Organ-specific response to [Lu]DOTATATE peptide receptor radionuclide therapy (PRRT) assessed by sequential [Ga]DOTATOC PET/CT in patients with metastatic small intestine neuroendocrine tumors.

Purpose: To evaluate organ-specific response to [Lu]DOTATATE Peptide Receptor Radionuclide Therapy (PRRT) in patients with small intestine neuroendocrine tumor (SiNET) through [Ga]DOTATOC PET/CT, and to analyze tumor uptake and functional volume variations at different metastatic sites in relation to disease progression during clinical follow-up after treatment.

Methods: A retrospective analysis was conducted on 33 metastatic patients. PET/CT were performed pre-treatment (PET0), mid-treatment after two PRRT cycles (PET2), and post-treatment (PET4).

Acute Kidney Injury During Hospitalization Increases the Risk of VTE.

Background: Kidney disease has been linked to risk for hospitalization-related (HR) VTE, but the effect size and differences across types of kidney disease are described poorly.

Research Question: Can the risk for HR VTE among patients with acute kidney injury (AKI) and chronic kidney disease be quantified, and if so, how?

Study Design And Methods: We prospectively collected data on hospitalized adult patients and documented HR VTE events. We recorded creatinine clearance (CrCl) daily throughout hospitalization and modeled the effects that admission CrCl, peak CrCl, average CrCl, and AKI had on HR VTE.

Pulmonary function changes following helical tomotherapy in patients with inoperable, locally advanced non-small cell lung cancer.

Purpose: To evaluate alterations in pulmonary function indices after helical tomotherapy and explore potential associations with biologically corrected dosimetric parameters.

Patients And Methods: In 64 patients with inoperable locally advanced non-small cell lung cancer, pulmonary function tests before and within 6 months after radiotherapy were evaluated retrospectively. In the case of concurrent chemotherapy a total dose of 67.

The METABANK score: A clinical tool to predict survival after stereotactic radiotherapy for oligometastatic disease.

Background And Purpose: Stereotactic radiotherapy (SRT, SBRT) is widely used in oligometastatic cancer, but the heterogeneity of the population complicates estimation of the prognosis. We investigated the role of different clinical and inflammatory parameters.

Materials And Methods: We included all patients treated with SRT for 1-5 oligometastases between 2003 and 2017 in our center.

The long- and short-term variability of breathing induced tumor motion in lung and liver over the course of a radiotherapy treatment.

Purpose: To evaluate the short and long-term variability of breathing induced tumor motion.

Materials And Methods: 3D tumor motion of 19 lung and 18 liver lesions captured over the course of an SBRT treatment were evaluated and compared to the motion on 4D-CT. An implanted fiducial could be used for unambiguous motion information.

Treating patients with Dynamic Wave Arc: First clinical experience.

Background And Purpose: Dynamic Wave Arc (DWA) is a system-specific noncoplanar arc technique that combines synchronized gantry-ring rotation with D-MLC optimization. This paper presents the clinical workflow, quality assurance program, and reports the geometric and dosimetric results of the first patient cohort treated with DWA.

Methods And Materials: The RayStation TPS was clinically integrated on the Vero SBRT platform for DWA treatments.

Motion management during SBRT for oligometastatic cancer: Results of a prospective phase II trial.

Purpose: To optimize the local control of stereotactic body radiotherapy (SBRT) using the Vero-SBRT system and respiratory motion management in patients with oligometastatic cancer.

Materials And Methods: Patients with five or less metastases were eligible. In metastases with significant motion, a fiducial was implanted for Vero dynamic tracking.

Initial characterization, dosimetric benchmark and performance validation of Dynamic Wave Arc.

Background: Dynamic Wave Arc (DWA) is a clinical approach designed to maximize the versatility of Vero SBRT system by synchronizing the gantry-ring noncoplanar movement with D-MLC optimization. The purpose of this study was to verify the delivery accuracy of DWA approach and to evaluate the potential dosimetric benefits.

Methods: DWA is an extended form of VMAT with a continuous varying ring position.

Feasibility of markerless tumor tracking by sequential dual-energy fluoroscopy on a clinical tumor tracking system.

A novel approach to dual-energy imaging for markerless tumor tracking was proposed consisting of sequential dual-energy fluoroscopy, omitting the need for fast-switching kV generators. The implementation of this approach on a clinical tumor tracking system and its efficacy is shown feasible through optimization of the imaging parameters.

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy.

Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable risks for normal tissue injury and the hazards of physical tumor miss. A first-of-its-kind SBRT platform achieves high-precision ablative radiation treatment through a combination of versatile real-time imaging solutions and sophisticated tumor tracking capabilities. It uses dual-diagnostic kV x-ray units for stereoscopic open-loop feedback of cancer target intrafraction movement occurring as a consequence of respiratory motions and heartbeat.

A multi-centre analysis of treatment procedures and error components in dynamic tumour tracking radiotherapy.

Purpose: This study aimed to compare procedures for dynamic tumour tracking (DTT) using a gimbal-mounted linac between centres in Japan (KU-IBRI) and Belgium (UZB), to quantify tracking error (TE), and to estimate tumour-fiducial uncertainties and PTV margins.

Methods: Twenty-two patients were evaluated. TE was divided into components originating from the patient, fraction, segment, and residuals.

Improving the intra-fraction update efficiency of a correlation model used for internal motion estimation during real-time tumor tracking for SBRT patients: fast update or no update?

Background And Purpose: For tumor tracking, a correlation model is used to estimate internal tumor position based on external surrogate motion. When patients experience an internal/external surrogate drift, an update of the correlation model is required to continue tumor tracking. In this study, the accuracy of the internal tumor position estimation for both the clinical available update at discrete points in time (rebuild) and an in-house developed non-clinical online update approach was investigated.

Phase II study of stereotactic body radiotherapy to primary tumor and metastatic locations in oligometastatic nonsmall-cell lung cancer patients.

Background: Stereotactic body radiotherapy (SBRT) has emerged as a treatment modality in patients presenting with oligometastatic nonsmall-cell lung cancer (NSCLC). SBRT is used as a local consolidative treatment to metastatic disease sites. The majority of patients included in SBRT trials for oligometastatic NSCLC have controlled primary tumors and brain metastases.

Treating patients with real-time tumor tracking using the Vero gimbaled linac system: implementation and first review.

Purpose: To report on the first clinical application of a real-time tumor tracking (RTTT) solution based on the Vero SBRT gimbaled linac system for treatment of moving tumors.

Methods And Materials: A first group of 10 SBRT patients diagnosed with NSCLC or oligometastatic disease in lung or liver was treated with the RTTT technique. The PTV volumes and OAR exposure were benchmarked against the widely used ITV approach.

A complementary dual-modality verification for tumor tracking on a gimbaled linac system.

Background And Purpose: For dynamic tracking of moving tumors, robust intra-fraction verification was required, to assure that tumor motion was properly managed during the course of radiotherapy. A dual-modality verification system, consisting of an on-board orthogonal kV and planar MV imaging device, was validated and applied retrospectively to patient data.

Methods And Materials: Real-time tumor tracking (RTTT) was managed by applying PAN and TILT angular corrections to the therapeutic beam using a gimbaled linac.

Initial assessment of tumor tracking with a gimbaled linac system in clinical circumstances: a patient simulation study.

Purpose: To have an initial assessment of the Vero Dynamic Tracking workflow in clinical circumstances and quantify the performance of the tracking system, a simulation study was set up on 5 lung and liver patients.

Methods And Materials: The preparatory steps of a tumor tracking treatment, based on fiducial markers implanted in the tumor, were executed allowing pursuit of the tumor with the gimbaled linac and monitoring X-rays acquisition, however, without activating the 6 MV beam. Data were acquired on workflow time-efficiency, tracking accuracy and imaging exposure.

Dosimetric comparison of different treatment modalities for stereotactic radiosurgery of arteriovenous malformations and acoustic neuromas.

Purpose: We investigated the influence of beam modulation on treatment planning by comparing four available stereotactic radiosurgery (SRS) modalities: Gamma-Knife-Perfexion, Novalis-Tx Dynamic-Conformal-Arc (DCA) and Dynamic-Multileaf-Collimation-Intensity-Modulated-radiotherapy (DMLC-IMRT), and Cyberknife.

Material And Methods: Patients with arteriovenous malformation (n = 10) or acoustic neuromas (n = 5) were planned with different treatment modalities. Paddick conformity index (CI), dose heterogeneity (DH), gradient index (GI) and beam-on time were used as dosimetric indices.

Single fraction versus fractionated linac-based stereotactic radiotherapy for vestibular schwannoma: a single-institution experience.

Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT).

Methods And Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator.

Setup accuracy of the Novalis ExacTrac 6DOF system for frameless radiosurgery.

Purpose: Stereotactic radiosurgery using frame-based positioning is a well-established technique for the treatment of benign and malignant lesions. By contrast, a new trend toward frameless systems using image-guided positioning techniques is gaining mainstream acceptance. This study was designed to measure the detection and positioning accuracy of the ExacTrac/Novalis Body (ET/NB) for rotations and to compare the accuracy of the frameless with the frame-based radiosurgery technique.

Prospective, risk-adapted strategy of stereotactic body radiotherapy for early-stage non-small-cell lung cancer: results of a Phase II trial.

Purpose: Validation of a prospective, risk-adapted strategy for early-stage non-small-cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT).

Methods And Materials: Patients with a T1-3N0M0 (American Joint Committee on Cancer 6th edition) NSCLC were accrued. Using the Radiation Therapy Oncology Group definition, patients were treated to a total dose of 60,Gy in three fractions for peripherally located lesions and four fractions for centrally located lesions.

Volumetric imaging by megavoltage computed tomography for assessment of internal organ motion during radiotherapy for cervical cancer.

Purpose: To assess the internal organ motion of the cervix and uterus by megavoltage computed tomography (MVCT) during intensity-modulated radiotherapy (IMRT).

Methods And Materials: Ten patients with Stage IIB-IVA cervical cancer underwent daily MVCT imaging. Internal organ motion was evaluated on 150 pretreatment MVCT images by measuring shifts in their boundaries between the MVCT and kilovoltage (kV) planning CT scan in the anterior, posterior, left and right lateral, and superior and inferior direction.

Toxicity report of a phase 1/2 dose-escalation study in patients with inoperable, locally advanced nonsmall cell lung cancer with helical tomotherapy and concurrent chemotherapy.

Background: The objective of the current study was to evaluate the feasibility and toxicity of radiation dose escalation with concurrent chemotherapy using helical tomotherapy (HT) in patients with inoperable, locally advanced, stage III nonsmall cell lung cancer (LANSCLC) (grading determined according to the American Joint Committee on Cancer 6th edition grading system).

Methods: This phase 1/2 study was designed to determine the maximum tolerated dose (MTD) of radiotherapy in patients with LANSCLC administered concurrently with docetaxel and cisplatin. Radiotherapy was delivered using HT.