<div style="text-align:justify;"> The arms-up position is the most common treatment position adopted for lung cancer patients treated with radiation therapy. However, many elderly or frail patients hav...<div style="text-align:justify;"> The arms-up position is the most common treatment position adopted for lung cancer patients treated with radiation therapy. However, many elderly or frail patients have shoulder problems and cannot tolerate such an overstretched position for an extended period. Therefore, the arms-down position becomes the only alternative for this group of patients during radiation therapy. Even though the arms-down position is not ideal, it does provide a stable and comfortable patient immobilization position for radiation treatments that require a longer delivery time, such as stereotactic body radiation therapy (SBRT). In this study, we designed a protocol to treat lung cancer patients with VMAT stereotactic body radiation therapy (VMAT SBRT) and deep inspiration breath-hold (DIBH) in the arms-down position. Our initial clinical experience with this protocol indicates that it is reliable for patient immobilization and accurate in delivered dosimetry. </div>展开更多
<strong>Background:</strong><span style="font-family:Verdana;"> Post-operative breast radiotherapy is used to reduce recurrence</span><span style="font-family:"">...<strong>Background:</strong><span style="font-family:Verdana;"> Post-operative breast radiotherapy is used to reduce recurrence</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The aim of this study was</span><span style="font-family:Verdana;"> to investigate the outcomes of </span><span style="font-family:Verdana;">Deep</span><span style="font-family:Verdana;"> Inspiration Breath-Hold (DIBH) technique with indigenous </span><span style="font-family:Verdana;">breath holding</span><span style="font-family:Verdana;"> indicator scale in 3DCRT for breast cancer radiotherapy over </span><span style="font-family:Verdana;">Free</span><span style="font-family:Verdana;"> Breathing (FB) technique. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> An observational study </span><span style="font-family:Verdana;">conducted</span> </span><span style="font-family:""><span style="font-family:Verdana;">at the </span><span style="font-family:Verdana;">Department</span><span style="font-family:Verdana;"> of Radiation Oncology </span></span><span style="font-family:""><span style="font-family:Verdana;">at </span><span style="font-family:Verdana;">National</span><span style="font-family:Verdana;"> Institute of Cancer Research and Hospital, Dhaka and Square Hospital Limited, Dhaka, Bangladesh from June 2015 to May 2016. A total of 60</span></span><span style="font-family:""><span style="font-family:Verdana;"> confirmed breast cancer patients who underwent adjuvant radiotherapy were included. An indigenous reproducible plastic tool (Perspex) was used as </span><span style="font-family:Verdana;">breath holding</span><span style="font-family:Verdana;"> indicator scale with </span></span><span style="font-family:Verdana;">DIBH</span><span style="font-family:""><span style="font-family:Verdana;"> technique in 3DCRT</span><i><span style="font-family:Verdana;">. </span></i><span><span style="font-family:Verdana;">Paired sample t-展开更多
A technique for multiple deep-inspiration breath-hold (DIBH) volumetric modulated arc therapy (VMAT) for a lung tumor has been proposed with 10 MV flattening-filter-free beams and an image sensor measuring a distance ...A technique for multiple deep-inspiration breath-hold (DIBH) volumetric modulated arc therapy (VMAT) for a lung tumor has been proposed with 10 MV flattening-filter-free beams and an image sensor measuring a distance map to thorax surface. Planning CT images were acquired under a DIBH condition and a clinical target volume (CTV) was contoured. This procedure was repeated five times and an internal target volume (ITV) among the multiple DIBHs was created by integrating the five CTVs. A planning target volume (PTV) was defined by adding an isotropic margin of 5 mm to the ITV. Immediately before treatment, a 30-second half-arc cone-beam computer tomography (CBCT) imaging was performed under another DIBH condition, and the couch was repositioned so that tumor may be located inside the PTV contours. An infrared distance measurement device having laser diodes and an image sensor was attached to the couch, and a distance map to the patient thorax surface was recorded as a reference during still another DIBH condition. A half-arc segmented VMAT beams with two beam interrupts were delivered to the patient under multiple DIBHs, where the delivery time of each of the three segmented beams was 30 seconds. During the beam delivery, the distance map was monitored in real time to confirm that the distance to the thorax surface remained unchanged. In-treatment CBCT images suggested that the tumor position at the time of tumor registration was accurately reproduced during the DIBH VMAT delivery.展开更多
The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study util...The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study utilizing free-breathing and static DIBH scans from eleven patients treated with radiotherapy for breast cancer. The anterior-posterior displacement along the length of the LAD was measured in each respiratory phase. Standard treatment plans targeting the whole breast without treatment of the internal mammary lymph nodes were generated and dose to the LAD and LV calculated. Non-uniform movement of the LAD during respiratory maneuvers with the proximal third exhibiting the greatest displacement was observed. In DIBH compared to end-expiration (EP), the mean posterior displacement of the proximal 1/3 of the LAD was 8.99 mm, the middle 1/3 of the artery was 6.37 mm, and the distal 1/3 was 3.27 mm. In end-inspiration (IP) compared to end-expiration the mean posterior displacements of the proximal 1/3 of the LAD was 2.08 mm, the middle 1/3 of the artery was 0.91 mm, and the distal 1/3 was 0.97 mm. Mean doses to the LAD using tangential treatment fields and a prescribed dose of 50.4 Gy were 11.32 Gy in EP, 8.98 Gy in IP, and 3.50 Gy in DIBH. Mean doses to the LV were 2.38 Gy in EP, 2.31 Gy in IP, and 1.24 Gy in DIBH. In conclusion, inspiration and especially DIBH, cause a displacement of the origin and proximal 2/3 of the LAD away from the chest wall, resulting in sparing of the most critical segment of the artery during tangential radiotherapy.展开更多
文摘<div style="text-align:justify;"> The arms-up position is the most common treatment position adopted for lung cancer patients treated with radiation therapy. However, many elderly or frail patients have shoulder problems and cannot tolerate such an overstretched position for an extended period. Therefore, the arms-down position becomes the only alternative for this group of patients during radiation therapy. Even though the arms-down position is not ideal, it does provide a stable and comfortable patient immobilization position for radiation treatments that require a longer delivery time, such as stereotactic body radiation therapy (SBRT). In this study, we designed a protocol to treat lung cancer patients with VMAT stereotactic body radiation therapy (VMAT SBRT) and deep inspiration breath-hold (DIBH) in the arms-down position. Our initial clinical experience with this protocol indicates that it is reliable for patient immobilization and accurate in delivered dosimetry. </div>
文摘<strong>Background:</strong><span style="font-family:Verdana;"> Post-operative breast radiotherapy is used to reduce recurrence</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The aim of this study was</span><span style="font-family:Verdana;"> to investigate the outcomes of </span><span style="font-family:Verdana;">Deep</span><span style="font-family:Verdana;"> Inspiration Breath-Hold (DIBH) technique with indigenous </span><span style="font-family:Verdana;">breath holding</span><span style="font-family:Verdana;"> indicator scale in 3DCRT for breast cancer radiotherapy over </span><span style="font-family:Verdana;">Free</span><span style="font-family:Verdana;"> Breathing (FB) technique. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> An observational study </span><span style="font-family:Verdana;">conducted</span> </span><span style="font-family:""><span style="font-family:Verdana;">at the </span><span style="font-family:Verdana;">Department</span><span style="font-family:Verdana;"> of Radiation Oncology </span></span><span style="font-family:""><span style="font-family:Verdana;">at </span><span style="font-family:Verdana;">National</span><span style="font-family:Verdana;"> Institute of Cancer Research and Hospital, Dhaka and Square Hospital Limited, Dhaka, Bangladesh from June 2015 to May 2016. A total of 60</span></span><span style="font-family:""><span style="font-family:Verdana;"> confirmed breast cancer patients who underwent adjuvant radiotherapy were included. An indigenous reproducible plastic tool (Perspex) was used as </span><span style="font-family:Verdana;">breath holding</span><span style="font-family:Verdana;"> indicator scale with </span></span><span style="font-family:Verdana;">DIBH</span><span style="font-family:""><span style="font-family:Verdana;"> technique in 3DCRT</span><i><span style="font-family:Verdana;">. </span></i><span><span style="font-family:Verdana;">Paired sample t-
文摘A technique for multiple deep-inspiration breath-hold (DIBH) volumetric modulated arc therapy (VMAT) for a lung tumor has been proposed with 10 MV flattening-filter-free beams and an image sensor measuring a distance map to thorax surface. Planning CT images were acquired under a DIBH condition and a clinical target volume (CTV) was contoured. This procedure was repeated five times and an internal target volume (ITV) among the multiple DIBHs was created by integrating the five CTVs. A planning target volume (PTV) was defined by adding an isotropic margin of 5 mm to the ITV. Immediately before treatment, a 30-second half-arc cone-beam computer tomography (CBCT) imaging was performed under another DIBH condition, and the couch was repositioned so that tumor may be located inside the PTV contours. An infrared distance measurement device having laser diodes and an image sensor was attached to the couch, and a distance map to the patient thorax surface was recorded as a reference during still another DIBH condition. A half-arc segmented VMAT beams with two beam interrupts were delivered to the patient under multiple DIBHs, where the delivery time of each of the three segmented beams was 30 seconds. During the beam delivery, the distance map was monitored in real time to confirm that the distance to the thorax surface remained unchanged. In-treatment CBCT images suggested that the tumor position at the time of tumor registration was accurately reproduced during the DIBH VMAT delivery.
文摘The purpose of this study was to analyze motion of the left anterior descending coronary artery (LAD) and left ventricle during normal breathing and deep inspiration breath hold (DIBH). This is a dosimetric study utilizing free-breathing and static DIBH scans from eleven patients treated with radiotherapy for breast cancer. The anterior-posterior displacement along the length of the LAD was measured in each respiratory phase. Standard treatment plans targeting the whole breast without treatment of the internal mammary lymph nodes were generated and dose to the LAD and LV calculated. Non-uniform movement of the LAD during respiratory maneuvers with the proximal third exhibiting the greatest displacement was observed. In DIBH compared to end-expiration (EP), the mean posterior displacement of the proximal 1/3 of the LAD was 8.99 mm, the middle 1/3 of the artery was 6.37 mm, and the distal 1/3 was 3.27 mm. In end-inspiration (IP) compared to end-expiration the mean posterior displacements of the proximal 1/3 of the LAD was 2.08 mm, the middle 1/3 of the artery was 0.91 mm, and the distal 1/3 was 0.97 mm. Mean doses to the LAD using tangential treatment fields and a prescribed dose of 50.4 Gy were 11.32 Gy in EP, 8.98 Gy in IP, and 3.50 Gy in DIBH. Mean doses to the LV were 2.38 Gy in EP, 2.31 Gy in IP, and 1.24 Gy in DIBH. In conclusion, inspiration and especially DIBH, cause a displacement of the origin and proximal 2/3 of the LAD away from the chest wall, resulting in sparing of the most critical segment of the artery during tangential radiotherapy.
