• Radiation Oncology Journal
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• 제36권1호
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• pp.79-84
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• 2018

Deep inspiration breathing hold (DIBH) compared to free-breathing (FB) during radiotherapy (RT) has significantly decreased radiation dose to heart and has been one of the techniques adopted for patients with breast cancer. However, patients who are unable to make suitable deep inspiration breath may not be eligible for DIBH, yet still need to spare the heart and lung during breast cancer RT (left-sided RT in particular). Continuous positive airway pressure (CPAP) is a positive airway pressure ventilator, which keeps the airways continuously open and subsequently inflates the thorax resembling thoracic changes from DIBH. In this report, authors applied CPAP instead of FB during left-sided breast cancer RT including internal mammary node in a patient who was unable to tolerate DIBH, and substantially decreased radiation dose the heart and lung with CPAP compared to FB.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.43-45
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• 2013

Background: The aim of this epidemiological study was to establish the laterality of breast cancer (BC) and its association with size, receptor status of the primary tumor and bone metastasis (BM) in a local population. Materials and Methods: This retrospective study included cases of BC from Jan-2009 to Dec-2011 who were referred for metastatic work up or follow up survey with Technetium-99m MDP bone scan (BS) to the Nuclear Medicine Department of Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN). A total of 384 patients out of 521 were included and all reviewed for age, primary tumor size (PTS), laterality, receptor status like estrogen receptor (ER) progesterone receptor (PR) and Her-2-Neu receptor, presence or absence of BM with sites of involvement and time interval between diagnosis of BC and appearance of BM. Results: The left to right sided BC proportion was significantly higher than unity (59%:41%; p<0.001). The right sided BC was observed in younger age group (46:52 years; p<0.0001) and with a smaller PTS than the left sided (3.43:4.15 cm; p<0.0001). The patients with BM had relatively higher negative receptor status with a significant predominance of right sided BC. The overall incidence of BM on BS was 28% and relatively higher in right than left breast (33%:24% p=0.068). The average number of BM sites was also significantly greater for the right side (6:4, P<0.0001). The % cumulative risk of BM in right breast was noted at significantly smaller PTS than left side with log rank value of 5.579; p<0.05. The Kaplan Meier survival plot for event free survival of BM in left sided BC was significantly higher than for the right side (log rank value=4.155, p<0.05), with an earlier appearance of BM in right BC. Conclusions: 1) A left sided predominance of BC was seen in local population; 2) right sided BC had a more aggressive behavior with extensive and earlier appearance of BM at relatively younger age, smaller PTS and receptor (s) negativity.

• Radiation Oncology Journal
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• 제32권2호
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• pp.84-94
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• 2014

Purpose: To quantify the cardiac dose reduction during breathing adapted radiotherapy using Real-time Position Management (RPM) system in the treatment of left-sided breast cancer. Materials and Methods: Twenty-two patients with left-sided breast cancer underwent CT scans during breathing maneuvers including free breathing (FB), deep inspiration breath-hold (DIBH), and end inspiration breath-hold (EIBH). The RPM system was used to monitor respiratory motion, and the in-house self respiration monitoring (SRM) system was used for visual feedback. For each scan, treatment plans were generated and dosimetric parameters from DIBH and EIBH plans were compared to those of FB plans. Results: All patients completed CT scans with different breathing maneuvers. When compared with FB plans, DIBH plans demonstrated significant reductions in irradiated heart volume and the heart $V_{25}$, with the relative reduction of 71% and 70%, respectively (p < 0.001). EIBH plans also resulted in significantly smaller irradiated heart volume and lower heart $V_{25}$ than FB plans, with the relative reduction of 39% and 37%, respectively (p = 0.002). Despite of significant expansion of lung volume using inspiration breath-hold, there were no significant differences in left lung $V_{25}$ among the three plans. Conclusion: In comparison with FB, both DIBH and EIBH plans demonstrated a significant reduction of radiation dose to the heart. In the training course, SRM system was useful and effective in terms of positional reproducibility and patient compliance.

• Radiation Oncology Journal
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• 제37권3호
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• pp.201-206
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• 2019

Purpose: To observe the effectiveness of the practical instruction sheet and the educational video for left-sided breast treatment in a patient receiving deep inspiration breath hold (DIBH) technique. Two parameters, simulation time and patient satisfaction, were assessed through the questionnaire. Methods: Two different approaches, which were the instruction sheet and educational video, were combinedly used to assist patients during DIBH procedures. The guideline was assigned at least 1 week before the simulation date. On the simulation day, patients would fill the questionnaire regarding their satisfaction with the DIBH instruction. The questionnaire was categorized into five levels: extremely satisfied to dissatisfied, sequentially. The patients were divided into four groups: not DIBH technique, DIBH without instruction materials, the DIBH with instruction sheet or educational video, and DIBH with both of instruction sheet and educational video. Results: Total number of 112 cases of left-sided breast cancer were analyzed. The simulation time during DIBH procedure significantly reduced when patients followed the instruction. There was no significant difference in simulation time on the DIBH procedures between patient compliance via instruction sheet or educational video or even following both of them. The excellent level was found at 4.6 ± 0.1 and 4.5 ± 0.1, for patients coaching via instruction sheet as well as on the educational video, respectively. Conclusion: Patient coaching before simulation could potentially reduce the lengthy time in the simulation process for DIBH technique. Practicing the DIBH technique before treatment is strongly advised.

• Radiation Oncology Journal
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• 제37권4호
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• pp.254-258
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• 2019

Purpose: Deep inspiration breath hold (DIBH) is a well-established technique that enables efficient cardiac sparing in patients with left-sided breast cancer. The aim of the current study was to determine if DIBH is effective for reducing radiation exposure of of liver and other organs at risk in right breast radiotherapy (RT). Materials and Methods: Twenty patients with right-sided breast cancer were enrolled in this study. Three-dimensional conformal RT plans were generated for each patient, with two different computed tomography scans of free breathing (FB) and DIBH. Nodes were contoured according to the Radiation Therapy Oncology Group contouring guidelines. Dose-volume histograms for the target volume coverage and organs at risk were evaluated and analyzed. Results: DIBH plans showed significant reduction in mean liver dose (5.59 ± 2.07 Gy vs. 2.54 ± 1.40 Gy; p = 0.0003), V_20Gy (148.38 ± 73.05 vs. 64.19 ± 51.07 mL; p = 0.0003) and V_10Gy (195.34 ± 93.57 vs. 89.81 ± 57.28 mL; p = 0.0003) volumes compared with FB plans. Right lung doses were also significantly reduced in DIBH plans. Heart and left lung doses showed small but statistically significant improvement with application of the DIBH technique. Conclusion: We report that the use of DIBH for right-sided breast cancer significantly reduces the radiation doses to the liver, lungs, and heart.

• Radiation Oncology Journal
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• 제31권4호
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• pp.239-246
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• 2013

Purpose: We explored whether the deep inspiration breath hold (DIBH) technique using Abches during left-sided breast irradiation was effective for minimizing the amount of radiation to the heart and lung compared to free breathing (FB). Materials and Methods: Between February and July 2012, a total of 25 patients with left-sided breast cancer underwent two computed tomography scans each with the DIBH using Abches and using FB after breast-conserving surgery. The scans were retrospectively replanned using standardized criteria for the purpose of this study. The DIBH plans for each patient were compared with FB plans using dosimetric parameters. Results: All patients were successfully treated with the DIBH technique using Abches. Significant differences were found between the DIBH and FB plans for mean heart dose (2.52 vs. 4.53 Gy), heart V30 (16.48 vs. $45.13cm^3$), V20 (21.35 vs. $54.55cm^3$), mean left anterior descending coronary artery (LAD) dose (16.01 vs. 26.26 Gy, all p < 0.001), and maximal dose to $0.2cm^3$ of the LAD (41.65 vs. 47.27 Gy, p = 0.017). The mean left lung dose (7.53 vs. 8.03 Gy, p = 0.073) and lung V20 (14.63% vs. 15.72%, p = 0.060) of DIBH using Abches were not different significantly compared with FB. Conclusion: We report that the use of a DIBH technique using Abches in breathing adapted radiotherapy for left-sided breast cancer is easily feasible in daily practice and significantly reduces the radiation doses to the heart and LAD, therefore potentially reducing cardiac risk.

• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.7-13
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• 2019

Purpose: To compare the dosimetrical and radiobiological parameters among various volumetric modulated arc therapy (VMAT) techniques using restricted and continuous arc beams for left-sided breast cancer. Materials and Methods: Ten patients with left-sided breast cancer without regional nodes were retrospectively selected and prescribed the dose of 42.6 Gy in 16 fractions on the planning target volume (PTV). For each patient, three plans were generated using the $Eclipse^{TM}$ system (Varian Medical System, Palo Alto, CA) with one partial arc 1pVMAT, two partial arcs 2pVMAT, and two tangential arcs 2tVMAT. All plans were calculated through anisotropic analytic algorithm and photon optimizer with 6 MV photon beam of $VitalBEAM^{TM}$. The same dose objectives for each plan were used to achieve a fair comparison during optimization. Results: For PTV, dosimetrical parameters such as Homogeneity index, conformity index, and conformal number were superior in 2pVMAT than those in both techniques. $V_{95%}$, which indicates PTV coverage, was 91.86%, 96.60%, and 96.65% for 1pVMAT, 2pVMAT, and 2tVMAT, respectively. In most organs at risk (OARs), 2pVMAT significantly reduced the delivered doses compared with the other techniques, excluding the doses to contralateral lung. For the analysis of radiobiological parameters, a significant difference in normal tissue complication probability was observed in ipsilateral lung while no difference was observed in the other OARs. Conclusions: Our study showed that 2pVMAT had better plan quality and normal tissue sparing than 1pVMAT and 2tVMAT but not for all parameters. Therefore, 2pVMAT could be considered the priority choice for the treatment planning for left breast cancer.

• 대한방사선치료학회지
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• 제27권2호
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• pp.175-181
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• 2015

목 적 : 좌측 유방암 환자의 방사선 치료 시 바로 누운 자세 및 엎드린 자세 에 따른 환자 자세변화 시 발생하는 반대편 유방의 산란선량을 사방향 조사방법에 따라 측정하여 분석하고자 한다. 대상 및 방법 : Human Phantom (Anderson Rando Phantom. USA)을 대상으로 실제 좌측 유방암 환자로 가정한 후, Supine용 Breast Board와 본원에서 주문 제작된 Prone Breast Board를 이용하여 처방선량 50 Gy/25회로 치료계획(Conventional technique, Field-in-Field, IMRT)을 수립하였다. 치료 계획 수립 후 Human Phantom 의 중심축을 기준점으로 하여 우측방향으로 0 mm, 10 mm, 30 mm, 50 mm 떨어진 위치에 유리 선량계(GD-302M, SRS Technol, Japan)를 부착한 후 환자 자세에 따른 치료 방법에 따라 산란선량을 측정하였다. 이 때 각각의 자세 측정 시 모의치료 계획과 동일한 자세를 유지하기 위해 측정 전 EPID를 이용하여 L-gram 촬영을 실시하였으며 Prone-Device를 이용한 측정 시에는 동일한 입사 점을 확인하기 위해 Human Phantom 에 입사점을 표시하여 5회 측정된 평균값으로 각각의 치료계획 선량과 비교 분석하였다. 결 과 : 각각의 자세에 따른 치료방법에 따라 반대 측 유방의 산란선량을 측정한 결과 바로 누운 자세가 엎드린 자세에 비하여 평균 1.2%~1.8% 이상 치료계획 선량 보다 증가함을 보였고 엎드린 자세일 때는 오히려 치료계획 선량보다 평균 0.81~0.9% 이상 감소함을 보였다. 그러나 엎드린 자세 일 때 반대 측 유방의 위치 별 흡수선량 값은 바로 누운 자세일 때 비하여 총 처방선량의 평균 2.7%로 최대 4% 이상 나타났으며 Conventional technique이 Field-in-Field나 IMRT 비하여 평균 3.3%이상 높게 나타남을 보였다. 결 론 : 본 연구는 Human Phantom 을 이용하여 좌측 유방암 환자의 방사선 치료 시 환자의 자세 변화에 따른 반대편 유방의 산란선량을 치료 방법 별로 비교분석 하였다. 실제 환자의 자세 변화에 따른 유방변화를 가정하여 Human Phantom을 위치시켰으나 실제 환자의 개별적 특성에 따라 차이가 발생할 수 있으며 특히 엎드린 자세 시 환자의 자세 재현의 어려움에 따른 오차가 더욱 크게 발생할 수 있다. 이런 오차로 인하여 좌측 폐 및 심장 등의 선량을 급격히 줄여주는 장점에도 불구하고 반대측 유방에 산란선량을 증가시킬 수 있는 가능성이 있음을 확인하였다. 따라서 실제 환자를 대상으로 prone position을 적용할 경우, 치료방법 및 환자 자세확인을 위한 정확한 검증과정의 임상적 노력이 필요할 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3257-3265
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• 2015

Background: Radiotherapy is an important treatment of choice for breast cancer patients after breast-conserving surgery, and we compare the feasibility of using dual arc volumetric modulated arc therapy (VMAT2), single arc volumetric modulated arc therapy (VMAT1) and Multi-beam Intensity Modulated Radiotherapy (M-IMRT) on patients after breast-conserving surgery. Materials and Methods: Thirty patients with breast cancer (half right-sided and half left-sided) treated by conservative lumpectomy and requiring whole breast radiotherapy with tumor bed boost were planned with three different radiotherapy techniques: 1) VMAT1; 2) VMAT2; 3) M-IMRT. The distributions for the planning target volume (PTV) and organs at risk (OARs) were compared. Dosimetries for all the techniques were compared. Results: All three techniques satisfied the dose constraint well. VMAT2 showed no obvious difference in the homogeneity index (HI) and conformity index (CI) of the PTV with respect to M-IMRT and VMAT1. VMAT2 clearly improved the treatment efficiency and can also decrease the mean dose and V5Gy of the contralateral lung. The mean dose and maximum dose of the spinal cord and contralateral breast were lower for VMAT2 than the other two techniques. The very low dose distribution (V1Gy) of the contralateral breast also showed great reduction in VMAT2 compared with the other two techniques. For the ipsilateral lung of right-sided breast cancer, the mean dose was decreased significantly in VMAT2 compared with VMAT1 and M-IMRT. The V20Gy and V30Gy of the ipsilateral lung of the left-sided breast cancer for VMAT2 showed obvious reduction compared with the other two techniques. The heart statistics of VMAT2 also decreased considerably compared to VMAT1 and M-IMRT. Conclusions: Compared to the other two techniques, the dual arc volumetric modulated arc therapy technique reduced radiation dose exposure to the organs at risk and maintained a reasonable target dose distribution.

• Radiation Oncology Journal
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• 제38권1호
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• pp.68-76
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• 2020

Purpose: The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software. Materials and Methods: Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them. The prescribed dose was 50 Gy to the clinical target volume. In addition to the dosimetric parameters, the irradiated volumes and both displacement magnitudes and vectors for the heart and left lung were assessed using 3D Slicer software. Results: The average of the heart mean dose (D_mean) decreased from 5.97 to 3.83 Gy and V₂₅ from 7.60% to 3.29% using DIBH (p < 0.001). Furthermore, the average of D_mean for the left lung was changed from 8.67 to 8.95 Gy (p = 0.389) and V₂₀ from 14.84% to 15.44% (p = 0.387). Both of the absolute and relative irradiated heart volumes decreased from 42.12 to 15.82 mL and 8.16% to 3.17%, respectively (p < 0.001); however, these parameters for the left lung increased from 124.32 to 223.27 mL (p < 0.001) and 13.33% to 13.99% (p = 0.350). In addition, the average of heart and left lung displacement magnitudes were calculated at 7.32 and 20.91 mm, respectively. Conclusion: The DIBH is an effective technique in the reduction of the heart dose for tangentially treated left sided-breast cancer patients, without a detrimental effect on the left lung.