Assessment of treatment response after lung stereotactic body radiotherapy using diffusion weighted magnetic resonance imaging and positron emission tomography: A pilot study.

Background And Purpose: There is no early predictor of treatment response after lung stereotactic body radiotherapy (SBRT). We conducted this pilot study to evaluate whether serial diffusion weighted magnetic resonance imaging (DW-MRI) or positron emission tomography (PET) could predict response after SBRT.

Material And Methods: Early stage non-small cell lung cancer patients who received SBRT were eligible.

Three-dimensional intrafractional internal target motions in accelerated partial breast irradiation using three-dimensional conformal external beam radiotherapy.

Purpose: We evaluated three-dimensional intrafractional target motion, divided into respiratory-induced motion and baseline drift, in accelerated partial breast irradiation (APBI).

Methods: Paired fluoroscopic images were acquired simultaneously using orthogonal kV X-ray imaging systems at pre- and post-treatment for 23 patients who underwent APBI with external beam radiotherapy. The internal target motion was calculated from the surgical clips placed around the tumour cavity.

Impact of sampling interval in training data acquisition on intrafractional predictive accuracy of indirect dynamic tumor-tracking radiotherapy.

Purpose: To explore the effect of sampling interval of training data acquisition on the intrafractional prediction error of surrogate signal-based dynamic tumor-tracking using a gimbal-mounted linac.

Materials And Methods: Twenty pairs of respiratory motions were acquired from 20 patients (ten lung, five liver, and five pancreatic cancer patients) who underwent dynamic tumor-tracking with the Vero4DRT. First, respiratory motions were acquired as training data for an initial construction of the prediction model before the irradiation.

Development of a four-dimensional Monte Carlo dose calculation system for real-time tumor-tracking irradiation with a gimbaled X-ray head.

Purpose: To develop a four-dimensional (4D) dose calculation system for real-time tumor tracking (RTTT) irradiation by the Vero4DRT.

Methods: First, a 6-MV photon beam delivered by the Vero4DRT was simulated using EGSnrc. A moving phantom position was directly measured by a laser displacement gauge.

Long-term outcomes of intensity-modulated radiotherapy following extra-pleural pneumonectomy for malignant pleural mesothelioma.

Background: The purpose was to evaluate safety and efficacy of intensity-modulated radiotherapy (IMRT) following extra-pleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM).

Material And Methods: Patients with MPM of clinical stage I-III, which were macroscopic completely resected with EPP were eligible for this prospective study. The ipsilateral hemithorax was irradiated with a prescribed dose of 50.

Development of a four-axis moving phantom for patient-specific QA of surrogate signal-based tracking IMRT.

Purpose: The purposes of this study were two-fold: first, to develop a four-axis moving phantom for patient-specific quality assurance (QA) in surrogate signal-based dynamic tumor-tracking intensity-modulated radiotherapy (DTT-IMRT), and second, to evaluate the accuracy of the moving phantom and perform patient-specific dosimetric QA of the surrogate signal-based DTT-IMRT.

Methods: The four-axis moving phantom comprised three orthogonal linear actuators for target motion and a fourth one for surrogate motion. The positional accuracy was verified using four laser displacement gauges under static conditions (±40 mm displacements along each axis) and moving conditions [eight regular sinusoidal and fourth-power-of-sinusoidal patterns with peak-to-peak motion ranges (H) of 10-80 mm and a breathing period (T) of 4 s, and three irregular respiratory patterns with H of 1.

Efficacy of Ifosfamide-Cisplatin-Etoposide (ICE) Chemotherapy for a CNS Germinoma in a Child With Down Syndrome.

Intracranial germ cell tumor is sometimes associated with Down syndrome; however, no optimal treatment has been developed due to the high risk of recurrence and treatment-related mortality. Here, we report on a patient with an intracranial germinoma in the bilateral basal ganglia. The patient received 3 courses of ifosfamide-cisplatin-etoposide in combination with whole-brain irradiation (24 Gy), with no serious complications.

The accuracy of extracted target motion trajectories in four-dimensional cone-beam computed tomography for lung cancer patients.

Purpose: To quantify the accuracy of extracted target motion trajectories in dual-source four-dimensional cone-beam computed tomography (4D-CBCT) by comparison with the actual three-dimensional (3D) target motion acquired simultaneously during 4D-CBCT scan.

Materials And Methods: 4D-CBCT scans were performed for 19 different sinusoidal-like patterns and 13 lung cancer patients with implanted markers. Internal (In) or external (Ex) surrogates with amplitude (Amp)- or phase (Ph)-based sorting were used for the reconstructions.

Difference in dose-volumetric data between the analytical anisotropic algorithm, the dose-to-medium, and the dose-to-water reporting modes of the Acuros XB for lung stereotactic body radiation therapy.

The purpose of this study was to evaluate the difference in dose-volumetric data between the analytical anisotropic algorithms (AAA) and the two dose reporting modes of the Acuros XB, namely, the dose to water (AXB_Dw) and dose to medium (AXB_Dm) in lung stereotactic body radiotherapy (SBRT). Thirty-eight plans were generated using the AXB_Dm in Eclipse Treatment Planning System (TPS) and then recalculated with the AXB_Dw and AAA, using identical beam setup. A dose of 50 Gy in 4 fractions was prescribed to the isocenter and the planning target volume (PTV) D95%.

Dosimetric comparison of lung stereotactic body radiotherapy treatment plans using averaged computed tomography and end-exhalation computed tomography images: Evaluation of the effect of different dose-calculation algorithms and prescription methods.

The purpose of this article is to quantitatively evaluate differences in dose distributions calculated using various computed tomography (CT) datasets, dose-calculation algorithms, and prescription methods in stereotactic body radiotherapy (SBRT) for patients with early-stage lung cancer. Data on 29 patients with early-stage lung cancer treated with SBRT were retrospectively analyzed. Averaged CT (Ave-CT) and expiratory CT (Ex-CT) images were reconstructed for each patient using 4-dimensional CT data.

A surveillance study of the current status of reirradiation and patterns of practice.

The aim of this study was to survey the current status of reirradiation (Re-RT) and patterns of practice in Japan. An email questionnaire was sent to Kansai Cancer Therapist Group partner institutions, using questions similar to those in the Canadian radiation oncologist (RO) survey (2008). A total of 34 ROs from 28 institutions returned the survey.

Technical Note: Introduction of variance component analysis to setup error analysis in radiotherapy.

Purpose: The purpose of this technical note is to introduce variance component analysis to the estimation of systematic and random components in setup error of radiotherapy.

Methods: Balanced data according to the one-factor random effect model were assumed.

Results: Analysis-of-variance (anova)-based computation was applied to estimate the values and their confidence intervals (CIs) for systematic and random errors and the population mean of setup errors.

Comparative evaluation of respiratory-gated and ungated FDG-PET for target volume definition in radiotherapy treatment planning for pancreatic cancer.

Objective: The purpose of this study was to evaluate the usefulness of respiratory-gated positron emission tomography (4D-PET) in pancreatic cancer radiotherapy treatment planning (RTTP).

Materials And Methods: Fourteen patients with 18F-fluorodeoxyglucose (FDG)-avid pancreatic tumours were evaluated between December 2013 and March 2015. Two sets of volumes were contoured for the pancreatic tumour of each patient.

Long-term complications of definitive chemoradiotherapy for esophageal cancer using the classical method.

Chemoradiation therapy is widely used to treat both inoperable and operable patients, and is less invasive than surgery. Although the number of long-term survivors who have received chemoradiation therapy is increasing, the long-term toxicity pattern and cumulative incidence of toxicity regarding this modality are poorly understood. Classically, chemoradiation therapy for esophageal cancer consists of an anterior-posterior field and a subsequent oblique boost field.

Feasibility evaluation of hypofractionated radiotherapy with concurrent temozolomide in elderly patients with glioblastoma.

Background: Although hypofractionated radiotherapy (HFRT) is preferred to conventionally fractionated radiotherapy when treating elderly patients with glioblastoma, the benefits and tolerability of HFRT with concurrent temozolomide (TMZ) remain unknown for such patients. We assessed the feasibility and outcomes of elderly patients with glioblastoma treated with HFRT and concurrent TMZ.

Methods: We retrospectively reviewed the medical records of 11 patients aged ≥70 years who were treated with HFRT and concurrent TMZ.

Non-coplanar volumetric-modulated arc therapy (VMAT) for craniopharyngiomas reduces radiation doses to the bilateral hippocampus: a planning study comparing dynamic conformal arc therapy, coplanar VMAT, and non-coplanar VMAT.

Background: Recent studies suggest that radiation-induced injuries to the hippocampus play important roles in compromising neurocognitive functioning for patients with brain tumors and it could be important to spare the hippocampus using modern planning methods for patients with craniopharyngiomas. As bilateral hippocampus are located on the same level as the planning target volume (PTV) in patients with craniopharyngioma, it seems possible to reduce doses to hippocampus using non-coplanar beams. While the use of non-coplanar beams in volumetric-modulated arc therapy (VMAT) of malignant intracranial tumors has recently been reported, no dosimetric comparison has yet been made between VMAT using non-coplanar arcs (ncVMAT) and VMAT employing only coplanar arcs (coVMAT) among patients with craniopharyngiomas.

[Successful Treatment of Repeated Bilateral Middle Cerebral Artery Occlusion by Performing Mechanical Thrombectomy in a Patient with Trousseau Syndrome].

We report a patient with Trousseau syndrome who presented with repeated acute middle cerebral artery (MCA) occlusion, which was successfully treated by performing mechanical thrombectomy. A 66-year-old man with a lung lesion and abdominal lymph node swelling experienced a sudden onset of left hemiparesis. Magnetic resonance angiography (MRA) revealed a right MCA occlusion.

Rapid tumor growth with glial differentiation of central neurocytoma after stereotactic radiosurgery.

Although stereotactic radiosurgery (SRS) is effective for central neurocytoma (CN), the long-term outcome of SRS remains unclear. We present a case of recurrent CN that was diagnosed 10years after surgical resection and consecutive stereotactic radiotherapy. The patient was treated with SRS for the recurrent tumor, but underwent two-staged surgery once again due to rapid tumor growth.

Duplex-assisted carotid artery stenting without administration of contrast medium for patients with chronic kidney disease or allergic reaction.

Introduction: We aimed to investigate the safety and feasibility of duplex-assisted carotid artery stenting (CAS) without administration of contrast medium for the prevention of adverse reactions.

Methods: Fifteen patients (9 % of all CASs) with severe carotid stenosis (≥70 %) associated with chronic kidney disease (CKD) (stage ≥3) or allergy to contrast medium underwent duplex-assisted CAS without administration of contrast medium over 4 years. The procedural success rate and perioperative complication rates were compared between the duplex-assisted CAS (n = 15) and conventional CAS (n = 153) groups.

Multivariate analysis for the estimation of target localization errors in fiducial marker-based radiotherapy.

Purpose: To assess the target localization error (TLE) in terms of the distance between the target and the localization point estimated from the surrogates (|TMD|), the average of respiratory motion for the surrogates and the target (|aRM|), and the number of fiducial markers used for estimating the target (n).

Methods: This study enrolled 17 lung cancer patients who subsequently underwent four fractions of real-time tumor tracking irradiation. Four or five fiducial markers were implanted around the lung tumor.

Ten-year outcomes of intensity-modulated radiation therapy combined with neoadjuvant hormonal therapy for intermediate- and high-risk patients with T1c-T2N0M0 prostate cancer.

Background: We aimed to analyze the 10-year outcomes of intensity-modulated radiation therapy (IMRT) combined with neoadjuvant hormonal therapy (HT) for patients with intermediate- and high-risk T1c-T2N0M0 prostate cancer.

Methods: Fifty patients with T1c-T2N0M0 prostate cancer, who were treated with high-dose IMRT combined with neoadjuvant HT, were evaluated. Of these patients, 19 and 31 were classified into the intermediate- and high-risk groups, respectively.

Long-term stability assessment of a 4D tumor tracking system integrated into a gimbaled linear accelerator.

We assessed long-term stability of tracking accuracy using the Vero4DRT system. This metric was observed between September 2012 and March 2015. A programmable respiratory motion phantom, designed to move phantoms synchronously with respiratory surrogates, was used.

Pretreatment C-reactive protein level predicts outcome and patterns of failure after chemoradiotherapy for locally advanced pancreatic cancer.

Objectives: In this study we evaluated the predictive value of pretreatment C-reactive protein (CRP) levels on patterns of failure and survival outcomes in patients with locally advanced pancreatic cancer (LAPC) who received chemoradiotherapy (CRT).

Methods: Data from 65 patients who underwent CRT for LAPC from July 2001 to May 2013 were retrospectively collected. Factors, including age, gender, Eastern Cooperative Oncology Group performance status (PS), histological confirmation, tumor size, tumor location, biliary drainage, stage, induction chemotherapy, CRP levels, neutrophil-to-lymphocyte ratio, platelet-lymphocyte ratio, albumin and carbohydrate antigen 19-9, were evaluated with regard to overall survival (OS) and patterns of failure using a Cox proportional hazards model.