S. Huh

Prognostic value of pre-treatment circulating monocyte count in patients with cervical cancer: Comparison with SCC-Ag level

OBJECTIVE Higher level of circulating monocyte has been reported to be related with higher cancer incidence and mortality. We investigated the role of pre-treatment circulating monocyte count for cancer specific survival in cervical squamous cell carcinoma patients comparing with pre-treatment squamous cell carcinoma-related antigen (SCC-Ag) level. METHODS We retrospectively enrolled patients with squamous cell carcinoma of the cervix (FIGO stage IB to IVA) who had complete blood cell counts with differential cell count and serum SCC-Ag level within 2 weeks before starting initial treatment and were treated at Samsung Medical Center, Seoul, Korea, from 1996 to 2007. RESULTS The 788 patients in our study group had a median follow-up of 53.4 months and a five-year survival rate of 87.8%. The median value for pre-treatment circulating monocyte count was 349/μl (21-1463), and the median concentration of SCC-Ag was 1.6 ng/ml (0.1-362.0). In multivariable analysis, the pre-treatment circulating monocyte count was an independent prognostic factor for progression-free survival and overall survival in locally advanced disease (P=0.007 and P=0.038) but not in case of SCC-Ag for overall survival. The combined index of monocyte count and SCC-Ag level could enhance the prognostic value of SCC-Ag alone in patients with locally advanced cervical squamous cell carcinoma. CONCLUSIONS A higher pre-treatment circulating monocyte count is independently associated with poor prognosis in patients with locally advanced cervical squamous cell carcinoma. The pre-treatment circulating monocyte count may be considered as an adjunctive biomarker with SCC-Ag.

Anal canal carcinoma: experience from a single Korean institution.

Purpose The clinical features, treatment modality approaches in clinical practice, and prognostic factors for anal canal carcinoma patients were retrospectively analyzed. Materials and Methods Between October 1994 and December 2005, 50 patients with anal canal cancer were treated at Samsung Medical Center, Seoul, Korea. Results After a median follow up of 37.8 months (range, 6.6 - 136.1 months), the 5-year and 10-year survival rates for the 38 patients with early and locally advanced squamous and cloacogenic carcinoma (squamous cell carcinoma and cloacogenic carcinoma) were 74.8% and 66.5%, respectively. The 5-year survival and disease-free survival rates (DFS) of the 31 patients who received chemoradiation therapy (CRT) were 83.6% and 74.3%, respectively. The overall and DFS could not be determined for the adenocarcinoma group due to the small number of cases (n = 8). Univariate analysis showed that tumor size (p = 0.04) and inguinal node status (p = 0.04) significantly influenced patient survival in patients with squamous cell and cloacogenic carcinomas. Furthermore, univariate analysis also showed that, inguinal node status influenced patient survival in the adenocarcinoma group. Multivariate analysis showed that inguinal node metastasis is a single independent prognostic variable for survival (p = 0.04) in patients with squamous cell and cloacogenic carcinomas. Conclusion Combined CRT has been adopted as standard treatment with outcomes that are comparable to those reported in randomized clinical trials. Due to the rarity and complexity of anal canal carcinoma, interdepartmental cooperation is required for disease treatment. Thus, proper treatment of patients should incorporate a team-approach and should be available to as many patients as possible.

SU-E-T-292: Dosimetric Advantage of Prone Breast Radiotherapy for Korean Left-Sided Breast Cancer Patients

Purpose: To evaluate the dosimetric benefit of prone breast radiotherapy for Korean left-sided early-stage breast cancer patients who have relatively small breast Methods: From April to June, 2014, 10 left-sided breast cancer patients received the whole breast irradiation in prone position after partial mastectomy with sentinel lymph node biopsy or axillary lymph node dissection. All patients were pTmi-2N0-1mi. Each patient underwent two computed tomoradiography (CT) simulations in supine and prone positions. The whole breast, ipsilateral lung, heart, and left anterior descending coronary artery (LAD) were contoured on each simulation CT images, and then tangential-fields treatment plan in each position was designed for the whole breast irradiation with the total dose of 50 Gy in 2 Gy fractions. Dose-volume histograms of two setups were compared for target coverage and radiation dose to normal organs with Wilcoxon signed rank tests. Results: The median age of patients was 47 years (range, 37 to 53). The median chest size was 82.5 cm (range, 75 to 90) and bra cup size was A in 4, B in 4, and C in 2 patients. The radiation dose to the whole breast was similar when comparing mean dose (Dmean) and dose covering 95% of the breast volume, but maximum dose (Dmax) of breast was higher in supine (median 52.3 vs. 52.7 Gy, p=0.013). Prone position reduced significantly the radiation dose in ipsilateral lung, heart, and LAD by median 5.7, 1.1, and 6.9 Gy of Dmean (p=0.005, 0.007, and 0.005) and 28.2, 18.8, and 35.0 Gy of Dmax (p=0.005, 0.005, and 0.007), respectively. Conclusion: Prone breast radiotherapy could be beneficial for Korean breast cancer patients since it substantially spared normal organs while achieving adequate coverage of the breast tissue. Further prospective study is required to validate the potential benefit of prone breast radiotherapy.

SU‐FF‐T‐18: A Simple Theoretical Verification of HDR Calculation Dose Using Point and Line Source Approximation

Purpose: In order to reduce potential error that can occur in the planning and delivery of brachytherapy treatment, software which is able to be used for three commercial HDR sources was developed. The feasibility of the program was investigated. Method and Materials: This windows based program was developed by Visual‐Basic language. The TG‐43 algorithm was used for the dose computation at interested points. For source geometry, both point source and line source approximations were employed to be capable for most commercial HDR sources. Anisotropy tables for Nucletron microselectron, Gammamed 12i, and Veri Source were included. User is required to select the HDR source type in the beginning of the program, and to enter the number of catheters and dwelling position of a source. The position and the dose at the interested points, such as A and B points, are required to enter. The developed program used the treatment source position and interest point position in the reference frame of the catheters. The computed dose is compared to that in the RTP by calculating the percent dose difference. The accuracy of the code was validated by comparing with commercial RTP computation and hand calculation results for various prototype of treatment ranging from a single catheter to complex multi‐catheter plans as well as clinical plans. Result: The acceptance levels of performed tests were 5.0% for the percent dose difference at each interested point. For few real patient treatment plans using Nucletron sources, results of the developed program agreed with RTP (Plato, Nucletron) results within 3% error. For Veri Source, large difference between the developed program and RTP was observed if anisotropy was not used in the RTP.Discussion: The developed program was adequate for independent dose verification as a part of brachytherapyquality assurance procedure.

SU‐FF‐T‐322: Statistical Analysis of Failures of a Medical Linear Accelerator Over Ten Years

Purpose: In order for better management of a medicallinear accelerator. the records of the operational failures of Varian CL2100C over ten years were analyzed.Method and Materials: The failures were classified according to the involved functional subunits and each class was rated into three levels depending on operational conditions. The relationship between the failure rate and working ratio and the relationship between the failure rate and outside temperature were investigated. in addition, the average life time of main part and operating efficiency for last 4 years were analysed.Results: Among the recorded failures ( total 587 failures), the most frequent failure, which was 20% of the total, was observed in the parts related to the collimation system including monitor chamber. Regarding to the operational conditions, the 2nd level of failures, that temporally interrupted treatments, was the most frequent. The 3rd level of failures, that interrupted treatment for more than several hours, was mostly caused by the accelerating subunit. The number of failures was increased with number of treatments and used time. The average life‐time of a Klystron and Thyratron became shorter as the working ratio increased, which was 42 and 83% of the expected values, respectively. The operating efficiency of 95% or higher was maintained, but value slightly decreased. There were no significant correlations between the number of failures and outside temperature. Conclusion: Recording equipment problems and failures in detail over a long period of time can provide a good knowledge of equipment function as well as the capability to forecast future failure. More rigorous equipment maintenance is required for old medicallinear accelerator to avoid the serious failure in advance, and improve the patient treatment quality.

Patterns of failure in gastric adenocarcinoma treated with surgery plus postoperative chemoradiotherapy: view from radiation oncologist

Purpose/Objective: The risk of locoregional recurrence and distant metastasis is very high in resectable gastric adenocarcinoma, but the benefit of adjuvant treatment is controversial. Especially after the extended regional lymph node dissection, the role of radiotherapy has been doubtful. The purpose of this study is to analyze the patterns of failure and the related risk factors after postoperative chemoradiothearpy in resected gastric adenocarcinoma and to find out any role of radiotherapy.

Interfractional variation in position and volume of the uterus during radical radiotherapy for cervical cancer

Background and purpose: This study was conducted to investigate the positional change of the uterus during radiotherapy which can degrade the accuracy of three-dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT). Patients and methods: Sixty-six patients received radical radiotherapy for cervical cancer in Samsung Medical Center. For each patient, two MRI scans were taken; one was before beginning radiotherapy and the other was in the third or fourth week of radiotherapy. In T2-weighted MRI images, the positional change of the uterus was quantified by measuring six parameters; the distance from the external uterine opening to the isthmus of the uterus (Dcx), the distance from the isthmus of the uterus to the uterine fundus (Dco), the perpendicular distance of the uterine body to the uterine corpus (Dco-per), the angle between the vertical line and the cervical canal in sagittal images (Acx), the uterine corpus angle from the vertical line in sagittal plan (Aco), the angle between the uterine corpus from an arbitrary bony landmark and a vertical mid line in axial images (Aco-axi) Results: Mean value of change in Dcx þ Dco of tumor size during treatment was 8.0 mm in small tumors and 17.9 mm in large tumors. Among 44 anteflexed uterus patients, 5 changed into a retroflexed position. 12 patients (18%) had a greater than 308 variation in any angle. For patients under 60 years, the difference in Acx was statistically significant. Conclusions: Positional changes of the uterus during radiotherapy should be considered in the treatment planning of 3DCRT or IMRT, particularly in patients under 60 years or those with tumor size greater than 4 cm in diameter. q 2004 Elsevier Ireland Ltd. All rights reserved.