Intra-fraction organ motion during the dynamic delivery of IMRT treatment of lung tumors may cause unexpected hot/cold spots even within the target volume, due to the interplay effect between tumor motion and multi-leaf collimator (MLC) leaf motion. In the past, this has been investigated through theoretical analysis, computer simulation, and experimental measurement using an ionization chamber...

IMRT often requires delivering small fields which may suffer from electronic disequilibrium effects. The presence of heterogeneities, particularly low-density tissues in patients, complicates such situations. In this study, we report on verification of the DPM MC code for IMRT treatment planning in heterogeneous media, using a previously developed model of the Varian 120-leaf MLC. The purpose o...

Introduction: This study was conducted to evaluate and quantify the treatment planning performance of MLC-optimized field-in-field planning technique (FIF), also named forward IMRT, versus wedge-based three field (W3F) technique in terms of dosimetric and radiobiological parameters for esophageal carcinoma.   Material and Methods: Twenty patients with esophag...

The Delta(4) diode array phantom (Scandidos, Uppsala, Sweden) was evaluated for verification of segmental intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) on an Elekta linear accelerator (Crawley UK). The device was tested for angular sensitivity by irradiating it from 36 different gantry angles, and the responses of the device to various step-and-shoot s...

The purpose of this study was to evaluate the feasibility of delineating the substructure of the heart by using 64-slice spiral CT coronary angiography (CTA) in breast cancer patients who underwent left breast-conserving surgery, and to compare the dosimetric differences between the targets and organs at risk in the prone and supine positions in intensity-modulated radiation therapy (IMRT) plan...

Background: This study evaluated whether IMRT using fewer beams and segments could reduce delivery time without compromising plan quality in gastric cancer adjuvant radiotherapy. Materials and Methods: Fifteen patients with advanced gastric cancer who underwent D2, R0 surgery were included in this study. IMRT plans for each patient were designed as 7 equal beams with 40 segments, 5 beams with 2...

Purpose: To compare the dose distribution of three-dimensional conformal radiation therapy (3DCRT) with intensity-modulated (IMRT) for post-mastectomy radiotherapy (PMRT) to left chest wall. Materials and Methods: 30 post-MRM female breast cancer patients histologically confirmed infiltrating ductal carcinoma unilateral without evidence distant metastasis or second malignancy were found eligibl...

Purpose: An optimal once-daily radiotherapy (RT) regimen is under investigation for definitive concurrent chemoradiotherapy (CCRT) in limited disease small cell lung cancer (LD-SCLC). We compared the efficacy and safety of dose escalation with intensity-modulated (IMRT).Materials Methods: Between January 2016 March 2021, patients treated CCRT LD-SCLC IMRT were retrospectively reviewed. Patients...

Introduction: The present study aimed to measure the scatter and leakage dose received by out-of-field organs while delivering Radiotherapy (RT) treatment of cervical cancer. Moreover, this study estimated the risk of second cancer (SC). The doses to out-of-field organs were measured using a lithium fluoride (TLD 100) dosimeter while delivering External Beam Radiothera...