• Archives of Plastic Surgery
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• v.44 no.6
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• pp.509-515
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• 2017

Background Skin flap necrosis is a common complication after mastectomy and breast reconstruction. It has been proven that nitroglycerin ointment, as a topical vasodilator, can decrease the rate of skin flap necrosis after mastectomy and breast reconstruction. However, nitroglycerin can cause several side effects, including headache, dizziness, and hypotension. The purpose of this study was to evaluate whether the application of a low dose of nitroglycerin ointment reduced the rate of skin flap necrosis in breast reconstruction after skin-sparing or nipple-sparing mastectomy. Methods A total of 73 cases of breast reconstruction after nipple-sparing and skin-sparing mastectomy at our institution from March 2012 to January 2017 were retrospectively studied. Of these patients, 52 received nitroglycerin ointment (4.5 mg) application to the skin around the nipple-areolar complex from August 2015 to January 2017, while 21 received fusidic acid ointment from March 2012 to August 2015. The number of patients who experienced necrosis of the breast skin flap was counted in both groups. Results Skin flap necrosis developed in 2 (3.8%) patients who were treated with nitroglycerin ointment and 5 (23.8%) patients who did not receive nitroglycerin ointment treatment. Patients who did not receive nitroglycerin ointment treatment had a significantly higher risk of mastectomy skin flap necrosis than patients who did (odds ratio=7.81; 95% confidence interval, 1.38 to 44.23; P=0.02). Conclusions Low-dose nitroglycerin ointment administration significantly decreased the rate of skin flap necrosis in patients who underwent breast reconstruction after skin-sparing or nipple-sparing mastectomy, without increasing the incidence of the side effects of nitroglycerin.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.449-454
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• 1993

The skin sparing effect associated with high energy x-ray or gamma ray beams may be reduce or lost under certain conditions of treatment. Current trends in using large fields. Shield carrying trays, compensating filters, and isocentric methods of treatment have posed problems of increased skin dose which sometimes become a limiting factor in giving adquate tumor doses. We used the shallow ion chamber to measure the phantom surface dose and the physical treatment variables for Co-60 gamma ray, 4MV and 10 MV x-ray beam. The dependence of percent surface dose on field sizes, atomic number of the shielding tray materials and its distance from the surface for 4, 10MV x-rays and Co-60 gamma ray is qualitatively similar. The use of 2 mm thick tin filter is recommended for situations where a low atomic number tray is introduced into the beam at distances less than 15 cm from the surface and with the large field sized for 4 MV x-ray beam. In case of Co-60 gamma ray, the lead glass tray is suitable for enhancement of skin sparing. Also, the filter distance should be as large as possible to achieve substantial skin sparing.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.109-116
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• 1988

The Alcyon Co-60 gamma rays was studied for electron contamination. The surface dose, attributable almost entirely to contamination electrons, has a linear dependence on field width for square fields and an inverse square dependence on distance from the bottom of the fixed head assembly Build-up and surface dose measurements were taken with and without an acrylic blocking tray in place. Further measurements were made with a copper filter designed to reduce secondary electrons emitted by photon interactions with the acrylic tray. The results are discussed in relation to skin sparing effect for radiation therapy Patients. And to achieve the maximum skin sparing effect, the selection of the optimum SSD and TSD is needed.

• Journal of Radiation Protection and Research
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• v.13 no.1
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• pp.21-30
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• 1988

The 6 MV photon beam of a linear accelerator (Mevatron 67) was studied for electron contamination. The surface dose, attributable almost entirely to contamination electrons, has a linear dependence on field width for square fields and an inverse square dependence on distance from the bottom of the fixed head assembly. Build-up and surface dose measurements were taken with and without an acrylic blocking tray in place. Further measurements were made with a copper filter designed to reduce secondary electrons emitted by photon interactions with the acrylic tray. The results are discussed in relation to skin sparing effect for radiation therapy patients. To achieve the maximum skin sparing effect, the selection of the optimum SSD and TSD is needed.

• The Journal of Korean Society for Radiation Therapy
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• v.7 no.1
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• pp.176-184
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• 1995

It is very useful benefits to use the megavoltage photon beams in deep site tumor radiotherapy for skin sparing effects. But, In some cases of head and mock tumors, it is often necessary to use spoiler for rapid buildup on skin region. A spoiler with tissue equivalent material to be moved between the patients and the collimator can increase or control the skin dose and buildup region due to position and thickness of the spoiler was measured. Then, the effect of spoiler on skin dose and build up region in protruded tumor of head and neck was evaluated quantitatively. The measurements were abtained with PTW 2334 chamber (Markus type) on a polystylene phantom for 6MV x-ray from an accelerator.

• Radiation Oncology Journal
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• v.10 no.2
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• pp.147-153
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• 1992

It is ideal thing to compensate tissue deficit without skin contamination in curvatured irradiation field of high energy photon beam. The 3-dimensional compensating technique utilizing tissue equivalent materials to ensure an adequate dose distribution and skin sparing effect was described. This compensator was made of paraffin ($70\%$) and stearin wax ($30\%$) compound. The parameters for evaluation of the effect on skin dose in application of compensator were considered in the size of the field, the thickness of the compensator and the source-to-axis distance. The results are as follows; the skin doses were not changed even though application of the compensator, but depended on the field size and the source-to-axis distance, and the skin doses were only slightly changed within $1\%$ relative errors as increasing the thickness of the compensator in these experiments.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.1
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• pp.21-28
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• 2006

Purpose: The purpose of this study is to find a optimal beam spoiler condition on the dose distribution near the surface, when treating a squamous cell carcinoma of the head and neck and a lymphatic region with 10 MV photon beam. The use of a optimal spoiler allows elivering high dose to a superficial tumor volume, while maintaining the skin-sparing effect in the area between the surface to the depth of 0.4 cm. Materials and Methods: The lucite beam spoiler, which were a tissue equivalent, were made and placed between the surface and the photon collimators of linear accelerator. The surface-dose, the dose at the depth of 0.4 cm, and the maximum dose at the dmax were measured with a parallel-plate ionization chamber for $5{\times}5cm\;to\;30{\times}30cm^2$ field sizes using lucite spoilers with different thicknesses at varying skin-to-spoiler separation (SSS). In the same condition, the dose was measured with bolus and compared with beam spoiler. Results: The spoiler increased the surface and build-up dose and shifted the depth of maximum dose toward the surface. With a 10 MV x-ray beam and a optimal beam spoiler when treating a patient, a similer build-up dose with a 6 MV photon beam could be achieved, while maintaining a certain amount of skin spring. But it was provided higher surface dose under SSS of less than 5 cm, the spoiler thickness of more than 1.8 cm or more, and larger field size than $20{\times}20cm^2$ provided higher surface dose like bolus and obliterated the spin-sparing effect. the effects of the beam spoiler on beam profile was reduced with increasing depths. Conclusion: The lucite spoiler allowed using of a 10 MV photon beam for the radiation treatment of head and neck caner by yielding secondary scattered electron on the surface. The dose at superficial depth was increased and the depth of maximum dose was moved to near the skin surface. Spoiling the 10 MV x-ray beam resulted in treatment plans that maintained dose homogeneity without the consequence of increased skin reaction or treat volume underdose for regions near the skin surface. In this, the optimal spoiler thickeness of 1.2 cm and 1.8 cm were found at SSS of 7 cm for $10{\times}10cm^2$ field. The surface doses were measured 60% and 64% respectively. In addition, It showed so optimal that 94% and 94% at the depth of 0.4 cm and dmax respectively.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.261-267
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• 1986

Development of supervoltage treatment machine may minimize skin reaction by skin-sparing effect, but skin damage is still one of "the dose limiting factor" in radiation therapy. In spite of these importance, systemic histopathologic studies of skin in similar conditions which used in clinical treatment has not been performed so far. 60mice were irradiated with conventional fraction ($200{\times}5/wk$) and whole abdominal field ($2{\times}3cm$, from symphysis pubis to xyphoid process). Used machine was 250KV, 24mA, orthovoltage x-ray machine. Histopathological changes of acute skin reaction at the level of total irradiation dose were analyzed and the possible mechanism of later chronic changes were investigated. Obtained results are as follows: 1. In 1,000 rad irradiated group, only mild epidermal edema is noted. 2. In 2,000 rad irradiated group, slightly decreased number and size of hair follicles and appendages, dermal edema and scanty infiltration of inflammatory cells are visible. 3. In 3,000 rad irradiated group, marked increased capillary congestion and prominant infiltration of inflammatory cells are observed. 4. In 4,000 rad irradiated group, vascular wall thickening with proliferation of endothelial cells are prominant. Dermal thinning and hyalinization are newly developed. 5. In 5,000 rad irradiated group, complete desquamation of epidermis is not seen, despite of acceleration of all above mentioned changes.

• Journal of radiological science and technology
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• v.43 no.1
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• pp.9-14
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• 2020

Commercial plate bolus is generally used for treatment of surface tumor and required surface dose. We fabricated 3D-printed bolus by using 3D printing technology and usability of 3D-printed bolus was evaluated. RT-structure of contoured plate bolus in the TPS was exported to DICOM files and converted to STL file by using converting program. The 3D-printed bolus was manufactured with rubber-like translucent materials using a 3D printer. The dose distribution calculated in the TPS and compared the characteristics of the plate bolus and the 3D printed bolus. The absolute dose was measured inserting an ion chamber to the depth of 5 cm and 10 cm from the surface of the blue water phantom. HU and ED were measured to compare the material characteristics. 100% dose was distributed at Dmax of 1.5 cm below the surface when was applied without bolus. When the plate bolus and 3D-plate bolus were applied, dose distributed at 0.9 cm and 0.8 cm below the surface of the bolus. After the comparative analysis of the radiation dose at the reference depth, differences in radiation dose of 0.1 ~ 0.3% were found, but there was no difference dose. The usability of the 3D-printed bolus was thus confirmed and it is considered that the 3D-printed bolus can be applied in radiation therapy.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.95-100
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• 1995

Purpose : To evaluate the effect on surface dose due to Aquaplast used for immobilizing the patients with head and neck cancers in photon beam radiotherapy Materials and Methods: To assess surface and buildup region dose for 6MV X-ray from linear accelerator(Siemens Mevatron 6740), we measured percent ionization value with the Markus chamber model 30-329 manufactured by PTW Frieburg and Capintec electrometer, model WK92. For measurement of surface ionization value, the chamber was embedded in $25{\times}25{\times}3cm^3$ acrylic phantom and set on $25{\times}25{\times}5cm^3$ polystyrene phantom to allow adequate scattering. The measurements of percent depth ionization were made by placing the polystyrene layers of appropriate thickness over the chamber. The measurements were taken at 100cm SSD for $5{\times}5cm^2$, $10{\times}10cm^2$ and $15{\times}15cm^2$ field sizes, respectively. Placing the layer of Aquaplast over the chamber, the same procedures were repeated. We evaluated two types of Aquaplast: 1.6mm layer of original Aquaplast(manufactured by WFR Aquaplast Corp.) and transformed Aquaplast similar to moulded one for immobilizing the patients practically. We also measured surface ionization values with blocking tray in presence or absence of transformed Aquaplast. In calculating percent depth dose, we used the formula suggested by Gerbi and Khan to correct overresponse of the Markus chamber. Results : The surface doses for open fields of $5{\times}5cm^2$, $10{\times}10cm^2$, and $15{\times}15cm^2$ were $79\%$, $13.6\%$, and $18.7\%$, respectively. The original Aquaplast increased the surface doses upto $38.4\%$, $43.6\%$, and $47.4\%$, respectively. For transformed Aquaplast, they were $31.2\%$, $36.1\%$, and $40.5\%$, respectively. There were little differences in percent depth dose values beyond the depth of Dmax. Increasing field size, the blocking tray caused increase of the surface dose by $0.2\%$, $1.7\%$, $3.0\%$ without Aquaplast, $0.2\%$, $1.9\%$, $3.7\%$ with transformed Aquaplast, respectively. Conclusion: The original and transformed Aquaplast increased the surface dose moderately. The percent depth doses beyond Dmax, however, were not affected by Aquaplast. In conclusion, although the use of Aquaplast in practice may cause some increase of skin and buildup region dose, reductioin of skin-sparing effect will not be so significant clinically.