Nationwide multi-institutional retrospective analysis of high-dose-rate brachytherapy combined with external beam radiotherapy for localized prostate cancer: An Asian Prostate HDR-BT Consortium.

Purpose: To report outcomes and risk factors of high-dose-rate (HDR) brachytherapy combined with external beam radiotherapy with or without androgen deprivation therapy (ADT) in prostate cancer patients.

Materials And Methods: This multi-institutional retrospective analysis comprised 3424 patients with localized prostate cancer at 16 Asian hospitals. One-thirds (27.

Three-dimensional conformal arc radiotherapy using a C-arm linear accelerator with a computed tomography on-rail system for prostate cancer: clinical outcomes.

Background: We report the feasibility and treatment outcomes of image-guided three-dimensional conformal arc radiotherapy (3D-CART) using a C-arm linear accelerator with a computed tomography (CT) on-rail system for localized prostate cancer.

Methods And Materials: Between 2006 and 2011, 282 consecutive patients with localized prostate cancer were treated with in-room CT-guided 3D-CART. Biochemical failure was defined as a rise of at least 2.

NUT Midline Carcinoma in Elderly Patients: Usefulness of 18F-FDG PET/CT for Treatment Assessment.

Nuclear protein in testis (NUT) midline carcinoma is a rare disease that generally arises in adolescents and young adults. However, we encountered a rare NUT midline carcinoma case in an elderly patient. F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (PET/CT) studies were performed before and during the treatment course.

[Additional external radiotherapy to multiple metastases originating from thymic neuroendocrine tumor following peptide receptor radionuclide therapy: a case report].

We describe the case of a 60-year-old man suffering from an advanced thymic neuroendocrine tumor with left supraclavicular lymph node and multiple bone metastases. The patient initially underwent systemic therapy with somatostatin analogues. Thereafter, peptide receptor radionuclide therapy (PRRT) was considered because the lesions had remained stable despite the pharmacological therapy.

Surgical therapy and chemoradiotherapy for postoperative recurrent esophageal cancer.

Background/aims: A retrospective analysis of therapeutic modalities used in postoperative recurrent esophageal cancer.

Methodology: Among 43 esophageal cancer patients who underwent esophagectomy between 2003 and 2010, recurrence was found in 15. Best supportive care was given to two patients and another patient was referred to another hospital.

Converging stereotactic radiotherapy using kilovoltage X-rays: experimental irradiation of normal rabbit lung and dose-volume analysis with Monte Carlo simulation.

Purpose: To validate the feasibility of developing a radiotherapy unit with kilovoltage X-rays through actual irradiation of live rabbit lungs, and to explore the practical issues anticipated in future clinical application to humans through Monte Carlo dose simulation.

Methods And Materials: A converging stereotactic irradiation unit was developed, consisting of a modified diagnostic computed tomography (CT) scanner. A tiny cylindrical volume in 13 normal rabbit lungs was individually irradiated with single fractional absorbed doses of 15, 30, 45, and 60 Gy.

Extrapulmonary soft-tissue fibrosis resulting from hypofractionated stereotactic body radiotherapy for pulmonary nodular lesions.

Purpose: To clarify the incidence, symptoms, and timing of extrapulmonary fibrosis developing after hypofractionated stereotactic body radiotherapy.

Patients And Methods: We analyzed 379 consecutive patients who underwent stereotactic body radiotherapy for lung tumors at four institutions between February 2001 and March 2007. The median follow-up time was 29 months (range, 1-72).

Intense accumulation of Tc-99m MDP in pericardial metastasis from breast cancer.

Extraosseous uptake often seen on Tc-99m methylene diphosphonate bone scintigraphy has clinical significance. In a routine follow-up study on a 54-year-old female patient with breast cancer, we encountered a rare finding of pericardial metastasis clearly demonstrated by Tc-99m methylene diphosphonate bone scintigraphy. This incidental finding of increased uptake in the periphery of the cardiac contour on a bone scan reflects radionuclide accumulation in pericardium, myocardium, or pericardial effusion itself.

Experimental stereotactic irradiation of normal rabbit lung: computed tomographic analysis of radiation injury and the histopathological features.

Purpose: The aim of this study was to establish an animal experimental model of pulmonary stereotactic irradiation and clarify the morphological patterns of pulmonary radiation injury with computed tomography and the histopathological features.

Materials And Methods: Tiny spherical regions in the lungs of seven anesthetized rabbits were irradiated stereotactically with a single fractional dose of 21-60 Gy. Subsequently, the irradiated lungs were observed biweekly with computed tomography (CT) for 24 weeks.

Differences in the definition of internal target volumes using slow CT alone or in combination with thin-slice CT under breath-holding conditions during the planning of stereotactic radiotherapy for lung cancer.

Purpose: To investigate how the delineations of the internal target volume (ITV) made from 'slow' CT alter with reference to 'thin-slice' CT.

Materials And Methods: Thin-slice CT images taken under breath-holding conditions and slow CT images taken under shallow-breathing conditions (8s/image) of 11 lung cancers were used for this study. Five radiation oncologists delineated ITV of the 11 lesions using slow CT images (ITV1), and then redefined them with reference to thin-slice CT images (ITV2).

Interface software for DOSXYZnrc Monte Carlo dose evaluation on a commercial radiation treatment planning system.

Purpose: As the conventional graphical user interface (GUI) associated with DOSXYZnrc or BEAMnrc is unable to define specific structures such as gross tumor volume (GTV) on computed tomography (CT) data, the quantitative analysis of doses in the form of dose-volume histograms (DVHs) is difficult. The purpose of this study was to develop an interface that enables us to analyze the results of DOSXYZnrc output with a commercial radiation treatment planning (RTP) system and to investigate the validity of the system.

Materials And Methods: Interface software to visualize three-dimensional radiotherapy Monte Carlo (MC) dose data from DOSXYZnrc on the XiO RTP system was developed.

Investigations of different kilovoltage X-ray energy for three-dimensional converging stereotactic radiotherapy system: Monte Carlo simulations with CT data.

We are investigating three-dimensional converging stereotactic radiotherapy (3DCSRT) with suitable medium-energy x rays as treatment for small lung tumors with better dose homogeneity at the target. A computed tomography (CT) system dedicated for non-coplanar converging radiotherapy was simulated with BEAMnrc (EGS4) Monte-Carlo code for x-ray energy of 147.5, 200, 300, and 500 kilovoltage (kVp).

Rotational and translational reproducibility of newly developed Leksell frame-based relocatable fixation system.

Purpose: The aim of this study was to evaluate three-dimensional movement of the cranium in a relocatable frame using positions of anatomical landmarks obtained from repeated quality-assurance (QA) computed tomography (CT) studies.

Materials And Methods: We analyzed 17 series of QA-CT data representing five patients who underwent stereotactic radiotherapy for treatment of acoustic neurinoma. Helical-CT scans with 1-mm collimation were obtained at the time of treatment planning and during the course of treatment.

Small lung tumors: long-scan-time CT for planning of hypofractionated stereotactic radiation therapy--initial findings.

Purpose: To prospectively use long-scan-time computed tomography (CT) to visualize the trajectory of tumor movements or the internal target volume.

Materials And Methods: The study was approved by the institutional review board. Written informed consent was obtained from participants after the study and the role of procedures were explained fully.

Effects of density changes in the chest on lung stereotactic radiotherapy.

To experimentally and theoretically evaluate dose distribution during lung stereotactic radiotherapy, we investigated the relative electron densities in lung and tumor tissues using X-ray computed tomography images obtained from 30 patients in three breathing states: free breathing, inspiration breath-hold, and expiration breath-hold. We also calculated dose distribution using Monte Carlo simulation for lung tissue with two relative electron densities. The effect of changes in relative electron density on dose distribution in lung tissue was evaluated using calculated differential and integral dose volume histograms.

Measurement of beam-axis displacement from the isocenter during three-dimensional conformal radiosurgery with a micro-multileaf collimator.

We describe the displacement of the beam-axis from the planning isocenter in clinical situations during three-dimensional conformal radiosurgery using an Acculeaf bi-directional micro-multileaf collimator. The displacements were recorded for 64 ports using a video imaging system and a stereotactic arc. The mean displacement was 0.

Monitoring of response to radiation therapy for human tumor xenografts using 99mTc-HL91 (4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime).

Purpose: Oxygenation status of tumor tissue is an important factor to discriminate it with respect to its radiosensitivity. 99mTc-4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime (99mTc-HL91) is retained in hypoxic tissues, making it possible to use it as hypoxic imaging agent. We evaluated if the accumulation of 99mTc-HL91 in tumors could aid in the prediction of sensitivity of radiation therapy of cancers.