL who received six to eight cycles of R-CHOP and achieved a good response after a full course of chemotherapy. Propensity-score matching was used to assess the role of consolidative RT. The R-CHOP alone group (n = 184) was matched in a 1:2 ratio with the R-CHOP plus RT group (n = 92). Twenty-four (13.0%) of 184 patients receiving R-CHOP alone and 8 (8.7%) of 92 patients receiving R-CHOP plus RT had bulky diseases (>7.5 cm). A Deauville score of 1–2 was achieved for 159 (86.4%) of 184 patients receiving R-CHOP alone and 84 (91.3%) of 92 patients receiving R-CHOP plus RT. After a median follow-up time of 42 months, the recurrence-free survival (RFS) rate (86.7% vs 93.0%, P = 0.464) and overall survival rate (88.3% vs 95.1%, P = 0.295) at 5 years did not differ significantly between the R-CHOP alone and R-CHOP plus RT arms. In the additional multivariate analyses, large tumor size (>7.5 cm) was significantly associated with decreased RFS (hazard ratio, 2.368 and confidence interval, 1.837–6.697; P = 0.048). Consolidative radiation was not a significant factor for RFS (P = 0.563). Tumor size was a significant factor for RFS in the rituximab era. The outcome of omitting consolidative RT for good responders after six to eight cycles of R-CHOP chemotherapy was acceptable in early-stage DLBCL without a bulky disease.

To evaluate the role of adjuvant radiotherapy (RT) after curative resection in patients with extrahepatic bile duct (EHBD) cancer.Between January 2000 and December 2015, 1475 patients with EHBD cancer who underwent curative resection were accrued from 14 institutions in Korea. Among these, 959 patients did not receive any adjuvant therapy (RT(-) group), while 516 underwent postoperative RT with or without chemotherapy (RT(+) group).The median age was 67 years. Nodal involvement was present in 482 patients (32.7%), and resection margin was involved in 293 patients (19.9%). RT(+) group had more patients with proximal tumours, advanced tumours, nodal involvement, perineural invasion, and involved resection margin than RT(-) group (all p 0.001). With a median follow-up of 36 months, there were 211 locoregional recurrences, 307 distant metastases and 322 combined locoregional and distant failures. On multivariate analysis incorporating age, tumour location, differentiation, pT classification, pN classification, perineural invasion and resection margin, adjuvant RT was associated with improved overall survival (hazard ratio, 0.74; 95% confidence interval, 0.63-0.86; p 0.001). When RT(+) group was separated into RT alone, concurrent chemoradiotherapy (CCRT) and CCRT followed by chemotherapy, the greatest benefit was observed in patients treated with CCRT followed by chemotherapy (hazard ratio, 0.52; 95% confidence interval, 0.41-0.68).Adjuvant RT combined with chemotherapy improved survival outcomes of resected EHBD cancer patients. Considering the greatest benefit observed in patients receiving CCRT followed by chemotherapy, a randomised controlled trial comparing chemotherapy alone and CCRT followed by chemotherapy is urgently needed.

This study aimed to assess the trends in the incidence of thyroid cancer in Incheon Province, South Korea, from 2004 to 2013 and to identify its association with thyroid cancer screening.We evaluated randomly sampled data of 10% of thyroid cancer patients collected between 2004 and 2013 from the Incheon Cancer Registry, Incheon, South Korea. The expected annual incidence rates of thyroid cancer from 2004 to 2013 were calculated, and the trends in annual incidence change were assessed using a Poisson regression model. In addition, the annual proportion change in the thyroid cancer population according to the detection method and tumor size was also calculated by evaluating the linear-by-linear association.The average expected prevalence of thyroid cancer was 30 per 100,000 individuals from 2004 to 2013. The expected annual incidence of thyroid cancer per 100,000 individuals increased from 7 in 2004 to 49 in 2013, with an annual 1.25-fold difference (p 0.001). Screening helped improve the detection of thyroid cancer annually, with the proportion increasing by screening detection (p 0.001). Majority (54%) of the tumors were small ( 10 mm) and their detection rate increased from 2004 to 2013 (p 0.001).The incidence of thyroid cancer has increased from 2004 to 2013 in Incheon Province, South Korea, with the increase being most significant for small tumors. These findings indicate that the increased incidence is primarily due to the widespread use of screening and not an actual increase in clinically significant thyroid cancer.

BACKGROUND: Growing evidence suggests that metastasis-directed therapy and/or prostate-directed therapy may benefit patients with oligometastatic prostate cancer (OMPC). Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastases in various cancers. The purpose of this study was to investigate the current patterns of curative-intent SBRT for OMPC in Korea. METHODS: A 20-item questionnaire was sent to 326 radiation oncologists in 93 institutions in Korea. Only 1 physician per institution was required to complete the survey. Subsequently, the second survey consisting of 3 clinical scenarios was sent to 64 physicians with clinical experience in SBRT: case 1, cT4N0M1 (direct invasion to two pelvic bones); case 2, cT2N0M1 (three bone metastases); and case 3, solitary spine metastasis after radical prostatectomy. RESULTS: Seventy-six physicians from 93 institutions (82%) answered the first survey. The multidisciplinary team approach was practiced in 16 institutions (21%). Most physicians (75%) agreed on the definition of oligometastases as limited lesions and/or organs ≤5: 25% agreed with low-volume disease according to CHAARTED trial. During the last year, 49 physicians (64%) treated OMPC patients with curative intent. Sixty four physicians (84%) had a clinical experience with SBRT: 48 (75%) stated that both dose and fraction number should be considered when defining SBRT, whereas others (25%) stated that only fraction size should be considered. Fifty-five faculties (86%) answered the second survey. Physicians agreed with oligometastases in 89% for case 1, in 80% for case 2, and in 100% for case 3. The rate of SBRT application was the highest in case 3 (70%). CONCLUSIONS: There was diversity in the patterns of SBRT for OMPC in Korea. Additional prospective studies are necessary to strengthen evidence regarding role of SBRT in OMPC.

Background This study was to assess the rate of radiotherapy (RT) utilization according to the modality in South Korea to identify the implications of contemporary RT patterns. Methods We collected information from claims and reimbursement records of the National Health Insurance Service from 2010 to 2019. We classified the location of each institution as capital (Seoul, Incheon, and Gyeonggi-do) and non-capital areas. Results The rate of RT utilization in total cancer patients nationwide was 24.5% in 2010, which consistently has increased to 36.1% in 2019 (annual increase estimate [AIE], 4.5%). There was an abrupt increase in patients receiving intensity-modulated RT (IMRT), with an AIE of 33.5%, and a steady decline in patients receiving three-dimensional conformal RT (3DCRT), with an AIE of −7.1%. The commonest RT modality was IMRT (44.5%), followed by 3DCRT and stereotactic RT (SRT) (37.2% and 13.5%) in 2019. An increasing trend of advanced RT (such as IMRT and SRT) utilization was observed regardless of the region, although the AIE in the capital areas was slightly higher than that in non-capital areas. Conclusion The utilization of overall RT application and especially of advanced modalities remarkably increased from 2010 to 2019. We also found gaps in their AIEs between capital and non-capital areas. We should ensure that advanced RT is accessible to all cancer patients across South Korea., Graphical Abstract

BACKGROUND To evaluate the impact of adjuvant postoperative radiotherapy (PORT) in adult WHO grade II–III intracranial ependymoma (IEPN). METHODS A total of 172 pathologically confirmed adult grade II–III IEPN patients from 12 institutions were eligible. Of them, 106 (61.6%) and 66 (38.4%) patients were grade II and III, respectively. For grade II and III IEPNs, 51 (48.1%) and 59 (89.4%) patients received PORT, respectively. The median dose to the primary tumor bed was 54.0 Gy and 59.4 Gy for grade II and III patients, respectively. The prognostic impact of sex, age, performance, WHO grade, location, size, surgical extent, and PORT on local control (LC), progression-free survival (PFS), and overall survival (OS) were evaluated by univariate and multivariate analysis. RESULTS The median follow-up period for survivors was 88.1 months. The 5-/10-year LC, PFS, and OS rates were 64.8%/54.0%, 56.4%/44.8%, and 76.6%/71.0%, respectively. On multivariate analysis, adjuvant PORT significantly improved LC (P=0.002), PFS (P=0.002), and OS (P=0.043). Older age (P< 0.001), WHO grade III (P< 0.001), larger tumor size (P=0.004), and lesser surgical extent (P< 0.001) were also negative factors for OS. Adjuvant PORT also improved LC (P=0.010), PFS (P=0.007), and OS (P=0.069) on multivariate analysis for grade II IEPNs. CONCLUSION This multicenter retrospective study supports the role of adjuvant PORT in terms of disease control and survival in adult grade II–III IEPNs. Prospective randomized trials focused on individualized treatment based on molecular subtypes is warranted.

Radiotherapy techniques for breast cancer have evolved with efforts to reduce treatment-related side effects. In the present study, we conducted dosimetric analysis of incidental axillary irradiation between volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiotherapy (3D-CRT). A total of 20 patients with early stage left breast cancer who underwent breast-conserving surgery followed by postoperative radiotherapy were analyzed. For VMAT plans, dose-volume constraints were not imposed on the axilla, as with 3D-CRT. We compared the dosimetric parameters of the planning target volumes, organs at risk and axillary level I-III of the two plans. VMAT showed better target coverage and a normal organ-sparing effect compared with 3D-CRT. The incidental axillary irradiation of VMAT was lower; the mean dose and the V40(Gy) were significantly reduced at all axillary levels, with the exception of no difference in the maximum dose to axillary level I. In conclusion, VMAT decreased incidental axillary irradiation, even in the absence of a dose-volume constraint on the axilla, and can, therefore, decrease the risk of radiotherapy-related lymphedema. However, caution is also required because it is unclear whether this incidental axillary irradiation is beneficial for reducing recurrence on the axilla.

To evaluate the impact of adjuvant postoperative radiotherapy (PORT) in adult WHO grade II-III intracranial ependymoma (IEPN).A total of 172 pathologically confirmed adult grade II-III IEPN patients from 12 institutions were eligible. Of them, 106 (61.6%) and 66 (38.4%) patients were grade II and III, respectively. For grade II and III IEPNs, 51 (48.1%) and 59 (89.4%) patients received PORT, respectively. The median dose to the primary tumor bed was 54.0 Gy and 59.4 Gy for grade II and III patients, respectively. The prognostic impact of sex, age, performance, WHO grade, location, size, surgical extent, and PORT on local control (LC), progression-free survival (PFS), and overall survival (OS) were evaluated by univariate and multivariate analysis.The median follow-up period for survivors was 88.1 months. The 5-/10-year LC, PFS, and OS rates were 64.8%/54.0%, 56.4%/44.8%, and 76.6%/71.0%, respectively. On multivariate analysis, adjuvant PORT significantly improved LC (P = 0.002), PFS (P = 0.002), and OS (P = 0.043). Older age (P 0.001), WHO grade III (P 0.001), larger tumor size (P = 0.004), and lesser surgical extent (P 0.001) were also negative factors for OS. Adjuvant PORT also improved LC (P = 0.010), PFS (P = 0.007), and OS (P = 0.069) on multivariate analysis for grade II IEPNs.This multicenter retrospective study supports the role of adjuvant PORT in terms of disease control and survival in adult grade II-III IEPNs. Prospective randomized trials focused on individualized treatment based on molecular subtypes is warranted.

Background/Aims: To evaluate the technical feasibility of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC) with the major portal vein tumor thrombosis (PVTT). Methods: Ten institutions affiliated with the Korean Stereotactic Radiosurgery Group were provided the contours of four cases: the first case was the first branch PVTT with sufficient normal liver volume (NLV), the second was the first branch PVTT with insufficient NLV, the third was the main trunk PVTT at confluence level, and the fourth was the main trunk PVTT with entire length. The institutions were asked to make SBRT plans according to their current treatment protocols and to complete facility questionnaires. Results: Based on institutional protocols, SBRT was feasible in nine institutions for the first case (32-60 Gy in 3-5 fractions), in eight institutions for the second case (32-50 Gy in 3-5 fractions), in seven institutions for the third case (35-60 Gy in 3-5 fractions), and in four institutions for the fourth case (35-42 Gy in 4-5 fractions). The other institutions recommended hypo- or conventional fractionation due to insufficient NLV or gastrointestinal organ proximity. With analysis of the SBRT dose to the central hepatobiliary tract, the major PVTT could theoretically be associated with a high risk of hepatobiliary toxicity. Conclusions: Although SBRT is a technically feasible option for HCC with the major PVTT, there was a variability among the participating institutions. Therefore, further studies will be necessary to standardize the practice of SBRT for the major PVTT. (J Liver Cancer 2018;18:130-141)

We performed this study to identify the treatment patterns of patients with low-grade gliomas (LGG) in Korea. A total of 555 patients diagnosed as WHO grade II gliomas between 2000 and 2010 at 14 Korean institutions were included. The patients were divided into four adjuvant treatment groups: adjuvant fractionated radiotherapy (RT, N = 204), adjuvant chemotherapy (N = 20), adjuvant fractionated RT and chemotherapy (N = 65), and non-adjuvant treatment (N = 266) groups. We examined differences among the groups and validated patient/tumor characteristics associated with the adjuvant treatments. Astrocytoma was diagnosed in 210 patients (38%), oligoastrocytoma in 85 patients (15%), and oligodendroglioma in 260 patients (47%). Gross total resection was performed in 200 patients (36%), subtotal resection in 153 (28%), partial resection in 71 patients (13%), and biopsy in 131 patients (24%). RT was most commonly applied as an adjuvant treatment. The use of chemotherapy with or without RT decreased after 2008 (from 38 to 4%). The major chemotherapeutic regimen was procarbazine, lomustine, and vincristine (PCV); however, the proportion of temozolomide increased since 2005 (up to 69%). Patient/tumor characteristics related with RT were male gender, non-seizure, multiple lobes involvement, and non-gross total resection. Chemotherapy was associated with non-gross total resection and non-astrocytoma. A preference for RT and increased use of temozolomide was evident in the treatment pattern of LGG. The extent of resection was associated with a decision to perform RT and chemotherapy. To establish a robust guideline for LGG, further studies including molecular information are needed.

We analyzed patterns of care and outcomes for patients with primary central nervous system lymphoma (PCNSL) in this multi-institutional retrospective study. Between January 2000 and December 2011, 220 patients with PCNSL received radiotherapy (RT). Among these patients, 26 patients received RT alone; 179 patients were treated with chemotherapy and radiotherapy; the rest of the patients (N = 15) initially underwent chemotherapy alone, then received RT as a salvage treatment. Most of the patients (N = 188) received methotrexate-based chemotherapy. The median follow up duration was 38 months (range 3-179 months). The median RT dose and whole brain RT (WBRT) dose were 45.0 Gy (range 20.0-59.4) and 30.6 Gy (range 18.0-45.0), respectively. Seventy-seven (35%) patients received WBRT alone, and 143 patients (65%) underwent WBRT plus boost RT. Total RT dose and WBRT dose decreased during the study period. The median survival was 64 months and actuarial 5-year overall survival was 51.4%. In multivariate analysis, age (P

The purpose of this study is to perform a comparison and on analysis of measured dose factor values by using various commercially available high-energy electron beam detectors to measure dose profiles and energy property data. By analyzing the high-energy electron beam data from each detector, we determined the optimal detector for measuring electron beams in clinical applications. The dose linearity, dose-rate dependence, percentage depth dose, and dose profile of each detector were measured to evaluate the dosimetry characteristics of high-energy electron beams. The dose profile and the energy characteristics of high-energy electron beams were found to be different when measured by different detectors. Through comparison with other detectors based on the analyzed data, the microdiamond detector was found to have outstanding dose linearity, a low dose-rate dependency, and a small effective volume. Thus, this detector has outstanding spatial resolution and is the optimal detector for measuring electron beams. Radiation therapy results can be improved and related medical accidents can be prevented by using the procedure developed in this research in clinical practice for all beam detectors when measuring the electron beam dose.

AIM This study aims to evaluate the usage of brain metastases (BM) tumor volume and sphericity as prognostic factors in local control (LC) after stereotactic radiosurgery (SRS) for limited number (1-4) BM from nonsmall cell lung cancer (NSCLC). METHODS We retrospectively reviewed 80 patients, with 141 BM, who were treated with SRS from 2012 to 2017. Local failure was defined as an increase in lesion size after SRS. LC and overall survival (OS) were estimated using Kaplan-Meier method. The Cox proportional hazards model was used for univariate and multivariate analysis. RESULTS The median clinical and radiographic follow-up was 11.2 and 9.0 months, respectively. The median BM tumor volume was 0.31 cm3 (0.01-21.64 cm3 ) and the median tumor sphericity was 0.76 (0.39-0.95). The median LC of the entire cohort was 28.8 months. LC rate at last follow-up was achieved in 84.4% of patients (35.5% CR, 35.5% PR, and 13.5% SD). LC was 83.8% at 1 year and 56.3% at 2 years. On multivariate analysis, only sphericity (P

Purpose Stereotactic body radiotherapy (SBRT) takes advantage of low α/β 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.

Aim The purpose of this study was to compare the prostate-specific antigen (PSA) kinetics between stereotactic body radiotherapy (SBRT) using Cyberknife and conventionally fractionated external beam radiotherapy (CF-EBRT) in low- and intermediate-risk prostate cancer. Methods A total of 69 patients with low- and intermediate-risk prostate cancer were enrolled. Thirty-four patients were treated with SBRT (36.25 Gy in five fractions) using Cyberknife and 35 patients treated with CF-EBRT (70.2–75.6 Gy in 39–42 fractions). PSA nadir, rate of PSA decline and biochemical failure (BCF) free survival were calculated and compared. Results With a median follow-up of 53.6 months (range, 14–74), the median slopes for SBRT were −0.430, −0.199, −0.127 and −0.094 ng/mL/month, respectively, for durations of 1, 2, 3 and 4 years following radiotherapy. Similarly, for CF-EBRT, the median slopes were −0.529, −0.138, −0.109 and −0.056 ng/mL/month, respectively. The slope of CF-EBRT was significantly different with a greater median rate of change for 1 year than SBRT (P = 0.018). Conversely, the slopes of SBRT for duration for 2, 3 and 4 year tended to be continuously greater than CF-EBRT (P = 0.028, P = 0.058 and P = 0.128, respectively). The significantly lower PSA nadir was observed in SBRT (nadir 0.23 ng/mL) compared with CF-EBRT (nadir 0.37 ng/mL) (P = 0.011). Five-year BCF free survivals were 100% for SBRT and 80.8% for CF-EBRT (P = 0.031). Conclusions Patients treated with SBRT experienced a lower PSA nadir and tended to a continuously greater rate of decline of PSA for duration 2, 3 and 4 years than CF-EBRT. The improved PSA kinetics of SBRT leaded to favorable BCF-free survival.

In recent years, concurrent chemoradiotherapy (CCRT) has become a standard treatment modality for patients with locally advanced esophageal cancer. On the other hand, there is no international consensus regarding an accurate definition of the clinical target volume (CTV). This study evaluated the clinical outcomes in patients with locally advanced esophageal cancer treated definitively with either (ENI) elective nodal irradiation or (IFI) involved-field irradiation. Retrospective analysis of the treatment results for patients with locally advanced esophageal cancer between 2001.5 and 2013.5 was carried out. The eligible patients had T2-4N0-2M0 biopsy-proven squamous cell carcinoma (SCC) of the esophagus and were treated with a curative aim. Patients treated with surgery or radiotherapy alone were excluded. The gross tumor volume (GTV) was delineated based on the FDG-PET CT scans. Patients treated with ENI received radiotherapy on the supraclavicular or celiac area as the clinical target volume (CTV). For IFI planning, CTV is defined as a 3-cm superoinferior margin and a 1-cm lateral margin from the GTV. The 3-year progression-free survival, overall survival and patterns of the failures were analyzed. A total of 99 patients who completed CCRT were eligible for the analysis. Of the patients, 50 patients had ENI and 49 patients had IFI. The age, gender and staging were similar in both groups. The median follow-up was 21 months. Both groups showed a similar overall survival (p = 0.293). On the other hand, although not statistically significant, the IFI group showed a tendency for lower 3-year progression-free survival rates, particularly the non-surgery group (25 vs. 46 %, p = 0.075). The cumulative failure rates were significantly lower in the ENI group than in the IFI group. (35 vs. 56 %, p = 0.04). Definitive CCRT with ENI did not improve the survival and disease control for patients with esophageal SCC. The omission of ENI was associated with a higher failure rate, but it did not affect the survival time. PET-CT-guided involved-field irradiation is a reasonable option for most locally advanced thoracic esophageal cancer but needs caution for patients who will not undergo surgery.

Aim Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate specific antigen (PSA) kinetics after SBRT has not been well characterized. The objective of the current study is to analyze the rate of PSA decline and PSA nadir following SBRT boost after whole pelvis radiotherapy (WPRT) in intermediate- and high-risk prostate cancer. Methods From March 2008 to July 2014, 42 patients newly diagnosed, intermediate- and high-risk (NCCN definition) localized prostate cancer were treated with SBRT boost using Cyberknife after WPRT. The whole pelvis dose was 45 Gy (25 fractions of 1.8 Gy) and the SBRT boost dose was 21 Gy (3 fractions of 7 Gy). No one received androgen deprivation therapy (ADT) before biochemical relapse. PSA nadir and rate of change in PSA (slope) were calculated and compared. Results With a median follow-up of 53.6 months (range, 14–74), the median rates of decline of PSA were –0.605, –0.229 and –0.166 ng/mL/month, respectively, for durations of 1, 2 and 3 years postradiotherapy, respectively. The median PSA nadir was 0.32 ng/mL after a median 36 months. 4-year biochemical failure (BCF) free survival was 100 percent for intermediate-risk and 71.4 percent for high-risk patients (P = 0.002). Conclusions In this report of intermediate- and high-risk prostate cancer, continuously greater rates of decline PSA for duration 1, 2 and 3 year following SBRT boost after WPRT resulted in lower PSA nadir. Also, SBRT boost after WBPT leads to favorable BCF-free survival.

Aim We report our experience with Cyberknife to deliver hypofractionated stereotactic body radiotherapy (SBRT) boost combined with whole pelvis radiotherapy (WPRT) to patients with intermediate- to high-risk prostate cancer. Methods From March 2008 to July 2014, 39 patients with newly diagnosed, intermediate- and high-risk (National Comprehensive Cancer Network definition) localized prostate cancer were treated with WPRT and SBRT boost. The whole pelvis dose was 45 Gy (25 fractions of 1.8 Gy) and the SBRT boost dose was 21 Gy (3 fractions of 7 Gy). No one received androgen deprivation therapy before biochemical relapse. The acute and late toxicities were recorded using the Radiation Therapy Oncology Group scale. Prostate-specific antigen (PSA) response was monitored. Results Thirty-nine patients with a median 53.6 months (range 14–74 months) follow-up were analyzed. The median pretreatment PSA was 15.97 ng/mL. The estimated 5-year biochemical failure (BCF)-free survival was 94.7%. Two BCFs were observed in only high-risk group. The median PSA nadir was 0.30 ng/mL at median 36 months and PSA bounce occurred in 15.4% (n = 6) of patients at median 12 months. No grade 3 acute toxicity was noted. A total of 23% of the patients had grade 2 acute genitourinary (GU) toxicities and 21% had grade 2 acute gastrointestinal (GI) toxicities. At 2 months, most complications had returned to baseline. GU and GI toxicities were observed. Conclusions WPRT followed by SBRT boost using Cyberknife in intermediate- and high-risk prostate cancer is feasible with minimal toxicity and encouraging BCF-free survival.

Background Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate-specific antigen (PSA) kinetics after SBRT has not been well characterized. The objective of the current study is to analyze the rate of PSA decline and PSA nadir following hypofractonated SBRT in low- and intermediate-risk prostate cancer. Methods From 2008 to 2014, 36 patients newly diagnosed, low- and intermediate-risk (NCCN definition) prostate cancer were treated with SBRT using Cyberknife. Total dose of 36.25 Gy in 5 fractions of 7.25 Gy were administered. No one received androgen deprivation therapy (ADT). PSA nadir and rate of change in PSA (slope) were calculated and compared. Results With a median follow-up of 52 months (range, 13–71), the median rates of decline of PSA were −0.359, −0.199 and −0.127 ng/mL/month, respectively, for durations of 1, 2 and 3 years after radiotherapy, respectively. The decline of PSA was maximal in the first year and continuously decreased for durations of 2 and 3 year. The median PSA nadir was 0.27 ng/mL after a median 33 months. 5-year biochemical failure (BCF)-free survival was 100% for low- and intermediate-risk patients. Conclusions In this report of low- and intermediate-risk prostate cancer, continuous decrease of PSA level for duration 1, 2 and 3 year following SBRT using Cyberknife resulted in lower PSA nadir. Also, SBRT leaded to long-term favorable BCF-free survival in low- and intermediate-risk prostate cancer.

Objectives We conducted a meta-analysis and systematic review of stereotactic body radiotherapy (SBRT)-based reirradiation efficacy in patients with recurrent or second primary head and neck cancer (RSHNC). Methods We systematically reviewed PubMed/MEDLINE, Embase, and Cochrane Library. The primary endpoint was 2-year overall survival (OS); secondary endpoints were grade >3 complications and response rate. Results We included 10 studies involving 575 patients (only 12% of whom underwent salvage surgery post-recurrence) with RSHNC who underwent SBRT; median SBRT reirradiation doses ranged from 24 to 44 Gy (median, 30 Gy) delivered with 3–6 fractions (median, 5 fractions). Median target volume of SBRT reirradiation was measured from 19 to 103 cm3. The pooled event rate of 2-year OS following SBRT reirradiation for RSHNC was 30.0% (95% confidence interval [CI] 24.5–36.1). The pooled rates of late grade ≥3 and grade 5 toxicity were 9.6% (95% CI 5.0–17.6) and 4.6% (95% CI 2.4–8.6), respectively. Grade 5 toxicity was not observed in five studies (range: 0–10.7%). The pooled rates of clinical response and complete response were 61.7% (95% CI 51.1–71.3) and 31.3% (95% CI 23.3–40.5), respectively, and the 2-year local control rate was 47.3% (95% CI 3.1–62.1). Conclusions SBRT with median 30 Gy in 5 fractions is a feasible therapy showing good responses for patients with RSHNC not suitable for salvage surgery. However, to improve OS, SBRT reirradiation strategy should be investigated in terms of dose escalation for sustained control and combined systemic therapy.

Objective The prognostic value of metabolic parameters using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has not been established for early non-small cell lung cancer (NSCLC). Accordingly, the authors investigated the prognostic value of metabolic parameters in terms of failure patterns in patients with early NSCLC who underwent stereotactic body radiation therapy (SBRT). Methods Data from 35 patients with Stage I NSCLC who underwent SBRT using CyberKnife and received pretreatment FDG PET/CT between 2008 and 2016 were retrospectively reviewed. Maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis were measured. The significance of these parameters with regard to failure patterns was assessed. Results The median follow-up was 23 months for all patients and 34 months for living patients. Ten patients experienced recurrence: three local failures, five regional failures (RF), and eight distant failures (DF). Three-year local, regional and distant control rates were 96.7%, 86.4% and 71.1%, respectively. High SUVmax (

Background This study aimed to assess the recent changes of radiation therapy (RT) modalities in Korea. In particular, we focused on intensity-modulated radiation therapy (IMRT) utilization as the main index, presenting the application status of advanced RT. Methods We collected information from the Korean Health and Insurance Review and Assessment Service data based on the National Health Insurance Service claims and reimbursements records by using treatment codes from 2010 to 2016. We classified locating region of each institution as capital vs. non-capital areas and metropolitan vs. non-metropolitan areas to assess the regional difference in IMRT utilization in Korea. Results IMRT use has been steadily increased in Korea, with an annual increase estimate (AIE) of 37.9% from 2011 to 2016 (P < 0.001) resulting in IMRT being the second most common RT modality following three-dimensional conformal radiotherapy. In general, an increasing trend of IMRT utilization was observed, regardless of the region. The rate of AIE in the capital areas or metropolitan areas was higher than that in non-capital areas or non-metropolitan areas (40.7% vs. 31.9%; P < 0.001 and 39.7% vs. 29.4%; P < 0.001, respectively). Discussion The result of our survey showed that IMRT has become one of the most common RT modalities. IMRT is becoming popular in both metropolitan and non-metropolitan areas, while metropolitan area has faster AIE possibly due to concentration of medical resources and movement of advanced patients., Graphical Abstract

Purpose: Stereotactic body radiotherapy (SBRT) has emerged as an effective treatment for localized prostate cancer. However, prostate-specific antigen (PSA) kinetics after SBRT has not been well characterized. The purpose of the current study is to assess the kinetics of PSA for low- and intermediate-risk prostate cancer patients treated with SBRT using Cyberknife as both monotherapy and boost after whole pelvic radiotherapy (WPRT) in the absence of androgen deprivation therapy. Methods: A total of 61 patients with low- and intermediated-risk prostate cancer treated with SBRT as monotherapy (36.25 Gy in 5 fractions in 32 patients) and SBRT (21 Gy in 3 fractions in 29 patients) boost combined with WPRT (45 Gy in 25 fractions). Patients were excluded if they failed therapy by the Phoenix definition or had androgen deprivation therapy. PSA nadir and rate of change in PSA over time (slope) were calculated and compared. Results: With a median follow-up of 52.4 months (range, 14–74 months), for SBRT monotherapy, the median PSA nadir was 0.31 ng/mL (range, 0.04–1.15 ng/mL) and slopes were –0.41 ng/mL/mo, –0.17 ng/mL/mo, –0.12 ng/mL/mo, and –0.09 ng/mL/mo, respectively, for durations of 1 year, 2 years, 3 years, and 4 years postradiotherapy. Similarly, for SBRT boost after WPRT, the median PSA nadir was 0.34 ng/mL (range, 0.04–1.44 ng/mL) and slopes were –0.53 ng/mL/mo, –0.25 ng/mL/mo, –0.14 ng/mL/mo, and –0.09 ng/mL/mo, respectively. The median nadir and slopes of SBRT monotherapy did not differ significantly from those of SBRT boost after WPRT. Benign PSA bounces were common in 30.4% of all cohorts, and the median time to PSA bounce was 12 months (range, 6–25 months). Conclusions: In this report of low- and intermediate-risk prostate cancer patients, an initial period of rapid PSA decline was followed by a slow decline, which resulted in a lower PSA nadir. The PSA kinetics of SBRT monotherapy appears to be comparable to those achieved with SBRT boost with WPRT.