The Effect of Modulation Complexity Score (MCS) on the IMRT Treatment Planning Delivery Accuracy

Abstract

Intensity modulated radiation therapy (IMRT) is an effective treatment planning technique for various types of tumors such as head and neck (H&N) or pelvis. A complexity algorithm was invented to predict the deliverability and the accuracy for IMRT plans called the Modulation Complexity Score ranging from 0 to 1. The %GP is a metric depends on %DD /DTA to find the variation between the calculated dose from TPS and the measured dose from the phantom during the QA. This study is trying to assess the correlation between the MCS and planning verification outcome. Thirty-four patients treated with step and shoot IMRT technique for anatomical sites: H&N and pelvis. The planning process performed using Monaco 5.1 TPS then exported to Elekta Synergy linear accelerator. The phantom is used for the QA procedure is Octavius 4D-1500 with Verisoft 7.1 software analysis to evaluate the gamma passing rate for commonly used criteria 3%/3 mm at a 5% threshold. The MCS calculated using MATLAB 2019a. It results that the H&N plans are significantly more complex than the pelvis once with p-value 0.0192. The analysis shows a weak correlation between the MCS and MU for both treated sites. The complex H&N plans give a good value for %GP. Also, simpler pelvis plans obtain better global %GP results. Thus, modulation Complexity score can give a simple indication for pretreatment verifications of the IMRT plans for H&N and pelvis sites.

Impact of the gradient in gantry‐table rotation on dynamic trajectory radiotherapy plan quality

“…$$G\ $$and $$\Delta G$$ complement the frequently used MCS, which has been related to delivery accuracy, 28,37 in characterizing the dynamics and complexity of DTRT plans. While MCS decreases slightly from VMAT to DTRT‐1 for the investigated cases, it does not decrease further with increasing $${G}_{max}\& \Delta {G}_{max}$$.…”

Optimizing Treatment Quality in Head and Neck Cancer Therapy: Impact of Adaptive Intensity-Modulated Radiotherapy on Plan Quality and Tumor Volume Changes

“…Since the radiation beam intensity may be adjusted all across the treatment region using IMRT, tumors can be targeted more precisely. 1 As the patient undergoes treatment, adaptive IMRT makes real-time adjustments to the imaging and treatment protocols. To evaluate the tumor's size, form, and position, in addition to the patient's anatomy, regular CT or MRI scans are required.…”

“…2,3 A promising new approach to improving radiation treatment accuracy and accommodating internal anatomical changes is adaptive intensity-modulated radiation therapy, more commonly known as adaptive IMRT. 4,5 Advanced radiation therapy techniques like adaptive radiation therapy (ART) allow for real-time adjustments to radiation dose in response to tumor characteristics and other anatomical changes. Incorporating real-time dynamic adjustment allows for better-targeted radiation treatment, which improves the therapeutic ratio by reducing radiation damage to nearby healthy tissues and guaranteeing efficient tumor localization.…”

Study the Quality of IMRT and VMAT Treatment Planning Techniques (TPS) Using Indices of Achievement (IOA) Nasopharyngeal Cancer Plans

“…Intensity-Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) are modern planning approaches that combine linear accelerators to safely deliver precision radiation to a tumor while limiting the exposure to surrounding normal tissue. To improve the composite dose distribution, a non-uniform fluence of radiation is provided to the patient from any given point of the therapy beam [8,9]. Nasopharyngeal cancer (NPC) is difficult to treat with radiation treatment (RT).…”