• Journal of radiological science and technology
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• v.35 no.3
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• pp.249-254
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• 2012

The aim of this study was to investigate the setup accuracy for tangential breast treatment patients using electronic portal image and 2-D reconstruction image Twenty two patients undergoing tangential breast treatment. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters. The difference between measured reference parameters on simulation films and electronic portal images (EPIs) was calculated as the setup error. A total of 22 simulation films and 110 EPIs were evaluated. In the tangential fields, the calculated reference parameters were the central lung distance (CLD), central soft-tissue distance (CSTD), and above lung distance (ALD), below lung distance (BLD). In the medial tangential field, the average difference values for these parameters were 1.0, -6.4, -2.1 and 2.0, respectively; and the ${\sigma}$ values were 1.5, 2.3, 4.1 and 1.1, respectively. In the lateral tangential field, the average difference values for these parameters were -1.5, -4.3, -2.7 and -1.3, respectively; and the ${\sigma}$ values were 3.3, 2.1, 2.9 and 2.5, respectively. CLD, CSTD, ALD and BLD in the tangential fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing tangential breast radiotherapy treatment.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.620-631
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• 2022

Purpose This study aimed to investigate the diagnostic performance of features suggestive of nodal metastasis on preoperative MRI in patients with invasive breast cancer. Materials and Methods We retrospectively reviewed the preoperative breast MRI of 192 consecutive patients with surgically proven invasive breast cancer. We analyzed MRI findings of axillary lymph nodes with regard to the size, long/short ratio, cortical thickness, shape and margin of the cortex, loss of hilum, asymmetry, signal intensity (SI) on T2-weighted images (T2WI), degree of enhancement in the early phase, and enhancement kinetics. Receiver operating characteristic (ROC) analysis, chi-square test, t test, and McNemar's test were used for statistical analysis. Results Increased shorter diameter, uneven cortical shape, increased cortical thickness, loss of hilum, asymmetry, irregular cortical margin, and low SI on T2WI were significantly suggestive of metastasis. ROC analysis revealed the cutoff value for the shorter diameter and cortical thickness as 8.05 mm and 2.75 mm, respectively. Increased cortical thickness (> 2.75 mm) and uneven cortical shape showed significantly higher sensitivity than other findings in McNemar's test. Irregular cortical margins showed the highest specificity (100%). Conclusion Cortical thickness > 2.75 mm and uneven cortical shape are more sensitive parameters than other findings, and an irregular cortical margin is the most specific parameter for predicting axillary metastasis in patients with invasive breast cancer.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.1
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• pp.37-43
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• 2008

Purpose: To evaluate dosimetry results of three different techniques for whole breast irradiation after conservative surgery of large pendulous breast patient. Materials and Methods: Planning computed tomography (CT) scans for three techniques were performed on a GE Hi-speed advantage CT scanner in the supine (SP), supine with breast supporting Device (SD) and prone position on a custom prone mattress (PP). Computed tomography images were acquired at 5 mm thickness. The clinical target volumes (CTV), ipsilateral lung and heart were delineated to evaluate the dose statistic, and all techniques were planned with the tangential photon beams (Pinnacle$^3$, Philips Medical System, USA). The prescribed dose was 50 Gy delivered in 25 fractions. To evaluate the dose coverage for CTV, we analysed percent volume of CTV receiving minimum of 95%, 100%, 105%, and 110% of prescription dose ($V_{95}$, $V_{100}$, $V_{105}$, and $V_{110}$) and minimal dose covering 95% ($D_{95}$) of CTV. The dosimetric comparison for heart and ipsilateral lung was analysed using the minimal dose covering 5% of each organs ($D_5$) and the volume that received >18 Gy for the heart and >20 Gy for the ipsilateral lung. Results: Target volume coverage ($V_{95}$ and $V_{100}$) was not significantly different for all technique. The V105 was lower for PP (1.2% vs. 4.4% for SP, 11.1% for SD). Minimal dose covering 95% ($D_{95}$) of target was 47.5 Gy, 47.7 Gy and 48 Gy for SP, SD and PP. The volume of ipsilateral lung received >20 Gy was 21.7%, 11.6% and 4.9% for SP, SD and PP. The volume of heart received >18 Gy was 17.0%, 16.1% and 9.8% for SP, SD and PP. Conclusion: Prone positioning of patient for large pendulous breast irradiation enables improving dose uniformity with minimal heart and lung doses.

• Progress in Medical Physics
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• v.23 no.4
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• pp.261-268
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• 2012

Breast cancer is the second leading cause of women cancer death in Korea. The key for reducing disease mortality is early detection. Although digital mammography (DM) has been credited as one of the major reasons for the early detection to decrease in breast cancer mortality observed in the last 20 years, DM is far from perfect for several limitations. Digital breast tomosynthesis (DBT) is expected to overcome some inherent limitations of conventional mammography caused by overlapping of normal tissue and pathological tissue during the standard 2D projections for the improved lesion margin visibility and early breast cancer detection. In this study, we compared a DM system and DBT system acquired with different thickness of breast phantom. We acquired breast phantom data with same average glandular dose (AGD) from 1 mGy to 4 mGy under same experimental condition. The contrast, micro-calcification measurement accuracy and observer study were conducted with breast phantom images. As a result, the higher accuracy of lesion detection with DBT system compared to DM system was demonstrated in this study. Furthermore, the pain of patients caused by severe compression can be reduced with DBT system. In conclusion, the results indicated that DBT system play an important role in breast cancer detection.

• Investigative Magnetic Resonance Imaging
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• v.17 no.3
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• pp.207-214
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• 2013

Purpose : To evaluate the MRI findings of breast cancer with BRCA mutation. Materials and Methods: We collected information of the breast cancer patients who underwent the test for BRCA gene mutation as well as preoperative breast MRI from January 2007 to December 2010. A total of 185 patients were enrolled; 33 of these patients had BRCA mutations and 152 patients did not. Among them, a total of 231 breast cancers were detected. Images of the 47 breast cancers with BRCA mutation and of the 184 breast cancers without mutations were evaluated to compare the morphologic and enhancement features on MRI. Results: With MR imaging, there were no significant difference in morphologic characteristic between two groups. However, enhancement pattern in the group with BRCA mutation were more likely to have persistent enhancement (p < 0.233), and LN metastasis was more common in breast cancers without BRCA mutation. Breast cancers with BRCA 2 mutation tend to show more persistent enhancement pattern than BRCA 1 mutation. Conclusion: In breast cancer patients with BRCA mutation, MRI didn't show significant difference in morphologic characteristics, however breast cancers with BRCA gene mutation carriers tend to have benign morphologic features on MRI, such as Type 1 kinetic curve enhancement.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.99-108
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• 2021

Purpose: The goal of this study is to evaluate usefulness of noninvasive method instead of previous inserting Fiducial Marker Method when performing Stereotactic Partial Breast Irradiation in CyberKnife. Material and methods: For consistency of Imaging Center, we evaluated both oblique images at angle 45 and 315 acquired from 2D Simulator and CyberKnife quantitatively through dice similarity coefficient. Also, location reproducibility of Surface Fiducial Marker was analyzed from 2D Simulator, treatment plans and CyberKinfe images by using 8 Fiducial Markers made of gold attached to ATOM Phantom based on our institution's protocols. Results: The results of the estimated consistency were 0.87 and 0.9 at the oblique angle 45 and 315, respectively. For location consistency of Surface Fiducial Markers, values of horizontal vertical direction of left breast were Superior/Inferior 0.3 mm, Left/Right -0.3 mm, Anterior/Posterior 0.4 mm, and the values of rotational direction were Roll 0.3 °, Pitch 0.2 °, Yaw 0.4 °. The values of horizontal vertical direction of right breast were Superior/Inferior -0.1 mm, Left/Right -0.1 mm, Anterior/Posterior -0.1 mm, and the values of rotational direction were Roll 0.2°, Pitch 0.1°, Yaw 0.1°. Conclusions: We expect that the protocols used by Surface Fiducial Markers when performing Stereotactic Partial Breast Irradiation in CyberKnife will provide protection from pain and cut expenses for treatment and reduce treatment errors and make treatment more accurate by suggesting treatment protocols based on high consistency of Imaging Center and reproducibility of Fiducial Markers.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.329-336
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• 2014

Purpose : To evaluate the dose on a contralateral breast and the usefulness of shielding according to the distance between the contralateral breast and the side of the beam by breast size when patients who got breast implant receive radiation therapy. Materials and Methods : We equipped 200 cc, 300 cc, 400 cc, and 500 cc breast model on the human phantom (Rando-phantom), acquired CT images (philips 16channel, Netherlands) and established the radiation treatment plan, 180 cGy per day on the left breast (EclipseTM ver10.0.42, Varian Medical Systems, USA) by size. We set up each points, A, B, C, and D on the right(contralateral) breast model for measurement by size and by the distance from the beam and attached MOSFET at each points. The 6 MV, 10 MV and 15 MV X-ray were irradiated to the left(target) breast model and we measured exposure dose of contralateral breast model using MOSFET. Also, at the same condition, we acquired the dose value after shielding using only Pb 2 mm and bolus 3 mm under the Pb 2 mm together. Results : As the breast model is bigger from 200 cc to 500 cc, The surface of the contralateral breast is closer to the beam. As a result, from 200 cc to 500 cc, on 180 cGy basis, the measurement value of the scattered ray inclined by 3.22 ~ 4.17% at A point, 4.06 ~ 6.22% at B point, 0.4~0.5% at C point, and was under 0.4% at D point. As the X-ray energy is higher, from 6 MV to 15 MV, on 180 cGy basis, the measurement value of the scattered ray inclined by 4.06~5% at A point, 2.85~4.94% at B point, 0.74~1.65% at C point, and was under 0.4% at D point. As using Pb 2 mm for shield, scattered ray declined by average 9.74% at A and B point, 2.8% at C point, and is under 1% at D point. As using Pb 2 mm and bolus together for shield, scattered ray declined by average 9.76% at A and B point, 2.2% at C point, and is under 1% at D point. Conclusion : Commonly, in case of patients who got breast implant, there is a distance difference by breast size between the contralateral breast and the side of beam. As the distance is closer to the beam, the scattered ray inclined. At the same size of the breast, as the X-ray energy is higher, the exposure dose by scattered ray tends to incline. As a result, as low as possible energy wihtin the plan dose is good for reducing the exposure dose.

• The Korean Journal of Nuclear Medicine
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• v.34 no.6
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• pp.478-486
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• 2000

Purpose: The sentinel lymph node is defined as the first draining node from a primary tumor and reflects the histologic feature of the remainder of the lymphatic basin status. The aim of this study was to evaluate the usefulness of lymphoscintigraphy and intraoperative radioguided gamma probe for identification and removal of sentinel lymph node in breast cancer. Materials and Methods: Lymphoscintigraphy was performed preoperatively in 15 patients with biopsy proven primary breast cancer. Tc-99m antimony sulfide colloid was injected intradermally at four points around the tumor. Imaging acquisition included dynamic imaging, followed by early and late static images at 2 hours. The sentinel lymph node criteria on lymphoscintigraphy is the first node of the highest uptake in early and late static images. We tagged the node emitting the highest activity both in vivo and ex vivo. Histologic study for sentinel and axillary lymph node investigation was done by Hematoxylin-Eosin staining. Results: On lymphoscintigraphy, three of 15 patients had clear lymphatic vessels in dynamic images, and 11 of 15 patients showed sentinel lymph node in early static image and three in late static 2 hours image. Mean detection time of sentinel lymph node on lymphoscintigraphy was $33.5{\pm}48.4$ minutes. The sentinel lymph node localization and removal by lymphoscintigraphy and intraoperative gamma probe were successful in 14 of 15 patients (detection rate: 93.3%). On lymphoscintigraphy, 14 of 15 patients showed $2.47{\pm}2.00$ sentinel lymph nodes. On intraoperative gamma probe, $2.36{\pm}1.96$ sentinel lymph nodes were detected. In 7 patients with positive results of sentinel lymph node metastasis, 5 patients showed positive results of axillary lymph node (sensitivity: 72%) but two did not. In 7 patients with negative results of sentinel lymph node metastasis, all axillary nodes were free of disease (specificity: 100%). Conclusion: Sentinel lymph node biopsy with lymphoscintigraphy and intraoperative gamma probe is a reliable method to predict axillary lymph node metastasis in breast cancer, and unnecessary axillary lymph node dissection can be avoided.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.39-47
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• 2014

Purpose As breast cancer patients continue to increase every year, cases of BSGI are on the rise with a heavier reliance on it. However, BSGI protocol in hospitals was not studied enough despite it was covered by hospital's condition and recommendation of manufacturers. The objective of the study was an examination of methods to be applicable to BSGI protocols, putting the self-development phantom to use in quality assessment of the images. Materials and Methods Dilon 6800 (Dilon Technologies Inc, Newport News, USA) was used in the study and five different sizes of sphere were distinctively produced in the phantom. The study used $^{99m}TcO_4$. The cases were classified in to three categories that background radioactivity to region of interest as ratio of 2: 4: 8, They were acquired images for 5, 7, 10mins. The acquired image was set region of interest according to the size of sphere, and We analyzed quantitative and qualitative analysis. The acquired data statistically analyzed with SPSS ver.18.0. Results As the result of quantitative and qualitative analysis, count rate of each sphere in accordance with difference of injection dose showed that higher count rate as injection dose and sphere size increased (P<0.005). Count rate of each sphere in accordance with difference of acquisition time showed that higher count rate as acquisition time and sphere size increased (P<0.005). Contrast noise ratio of each sphere in accordance with difference of injection dose showed that higher contrast noise ratio as injection dose increased. Particularly, Contrast noise ratio of eight times ratio images was the highest among. Contrast noise ratio of each sphere in accordance with difference of acquisition time showed that higher contrast noise ratio as acquisition time increased. And, Contrast noise ratio of seven minute image was the highest among (P<0.005). Conclusion There was significant change of Contrast noise ratio through quantitative and qualitative analysis. Moreover, We found usefulness of phantom. If Institutions identified image through the phantom study and they made BSGI protocol, We expected to help the improvement of diagnostic value of the images.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.175-181
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• 2015

Purpose : To evaluate Contralateral Breast Doses with Supine and Prone Positions for tangential Irradiation techniques for left-sided breast Cancer Materials and Methods : We performed measurements for contralateral doses using Human Phantom at each other three plans (conventional technique, Field-in-Field, IMRT, with prescription of 50 Gy/25fx). For the measurement of contralateral doses we used Glass dosimeters on the 4 points of Human Phantom surface (0 mm, 10 mm, 30 mm, 50 mm). For the position check at every measurements, we had taken portal images using EPID and denoted the incident points on the human phantom for checking the constancy of incident points. Results : The contralateral doses in supine position showed a little higher doses than those in prone position. In the planning study, contralateral doses in the prone position increased mean doses of 1.2% to 1.8% at each positions while those in the supine positions showed mean dose decreases of 0.8% to 0.9%. The measurements using glass dosimeters resulted in dose increases (mean: 2.7%, maximum: 4% of the prescribed dose) in the prone position. In addition, the delivery techniques of Field-in-field and IMRT showed mean doses of 3% higher than conventional technique. Conclusion : We evaluated contralateral breast doses depending on different positions of supine and prone for tangential irradiations. For the phantom simulation of set-up variation effects on contralateral dose evaluation, although we used humanoid phantom for planning and measurements comparisons, it would be more or less worse set-up constancy in a real patient. Therefore, more careful selection of determination of patient set-up for the breast tangential irradiation, especially in the left-sided breast, should be considered for unwanted dose increases to left lung and heart. In conclusion, intensive patient monitoring and improved patient set-up verification efforts should be necessary for the application of prone position for tangential irradiation of left-sided breast cancer.