The impact of corrected field output factors based on IAEA/AAPM code of practice on small-field dosimetry to the calculated monitor unit in eclipse ™ treatment planning system.

The objective of this study was to investigate the effect of field output factors (FOFs) according to the current protocol for small-field dosimetry in conjunction to treatment planning system (TPS) commissioning. The calculated monitor unit (MU) for intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans in Eclipse™ TPS were observed. Micro ion chamber (0.01 CC) (CC01), photon field diode (shielded diode) (PFD), and electron field diode (unshielded diode) (EFD) were used to measure percentage depth doses, beam profiles, and FOFs from 1 × 1 cm2 to 10 × 10 cm2 field sizes of 6 MV photon beams. CC01 illustrated the highest percentage depth doses at 10 cm depth while EFD exhibited the lowest with the difference of 1.6% at 1 × 1 cm2 . CC01 also produced slightly broader penumbra, the difference with other detectors was within 1 mm. For uncorrected FOF of three detectors, the maximum percent standard deviation (%SD) was 5.4% at 1 × 1 cm2 field size. When the correction factors were applied, this value dropped to 2.7%. For the calculated MU in symmetric field sizes, beam commissioning group from uncorrected FOF demonstrated maximum %SD of 6.0% at 1 × 1 cm2 field size. This value decreased to 2.2% when the corrected FOF was integrated. For the calculated MU in IMRT-SRS plans, the impact of corrected FOF reduced the maxim...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research

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In this study, a phantom, containing a metal with high atomic number, was prepared for intensity-modulated radiotherapy (IMRT) treatment plans to be used in quality assurance (QA) procedures. Two sets of image files, one without metal artefact correction (ORG) and another with MAR correction (MAR+), were sent to the treatment planning system. In this study, 12 IMRT treatment plans with different fields and segment numbers were calculated. The normal tissue complication probability (NTCP) values of imaginary organs at risk (OARs), such as the rectum and bladder, were investigated, as was the difference in dose maps for ORG ...
Source: Radiation and Environmental Biophysics - Category: Physics Authors: Tags: Radiat Environ Biophys Source Type: research
Radiation therapy plays a critical role in the treatment of esophageal cancer (EC), especially for locally advanced EC [1]. Historically, three-dimensional conformal radiotherapy (3DCRT) has been the most widely used radiation technique for EC. Based on inverse planning algorithm and complex modulated beams, IMRT can provide improved target coverage and better sparing of organs at risk (OARs) [2]. Therefore, as an advanced conformal radiation modality, intensity-modulated radiotherapy (IMRT) has been increasingly adopted worldwide over the past decade [3,4].
Source: Radiotherapy and Oncology - Category: Radiology Authors: Tags: Original Article Source Type: research
Condition:   Head and Neck Squamous Cell Carcinoma Intervention:   Radiation: Intensity-modulated Radiation Therapy (IMRT) Sponsor:   University of Texas Southwestern Medical Center Not yet recruiting
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
Patient-specific quality assurance (QA) process is particularly important in modern radiation therapy treatment modalities, such as intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), in which radiation beams are delivered through complex collimating patterns shaped by multileaf collimators (MLCs). Conventionally, calculating and measuring radiation doses on a water equivalent phantom were performed as an essential part of patient-specific QA. Measurements have been made using a combination of ionization chamber and radiosensitive film or using a detector array [1 –6].
Source: Physica Medica: European Journal of Medical Physics - Category: General Medicine Authors: Tags: Original paper Source Type: research
ConclusionAfter great improvements in rectal cancer treatment, late gastrointestinal toxicity after radiotherapy is experienced less frequent and less severe; however, it remains a great concern associated with worse quality of life.
Source: International Journal of Colorectal Disease - Category: Gastroenterology Source Type: research
The use of a specific treatment technique in radiation therapy is mainly motivated by the achievable dose conformity to the target and the overall integral dose. Proton therapy offers a highly conformal and comprehensive treatment option with a lower integral dose (reduced low-dose bath) to organs at risk (OARs). Consequently, given the proximity of cardiopulmonary structures, proton therapy has been discussed as a treatment alternative for breast cancer patients [1 –3]. Treatment planning studies, comparing 3DCRT, IMRT, and proton therapy when irradiating the breast and regional nodes showed advantages of using prot...
Source: Radiotherapy and Oncology - Category: Radiology Authors: Tags: Original Article Source Type: research
CONCLUSIONS: Air cavities inside rectum affects rectum plan dosimetry due ERE. Location and magnitude of hot spots are dependent on the size of the air cavity. PMID: 32445292 [PubMed - as supplied by publisher]
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research
Conditions:   Glioblastoma;   Gliosarcoma Interventions:   Radiation: 3-Dimensional Conformal Radiation Therapy;   Radiation: Intensity-Modulated Radiation Therapy (IMRT);   Drug: Temozolomide;   Drug: Chloroquine;   Procedure: Tumor Treating Fields Therapy (TTF) Sponsors:   Barbara Ann Karmanos Cancer Institute;   National Cancer Institute (NCI) Not yet recruiting
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
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