scholarly journals Dose Calculation Algorithms for External Radiation Therapy: An Overview for Practitioners

2021 ◽  
Vol 11 (15) ◽  
pp. 6806
Author(s):  
Fortuna De Martino ◽  
Stefania Clemente ◽  
Christian Graeff ◽  
Giuseppe Palma ◽  
Laura Cella
Keyword(s):  
Radiation Therapy ◽  
Radiation Treatment ◽  
Dose Calculation ◽  
Physical Models ◽  
Therapeutic Technique ◽  
Calculation Algorithms ◽  
Medical Physicists ◽  
Dose Calculation Algorithms ◽  
External Radiation Therapy

Radiation therapy (RT) is a constantly evolving therapeutic technique; improvements are continuously being introduced for both methodological and practical aspects. Among the features that have undergone a huge evolution in recent decades, dose calculation algorithms are still rapidly changing. This process is propelled by the awareness that the agreement between the delivered and calculated doses is of paramount relevance in RT, since it could largely affect clinical outcomes. The aim of this work is to provide an overall picture of the main dose calculation algorithms currently used in RT, summarizing their underlying physical models and mathematical bases, and highlighting their strengths and weaknesses, referring to the most recent studies on algorithm comparisons. This handy guide is meant to provide a clear and concise overview of the topic, which will prove useful in helping clinical medical physicists to perform their responsibilities more effectively and efficiently, increasing patient benefits and improving the overall quality of the management of radiation treatment.

Radiotherapy dose calculations in high-Z materials: comprehensive comparison between experiment, Monte Carlo, and conventional planning algorithms (Preprint)

2021 ◽  
Author(s):  
Zhangkai Cheng ◽  
Regina Bromley ◽  
Brad Oborn ◽  
Jeremy Booth
Keyword(s):  
Monte Carlo ◽  
Radiation Therapy ◽  
Spinal Metastases ◽  
Dose Calculation ◽  
High Energy ◽  
The Body ◽  
Treatment Technique ◽  
Calculation Algorithms ◽  
Dose Calculation Algorithms ◽  
Ct Density

BACKGROUND Despite spinal metastases accounting for 10% to 30% of new tumors diagnoses annually, and radiation therapy is a standard treatment technique, the studies discussing the effects of small-size spinal prostheses on spinal radiation therapy are limited. OBJECTIVE To compare the accuracies of the AAA and AcurosXB dose calculation algorithms and to predict the change in the down-stream and lateral dose deposition of high energy photons in the presence of material with densities higher that commonly found in the body. METHODS Metal rods of titanium (d =4.5g/m2), stainless steel (d=8g/cm2) and tungsten (d=19.25 g/cm2) were positioned in a phantom. Film was position behind and laterally to the rods to measure the dose distribution for a 6 MV, 18 MV and 10 FFF photon beams. A DOSXYZnrc Monte Carlo simulation of the experimental setup was performed The AAA and AcurosXB dose calculation algorithms were used to predict the dose distributions. The dose from film and DOSXYZnrc were compared with the dose predicted by AAA and AcurosXB. RESULTS AAA overestimated the dose behind the rods by 15-25% and underestimated the dose laterally to the rods by 5-15% depending on the range of materials and energies investigated. AcurosXB overestimated the dose behind the rods by 1-18% and underestimated the dose laterally to the rods by up to 5% depending on the range of material and energies investigated. CONCLUSIONS AAA cannot deliver clinically acceptable dose calculation results at a distance less than 10 mm from metals, for a single field treatment. Acuros XB is able to handle metals of low atomic numbers (Z ≤ 26), but not tungsten (Z = 74). This can be due to the restriction of the CT-density table in EclipseTM TPS, which has an upper HU limit of 10501.

Comparison of CCC and ETAR dose calculation algorithms in pituitary adenoma radiation treatment planning; Monte Carlo evaluation

2014 ◽  
Vol 13 (4) ◽  
pp. 447-455 ◽  
Author(s):  
K. Tanha ◽  
S. R. Mahdavi ◽  
G. Geraily
Keyword(s):  
Monte Carlo ◽  
Pituitary Adenoma ◽  
Treatment Planning ◽  
Radiation Treatment ◽  
Dose Calculation ◽  
Planning System ◽  
Treatment Planning System ◽  
Significant Difference ◽  
Calculation Algorithms ◽  
Dose Calculation Algorithms

AbstractAimsTo verify the accuracy of two common absorbed dose calculation algorithms in comparison to Monte Carlo (MC) simulation for the planning of the pituitary adenoma radiation treatment.Materials and methodsAfter validation of Linac's head modelling by MC in water phantom, it was verified in Rando phantom as a heterogeneous medium for pituitary gland irradiation. Then, equivalent tissue-air ratio (ETAR) and collapsed cone convolution (CCC) algorithms were compared for a conventional three small non-coplanar field technique. This technique uses 30 degree physical wedge and 18 MV photon beams.ResultsDose distribution findings showed significant difference between ETAR and CCC of delivered dose in pituitary irradiation. The differences between MC and dose calculation algorithms were 6.40 ± 3.44% for CCC and 10.36 ± 4.37% for ETAR. None of the algorithms could predict actual dose in air cavity areas in comparison to the MC method.ConclusionsDifference between calculation and true dose value affects radiation treatment outcome and normal tissue complication probability. It is of prime concern to select appropriate treatment planning system according to our clinical situation. It is further emphasised that MC can be the method of choice for clinical dose calculation algorithms verification.

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