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SU-E-P-48: Evaluation of Intensity Modulated Radiotherapy (IMRT) with Three Different Commercial Planning Systems for the Treatment of Cervical Cancer

Purpose: To investigate the performances of three commercial treatment planning systems (TPS) for intensity modulated radiotherapy (IMRT) optimization regarding cervical cancer. Methods: For twenty cervical cancer patients, three IMRT plans were retrospectively re-planned: one with Pinnacle TPS,one with Oncentra TPS and on with Eclipse TPS. The total prescribed dose was 50.4 Gy delivered for PTV and 58.8 Gy for PTVnd by simultaneous integrated boost technique. The treatments were delivered using the Varian 23EX accelerator. All optimization schemes generated clinically acceptable plans. They were evaluated based on target coverage, homogeneity (HI) and conformity (CI). The organs at risk (OARs) were analyzed according to the percent volume under some doses and the maximum doses. The statistical method of the collected data of variance analysis was used to compare the difference among the quality of plans. Results: IMRT with Eclipse provided significant better HI, CI and all the parameters of PTV. However, the trend was not extension to the PTVnd, it was still significant better at mean dose, D50% and D98%, but plans with Oncentra showed significant better in the hight dosage volume, such as maximum dose and D2%. For the bladder wall, there were not notable difference among three groups, although Pinnacle and Oncentra systems provided a little lower dose sparing at V50Gy of bladder and rectal wall and V40Gy of bladder wall, respectively. V40Gy of rectal wall (p=0.037), small intestine (p=0.001 for V30Gy, p=0.010 for maximum dose) and V50Gy of right-femoral head (p=0.019) from Eclipse plans showed significant better than other groups. Conclusion: All SIB-IMRT plans were clinically acceptable which were generated by three commercial TPSs. The plans with Eclipse system showed advantages over the plans with Oncentra and Pinnacle system in the overwhelming majority of the dose coverage for targets and dose sparing of OARs in cervical cancer.

60 APPLIED LIFE SCIENCES↗

SU-E-I-05: A Correction Algorithm for Kilovoltage Cone-Beam Computed Tomography Dose Calculations in Cervical Cancer Patients

Purpose: To investigate the accuracy and feasibility of dose calculations using kilovoltage cone beam computed tomography in cervical cancer radiotherapy using a correction algorithm. Methods: The Hounsfield units (HU) and electron density (HU-density) curve was obtained for both planning CT (pCT) and kilovoltage cone beam CT (CBCT) using a CIRS-062 calibration phantom. The pCT and kV-CBCT images have different HU values, and if the HU-density curve of CBCT was directly used to calculate dose in CBCT images may have a deviation on dose distribution. It is necessary to normalize the different HU values between pCT and CBCT. A HU correction algorithm was used for CBCT images (cCBCT). Fifteen intensity-modulated radiation therapy (IMRT) plans of cervical cancer were chosen, and the plans were transferred to the pCT and cCBCT data sets without any changes for dose calculations. Phantom and patient studies were carried out. The dose differences and dose distributions were compared between cCBCT plan and pCT plan. Results: The HU number of CBCT was measured by several times, and the maximum change was less than 2%. To compare with pCT, the CBCT and cCBCT has a discrepancy, the dose differences in CBCT and cCBCT images were 2.48%±0.65% (range: 1.3%∼3.8%) and 0.48%±0.21% (range: 0.1%∼0.82%) for phantom study, respectively. For dose calculation in patient images, the dose differences were 2.25%±0.43% (range: 1.4%∼3.4%) and 0.63%±0.35% (range: 0.13%∼0.97%), respectively. And for the dose distributions, the passing rate of cCBCT was higher than the CBCTs. Conclusion: The CBCT image for dose calculation is feasible in cervical cancer radiotherapy, and the correction algorithm offers acceptable accuracy. It will become a useful tool for adaptive radiation therapy.

60 APPLIED LIFE SCIENCES↗

SU-E-J-226: Efficient Use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for Cervical-Cancer Brachytherapy

Purpose: To investigate image modality selection in an environment with limited access to interventional MRI for image-guided high-dose-rate cervical-cancer brachytherapy. Methods: Records of all cervical-cancer patients treated with brachytherapy between 1/2013 and 8/2014 were analyzed. Insertions were performed under CT guidance (CT group) or with >1 fraction under 3T MR guidance (MRI group; subMRI includes only patients who also had a CT-guided insertion). Differences between groups in clinical target volume (CTV), disease stage (I/II or III/IV), number of patients with or without interstitial needles, and CTV D90 were investigated. Statistical significance was evaluated with the Student T test and Fisher test (p <0.05). Results: 46 cervical-cancer patients were included (16 MRI [3 subMRI], 30 CT). CTV: overall, 55±53 cm3; MRI, 81±61 cm3; CT, 42±44 cm3 (p = 0.017). Stage: overall, 24 I/II and 22 III/IV; MRI, 3 I/II and 13 III/IV; CT, 21 I/II and 9 III/IV (p = 0.002). Use of needles: overall, 26 without and 20 with; MRI, 5 without and 11 with; CT, 21 without and 9 with (p = 0.015). CTV D90: overall, 82±5 Gy; MRI, 81±6 Gy; CT, 82±5 Gy (p = 0.78). SubMRI: CTV and D90 (as % of nominal fraction dose) were 23±6 cm3 and 124±3% for MRI-guided insertions and 21±5 cm3 (p = 0.83) and 106±12% (p = 0.15) for CT-guided insertions. Conclusion: Statistically significant differences in patient population indicate preferential use of MRI for patients with high-stage disease and large residual CTVs requiring the use of interstitial needles. CTV D90 was similar between groups, despite the difference in patient selection. For patients who underwent both CT and MRI insertions, a larger MR CTV D90 and similar CTVs between insertions were observed. While MRI is generally preferable to CT, MRI selection can be optimized in environments without a dedicated MRI brachytherapy suite. This work was partially funded by the NIH R21 CA167800 (PI: Viswanathan; aviswanathan@partners.org)

60 APPLIED LIFE SCIENCES↗

SU-E-T-807: VMAT Vs. DIMRT Vs. SsIMRT Assessing the Dosimetric Parameters of Cervical Carcinoma Treatment with a 20-Patient Sample

Purpose: The purpose of this study is to assess the dosimetric parameters of cervical carcinoma treatment using 3 different radiation therapy delivery Methods: volumetric-modulated arc therapy (VMAT), the static-field dynamic multileaf collimator intensity-modulated radiation therapy (dIMRT) and the static-field step-and-shoot intensity-modulated radiotherapy (ssIMRT). Methods: Twenty patients with cervical carcinoma were selected to be planned with dual arc VMAT, dIMRT and ssIMRT using Monaco 3.3 TPS on the Axesse™ linear accelerator in this investigation. The total dose of the planning target volume (PTV) is 60Gy. The homogeneity index (HI), conformity index (CI), dose volume histograms (DVHs), delivery efficiency, dose of organs at risks (bladder, rectum, and femoral heads), were all measured. Results: Dose distribution in 3 different radiation therapy delivery methods satisfied clinical requirements. Mean HI of PTV with VMAT, dIMRT and ssIMRT is 1.08, 1.10, and 1.09 (p>0.05). Mean CI of PTV with VMAT, dIMRT and ssIMRT is 0.82, 0.8 and 0.8 (p>0.05). For the DVH of V10, V20 and V30 in bladder, there was a significant difference: VMAT>dIMRT=ssIMRT (p <0.05). For the DVH of V40 and V50, there was a significant difference: VMAT dIMRT >ssIMRT (p <0.05). Conclusion: The results show that VMAT has a great advantage in delivery efficiency than dIMRT and ssIMRT, without compromise to the PTV coverage, HI and CI. The delivery methods should be considered under the actual cervical carcinoma radiotherapy situation.

60 APPLIED LIFE SCIENCES↗

Multihelix rotating shield brachytherapy for cervical cancer

Purpose: To present a novel brachytherapy technique, called multihelix rotating shield brachytherapy (H-RSBT), for the precise angular and linear positioning of a partial shield in a curved applicator. H-RSBT mechanically enables the dose delivery using only linear translational motion of the radiation source/shield combination. The previously proposed approach of serial rotating shield brachytherapy (S-RSBT), in which the partial shield is rotated to several angular positions at each source dwell position [W. Yang et al., “Rotating-shield brachytherapy for cervical cancer,” Phys. Med. Biol. 58, 3931–3941 (2013)], is mechanically challenging to implement in a curved applicator, and H-RSBT is proposed as a feasible solution. Methods: A Henschke-type applicator, designed for an electronic brachytherapy source (Xoft Axxent™) and a 0.5 mm thick tungsten partial shield with 180° or 45° azimuthal emission angles and 116° asymmetric zenith angle, is proposed. The interior wall of the applicator contains six evenly spaced helical keyways that rigidly define the emission direction of the partial radiation shield as a function of depth in the applicator. The shield contains three uniformly distributed protruding keys on its exterior wall and is attached to the source such that it rotates freely, thus longitudinal translational motion of the source is transferred to rotational motion of the shield. S-RSBT and H-RSBT treatment plans with 180° and 45° azimuthal emission angles were generated for five cervical cancer patients with a diverse range of high-risk target volume (HR-CTV) shapes and applicator positions. For each patient, the total number of emission angles was held nearly constant for S-RSBT and H-RSBT by using dwell positions separated by 5 and 1.7 mm, respectively, and emission directions separated by 22.5° and 60°, respectively. Treatment delivery time and tumor coverage (D{sub 90} of HR-CTV) were the two metrics used as the basis for evaluation and comparison. For all the generated treatment plans, the D{sub 90} of the HR-CTV in units of equivalent dose in 2 Gy fractions (EQD2) was escalated until the D{sub 2cc} (minimum dose to hottest 2 cm{sup 3}) tolerance of either the bladder (90 Gy{sub 3}), rectum (75 Gy{sub 3}), or sigmoid colon (75 Gy{sub 3}) was reached. Results: Treatment time changed for H-RSBT versus S-RSBT by −7.62% to 1.17% with an average change of −2.8%, thus H-RSBT treatments times tended to be shorter than for S-RSBT. The HR-CTV D{sub 90} also changed by −2.7% to 2.38% with an average of −0.65%. Conclusions: H-RSBT is a mechanically feasible delivery technique for use in the curved applicators needed for cervical cancer brachytherapy. S-RSBT and H-RSBT were clinically equivalent for all patients considered, with the H-RSBT technique tending to require less time for delivery.

60 APPLIED LIFE SCIENCES↗

SU-F-SPS-03: Direct Measurement of Organ Doses Resulting From Head and Cervical Spine Trauma CT Protocols

Purpose: This retrospective study analyzes the exposure history of emergency department (ED) patients undergoing head and cervical spine trauma computed tomography (CT) studies. This study investigated dose levels received by trauma patients and addressed any potential concerns regarding radiation dose issues. Methods: Under proper IRB approval, a cohort of 300 trauma cases of head and cervical spine trauma CT scans received in the ED was studied. The radiological image viewing software of the hospital was used to view patient images and image data. The following parameters were extracted: the imaging history of patients, the reported dose metrics from the scanner including the volumetric CT Dose Index (CTDIvol) and Dose Length Product (DLP). A postmortem subject was scanned using the same scan techniques utilized in a standard clinical head and cervical spine trauma CT protocol with 120 kVp and 280 mAs. The CTDIvol was recorded for the subject and the organ doses were measured using optically stimulated luminescent (OSL) dosimeters. Typical organ doses to the brain, thyroid, lens, salivary glands, and skin, based on the cadaver studies, were then calculated and reported for the cohort. Results: The CTDIvol reported by the CT scanner was 25.5 mGy for the postmortem subject. The average CTDIvol from the patient cohort was 34.1 mGy. From these metrics, typical average organ doses in mGy were found to be: Brain (44.57), Thyroid (33.40), Lens (82.45), Salivary Glands (61.29), Skin (47.50). The imaging history of the cohort showed that on average trauma patients received 26.1 scans over a lifetime. Conclusion: The average number of scans received on average by trauma ED patients shows that radiation doses in trauma patients may be a concern. Available dose tracking software would be helpful to track doses in trauma ED patients, highlighting the importance of minimizing unnecessary scans and keeping doses ALARA.

60 APPLIED LIFE SCIENCES↗

SU-F-P-29: Impact of Oral Contrast Agent for Assisting in Outlining Small Intestine On Pelvic IMAT Dose in Patients with Cervical Cancer

Purpose: As the advanced intensity modulated arc therapy(IMAT) delivery systems becoming a main role of treatment ways, which places even greater demands on delivering accuracy. The impact of oral contrast agent (meglumine diatrizoate) for assisting in outlining the small intestine on pelvic IMAT dose in patients with cervical cancer was investigated. Methods: Ten cervical cancer patients for postoperative radiotherapy underwent CT scans, and the planning target volumes (PTV) and organs at risk (including the small intestine, rectum, bladder, colon and the left and right femoral head) were contoured. The IMAT plans were generated on Oncentra v4.1 planning system for each case, PTV was prescribed to 50.4 Gy in 28 fractions. Then another plan was generated by re-calculating the radiation dose after changing the electron density of the small bowel. The first plan (plan A) was the conventional IMAT plan (with oral contrast agent), and the second one (plan B) specified the electron density of the small bowel (without oral contrast agent). Paired t-test was used to compare the dose distribution between the two plans. Results: The PTV’s D2, D50, D95, V110, conformity index, and homogeneity index of plans A and B were 5610.5 vs. 5611.4 cGy (P=0.175), 5348.5 vs. 5348.0 cGy (P=0.869), 5039 vs. 5042.3 (P=0.518), 6.0% vs. 6.1 %( P=0.886), 0.1269 vs. 0.1271 (P=0.34) and 0.8421 vs. 0.8416 (P=0.598), respectively. The volumes of the small bowel receiving at least 30 Gy (V30) and the minimum dose of 2% volume accepted (D2) for plans A and B were 31.6% vs. 31.9% (P=0.371) and 5067.8 vs. 5085.4 cGy (P=0.377), while rectum V50 of the two plans was 12.4% vs. 12.1% (P=0.489). Conclusion: The oral contrast agent (meglumine diatrizoate) filling the small intestine does not lead to a significant increase in the pelvic IMAT dose in patients with cervical cancer.

60 APPLIED LIFE SCIENCES↗

SU-F-T-355: Evaluation of Knowledge-Based Planning Model for the Cervical Cancer Radiotherapy

Purpose: The Varian RapidPlan™ is a commercial knowledge-based optimization process which uses a set of clinically used treatment plans to train a model that can predict individualized dose-volume objectives. The purpose of this study is to evaluate the performance of RapidPlan to generate intensity modulated radiation therapy (IMRT) plans for cervical cancer. Methods: Totally 70 IMRT plans for cervical cancer with varying clinical and physiological indications were enrolled in this study. These patients were all previously treated in our institution. There were two prescription levels usually used in our institution: 45Gy/25 fractions and 50.4Gy/28 fractions. 50 of these plans were selected to train the RapidPlan model for predicting dose-volume constraints. After model training, this model was validated with 10 plans from training pool(internal validation) and additional other 20 new plans(external validation). All plans used for the validation were re-optimized with the original beam configuration and the generated priorities from RapidPlan were manually adjusted to ensure that re-optimized DVH located in the range of the model prediction. DVH quantitative analysis was performed to compare the RapidPlan generated and the original manual optimized plans. Results: For all the validation cases, RapidPlan based plans (RapidPlan) showed similar or superior results compared to the manual optimized ones. RapidPlan increased the result of D98% and homogeneity in both two validations. For organs at risk, the RapidPlan decreased mean doses of bladder by 1.25Gy/1.13Gy (internal/external validation) on average, with p=0.12/p<0.01. The mean dose of rectum and bowel were also decreased by an average of 2.64Gy/0.83Gy and 0.66Gy/1.05Gy,with p<0.01/ p<0.01and p=0.04/<0.01 for the internal/external validation, respectively. Conclusion: The RapidPlan model based cervical cancer plans shows ability to systematically improve the IMRT plan quality. It suggests that RapidPlan has great potential to make the treatment planning process more efficient.

60 APPLIED LIFE SCIENCES↗

SU-F-T-397: Evaluating the Impact of Bladder Filling Status for the Organs at Risk Dose Distribution in Cervical Cancer Patients with Intensity Modulated Radiotherapy

Purpose: To investigate the impact of bladder filling status of the organs at risk (OARs) on dose distribution during intensity modulated radiotherapy (IMRT) for cervical cancer patients. Methods: Twelve cervical cancer patients treated with IMRT were selected for this study. The prescription dose was 45Gy/25 fractions with the 6 MV photon beam. All patients performed two CT scans, one with an empty bladder, the other one with bladder filled. For the registration of two CT scans, the fusion was automatically carried out upon the bony anatomy. The OARs (bladder, rectum, pelvic bone and small intestine) were delineated to planning CT to evaluate the dose distributions. These dose distributions were compared between empty bladder and bladder filling. Results: The bladder volume with empty bladder and bladder filling was 403.2±124.13cc and 101.4±87.5cc, respectively. There were no statistical differences between empty bladder and bladder filling in the mean value of pelvic bone V10Gy, V20Gy, V40Gy; rectum V40Gy and V45Gy. The bladder V40Gy and V45Gy were lower in the bladder filling group than in the empty bladder group (63.7%±5.8% vs 87.5%±7.8%, 45.1%±9.5% vs 62.4%±11.8%, respectively). The V45Gy for small intestine in the bladder filling group was significantly less than the empty bladder group (146.7cc±95.3cc vs 245.7cc±101.8cc). Conclusion: Our study finds that the bladder filling status did not have a significant impact on dose distribution in the rectum and pelvic bone. However, the changes of bladder filling have a large impact on bladder and small intestine doses. A full bladder is strongly recommended during treatment for cervical cancer patients.

60 APPLIED LIFE SCIENCES↗

SU-F-T-423: Automating Treatment Planning for Cervical Cancer in Low- and Middle- Income Countries

Purpose: To develop and test two independent algorithms that automatically create the photon treatment fields for a four-field box beam arrangement, a common treatment technique for cervical cancer in low- and middle-income countries. Methods: Two algorithms were developed and integrated into Eclipse using its Advanced Programming Interface:3D Method: We automatically segment bony anatomy on CT using an in-house multi-atlas contouring tool and project the structures into the beam’s-eye-view. We identify anatomical landmarks on the projections to define the field apertures. 2D Method: We generate DRRs for all four beams. An atlas of DRRs for six standard patients with corresponding field apertures are deformably registered to the test patient DRRs. The set of deformed atlas apertures are fitted to an expected shape to define the final apertures. Both algorithms were tested on 39 patient CTs, and the resulting treatment fields were scored by a radiation oncologist. We also investigated the feasibility of using one algorithm as an independent check of the other algorithm. Results: 96% of the 3D-Method-generated fields and 79% of the 2D-method-generated fields were scored acceptable for treatment (“Per Protocol” or “Acceptable Variation”). The 3D Method generated more fields scored “Per Protocol” than the 2D Method (62% versus 17%). The 4% of the 3D-Method-generated fields that were scored “Unacceptable Deviation” were all due to an improper L5 vertebra contour resulting in an unacceptable superior jaw position. When these same patients were planned with the 2D method, the superior jaw was acceptable, suggesting that the 2D method can be used to independently check the 3D method. Conclusion: Our results show that our 3D Method is feasible for automatically generating cervical treatment fields. Furthermore, the 2D Method can serve as an automatic, independent check of the automatically-generated treatment fields. These algorithms will be implemented for fully automated cervical treatment planning.

60 APPLIED LIFE SCIENCES↗

Understanding Barriers to Cervical Cancer Screening in Women With Access to Care, Behavioral Risk Factor Surveillance System, 2014

Cervical cancer screening can save lives when abnormal cervical lesions and early cancers are detected and treated; however, many women are not screened as recommended. We used the Behavioral Risk Factor Surveillance System survey to examine nonfinancial barriers to cervical cancer screening among women who reported having insurance and a personal doctor or health care provider. Among these women, a higher proportion who were never or rarely screened reported having multiple chronic conditions. The results of this study underscore the importance of incorporating preventive clinical services into the management of one or more chronic conditions.

60 APPLIED LIFE SCIENCES↗

A hidden Markov model for population-level cervical cancer screening data

The Cancer Registry of Norway has been administrating a national cervical cancer screening program since 1992 by coordinating triennial cytology exam screenings for the female population between 25 and 69 years of age. Up to 80% of cancers are prevented through mass screening, but this comes at the expense of considerable screening activity and leads to overtreatment of clinically asymptomatic precancers. Here, we present a continuous-time, time-inhomogeneous hidden Markov model which was developed to understand the screening process and cervical cancer carcinogenesis in detail. By leveraging 1.7 million individual's multivariate time-series of medical exams performed over a 25-year period, we simultaneously estimate all model parameters. We show that an age-dependent model reflects the Norwegian screening program by comparing empirical survival curves from observed registry data and data simulated from the proposed model. The model can be generalized to include more detailed individual-level covariates as well as new types of screening exams. By utilizing individual screening histories and covariate data, the proposed model shows potential for improving strategies for cancer screening programs by personalizing recommended screening intervals.

59 BASIC BIOLOGICAL SCIENCES↗

CSF1R inhibition delays cervical and mammary tumor growth in murine models by attenuating the turnover of tumor-associated macrophages and enhancing infiltration by CD8 + T cells

Increased numbers of tumor-infiltrating macrophages correlate with poor disease outcome in patients affected by several types of cancer, including breast and prostate carcinomas. The colony stimulating factor 1 receptor (CSF1R) signaling pathway drives the recruitment of tumor-associated macrophages (TAMs) to the neoplastic microenvironment and promotes the differentiation of TAMs toward a pro-tumorigenic phenotype. Twelve clinical trials are currently evaluating agents that target the CSF1/CSF1R signaling pathway as a treatment against multiple malignancies, including breast carcinoma, leukemia, and glioblastoma. The blockade of CSF1R signaling has been shown to greatly decrease the number of macrophages in a tissue-specific manner. However, additional mechanistic insights are needed in order to understand how macrophages are depleted and the global effects of CSF1R inhibition on other tumor-infiltrating immune cells. Using BLZ945, a highly selective small molecule inhibitor of CSF1R, we show that CSF1R inhibition attenuates the turnover rate of TAMs while increasing the number of CD8 + T cells that infiltrate cervical and breast carcinomas. Specifically, we find that BLZ945 decreased the growth of malignant cells in the mouse mammary tumor virus-driven polyomavirus middle T antigen (MMTV-PyMT) model of mammary carcinogenesis. Furthermore, we show that BLZ945 prevents tumor progression in the keratin 14-expressing human papillomavirus type 16 (K14-HPV-16) transgenic model of cervical carcinogenesis. Our results demonstrate that TAMs undergo a constant turnover in a CSF1R-dependent manner, and suggest that continuous inhibition of the CSF1R pathway may be essential to maintain efficacious macrophage depletion as an anticancer therapy.

59 BASIC BIOLOGICAL SCIENCES↗

Increasing risk of uterine cervical cancer among young Japanese women: Comparison of incidence trends in Japan, South Korea and Japanese‐Americans between 1985 and 2012

In Japan, cervical cancer incidence has increased since the late 1990s especially among young women, despite a decreasing trend in most developed countries. Here, we examined age, period and birth cohort trends in cervical cancer incidence rates from 1985 to 2012. Incidence rates were ascertained using three population‐based cancer registries and analyzed using Joinpoint regression and age‐period‐cohort models. We compared the findings in Japan to trends among Japanese‐Americans in the Surveillance, Epidemiology, and End Results Registries and among women in South Korea using the Korea Central Registry. Age‐standardized incidence rates in Japan decreased by 1.7% per year (95% confidence interval − 3.3%, 0.0%) until 1997 and thereafter increased by 2.6% per year (1.1%, 4.2%). Incidence rates increased among women under age 50, were stable among women aged 50–54, and decreased or remained stable among women aged 55 and over. The age‐standardized incidence rate ratio by birth cohort showed a U‐shaped pattern with the lowest rates in women born in the late 1930s and 1940s. In comparison, women born before 1920 and after 1970 had about double the incidence. Increasing risk in recent birth cohorts was not evident in Japanese‐American or South Korean women. The trends in Japan may be attributable to increasing prevalence of human papillomavirus (HPV) infection among young women. Screening and vaccination have been shown to be highly effective and would help reverse these trends.

Utada, Mai↗

Radiation Dose Reduction in CT Fluoroscopy-Guided Cervical Transforaminal Epidural Steroid Injection by Modifying Scout and Planning Steps

Background and PurposeIn CT fluoroscopy (CTF)-guided cervical transforaminal epidural steroid injection (TFESI), the majority of radiation dose is contributed by the planning CT scan rather than the CTF procedure itself. We replaced the planning helical CT with a spot CTF and accordingly changed the patient posture during scout and planning scans. The aim of this study was to test whether radiation dose reduction would be achieved by this protocol modification while still maintaining technical performance.MethodsOverall, 338 consecutive procedures before (control group: n = 163) and after (study group: n = 175) instituting the above-mentioned protocol modification were analyzed retrospectively, comparing patient characteristics (age, sex, neck diameter, and level injected) and technical performance [technical success rate, dose-length product (DLP), inadvertent contrast flow incidence, number of CTF acquisitions, and procedural time] between the two groups.ResultsAll injections were technically successful at every level from C3–C4 to C7–T1 without serious complications in both groups. The median DLP of the study group (7.92 mGy·cm) was significantly reduced compared to that of the control group (39.05 mGy·cm, P < 0.001). There were no significant differences between the two groups regarding the incidence of inadvertent contrast flow (20.6 vs. 17.2 %, P = 0.426), number of CTF acquisitions (median 5 vs. 4, P = 0.123), and the procedural time (median 6.62 vs. 6.90 min, P = 0.100).ConclusionsWhen conducting CTF-guided cervical TFESIs, a significant radiation dose reduction (median 79.7 % in DLP) can be achieved by modifying scout and planning steps, without compromising the technical performance.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Study on Tribological Properties of CoCrMo Alloys against Metals and Ceramics as Bearing Materials for Artificial Cervical Disc

CoCrMo alloys are believed to be a kind of potential material for artificial cervical disc. However, the tribological properties of CoCrMo alloys against different metals and ceramics are not systematically studied. In this study, the tribological behaviors of CoCrMo alloys against metals (316L, Ti6Al4V) and ceramics (Si{sub 3}N{sub 4}, ZrO{sub 2}) were focused under dry friction and 25 wt.% newborn calf serum (NCS)-lubricated conditions using a ball-on-disc apparatus under reciprocating motion. The microstructure, composition and hardness of CoCrMo alloys were characterized using x-ray diffraction, scanning electron microscopy (SEM) and hardness testers, respectively. The contact angles of the CoCrMo alloys with deionized water and 25 wt.% NCS were measured by the OCA contact angle measuring instrument. The maximum wear width, wear depth and wear volume were measured by three-dimensional white light interference. The morphology and the EDX analysis of the wear marks on CoCrMo alloys were examined by SEM to determine the basic mechanism of friction and wear. The dominant wear mechanism in dry friction for CoCrMo alloys against all pairings was severe abrasive wear, accompanied with a lot of material transfer. Under 25 wt.% NCS-lubricated condition, the wear mechanism for CoCrMo alloys against ceramics (Si{sub 3}N{sub 4}, ZrO{sub 2}) was also mainly severe abrasive wear. However, severe abrasive wear and electrochemical corrosion occurred for the CoCrMo-316L pairing under lubrication. Severe abrasive wear, adhesive wear and electrochemical corrosion occurred for the CoCrMo-Ti6Al4V pairing under lubrication. According to the results, the tribological properties of CoCrMo alloys against ceramics were better than those against metals. The CoCrMo-ZrO{sub 2} pairing displayed the best tribological behaviors and could be taken as a potential candidate bearing material for artificial cervical disc.

36 MATERIALS SCIENCE↗

Anticancer activity of arborinine from Glycosmis parva leaf extract in human cervical cancer cells

Highlights: • Arborinine extracted from Glycosmis parva leaves has strong anticancer activity. • It is significantly more cytotoxic to HeLa cancer cells than normal cells. • Arborinine inhibits tumor spheroid growth more potently than chemotherapeutic drugs cisplatin, gemcitabine, and bleomycin. • Arborinine induces DNA damage-independent apoptosis. • It inhibits cancer cell migration by downregulating epithelial-mesenchymal transition. Glycosmis parva is a small shrub found in Thailand. Ethyl acetate (EtOAc) extract from its leaves has been shown to exert anticancer effects in vitro; however, the compound responsible for this activity has not been isolated and characterized. In this study, we demonstrate that arborinine, a major acridone alkaloid in the EtOAc fraction, decreased proliferation and was strongly cytotoxic to HeLa cervical cancer cells without significantly affecting normal cells. The compound also inhibited tumor spheroid growth much more potently than chemotherapeutic drugs bleomycin, gemcitabine, and cisplatin. In addition, unlike cisplatin, arborinine activated caspase-dependent apoptosis without inducing DNA damage response. We further show that arborinine strongly suppressed cancer cell migration by downregulating expression of key regulators of epithelial-mesenchymal transition. Taken together, our data provide important insights into the molecular mechanism of arborinine’s anticancer activity, supporting its potential use for treating cervical cancer.

60 APPLIED LIFE SCIENCES↗

A novel MtHSP70-FPR1 fusion protein enhances cytotoxic T lymphocyte responses to cervical cancer cells by activating human monocyte-derived dendritic cells via the p38 MAPK signaling pathway

Highlights: • MtHSP70-FPR1 induces phenotypic and functional maturation of human monocyte-derived dendritic cells. • MtHSP70-FPR1-matured dendritic cells significantly increase cytotoxic T lymphocytes responses to cervical cancer cells. • P38 MAPK signaling pathway play a vital role in MtHSP70-FPR1-induced dendritic cells maturation. To evaluate the potential effects of recombinant mycobacterium tuberculosis heat shock protein 70-formyl peptide receptor 1 (MtHSP70-FPR1) fusion protein on human monocyte-derived dendritic cell (moDC) maturation; cytotoxic T lymphocyte (CTL) responses to cervical cancer (CC) cells; and the roles of the p38 MAPK, ERK, and JNK pathways in its transition.

60 APPLIED LIFE SCIENCES↗