Youngmin Choi

The efficacy of concurrent cisplatin and 5-flurouracil chemotherapy and radiation therapy for locally advanced cancer of the uterine cervix

OBJECTIVEnTo evaluate the efficacy of concurrent chemoradiation (CCRT) using 5-flurouracil (5-FU) and cisplatin for locally advanced cervical cancer.nnnMETHODSnWe reviewed the medical records of 57 patients with locally advanced cervical cancer (stage IIB-IVA and bulky IB2-IIA tumor) who underwent the CCRT at Dong-A University Hospital from January 1997 to June 2007. The CCRT consisted of 5-FU, cisplatin and pelvic radiation. Every three weeks, 75 mg/m(2) cisplatin was administered on the first day of each cycle and 5-FU was infused at the dose of 1,000 mg/m(2)/d from the second day to the fifth day of each cycle. Radiation was administered to the pelvis at a daily dose of 1.8 Gy for five days per week until a medium accumulated dose reached to 50.4 Gy. If necessary, the radiation field was extended to include paraaortic lymph nodes. Consolidation chemotherapy was performed using 5-FU and cisplatin.nnnRESULTSnFifty-seven patients were enrolled and the median follow-up duration was 53 months (range 7-120 months). The overall response rate was 91.5% (74% complete response and 17.5% partial response). The 5-year overall survival and 3-year progression free survival rates were 69.4% and 74.9%, respectively. During the follow-up period (median 23 months, range 7-60 months), fourteen patients were diagnosed as recurrent disease.nnnCONCLUSIONnCCRT with 5-FU and cisplatin which is the primary treatment for patients with locally advanced cervical cancer was effective and well tolerated.

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

Radiation therapy is an important treatment modality for abdominal or pelvic cancer, but there is a common and serious complication such as radiation-induced enteritis. Probiotics is reported to have positive effects against radiation-induced enteropathy. In this study, morphological changes of bowel mucosa were analyzed in rats to presume the effect of probiotics on radiation-induced enteritis and its correlation with radiation dose. A total of 48 adult male Sprague-Dawley rats were randomly assigned to two groups and received a solution containing 1.0×108 colony-forming units of Lactiobacillus acidophilus or water once daily for 10 days. Each of two groups was divided into three subgroups and abdomino-pelvic area of each subgroup was irradiated with 10, 15, and 20 Gy, respectively on the seventh day of feeding the solutions. All rats were sacrificed 3 days after irradiation and the mucosal thickness and villus height of jejunum, ileum and colon were measured. The morphological parameters of the small intestine represented significant differences between two solution groups irradiated 10 or 15 Gy, except for villus height of jejunum in 15 Gy-subgroup (P=0.065). There was no significant morphometric difference between two groups irradiated with 20 Gy of radiation. Probiotics appear to be effective for the morphological shortening of small intestinal mucosa damaged by radiation less than or equal to 15 Gy. Graphical Abstract

Interfraction prostate movement in bone alignment after rectal enema for radiotherapy.

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.

Multi-institutional Comparison of Intensity Modulated Radiation Therapy (IMRT) Planning Strategies and Planning Results for Nasopharyngeal Cancer

The intensity-modulated radiation therapy (IMRT) planning strategies for nasopharyngeal cancer among Korean radiation oncology facilities were investigated. Five institutions with IMRT planning capacity using the same planning system were invited to participate in this study. The institutions were requested to produce the best plan possible for 2 cases that would deliver 70 Gy to the planning target volume of gross tumor (PTV1), 59.4 Gy to the PTV2, and 51.5 Gy to the PTV3 in which elective irradiation was required. The advised fractionation number was 33. The planning parameters, resultant dose distributions, and biological indices were compared. We found 2-3-fold variations in the volume of treatment targets. Similar degree of variation was found in the delineation of normal tissue. The physician-related factors in IMRT planning had more influence on the plan quality. The inhomogeneity index of PTV dose ranged from 4 to 49% in Case 1, and from 5 to 46% in Case 2. Variation in tumor control probabilities for the primary lesion and involved LNs was less marked. Normal tissue complication probabilities for parotid glands and skin showed marked variation. Results from this study suggest that greater efforts in providing training and continuing education in terms of IMRT planning parameters usually set by physician are necessary for the successful implementation of IMRT.

Evaluation of Resistance Spot Weld Interfacial Fractures in Tensile-Shear Tests of TRIP 1180 Steels

The weldability of resistance spot welding of TRIP1180 steels for automobile components investigated enhance in order to achieve understanding of weld fracture during tensile-shear strength (TSS) test. The main failure modes for spot welds of TRIP1180 steels were nugget pullout and interfacial fracture. The peak load to cause a weld interfacial failure was found to be related to fracture toughness of the weld and the weld diameter. Although interfacial fracture occurred in the spot welded samples, the load-carrying capacity of the weld was high and not significantly affected by the fracture mode. Substantial part of the weld exhibits the characteristic dimple (or elongated dimple) fractures on interfacial fractured surface also, dimple fracture areas were drawmatically increased with heat input which is propotional to the applied weld current. In spite of the high hardness values associated with the martensite microstructures due to high cooling rate. The high load-carrying ability of the weld is directly associated with the area of ductile fracture occurred in weld. Therefore, the judgment of the quality of resistance spot welds in TRIP1180 steels, the load-carrying capacity of the weld should be considered as an important factor than fracture mode.

A multicenter analysis of adjuvant therapy after surgery for stage IIIC endometrial adenocarcinoma: A Korean Radiation Oncology Group study (KROG 13-17)

OBJECTIVEnTo investigate whether combined chemoradiotherapy (CTRT) confers a benefit for survival outcome over radiotherapy (RT) alone after primary surgery in patients with FIGO stage IIIC endometrial adenocarcinoma.nnnMETHODSnWe conducted a multicenter retrospective study of patients with surgical stage IIIC endometrial cancer from 1990 to 2011. Adjuvant RT alone was performed in 85 patients (40.3%) and adjuvant CTRT in 126 patients (59.7%). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazards model.nnnRESULTSnStage IIIC1 and stage IIIC2 accounted for 63% and 37%, respectively. FIGO IIIC2 had a higher recurrence rate than FIGO IIIC1 (38.5% vs. 29.3%, p=0.172). Five-year OS and DFS were lower in FIGO IIIC2 than FIGO IIIC1 (85.1% vs. 76.9%, p=0.417; 71.0% vs. 59.2%, p=0.108, respectively). Eighteen patients (13.5%) in stage IIIC1 developed PALN recurrence, whereas only one (3.3%) in stage IIIC2 had PALN recurrence (p=0.001). In multivariate analysis, predictors of DFS were parametrial invasion (HR, 3.49; 95% CI, 1.83-6.64; p<0.001), higher grade (HR, 2.78; 95% CI, 1.31-5.89; p=0.008), and >3 positive pelvic nodes (HR, 1.84; 95% CI, 1.11-3.05; p=0.019). Combined CTRT did not affect DFS or OS in IIIC1 and IIIC2 compared with RT alone.nnnCONCLUSIONnCTRT showed comparable survival outcome to RT alone. Half of relapses (46%) in stage IIIC1 occurred in PALN region, whereas relapse in stage IIIC2 primarily occurred in distant metastasis (90%). Future randomized studies are needed to determine which subgroup may be most likely to benefit from CCRT.

Epidermal Growth Factor Receptor Is Related to Poor Survival in Glioblastomas: Single-Institution Experience

Purpose There are conflicting results surrounding the prognostic significance of epidermal growth factor receptor (EGFR) status in glioblastoma (GBM) patients. Accordingly, we attempted to assess the influence of EGFR expression on the survival of GBM patients receiving postoperative radiotherapy. Materials and Methods Thirty three GBM patients who had received surgery and postoperative radiotherapy at our institute, between March 1997 and February 2006, were included. The evaluation of EGFR expression with immunohistochemistry was available for 30 patients. Kaplan-Meier survival analysis and Cox regression were used for statistical analysis. Results EGFR was expressed in 23 patients (76.7%), and not expressed in seven (23.3%). Survival in EGFR expressing GBM patients was significantly less than that in non-expressing patients (median survival: 12.5 versus 17.5 months, p=0.013). Patients who received more than 60 Gy showed improved survival over those who received up to 60 Gy (median survival: 17.0 versus 9.0 months, p=0.000). Negative EGFR expression and a higher radiation dose were significantly correlated with improved survival on multivariate analysis. Survival rates showed no differences according to age, sex, and surgical extent. Conclusion The expression of EGFR demonstrated a significantly deleterious effect on the survival of GBM patients. Therefore, approaches targeting EGFR should be considered in potential treatment methods for GBM patients, in addition to current management strategies.

Clinical practice patterns of radiotherapy in patients with hepatocellular carcinoma: A Korean radiation oncology group study (KROG 14-07)

Purpose The aim of this study was to examine patterns of radiotherapy (RT) in Korean patients with hepatocellular carcinoma (HCC) according to the evolving guideline for HCC established by the Korean Liver Cancer Study Group-National Cancer Center (KLCSG-NCC). Materials and Methods We reviewed 765 patients with HCC who were treated with RT between January 2011 and December 2012 in 12 institutions. Results The median follow-up period was 13.3 months (range, 0.2 to 51.7 months). Compared with previous data between 2004 and 2005, the use of RT as a first treatment has increased (9.0% vs. 40.8%). Increased application of intensity-modulated RT resulted in an increase in radiation dose (fractional dose, 1.8 Gy vs. 2.5 Gy; biologically effective dose, 53.1 Gy10 vs. 56.3 Gy10). Median overall survival was 16.2 months, which is longer than that reported in previous data (12 months). In subgroup analysis, treatments were significantly different according to stage (p < 0.001). Stereotactic body RT was used in patients with early HCC, and most patients with advanced stage were treated with three-dimensional conformal RT. Conclusion Based on the evolving KLCSG-NCC practice guideline for HCC, clinical practice patterns of RT have changed. Although RT is still used mainly in advanced HCC, the number of patients with good performance status who were treated with RT as a first treatment has increased. This change in practice patterns could result in improvement in overall survival.

Impact of paraaortic lymphadenectomy for endometrial cancer with positive pelvic lymph nodes: A Korean Radiation Oncology Group study (KROG 13-17)

AIMnWe investigated the role of paraaortic lymph node dissection (PALND) in patients with stage IIIC1 endometrial carcinoma after surgery followed by adjuvant radiotherapy (RT) alone or chemoradiotherapy (CTRT).nnnMETHODSnWe performed a subgroup analysis in 151 patients treated with adjuvant pelvic RT. Paraaortic-recurrence free survival, disease-free survival (DFS) and overall survival (OS) were analyzed.nnnRESULTSnIn adjuvant RT alone, PALND was significantly related to reduced risk of paraaortic recurrence (0% vs. 17.1%) and distant metastasis (4.5% vs. 19.5%) compared with the no PALND group. PALND affected 5-year DFS (90.2% vs. 58.9%, pxa0=xa00.016) and OS (100% vs. 83.1%, pxa0=xa00.022). For the CTRT group, the paraaortic recurrence rate was 19.5% for the no PALND group and 12.8% for the PALND group (pxa0=xa00.682). Of patients who underwent PALND in the CTRT group, less extensive PALND was significantly related to increased paraaortic recurrence (≤10 vs. >10 dissected LNs, 17.1% vs. 0%). In the no PALND group (nxa0=xa082), 5-year paraaortic-recurrence free survival was 79.4% for the CTRT group and 76.2% for the RT alone group (pxa0=xa00.941). In multivariate analysis, PALND was significantly associated with reduced risk of disease-specific death (HR, 0.50; 95% CI, 0.26-0.96; pxa0=xa00.037).nnnCONCLUSIONnPALND provided excellent paraaortic control and improved outcome in stage IIIC1 endometrial cancer with favorable tumor features treated with adjuvant RT alone. Less extensive PALND was associated with significantly increased paraaortic recurrence in patients with advanced tumor features treated with adjuvant CTRT. Combined CTRT did not affect disease control in the paraaortic region compared with RT alone.

Adjuvant Treatment after Surgery in Stage IIIA Endometrial Adenocarcinoma.

Purpose We evaluated the role of adjuvant therapy in stage IIIA endometrioid adenocarcinoma patients who underwent surgery followed by radiotherapy (RT) alone or chemoradiotherapy (CTRT) according to risk group. Materials and Methods A multicenter retrospective study was conducted including patients with surgical stage IIIA endometrial cancertreated by radical surgery and adjuvant RT or CTRT. Disease-free survival (DFS) and overall survival (OS) were analyzed. Results Ninety-three patients with stage IIIA disease were identified. Nineteen patients (20.4%) experienced recurrence, mostly distant metastasis (17.2%). Combined CTRT did not affect DFS (74.1% vs. 82.4%, p=0.130) or OS (96.3% vs. 91.9%, p=0.262) in stage IIIA disease compared with RT alone. Patients with age ≥ 60 years, grade G2/3, and lymphovascular space involvement had a significantly worse DFS and those variables were defined as risk factors. The high-risk group showed a significant reduction in 5-year DFS (≥ 2 risk factors) (49.0% vs. 88.0%, p < 0.001) compared with the low-risk group (< 2). Multivariate analysis confirmed that more than one risk factor was the only predictor of worse DFS (hazard ratio, 5.45; 95% confidence interval, 2.12 to 13.98; p < 0.001). Of patients with no risk factors, a subset treated with RT alone showed an excellent 5-year DFS and OS (93.8% and 100%, respectively). Conclusion We identified a low-risk subset of stage IIIA endometrioid adenocarcinoma patients who might be reasonable candidates for adjuvant RT alone. Further randomized studies are needed to determine which subset might benefit from combined CTRT.