In vivo dosimetry of skin surface for breast cancer radiotherapy using intensity-modulated radiation therapy technique and helical tomotherapy

Sung, Shih-Yu; Lee, Hsing-Yi; Tu, Pei-Chih; Lin, Cheng‐Chung; Yu, Pei-Chieh; Lui, Louis Tak; Shaw, Suzun; Wu, Chin-Pyng; Nien, Hsin-Hua

doi:10.21037/tro.2017.11.01

Cited by 7 publications

(7 citation statements)

References 14 publications

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“…The OSL was read using a MicroStar Reader (Landauer, Inc.) at least 30 min after irradiation for a stable number of counts. 1 The correction factor for skin dose measurement due to intrinsic buildup of the OSL dosimeter was calculated by determining the relationship between the surface and buildup dose of the Markus ionization chamber and OSL. 15 The positions of five OSLs were placed at the nipple and 2.0 cm in the lateral, medial, superior, and inferior from the nipple on the phantom, as shown in Figure 4.…”

Section: Skin Dose Measurementmentioning

confidence: 99%

“…9 The SF method, a field extension outside the skin surface, for fixed field IMRT as in Figure 1B, was used to deliver additional radiation on the space above the skin to cover the intrafractional movement caused by respiration. 1 The TomoDirect (TD) delivery mode which is a nonrotational treatment by coplanar static beams, with the couch moving at a constant speed through a fixed binary multileaf collimator that modulates the beam, was able to use SF methods to cover the movement due to respiration. 10 In contrast, a simple approach of SF is not applicable with Helical Tomotherapy (HT) which is a technique using continuous gantry rotations around the patient with thousands of narrow beamlets, which are individually optimized to cover the target.…”

Section: Introductionmentioning

confidence: 99%

“…Radiotherapy (RT) has played an important role in the multimodality treatment of breast cancer. 1 Patients with locally advanced-stage post-mastectomy breast cancer have a complex target volume, generally consisting of the chest wall (CW) and regional lymph nodes. The challenge of treatment planning is that it covers a large, superficial surface, which is a thin area.…”

Section: Introductionmentioning

confidence: 99%

“…It is used only during treatment planning and is not present in actual dose delivery. 1 Therefore, in clinical practice, the usual solutions for intrafraction movement issues can be taken into account using VB in HT. 1 , 3 However, it is becoming a challenge to accurately evaluate the skin dose that patients receive during treatment delivery.…”

Section: Introductionmentioning

confidence: 99%

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Impact of Respiratory Motion on the Skin Dose for Breast Cancer in Tomotherapy: A Study in the In-house Moving Phantom

Nobnop,

Lertananpipat,

Watcharawipha

et al. 2023

Technol Cancer Res Treat

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Purpose: The dose expansion methods as the skin flash and virtual bolus were used to solve intrafraction movement for breast planning due to breathing motion. We investigated the skin dose in each planning method by using optically stimulated luminescence on an in-house moving phantom for breast cancer treatment in tomotherapy. The impact of respiratory motion on skin dose between static and dynamic phantom's conditions was evaluated. Methods: A phantom was developed with movement controlled by the respirator for generating the respiratory waveforms to simulate respiratory motion. Five optically stimulated luminescence dosimeters were placed on the phantom surface to investigate the skin dose for the TomoDirect and TomoHelical under static and dynamic conditions. Eight treatment plans were generated with and without skin flash or virtual bolus by varying the thickness. The difference in skin dose between the two phantom conditions for each plan was explored. Results: All plans demonstrated a skin dose of more than 87% of the prescription dose under static conditions. However, the skin dose was reduced to 84.1% (TomoDirect) and 78.9% (TomoHelical) for dynamic conditions. The treatment plans without skin flash or virtual bolus showed significant skin dose differences under static and dynamic conditions by 4.83% (TomoDirect) and 9.43% (TomoHelical), whereas the skin flash with two leaves (TomoDirect 2L) or virtual bolus of at least 1.0 cm thickness (VB1.0) application compensated the skin dose in case of intrafraction movements by presenting a skin dose difference of less than 2% between the static and dynamic conditions. Conclusion: The skin dose was reduced under dynamic conditions due to breathing motion. The skin flash method with TomoDirect 2L or virtual bolus application with 1.0 cm thickness was useful for maintaining skin dose following the prescription by compensating for intrafraction movement due to respiratory motion for breast cancer in tomotherapy.

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Section: Skin Dose Measurementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of Respiratory Motion on the Skin Dose for Breast Cancer in Tomotherapy: A Study in the In-house Moving Phantom

Nobnop,

Lertananpipat,

Watcharawipha

et al. 2023

Technol Cancer Res Treat

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“…Megavoltage radiation dosimetry Gafchromic EBT3 (International Product, Wayne, U.S.A., NJ) for surface measurement having a thin thickness (thickness of 0.280 mm) was used. In this study, the dosimetry thickness was reduced to 0.150 mm to reduce the attenuation rate further [16][17][18]. Subsequently, the radiation absorption material was dried for 12 hours at a fixed temperature of 40 • C. The vector placement method was used to create an upper electrode on the top of the radiation absorption material.…”

Section: Fabrication Of Flexible Skin Dosimetermentioning

confidence: 99%

Development and evaluation of a monoxide-based flexible skin dosimeter for radiotherapy at photon energies

Yang¹,

Han²,

Park³

et al. 2021

J. Inst.

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Radiation therapy uses high-energy radiation that can cause various side effects depending on the patient's exposure. In particular, side effects occur in the skin due to its radiation exposure to reach the target volume. Therefore, side effects are reduced by clinical trials using various skin dosimeters such as lms and glass detectors to determine the dose exposed to the skin. However, accurately measuring the doses using these dosimeters is challenging due to human curvature. In this study, a exible skin dosimeter was produced using the photoconductor materials mercury oxide (HgO) and lead oxide (PbO).The performance of the proposed dosimeter was evaluated by measuring reproducibility, linearity, dose rate independency according to dose, and percent depth dose (PDD) at photon energy beam. The results showed that the exible skin dosimeter using HgO material has high applicability as a skin dosimeter due to its stability compared to PbO. The results provide useful insights for the radiation therapy eld, particularly in areas where radiation measurement is di cult, depending on the human curvature. The proposed exible skin dosimeter could serve in various radiation detection areas as a exible, functional material

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Dose prescription point in forward intensity-modulated radiotherapy of breast and head/neck cancers

Allaveisi

Amini

Pour

2018

Radiol Phys Technol

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In the forward intensity-modulated radiotherapy (FIMRT) technique of treatment planning, the isocenter cannot fulfill the requirements of the International Commission on Radiation Units and Measurements (ICRU) reference point. This study aimed to propose dose prescription points to be used in breast and head/neck cancer patients treated using the FIMRT technique. Two-hundred patients with head/neck (n = 100) and breast (n = 100) cancers were selected. Treatment plans involved using the FIMRT technique. The suggested reference points (SRPs) for dose prescription were placed at selected locations in the lateral neck site and the tangential site in breast and head/neck cancer patients, respectively. Next, doses at the SRPs (D) were compared to the planning treatment volume (PTV)-equivalent uniform dose (EUD) and mean dose in the PTV (D) extracted from dose-volume histograms. The differences between D and D for the PTVs were less than 2% in 78 cases and less than 1% in 28 cases. The D were comparable with the EUD in both types of PTVs; moreover, paired t test analyses indicated that the SRP doses and PTV EUD were statistically similar (p > 0.05). In 116 cases, the discrepancy between D and EUD was less than 2% and less than 1% in 74 cases. The SRPs satisfy the ICRU requirement that the reference point dose should be clinically relevant and representative of the dose throughout the PTV. A consensus on the definition of the reference point is expected to lead to accurate inter-comparison between results from different treatment centers, facilitating the optimization of treatment procedures.

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In vivo dosimetry of skin surface for breast cancer radiotherapy using intensity-modulated radiation therapy technique and helical tomotherapy

Cited by 7 publications

References 14 publications

Impact of Respiratory Motion on the Skin Dose for Breast Cancer in Tomotherapy: A Study in the In-house Moving Phantom

Impact of Respiratory Motion on the Skin Dose for Breast Cancer in Tomotherapy: A Study in the In-house Moving Phantom

Development and evaluation of a monoxide-based flexible skin dosimeter for radiotherapy at photon energies

Dose prescription point in forward intensity-modulated radiotherapy of breast and head/neck cancers

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