Examining electrometer performance checks with direct-current generator in a clinic: Assessment of generated charges and implementation of electrometer checks.

Purpose: Medical physicists use a suitable detector connected to an electrometer to measure radiotherapy beams. Each detector and electrometer has a lifetime (due to physical deterioration of detector components and electrical characteristic deterioration in electronic electrometer components), long-term stability [according to IEC 60731:2011, ≤0.5% (reference-class dosimeter)], and calibration frequency [according to Muir et al.

Uncertainty in positioning ion chamber at reference depth for various water phantoms.

Background: Uncertainty in the calibration of high-energy radiation sources is dependent on user and equipment type.

Aim: We evaluated the uncertainty in the positioning of a cylindrical chamber at a reference depth for reference dosimetry of high-energy photon beams and the resulting uncertainty in the chamber readings for 6- and 10-MV photon beams. The aim was to investigate major contributions to the positioning uncertainty to reduce the uncertainty in calibration for external photon beam radiotherapy.

Evaluation of obliteration of arteriovenous malformations after stereotactic radiosurgery with arterial spin labeling MR imaging.

Purpose: Complete obliteration of treated arteriovenous malformations (AVMs) can be diagnosed only by confirming the disappearance of arterio-venous (A-V) shunts with invasive catheter angiography. The authors evaluated whether non-invasive arterial spin labeling (ASL) magnetic resonance (MR) imaging can be used to diagnose the obliteration of AVMs facilitate the diagnosis of AVM obliteration after treatment with stereotactic radiosurgery (SRS).

Material And Methods: Seven patients with a cerebral AVM treated by SRS were followed up with ASL images taken with a 3T-MR unit, and received digital subtraction angiography (DSA) after the AVM had disappeared on ASL images.

Comparison of AAPM Addendum to TG-51, IAEA TRS-398, and JSMP 12: Calibration of photon beams in water.

The American Association of Physicists in Medicine (AAPM) Working Group on TG-51 published an Addendum to the AAPM's TG-51 protocol (Addendum to TG-51) in 2014, and the Japan Society of Medical Physics (JSMP) published a new dosimetry protocol JSMP 12 in 2012. In this study, we compared the absorbed dose to water determined at the reference depth for high-energy photon beams following the recommendations given in AAPM TG-51 and the Addendum to TG-51, IAEA TRS-398, and JSMP 12. This study was performed using measurements with flattened photon beams with nominal energies of 6 and 10 MV.

Long-Term Endoscopic Follow-Up of Patients with Chronic Radiation Proctopathy after Brachytherapy for Prostate Cancer.

Background. Chronic radiation proctopathy (CRP) is late toxicity and associated with morbidity. Aim.

Alpha 1-adrenoceptor blocker may improve not only voiding but also storage lower urinary tract symptoms caused by (125) I brachytherapy for prostate cancer.

Purpose. To assess changes in lower urinary tract symptoms (LUTS) within 1 year after brachytherapy in patients receiving alpha 1-adrenoceptor antagonists. Methods.

Arterial spin labeling perfusion-weighted MRI for long-term follow-up of a cerebral arteriovenous malformation after stereotactic radiosurgery.

We present a longitudinal series of arterial spin-labeling magnetic resonance imaging (ASL-MRI) in a patient with cerebral arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (SRS). Pretreatment ASL-MRI showed high signal intensity in both the nidus and draining veins, and the latter signal abnormality gradually moved proximally by 14 months after SRS. At 24 months, the signal abnormalities finally disappeared, indicating complete obliteration of the nidus.

Monitoring of extra-axial brain tumor response to radiotherapy using pseudo-continuous arterial spin labeling images: preliminary results.

Introduction: Technological developments have increased the ease of performing perfusion MRI by arterial spin labeling (ASL) in clinical settings. The objective of this study was to evaluate the effects of radiotherapy on extra-axial brain tumors by using MR perfusion images obtained using the pseudo-continuous arterial spin labeling (pcASL) method.

Materials And Methods: Six consecutive patients (nine lesions) with extra-axial brain tumors treated only with radiotherapy were enrolled in this study.

Thermosensitization and induction of apoptosis or cell-cycle arrest via the MAPK cascade by parthenolide, an NF-κB inhibitor, in human prostate cancer androgen-independent cell lines.

Parthenolide (PTL), a nuclear factor-κB (NF-κB) inhibitor, has a significant thermo-enhancement effect. Modification of thermosensitivity by treatment with PTL prior to hyperthermia was investigated in the human prostate cancer androgen-independent cell lines PC3 and DU145. In addition, we analyzed the mechanisms related to induction of apoptosis or G₂/M cell-cycle arrest via the effects of ERK1/2, p38 and SAPK/JNK signaling on mitogen-activated protein kinase (MAPK).

Inhibition of NF-kappaB by combination therapy with parthenolide and hyperthermia and kinetics of apoptosis induction and cell cycle arrest in human lung adenocarcinoma cells.

We investigated the mechanisms of thermosensitization related to combination therapy with sesquiterpene lactone parthenolide (PTL), a nuclear factor-kappaB (NF-kappaB) inhibitor, and hyperthermia using human lung adenocarcinoma cells A549. The kinetics of apoptosis induction and cell cycle of cells treated with PTL, heating, and combined treatment were examined by flow cytometric analysis. The flow cytometric distribution was calculated and expressed as a percentage.

Thermosensitization by parthenolide in human lung adenocarcinoma A549 cells and p53- and hsp72-independent apoptosis induction via the nuclear factor-kappaB signal pathway.

The thermo-enhancement effects of the sesquiterpene lactone parthenolide (PTL), which targets the transcription factor nuclear factor-kappaB (NF-kappaB), and hyperthermia at 40, 42 and 44 degrees C on the human lung adenocarcinoma A549 cell line were investigated in vitro. Thermotherapy using a combined treatment with PTL (0.02 microM) prior to hyperthermia showed synergistic thermo-enhancement effects towards A549 cells.

Neurocognitive function of patients with brain metastasis who received either whole brain radiotherapy plus stereotactic radiosurgery or radiosurgery alone.

Purpose: To determine how the omission of whole brain radiotherapy (WBRT) affects the neurocognitive function of patients with one to four brain metastases who have been treated with stereotactic radiosurgery (SRS).

Methods And Materials: In a prospective randomized trial between WBRT+SRS and SRS alone for patients with one to four brain metastases, we assessed the neurocognitive function using the Mini-Mental State Examination (MMSE). Of the 132 enrolled patients, MMSE scores were available for 110.

Enhancement of radiosensitivity by topoisomerase II inhibitor, amrubicin and amrubicinol, in human lung adenocarcinoma A549 cells and kinetics of apoptosis and necrosis induction.

The effects of amrubicin (AMR) and its active metabolite, amrubicinol (AMROH), on the sensitivity of human lung adenocarcinoma A549 cells to ionizing radiation were investigated in vitro. Further, the kinetics of apoptosis and necrosis induction were also analyzed. The cytocidal effects of X-ray irradiation on A549 cells resulted in a low level of radiosensitivity with a D0 value of 12 Gy.

Stereotactic radiosurgery plus whole-brain radiation therapy vs stereotactic radiosurgery alone for treatment of brain metastases: a randomized controlled trial.

Context: In patients with brain metastases, it is unclear whether adding up-front whole-brain radiation therapy (WBRT) to stereotactic radiosurgery (SRS) has beneficial effects on mortality or neurologic function compared with SRS alone.

Objective: To determine if WBRT combined with SRS results in improvements in survival, brain tumor control, functional preservation rate, and frequency of neurologic death.

Design, Setting, And Patients: Randomized controlled trial of 132 patients with 1 to 4 brain metastases, each less than 3 cm in diameter, enrolled at 11 hospitals in Japan between October 1999 and December 2003.

Modification of thermosensitivity by amrubicin or amrubicinol in human lung adenocarcinoma A549 cells and the kinetics of apoptosis and necrosis induction.

The effects of amrubicin (AMR) and its active metabolite, amrubicinol (AMROH), on the sensitivity of human lung adenocarcinoma A549 cell line to hyperthermia at 44 degrees C were investigated. The cell phase response as well as the kinetics of apoptosis and necrosis induction were also analyzed. The cytocidal effects of 44 degrees C hyperthermia on A549 cells exhibited low thermosensitivity with a T(0) value of 12 min.

P53-independent thermosensitization by mitomycin C in human non-small-cell lung cancer cells.

Purpose: To elucidate the relationship between p53 functions and the interactive effects of the combined treatment with mild hyperthermia and mitomycin C.

Methods And Materials: p53-deficient human non-small-cell lung cancer H1299 cells were transfected with a vector carrying a neomycin-resistant gene (neo) or together with a wild-type or mutant p53 gene. Sensitivities of these transfectants to mild hyperthermia at 42 degrees C, mitomycin C (0.

[Clinical results of LINAC-based stereotactic radiosurgery for pituitary adenoma].

Purpose: We retrospectively evaluated our clinical results of stereotactic radiosurgery (SRS) for pituitary adenoma.

Materials And Methods: Between 1995 and 2000, 13 patients were treated with SRS for pituitary adenoma. In all cases, the tumors had already been surgically resected.

Effects of combined treatment with 40 degrees C hyperthermia and bleomycin on the accumulation of heat shock protein in murine L cells.

Our research group has reported the enhanced cytotoxicity of combined treatment with bleomycin (BLM) and low hyperthermia at 40 degrees C, using murine L cells, and suggested that post-heating could inhibit BLM-induced sublethal damage repair. For further understanding of the involved mechanisms, we subsequently investigated the kinetics of the cellular accumulations of inducible 72-kDa heat shock protein (hsp72) after 40 degrees C hyperthermia and/or BLM treatment using the same cell line. Western blot analysis showed significantly enhanced accumulation of hsp72 after a low hyperthermia at 40 degrees C for 40, 105 or 180 min, and no significant enhancement of it after exposure to 10 microg/ml BLM at 37 degrees C for either 40 or 105 min.