Skin dose differences between intensity-modulated radiation therapy and volumetric-modulated arc therapy and between boost and integrated treatment regimens for treating head and neck and other cancer sites in patients

Penoncello, Gregory P.; Ding, G

doi:10.1016/j.meddos.2015.09.001

Cited by 12 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Skin toxicity has always been a major concern in radiotherapy treatments, even nowadays with modern techniques . As discussed earlier, surface dose and dose at 0.5 cm depth have been measured.…”

Section: Discussionmentioning

confidence: 99%

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy

Ferrer

Huertas

Plaza

et al. 2018

J Applied Clin Med Phys

View full text Add to dashboard Cite

This work aims to study the effect on surface dose and dose distribution caused by the Elekta Fraxion cranial immobilization system. The effect of Fraxion inclusion in Elekta Monaco treatment planning system and its calculation accuracy is also checked. To study the dose attenuation, a cylindrical phantom was located over the Elekta Fraxion with an IBA CC13 ionization chamber placed in the central insert at the linac isocenter. Dose measurements at multiple gantry angles were performed for three open fields, 10 × 10 cm, 5 × 5 cm and other smaller 2 × 2 cm. Measured doses were compared with the ones calculated by Monaco. Surface dose and dose distribution in the buildup region were measured placing several Gafchromic Films EBT3 at linac CAX between the slabs of a RW3 phantom located over Fraxion and read using FilmQA Pro software. Measures were performed for two open field sizes and results were compared with Monaco calculations. Measurements show a 1% attenuation for 180° gantry angle but it can be as high as 3.4% (5 × 5 open field) for 150°/210° gantry angle, as with these angles the beam goes through the Fraxion's headrest twice. If Fraxion is not included in the calculation Monaco calculation can result in a 3% difference between measured and calculated doses, while with Fraxion in the calculation, the maximum difference is 0.9%. Fraxion increases 3.7 times the surface dose, which can be calculated by Monaco with a difference lower than 2%. Monaco also calculated correctly the PDD for both open fields (2%) when Fraxion is included in the calculation. This work shows that the attenuation varies with gantry angle. The inclusion of Fraxion in Monaco improves the calculation from 3% difference to 1% in the worst case. Furthermore, the surface dose increment and the dose in the buildup region are correctly calculated.

show abstract

Section: Discussionmentioning

confidence: 99%

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy

Ferrer

Huertas

Plaza

et al. 2018

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Penoncello and Ding (2016) determined the average patient skin dose delivered by the MV treatment beam for a variety of prostate VMAT plans to be 8616.7 ± 1092.8 mGy,20 far above the estimated skin dose delivered as a result of KIM imaging. Deterministic skin effects may occur for skin doses of 2 Gy and above.…”

Section: Discussionmentioning

confidence: 99%

Technical note: TROG 15.01 SPARK trial multi‐institutional imaging dose measurement

Legge

Greer

Keall

et al. 2017

J Applied Clin Med Phys

View full text Add to dashboard Cite

PurposeThe Trans‐Tasman Radiation Oncology Group (TROG) 15.01 Stereotactic Prostate Adaptive Radiotherapy utilizing Kilovoltage intrafraction monitoring (SPARK) trial is a multicenter trial using Kilovoltage Intrafraction Monitoring (KIM) to monitor prostate position during the delivery of prostate radiation therapy. KIM increases the accuracy of prostate radiation therapy treatments and allows for hypofractionation. However, an additional imaging dose is delivered to the patient. A standardized procedure to determine the imaging dose per frame delivered using KIM was developed and applied at four radiation therapy centers on three different types of linear accelerator.MethodsDose per frame for kilovoltage imaging in fluoroscopy mode was measured in air at isocenter using an ion chamber. Beam quality and dose were determined for a Varian Clinac iX linear accelerator, a Varian Trilogy, four Varian Truebeams and one Elekta Synergy at four different radiation therapy centers. The imaging parameters used on the Varian machines were 125 kV, 80 mA, and 13 ms. The Elekta machine was measured at 120 kV, 80 mA, and 12 ms. Absorbed doses to the skin and the prostate for a typical SBRT prostate treatment length were estimated according to the IPEMB protocol.ResultsThe average dose per kV frame to the skin was 0.24 ± 0.03 mGy. The average estimated absorbed dose to the prostate for all five treatment fractions across all machines measured was 39.9 ± 2.6 mGy for 1 Hz imaging, 199.7 ± 13.2 mGy for 5 Hz imaging and 439.3 ± 29.0 mGy for 11 Hz imaging.ConclusionsAll machines measured agreed to within 20%. Additional dose to the prostate from using KIM is at most 1.3% of the prescribed dose of 36.25 Gy in five fractions delivered during the trial.

show abstract

“…The use of arcs, typical of the VMAT technique, may further minimize the high doses to the scalp because the surface dose is distributed over the length of the arc (19). The investigation of Penoncello et al (26) confirmed that VMAT may be superior in minimizing dose to the scalp than static-field IMRT.…”

Section: Dose-response Relationship For Chronic Alopeciamentioning

confidence: 99%

Dosimetric Predictors of Acute and Chronic Alopecia in Primary Brain Cancer Patients Treated With Volumetric Modulated Arc Therapy

et al. 2020

View full text Add to dashboard Cite

Purpose: To determine dose constraints that correlate with alopecia in patients treated with photon-based Volumetric Modulated Arc Therapy (VMAT) for primary brain tumors.Methods: During the treatment planning process, the scalp was drawn as a region of interest. Dose received by 0.1 cc (D 0.1cc ), mean dose (D mean ), absolute volumes receiving different doses (V 16Gy , V 20Gy , V 25Gy , V 30Gy , V 35Gy , V 40Gy , and V 43Gy ) were registered for the scalp. Alopecia was assessed according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Receiver operating characteristics (ROC) curve analysis was used to identify parameters associated with hair-loss.Results: One-hundred and one patients were included in this observational study. At the end of radiotherapy (RT), 5 patients did not develop alopecia (D mean scalp 3.1 Gy). The scalp of the patients with G1 (n = 11) and G2 (n = 85) alopecia received D mean of 10.6 Gy and 11.8 Gy, respectively. At ROC analysis, V 16Gy20Gy ≥ 5.2 cc were the strongest predictors of acute alopecia risk. Chronic hair-loss assessment was available for 74 patients: median time to recovery from G2 alopecia was 5, 9 months. The actuarial rate of hair regrowth was 98.1% at 18 months after the end of RT. At ROC analysis, V 40Gy43Gy ≥2.2 cc were the strongest predictors of chronic G2-alopecia risk. V 20Gy, V 40Gy , and D 0,1cc were shown to be independent variables according to correlation coefficient r.Conclusions: V 20Gy and V 40Gy were the strongest predictors for acute and chronic G2 hair-loss, respectively. The low-dose bath typical of VMAT corresponds to large areas of acute but transient alopecia. However, the steep dose gradient of VMAT allows to reduce the areas of the scalp that receive higher doses, minimizing the risk of permanent alopecia. Scoccianti et al. Predictors of Radiotherapy-Induced AlopeciaThe application of our dosimetric findings for the scalp may help in reducing the alopecia risk and also in estimating the probability of hair-loss during patient counseling before starting radiotherapy.

show abstract

Skin dose differences between intensity-modulated radiation therapy and volumetric-modulated arc therapy and between boost and integrated treatment regimens for treating head and neck and other cancer sites in patients

Cited by 12 publications

References 11 publications

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy

Dosimetric effects of a repositioning head frame system and treatment planning system dose calculation accuracy

Technical note: TROG 15.01 SPARK trial multi‐institutional imaging dose measurement

Dosimetric Predictors of Acute and Chronic Alopecia in Primary Brain Cancer Patients Treated With Volumetric Modulated Arc Therapy

Contact Info

Product

Resources

About