The goal of this research was to study the widely used criteria in Iraq and the suggested criteria from the American association of physics in medicine (AAPM). The breast cancer patients treated at Al-Andalus private hospital underwent a CT simulation. The data were exported to Monaco 5.1 treatment planning system for planning purposes using the intensity-modulated radiation therapy technique with X-ray energies of 6 or 10 MV. The planning was transferred to Agility linear accelerator for irradiation to Octavius-4D phantom detector for pre-treatment verification. The results show that there is no significant difference between the prescribed and measured point dose. In addition, the dose difference is acceptable and there was no significant correlation between the dose error and the result of gamma passing rates for all criteria. A high significant difference appeared between the 3%/2 mm and 3%/3 mm criteria for both local and global gamma passing rates at the two studied thresholds 5% and 10%. All the values of 10% thresholds were highly significant than 5% in local %GP but not significant for the global %GP. The number of segments and the total number of monitor units show an inverse relationship with gamma passing rates. The results clearly show that criteria and thresholds depend on the situation and health of the patient. This means the criteria are to be set at 3%/2 mm for plans which use high doses to organs at risk, while 3%/3 mm may be used for simpler plans with lower doses to organs at risk.

Dosimetric assessment of IMRT treatment planning for unilateral breast cancer patient using Octavius phantom detector

2-Dimensional IMRT dose audit: An Indonesian multicenter study.

Accurately calculating setup errors is crucial in ensuring quality assurance for patients undergoing radiation therapy treatment. This cross-sectional study aimed to determine the systematic, random, and planning target volume (PTV) margin errors for patients with head and neck cancer (n=48) and breast cancer (n=50). The treatment setup was performed using electronic portal imaging (EPIDs) and irradiated using Elekta linac. The errors were calculated using the van Herk formula. The systematic error for the head and neck was 0.89, 0.43, and 1.49 mm on the x, y, and z-axis, respectively, and 0.39, 0.74, 0.38 for the breast cases. The random error was 0.82, 0.68, 0.94 mm for the head and neck and 0.66, 0.72, 0.79 mm for the breast. The PTV margin shifting error for the head and neck were 2.79, 1.55, and 4.38 mm, while it was 1.43, 2.35, and 1.50 mm for the breast. The setup errors varied according to the tumor location. The study highlights the potential benefits of using EPIDs for reducing uncertainties in setup verification procedures.

/pdf/assessing-setup-errors-and-shifting-margins-for-planning-uibjftxu.pdf

Assessing setup errors and shifting margins for planning target volume in head, neck, and breast cancer

Combination technique for tattoo removal by Q switching Nd: YAG laser and high intensity focused ultrasound

Background: Step and shoot (SS) IMRT treatment technique is one of the modern planning techniques used in radiotherapy. It conforms to the dose to the possible minimum as to the OARs. Dosimetric error calculations used to estimate the sensitivity of reading and the dose difference between TPS and phantom detector. Monitor units (MUs) are measured by monitor chambers, which are ionization chambers that measure the dose delivered by a beam and are built into the treatment head of radiotherapy linear accelerators. Material and Method: Thirty cases of two regions (25 HN and 5 pelvic cases) performed with SS IMRT using MONACO5.1 Treatment Planning System (TPS). Then the QA tested using OCTAVIUS 4D-1500 phantom in Baghdad Center for Radiotherapy and Nuclear Medicine, Baghdad, Iraq. Gamma index and %GP calculated index by comparing the actual QA (using Octavius) with virtual QA (using MONACO TPS). Dosimetric error percentage with global and local %GP and the total Monitor Unit (MU) correlation with global and local %GP were measured. Results: The %GP was ≥95%, where 20% for local %GP for all cases and 73.3 % for global passing rate. A significant correlation found between the %DEs resulted in the %GP for both local and global. There was a correlation between the total MUs for global %GP. For a local %GP, it was statistically not correlated with MUs. Conclusion: There is a correlation found between dosimetric error percentage (%DE) and %GP for both local and global. There is a correlation between the total Monitor Unit (MU) and global %GP but not with local.

https://www.journal.atmph-specialissues.org/uploads/179/8761_pdf.pdf

The Correlation of Total MU Number and Percentage Dosimetric Error in Step and Shoot IMRT with Gamma Passing Rate Using OCTAVIUS 4D-1500 Detector Phantom

Mustafa JabbarAl-Musawi

Papers

The Correlation of Total MU Number and Percentage Dosimetric Error in Step and Shoot IMRT with Gamma Passing Rate Using OCTAVIUS 4D-1500 Detector Phantom