Impact of tumor size and location on lung dose difference between stereotactic body radiation therapy techniques for non-small cell lung cancer.

Background: To evaluate the lung dose differences between three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) techniques for lung stereotactic body radiation therapy (SBRT) and the correlations with tumor characteristics, such as size and location.

Methods: Dosimetric comparisons between the two SBRT techniques in high- and low- to intermediate-dose regions were retrospectively performed using four planning indices and lung-dose parameters in 31 lung tumors. The magnitude of differences in these parameters was analyzed with relation to the planning target volume (PTV) and location-related parameters.

Influence of tumor characteristics on correction differences between cone-beam computed tomography-guided patient setup strategies in stereotactic body radiation therapy for lung cancer.

Background: To evaluate the correction differences between vertebra and tumor matching as cone-beam computed tomography (CBCT)-guided setup strategies in lung stereotactic body radiation therapy (SBRT), and the correlations with tumor characteristics such as size, mobility, and location.

Methods: The manual registrations for 33 lung tumors treated with SBRT were retrospectively performed by matching thoracic vertebrae for vertebra matching and then by matching CBCT-visualized tumors within the internal target volume obtained from a four-dimensional CT dataset for tumor matching.

Results: The mean correction difference between the two matching methods during the SBRT fractions was larger in the anterior-posterior direction (2.

Usefulness of target delineation based on the two extreme phases of a four-dimensional computed tomography scan in stereotactic body radiation therapy for lung cancer.

Background: An evaluation of the usefulness of target delineation based only on the two extreme phases of a four-dimensional computed tomography (4D CT) scan in lung stereotactic body radiation therapy (SBRT).

Methods: Seventeen patients treated with SBRT via 4D CT scans for lung cancer were retrospectively enrolled. Volumetric and geometric analyses were performed for the internal target volumes (ITVs) and planning target volumes (PTVs) generated using different respiratory phases (all phases and 2 extreme phases) and setup margins (3 mm and 5 mm).

Modulation of radiation-induced alterations in oxidative stress and cytokine expression in lung tissue by Panax ginseng extract.

We investigated the modulating effect of Panax ginseng extract (PGE) on radiation-induced lung injury (RILI) by measuring early changes in oxidative stress levels, cytokine expression, and the histopathology of mouse lung tissue treated with high dose of X-ray radiation. The mice were pretreated with 25, 50, and 100-mg/kg doses of PGE orally for four consecutive days, and their thoraces were then exposed to 15-Gy X-ray radiation 1 h after the last administration of PGE on day 4. The pretreatments with 50 and 100 mg/kg PGE led to significant reductions in the elevation of lipid peroxidation levels at 2 and 10 days, respectively, after irradiation.

Three-dimensional conformal reirradiation for locoregionally recurrent lung cancer previously treated with radiation therapy.

Background: To evaluate the efficacy and toxicity of reirradiation using three-dimensional conformal radiotherapy (3D-CRT) in symptomatic patients with locoregionally recurrent lung cancer.

Methods: Between 2005 and 2012, 15 patients with locoregionally recurrent lung cancer were retreated with 3D-CRT after previously receiving thoracic radiotherapy. The median interval between the initial irradiation and reirradiation was 12 months (range, five to 41 months).

The impact of respiratory gating on lung dosimetry in stereotactic body radiotherapy for lung cancer.

The purpose of this study was to evaluate the impacts of respiratory gating and different gating windows (GWs) on lung dosimetry in stereotactic body radiotherapy (SBRT) for lung cancer. Gated SBRT plans were developed using the four-dimensional computed tomography data from 17 lung cancer patients treated with SBRT. Using amplitude-based end-exhalation gating, we established 2 fixed GWs with approximate duty cycles of 50% (50% GW) and 25% (25% GW), respectively, for this study.

Reconstitution of internal target volumes by combining four-dimensional computed tomography and a modified slow computed tomography scan in stereotactic body radiotherapy planning for lung cancer.

Background: To evaluate the volumetric and geometric differences in the ITVs generated by four-dimensional (4D) computed tomography (CT), a modified slow CT scan, and a combination of these CT methods in lung cancer patients treated with stereotactic body radiotherapy (SBRT).

Methods: Both 4D CT and modified slow CT using a multi-slice CT scanner were performed for SBRT planning in 14 patients with 15 pulmonary targets. Volumetric and geometric analyses were performed for (1) ITVall, generated by combining the gross tumor volumes (GTVs) from all 8 phases of the 4D CT; (2) ITV2, generated by combining the GTVs from 2 extreme phases of the 4D CT; (3) ITVslow, derived from the GTV on the modified slow CT scan; (4) ITVall+slow, generated by combining ITVall and ITVslow; and (5) ITV2+slow, generated by combining ITV2 and ITVslow.

Melatonin reduces X-ray radiation-induced lung injury in mice by modulating oxidative stress and cytokine expression.

Purpose: The modification of radiation-induced lung injuries by melatonin was studied by measuring changes in oxidative stress, cytokine expression and histopathology in the lung tissue of mice following irradiation.

Materials And Methods: The thoraces of C57BL/6 mice were exposed to a single X-ray radiation dose of 12 Gy with or without 200 mg/kg of melatonin pretreatment. The level and localization of transforming growth factor (TGF)-β1 protein were measured using an enzyme-linked immunosorbent assay (ELISA) method and immunohistochemical staining, respectively.

Prognostic significance of human apurinic/apyrimidinic endonuclease (APE/Ref-1) expression in rectal cancer treated with preoperative radiochemotherapy.

Purpose: Human apurinic endonuclease/redox factor 1 (APE/Ref-1) mediates repair of radiation-induced DNA lesions and regulates transcription via redox-based activation. We investigated the predictive and prognostic significance of APE/Ref-1 expression in pretreatment biopsy specimens in locally advanced rectal cancer (LARC) (cT3-T4 or N+).

Methods And Materials: APE/Ref-1 expression was analyzed by immunohistochemistry in pretreatment biopsy specimens obtained from 83 patients with LARC.