Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

Jia, Ming X.; Zhang, Xu; Yin, Ce; Feng, Ge; Li, Na; Gao, Song; Liu, Da W.

doi:10.1186/1748-717x-9-61

Cited by 27 publications

(34 citation statements)

References 28 publications

(25 reference statements)

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Section: Comparison With Other Studies Of Similar Investigation Typessupporting

confidence: 81%

“…Jia showed that the IMRT leakage dose is approximately 6 cGy, and it is uniformly distributed throughout the patient's skin, while the leakage dose from the RapidArc is about 3 cGy with a prescribed dose of 45 Gy [1]. This result fully supports our measurements [1]. In a recent paper, Dr. Tyan used a patient to evaluate in vivo doses of multi-slice computed tomography in abdominal examinations taken by 40-and 64 detector scanners, in-of-plane for males, and by 1.4 to 9.6 mSv (mean dose, 4.1 mSv) for females.…”

Section: Comparison With Other Studies Of Similar Investigation Typesmentioning

confidence: 99%

“…The target volume in the 70-kg phantom's lung was 64 cm 3 at a depth of 5 cm. A marker was used to place skin marks in three directions [1,2,14]. Figure 3(a) shows the treatment plan of the Pinnacle planning system (Philips The CT images and organ contours were transferred for VMAT at the Department of Radiation Oncology at Chung Shan Medical University Hospital (CSMUH) in Taichung ROC.…”

Section: Ct Simulation and Treatment Plan Of Lung Cancermentioning

confidence: 99%

“…All the computed tomography (CT) images (GE Aquillion 64, Toshiba Medical Solutions, Japan) of the phantoms were transferred and registered in the treatment planning system [1,2,[10][11][12][13]. Phantoms were introduced into a CT-based simulation in a supine position.…”

Section: Ct Simulation and Treatment Plan Of Lung Cancermentioning

confidence: 99%

“…VMAT is a powerful technique for irradiating many treatment sites and obtaining higher dose conformity to the tumor; it also decreases intra-fraction movements because of its shorter delivery times [1]. During treatment, the patient was exposed to significantly undesirable radiation that was primarily caused by out-of-field radiation resulting from collimators and beam modifiers.…”

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confidence: 99%

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In vivo evaluating skin doses for lung cancer patients undergoing volumetric modulated arc therapy treatment

Tseng

Pan

Chen

et al. 2015

BME

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Abstract. This study is the first to use 10-to 90-kg tissue-equivalent phantoms as patient surrogates to measure peripheral skin doses (D skin ) in lung cancer treatment through Volumetric Modulated Arc Therapy of the Axesse linac. Five tissueequivalent and Rando phantoms were used to simulate lung cancer patients using the thermoluminescent dosimetry (TLD-100H) approach. TLD-100H was calibrated using 6 MV photons coming from the Axesse linac. Then it was inserted into phantom positions that closely corresponded with the position of the represented organs and tissues. TLDs were measured using the Harshaw 3500 TLD reader. The ICRP 60 evaluated the mean D skin to the lung cancer for 1 fraction (7 Gy) undergoing VMAT. The D skin of these phantoms ranged from 0.51±0.08 (10-kg) to 0.22±0.03 (90-kg) mSv/Gy. Each experiment examined the relationship between the D skin and the distance from the treatment field. These revealed strong variations in positions close to the tumor center. The correlation between D skin and body weight was D skin (mSv) = -0.0034x + 0.5296, where x was phantom's weight in kg. R 2 is equal to 0.9788. This equation can be used to derive an equation for lung cancer in males. Finally, the results are compared to other published research. These findings are pertinent to patients, physicians, radiologists, and the public.

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Section: Comparison With Other Studies Of Similar Investigation Typessupporting

confidence: 81%

Section: Comparison With Other Studies Of Similar Investigation Typesmentioning

confidence: 99%

Section: Ct Simulation and Treatment Plan Of Lung Cancermentioning

confidence: 99%

Section: Ct Simulation and Treatment Plan Of Lung Cancermentioning

confidence: 99%

mentioning

confidence: 99%

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In vivo evaluating skin doses for lung cancer patients undergoing volumetric modulated arc therapy treatment

Tseng

Pan

Chen

et al. 2015

BME

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Risk for second bladder and rectal malignancies from cervical cancer irradiation

Mazonakis

Lyraraki

Tolia

et al. 2021

J Applied Clin Med Phys

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The objective of this study was to estimate the risk of developing second malignancies to partially in-field organs from volumetric modulated arc therapy (VMAT) of cervical cancer and to compare the above risks with those from the conventional three-dimensional conformal radiotherapy (3D-CRT). Seventeen consecutive patients with uterine cervix carcinoma were selected. VMAT and 3D-CRT plans were generated with 6 and 10 MV photons, respectively. The prescribed tumor dose was 45 Gy given in 25 fractions. Differential dose-volume histogram data from the treatment plans were obtained for the partially in-field organs such as bladder and rectum. These data were used to estimate the patient-specific lifetime attributable risk (LAR) for bladder and rectal cancer induction with a non-linear model based on a mixture of plateau and bell-shaped dose-response relationships. The estimated risks per 10000 people were compared with the baseline risks for unexposed population.The patient-specific rectal cancer risk estimates from VMAT were significantly lower than those from 3D-CRT (P = 0.0144). The LARs for developing bladder malignancies from VMAT were significantly high compared to those from conventional irradiation (P = 0.0003). The mean difference between the patient-specific LARs for radiation-induced bladder and rectal malignancies as derived from 3D-CRT and VMAT plans was 6.6% and 2.0%, respectively. The average LAR for developing bladder and rectal malignant diseases due to VMAT was 9.2 × 10 -4 and 43.7 × 10 -4 , respectively. The corresponding risks following 3D-CRT were 8.6 × 10 -4 and 44.6 × 10 -4 . These average risks showed that pelvic irradiation increases the baseline probability for cancer induction by 12.6-19.1%. The differences in the second cancer risks associated with the VMAT and 3D-CRT for cervical cancer were found to be small. Both treatment techniques resulted in considerable increased probabilities for developing bladder and rectal malignancies relative to those of unirradiated population.

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Development of a quasi‐humanoid phantom to perform dosimetric and radiobiological measurements for out‐of‐field doses from external beam radiation therapy

Kruszyna-Mochalska

Skrobała

Romański

et al. 2022

J Applied Clin Med Phys

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Our understanding of low dose, out‐of‐field radiation and their radiobiological effects are limited, in part due to the rapid technological advances in external beam radiotherapy, especially for non‐coplanar and dynamic techniques. Reliable comparisons of out‐of‐field doses produced by advanced radiotherapy techniques are difficult due to the limitations of commercially available phantoms. There is a clear need for a functional phantom to accurately measure the dosimetric and radiobiological characteristics of out‐of‐field doses, which would in turn allow clinicians and medical physicists to optimize treatment parameters. We designed, manufactured, and tested the performance of a quasi‐humanoid (Q‐H) adult phantom. To test the physics parameters, we used computed tomography (CT) scans of assembled Q‐H phantom. Static open field and dynamic techniques were measured both in‐ and out‐of‐field with ionization chambers and radiochromic films for two configurations (full solid and with water‐filled containers). In the areas simulating soft tissues, lung, and bones, median Hounsfield units and densities were, respectively: 129.8, ‐738.7, 920.8 HU and 1.110, 0.215, 1.669 g/cm3. Comparison of the measured to treatment planning systems (TPS) in‐field dose values for the sample volumetric arc therapy (VMAT) (6 MV flattening filter‐free (FFF)) plan, 96.4% of analyzed points passed the gamma evaluation criteria (L2%/2 mm, threshold (TH) 10%) and less than 1.50% for point dose verification. In the two phantom configurations: full poly(methyl) methacrylate (PMMA) and with water container, the off‐axis median doses for open field, relative to the central axis of the beam (CAX) were similar, respectively: 0.900% versus 0.907% (15 cm distance to CAX); 0.096% versus 0.120% (35 cm); 0.018% versus 0.018% (52 cm); 0.009% versus 0.008% (74 cm). For VMAT 6 MV FFF, doses relative the CAX were, respectively: 0.667% (15 cm), 0.062% (35 cm), 0.019% (52 cm), 0.016% (74 cm). The Q‐H phantom meets the International Commission on Radiation Units and Measurements (ICRU) and American Association of Physicists in Medicine (AAPM) recommended phantom criteria, providing medical physicists with a reliable, comprehensive system to perform dose calculation and measurements and to assess the impact on radiobiological response and on the risk of secondary tumor induction.

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Peripheral dose measurements in cervical cancer radiotherapy: a comparison of volumetric modulated arc therapy and step-and-shoot IMRT techniques

Cited by 27 publications

References 28 publications

In vivo evaluating skin doses for lung cancer patients undergoing volumetric modulated arc therapy treatment

In vivo evaluating skin doses for lung cancer patients undergoing volumetric modulated arc therapy treatment

Risk for second bladder and rectal malignancies from cervical cancer irradiation

Development of a quasi‐humanoid phantom to perform dosimetric and radiobiological measurements for out‐of‐field doses from external beam radiation therapy

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