• The Journal of Korean Society for Radiation Therapy
• /
• v.28 no.1
• /
• pp.65-75
• /
• 2016

Purpose : By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Materials and Methods : Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. Results : The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. Conclusion : As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

• Radiation Oncology Journal
• /
• v.28 no.3
• /
• pp.177-183
• /
• 2010

Purpose: Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Materials and Methods: Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inframammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. Results: The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. Conclusion: The use of 3D CT based planning reduced the radiation field in early breast cancer patients with small breasts in relation to conventional planning. Though a coherent definition of the breast is needed, CT-based planning generated the better plan in terms of reducing the irradiation volume of normal tissue. Moreover it was possible that 3D CT based planning showed better CTV coverage including postoperative change.

• The Journal of Korean Society for Radiation Therapy
• /
• v.25 no.2
• /
• pp.187-192
• /
• 2013

Purpose: We investigate the results of changed heart volume and heart dose in the left breast cancer patients while considering the movements of respiration. Materials and Methods: During the months of March and May in 2012, we designated the 10 patients who had tangential irradiation with left breast cancer in the department of radiation Oncology. With acquired images of free breathing pattern through 3D and 4D CT, we had planed enough treatment filed for covered up the whole left breast. It compares the results of the exposed dose and the volume of heart by DVH (Dose Volume histogram). Although total dose was 50.4 Gy (1.8 Gy/28 fraction), reirradiated 9 Gy (1.8 Gy/5 Fraction) with PTV (Planning Target Volume) if necessary. Results: It compares the results of heart volume and heart dose with the free breathing in 3D CT and 4D CT. It represents the maximum difference volume of heart is 40.5%. In addition, it indicated the difference volume of maximum and minimum, average are 8.8% and 27.9%, 37.4% in total absorbed dose of heart. Conclusion: In case of tangential irradiation (opposite beam) in left breast cancer patients, it is necessary to consider the changed heart volume by the respiration of patient and the heartbeat of patient.

• The Journal of Korean Society for Radiation Therapy
• /
• v.18 no.1
• /
• pp.35-41
• /
• 2006

Purpose: A various find of radiotherapy treatment plans have been made to determine appropriate doses for breasts, chest walls and loco-regional lymphatics in the radiotherapy of breast cancers. The aim of this study was to evaluate the optimum radiotherapy plan technique method by analyzing dose distributions qualitatively and quantitatively. Materials and Methods: To evaluate the optimum breast cancer radiotherapy plan technique, the traditional method(two dimensional method) and computed tomography image are adopted to get breast volume, and they are compared with the three-dimensional conformal radiography (3DCRT) and the intensity modulated radiotherapy (IMRT). For this, the regions of interest (ROI) such as breasts, chest walls, loco-regional lymphatics and lungs were marked on the humanoid phantom, and the computed tomography(Volume, Siemens, USA) was conducted. Using the computed tomography image obtained, radiotherapy treatment plans (XiO 5.2.1, FOCUS, USA) were made and compared with the traditional methods by applying 3DCRT and IMRT. The comparison and analysis were made by analyzing and conducting radiation dose distribution and dose-volume histogram (DVH) based upon radiotherapy techniques (2D, 3DCRT, IMRT) and point doses for the regions of interest. Again, treatment efficiency was evaluated based upon time-labor. Results: It was found that the case of using 3DCRT plan techniques by getting breast volume is more useful than the traditional methods in terms of tumor delineation, beam direction and confirmation of field boundary. Conclusion: It was possible to present the optimum radiotherapy plan techniques through qualitative and quantitative analyses based upon radiotherapy plan techniques in case of breast cancer radiotherapy. However, further studies are required for the problems with patient setup reproducibility arising from the difficulties of planning target volume (PVT) and breast immobilization in case of three-dimensional radiotherapy planning.

• Progress in Medical Physics
• /
• v.25 no.4
• /
• pp.199-204
• /
• 2014

The purpose of this study is to evaluate the dosimetric outcome of the field-in-field (FIF) plans compared with tangential wedged beams (TWB) plans for whole breast irradiation of breast cancer patients. Twenty patients with right-sided breast cancer and 10 patients with left-sided breast cancer were retrospectively enrolled in this study. We generated a FIF plan and a TWB plan for each patient to compare dosimetric outcomes. The dose the homogeneity index (HI), the conformity index (CI) and the uniformity index (UI) were defined and used for comparison of the dosimetric outcome of the planning target volume (PTV). To compare the dosimetric outcome of the organs at risk, the mean dose ($D_{mean}$) and the percentage of volumes receiving more than 10, 20 and 30 Gy of the ipsilateral lung and heart were used. The FIF plans had significantly lower HI (p=0.002), higher UI (p=0.000) and CI (p=0.000) than those of the TWB plans, which means that the FIF plans were better than the TWB plans in the dosimetric comparisons of the PTV. The $V10_{lung}$ ($17.1{\pm}7.1$ vs. $18.6{\pm}6.6%$, p=0.020) and $V30_{lung}$ ($10.3{\pm}5.1%$ vs. $10.7{\pm}5.2%$, p=0.000) were lower with the FIF plans compared with those of the TWB plans, with statistical significance. For the left-sided breast cancer patients, $D_{mean}$ of the heart ($2.6{\pm}1.3$ vs. $3.2{\pm}1.4$ Gy, p=0.000), $V20_{heart}$ ($3.4{\pm}2.6$ vs. $3.6{\pm}2.8%$, p=0.005) and $V30_{heart}$ ($2.6{\pm}2.3%$ vs. $2.9{\pm}2.4%$, p=0.004) were significantly lower for the FIF plans in comparison with those of the TWB plans. The FIF plans increased the dose homogeneity, conformity and uniformity of the target volume for the whole-breast irradiation compared with the TWB plans. Moreover, FIF plans reduced the doses to the ipsilateral lung and heart.

• Journal of the Korean Society of Radiology
• /
• v.12 no.3
• /
• pp.313-319
• /
• 2018

In radiation treatment, it is unavoidable to block the influence of scattered ray on a skin and prevent internal normal organs from being exposed to radiation. It is fair to say that radiation therapy aims to reduce an absorbed dose of normal tissues. In particular, in radiation therapy of left-sided breast cancer, the internal neighboring organs are normal breast tissues, the heart, and the lung. The side effects on the heart include cardioplegy and myocardial infarction. This study tried to observe changes in the volume and dose of the heart in general radiation therapy plan and respiratory control based radiation therapy plan for patients with left-sided breast cancer, and to find the heart's volume and dose generated by respiration. According to the 4D computer tomography (CT), a volume of the heart had $12.8{\pm}8.7cc$ on average, and its dose had $17.3{\pm}12.1cGy$ on average. The differences in the volume and dose may cause side effects in radiation treatment. Therefore, it is necessary to apply respiratory control technique to establish the radiation treatment plan based on an accurate position of the heart.

• The Journal of Korean Society for Radiation Therapy
• /
• v.19 no.2
• /
• pp.131-141
• /
• 2007

Purpose: Try to compare dose distribution and lung dose of radiation treatment plan of the breast cancer that used Irregular Surface Compensator (ISC) and treatment plan that used a wedge filter. Materials and Methods: Established a treatment plan to be distributed over 95% of prescription dose (5,040 cGy) of the two tangent-half fields that used a wedge filter and ISC at a breast organization as made to breast cancer patient having an irregular surfaces after surgery. Compared high dose area and DVH, and verified a treatment plan as used film with rectangular phantom. Results: Maximum dose point in breast tissue appeared to 107.5% in case of tangent-half fields Tx plan that used a wedge filter, and lung volumes exposed above 20 Gy by 7.63%. In case of ISC, maximum dose point in breast tissue appeared to 106.4%, and lung volumes exposed above 20 Gy by 6.5%. The film measurement results that used phantom, 105$\sim$110% high dose region was distributed to the upper part and both edges of phantom. However in case of ISC, appeared by 100$\sim$105% dose conformity distribution. Conclusion: In general, the Irregular Surface Compensator (ISC) can improve the dose conformity of breast tissues, as well as reduced hot spots in the lung and in the breast. Such an advantage by using ISC technique is more beneficial for patients who have more irregular surfaces after surgery.

• Radiation Oncology Journal
• /
• v.21 no.1
• /
• pp.82-93
• /
• 2003

Purpose : To reduce the Irradiation dose to the lungs and heart in the case of chest wail irradiation using an oppositional electron beam, we used an Individualized custom bolus, which was precisely designed to compensate for the differences In chest wall thickness. The benefits were evaluated by comparing the normal tissue complication probablilties (NTCPS) and dose statistics both with and without boluses. Materials and Methods : Boluses were made, and their effects evaluated in ten patients treated using the reverse hockey-stick technique. The electron beam energy was determined so as to administer 80% of the irradiation prescription dose to the deepest lung-chest wall border, which was usually located at the internal mammary lymph node chain. An individualized custom bolus was prepared to compensate for a chest wall thinner than the prescription depth by meticulously measuring the chest wall thickness at 1 emf intervals on the planning CT Images. A second planning CT was obtained overlying the individuailzed custom bolus for each patient's chest wall. 3-D treatment planning was peformed using ADAC-Pinnacle$^{3}$ for all patients with and without bolus. NTCPS based on 'the Lyman-Kutcher' model were analyzed and the mean, maximum, minimum doses, V$_{50}$ and V$_{95}$ for 4he heari and lungs were computed. Results .The average NTCPS in the ipsliateral lung showed a statistically significant reduction (p<0.01), from 80.2${\pm}$3.43% to 47.7${\pm}$4.61%, with the use of the individualized custom boluses. The mean lung irradiation dose to the ipsilateral iung was also significantly reduced by about 430 cGy, Trom 2757 cGy to 2,327 cGy (p<0.01). The V$_{50}$ and V$_{95}$ in the ipsilateral lung markedly decreased from the averages of 54.5 and 17.4% to 45.3 and 11.0%, respectively. The V$_{50}$ and V$_{95}$ In the heart also decreased from the averages of 16.8 and 6.1% to 9.8% and 2.2%, respectively. The NTCP In the contralateral lung and the heart were 0%, even for the cases with no bolus because of the small effective mean radiation volume values of 4.4 and 7.1%, respectively Conclusion : The use of an Individualized custom bolus in the radiotherapy of postrnastectorny chest wall reduced the NTCP of the ipsilateral lung by about 24.5 to 40.5%, which can improve the complication free cure probability of breast cancer patients.

• Journal of Life Science
• /
• v.30 no.6
• /
• pp.563-569
• /
• 2020

Oncoplastic surgery (OPS) combines oncologically safe tumor resection with aesthetically satisfying reconstruction of defects using established plastic surgery techniques. OPS is characterized by initial excision as extensive as is beneficial for oncological safety, and, once sufficient resection is complete, displacement or replacement techniques are selected based on remnant volume. The size of the lesion and the individual patient are important factors when considering the appropriate approach, and when pre-operative imaging, including MRI, is used to determine the technique, the complete removal of cancer cells by permanent pathology is essential. A frozen section is used during the operation to reduce the reoperation rate, but it is difficult to cover the entire margin surface theoretically and even harder in practice. A recent report about adequate margins has empowered OPS in its oncological safety. Considering the patients to whom each modality could be applied, basic breast volume is an important factor, and this is influenced by ethnic differences. In Europe or the US, for example, the average breast size is 36D (600 ㎤) and reduction mammoplasty is predominantly used. However, the average size of patients in our institution is 33A (300 ㎤), and so quite different approaches are selected in most cases. New techniques involving radiofrequency and fluorescence have been proposed as safe and easily accessible ways of reducing complications.

• Journal of radiological science and technology
• /
• v.40 no.1
• /
• pp.57-62
• /
• 2017

The purpose of this study is to reconstruct the treatment plan by applying CBCT and DIR to dose changes according to the change of the patient's motion and breast shape in the large breast cancer patients and to compare the doses using TWF, FIF and IMRT. CT and CBCT were performed with MIM6 to create DIRCT and each treatment plan was made. The patient underwent computed tomography simulation in both prone and supine position. The homogeneity index (HI), conformity index (CI), coverage index (CVI) to the left breast as planning target volume (PTV) were determined and the doses to the lung, heart, and right breast as organ at risk (OAR) were compared by using dose-volume histogram and the unique property of each organ. The value of HI of the PTV breast increased in all treatment planning methods using DIRCT, and CVI and CI were decreased in the treatment planning methods using DIRCT.