Average dose-volume histogram (DVH) comparison for lung and heart with four different planning techniques.

6F-IMRT = six large fields IMRT plans with fixed jaw; 6F-IMRT-T = six large fields IMRT plans with jaw tracking technique; 12F-IMRT = twelve small fields IMRT plans with fixed jaw; 12F-IMRT-T = twelve small fields IMRT plans with jaw tracking technique.</p

Isodose distributions for one patient with esophageal cancer in four treatment plans.

6F-IMRT = six large fields IMRT plans with fixed jaw; 6F-IMRT-T = six large fields IMRT plans with jaw tracking technique; 12F-IMRT = twelve small fields IMRT plans with fixed jaw; 12F-IMRT-T = twelve small fields IMRT plans with jaw tracking technique.</p

The number of monitor units (MU), beam-on time (BOT), and mean dose rate (MDR) for treatment plans created with different planning techniques.

The number of monitor units (MU), beam-on time (BOT), and mean dose rate (MDR) for treatment plans created with different planning techniques.</p

Delineated planning target volume (PTV) for esophageal cancer in beam’s eye view (BEV) and jaw setup of IMRT plans.

(A) Jaw setup of large field IMRT plans. (B) Jaw setup of small field IMRT plans.</p

Dosimetric parameters comparison for the organs at risk: Total lung, heart, spinal cord, and spinal cord PRV.

Dosimetric parameters comparison for the organs at risk: Total lung, heart, spinal cord, and spinal cord PRV.</p

Dosimetric parameters comparison for PTV in four treatment plans.

Dosimetric parameters comparison for PTV in four treatment plans.</p

Determination of Persistent Organic Pollutants (POPs) in Atmospheric Gases and Particles by Solid-Phase Extraction (SPE) and Gas Chromatography–Tandem Mass Spectrometry (GC–MS/MS)

Persistent organic pollutants (POPs) are harmful to the environment and human health. A simple method was developed for the determination of 58 POPs, including 16 polycyclic aromatic hydrocarbons (PAHs), 18 polychlorinated biphenyls (PCBs), and 24 organochlorine pesticides (OCPs), in atmospheric gaseous and particle-phase samples. Different extraction solvents, solid-phase extraction (SPE) cartridges and elution steps were used and compared to optimize the extraction efficiency. The POPs were isolated from the atmospheric samples by Soxhlet extraction using 1:1 acetone:n-hexane and separated using SPE cartridges. The fractions were collected by two-step elution with10 mL of n-hexane and 10 mL of 1:1 n-hexane:dichloromethane. The method validation showed that PAHs, PCBs and OCPs had good linearity, with the coefficients of determination higher than 0.995, from 2.5 to 800, 2.5 to 800, and 2.5 to 600 ng/mL, respectively. The average recoveries were 67–117%, 67–113%, and 73–114% for the PAHs, PCBs, and OCPs. The limits of detection for PAHs, PCBs, and OCPs were from 0.55 to 3.29, 0.09 to 2.00, and 0.57 to 4.86 pg/m3. The limits of quantification (LOQs) for PAHs, PCBs and OCPs were 1.80 to 10.48, 0.29 to 6.37, and 1.82 to 15.48 pg/m3. The applicability of the method was confirmed using an urban dust standard reference material. The method was employed for the analysis of atmospheric samples collected weekly for one-half year on the rooftop of a 14 m tall building in the downtown Mianyang, Sichuan, China. The developed method is demonstrated to accurately monitor persistent organic pollutants in the atmosphere.</p

Dose volume histogram of the target volume coverage and normal organs in VMAT (medium solid), IMRT (medium dashed), and IMRT-EB (thin solid).

<p>Dose volume histogram of the target volume coverage and normal organs in VMAT (medium solid), IMRT (medium dashed), and IMRT-EB (thin solid).</p

Dosimetric Comparison of the Simultaneous Integrated Boost in Whole-Breast Irradiation after Breast-Conserving Surgery: IMRT, IMRT plus an Electron Boost and VMAT

<div><p>Objectives</p><p>To compare the target volume coverage and doses to organs at risks (OARs) using three techniques that simultaneous integrated boost (SIB) in whole-breast irradiation (WBI) after breast-conserving surgery, including intensity-modulated radiation therapy (IMRT), IMRT plus an electron boost (IMRT-EB), and volumetric-modulated arc therapy (VMAT).</p><p>Methods</p><p>A total of 10 patients with early-stage left-sided breast cancer after breast-conserving surgery were included in this study. IMRT, IMRT-EB and VMAT plans were generated for each patient.</p><p>Results</p><p>The conformity index (CI) of the planning target volumes evaluation (PTV-Eval) of VMAT was significantly superior to those of IMRT and IMRT-EB (<i>P</i> < 0.05). The CI of the PTV Eval-boost of VMAT was better than that of IMRT (<i>P</i> = 0.018) and IMRT-EB (<i>P</i> < 0.001), while the CI of the PTV Eval-boost of IMRT was better than that of IMRT-EB (<i>P</i> = 0.002). The V5, V10 and Dmean in ipsilateral lung with VMAT were significantly higher than IMRT (<i>P</i> < 0.05) and IMRT-EB (<i>P</i> < 0.05). The Dmean, V5 and V10 in heart with VMAT were significantly greater than those of IMRT and IMRT-EB (<i>P</i> < 0.05). There was no significant difference in the OARs between IMRT and IMRT-EB (<i>P</i> > 0.05).</p><p>Conclusions</p><p>Considered the target volume coverage and radiation dose delivered to the OARs (especially the heart and lung), IMRT may be more suitable for the SIB in WBI than IMRT-EB and VMAT. Additional clinical studies with a larger sample size will be needed to assess the long-term feasibility and efficacy of SIB using different radiotherapy techniques.</p></div

Clinical characteristics of 10 patients.

<p><i>Abbreviations</i>: UIQ = upper inner quadrant, UOQ = upper outer quadrant, LIQ = lower inner quadrant, LOQ = lower outer quadrant.</p><p>Clinical characteristics of 10 patients.</p