CyberKnife

Workforce modelling for Radiation Oncology Medical Physicists (ROMPs) is evolving and challenging, prompting the development of the 2021 Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM) ROMP Workforce (ARW) Model. In the exploration of this model at Sir Charles Gairdner Hospital, a comprehensive productivity exercise was conducted to obtain a detailed breakdown of ROMP time at a granular level. The results provide valuable insights into ROMP activities and enabled an evaluation of ARW Model calculations...

The prognosis of patients with hepatocellular carcinoma (HCC) is closely related to their liver reserves. The Child-Pugh (CP) score has traditionally been used to evaluate this reserve, with CP Grade B (CP score ≥ 7) associated with a higher risk of radiation-induced liver disease after stereotactic body radiation therapy (SBRT). However, the CP score has limitations, as it does not accurately assess liver reserve capacity. The albumin-bilirubin (ALBI) score has been introduced as a meticulous indicator of liver reserve for the treatment of HCC...

The primary late toxicity of radiosurgery treatment for trigeminal neuralgia (TN) is facial numbness due to trigeminal nerve dysfunction. Although most patients prefer loss of facial sensation to TN, severe loss of facial sensation can be debilitating. In order to try to obtain high pain control rates while minimizing the risk of late facial numbness, we elected to treat patients on the distal trigeminal nerve with a three-fraction regimen over consecutive days instead of one fraction. Our goal was to relieve the pain while also allowing the trigeminal nerve time to repair radiation damage between treatments in an attempt to minimize the risk of permanent facial numbness...

BACKGROUND AND PURPOSE: Motion management is essential to reduce normal tissue exposure and maintain adequate tumor dose in lung stereotactic body radiation therapy (SBRT). Lung SBRT using an articulated robotic arm allows dynamic tracking during radiation dose delivery. Two stereoscopic X-ray tracking modes are available - fiducial-based and fiducial-free tracking. Although X-ray detection of implanted fiducials is robust, the implantation procedure is invasive and inapplicable to some patients and tumor locations...

OBJECTIVES: To evaluate patient-specific quality assurance (PSQA) of 3 targets in a single delivery using a novel film-based phantom. METHODS: The phantom was designed to rotate freely as a sphere and could measure 3 targets with film in a single delivery. After identifying the coordinates of 3 targets in the skull, the rotation angles about the equator and meridian were computed for optimal phantom setup, ensuring the film plane intersected the 3 targets. The plans were delivered on the CyberKnife system using fiducial tracking...

OBJECTIVES: Deviations in haemostasis are found in about 50 % of patients with cancer and up to 90% of those with metastatic disease. Many studies investigate the dynamics of the processes of coagulation and fibrinolysis and their role as a predictor of therapeutic response, early relapse, or metastasis risk. BACKGROUND: To investigate the serum levels of urokinase plasminogen activator (uPA) in patients with brain metastases treated with robotic stereotactic radiosurgery (SRS) with CyberKnife...

BACKGROUND: CyberKnife treatment for central lung tumors and mediastinal tumors can be difficult to perform with marker less. PURPOSE: We aimed to evaluate a novel tracheobronchial-based method (ie, tracheobronchial tracking) for the purpose of minimally invasive CyberKnife treatment for central lung and mediastinal tumors. METHODS: Five verification plans were created using an in-house phantom. Each plan included five irradiation sessions...

OBJECTIVES: This study compared plans of high definition (HD), 2.5 mm width multi-leaf collimator (MLC), to standard, 5 mm width, isocentric linear accelerator (linacs), CyberKnife (CK), and Gamma Knife (GK) for stereotactic radiosurgery (SRS) techniques on multiple brain metastases. METHODS: Eleven patients undergoing SRS for multiple brain metastases were chosen. Targets and organs at risk (OARs) were delineated and optimized SRS plans were generated and compared...

There is considerable controversy about the management of arteriovenous malformations (AVMs) that are high risk for surgical resection. Stereotactic radiosurgery (SRS) has a reported success rate of less than 50% with unacceptably high rates of radiation necrosis with larger AVM volumes. Neither volume staging nor hypo-fractionated SRS have conclusively been demonstrated to improve results. We hypothesized that the failure of previous hypo-fractionation SRS trials was due to an insufficient biologically effective dose (BED) of radiation...

PURPOSE: This study aims to establish a robust dose prescription methodology in stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) for brain metastases, considering geometrical uncertainty and minimising dose
exposure to the surrounding normal brain tissue. METHODS AND MATERIALS: Treatment plans employing 40-90% isodose lines (IDL) at 10% IDL intervals were created for variously sized brain metastases. The plans were constructed to deliver 21 Gy in SRS...

PURPOSE: Stereotactic radiosurgery (SRS) has been increasingly used to treat intracranial pathologies in elderly patients. The treatment efficiency of SRS has been demonstrated in meningiomas, with excellent local control. We aimed to analyze the safety of robotic SRS in elderly patients with meningiomas. METHODS: We searched for patients with suspected WHO °I meningioma ≥ 60 years old, who underwent CyberKnife (CK) SRS from January 2011 to December 2021...

BACKGROUND: Stereotactic radiotherapy (SRT) and Proton therapy (PT) are both options in the management of liver lesions. Limited clinical-dosimetric comparison are available. Moreover, dose-constraint routinely used in liver PT and SRT considers only the liver spared, while optimization strategies to limit the liver damaged are poorly reported. METHODS: Primary endpoint was to assess and compare liver sparing of four contemporary RT techniques. Secondary endpoints were freedom from local recurrence (FFLR), overall survival (OS), acute and late toxicity...

PURPOSE: In CyberKnife® respiratory tracking, tumor positions are predicted from external marker positions using correlation models. With available models, prediction accuracy may deteriorate when respiratory motion baseline drifts occur. Previous investigations have demonstrated that for linear models this can be mitigated by adding a time-dependent term. In this study, we have focused on added value of time-dependent terms for the available non-linear correlation models, and on phase shifts between internal and external motion tracks...

A 39-year-old woman was diagnosed with right breast cancer(cT3N1M0, cStage ⅢA, triple negative type). After preoperative chemotherapy using dose-dense doxorubicin and cyclophosphamide, followed by dose-dense paclitaxel every 2 weeks, the patient underwent right modified radical mastectomy. Postmastectomy radiotherapy to the right chest wall and right supraclavicular area and oral capecitabine therapy were administered. Computed tomography 1 year after surgery showed multiple lung metastases. The patient received atezolizumab and nab-paclitaxel therapy...

PURPOSE: To compare the dosimetric quality of automatic multiple brain metastases planning (MBM) with that of Cyberknife (CK) based on the clinical tumor condition, such as the tumor number, size, and location. METHODS: 76 treatment plans for 46 patients treated with CK were recalculated with the MBM treatment planning system. Conformity index (CI), homogeneity index (HI), gradient index (GI), lesion underdosage volume factor (LUF), healthy tissue overdose volume factor (HTOF), geometric conformity index (g) and mean dose to normal organs were compared between CK and MBM for tumor number, size, shape and distance from the brainstem or chiasm...

Aim of this paper is to evaluate short and long-term changes in <mml:math xmlns:mml="https://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math> relaxation times after radiotherapy in patients with low and intermediate risk localized prostate cancer. A total of 24 patients were selected for this retrospective study. Each participant underwent 1.5T magnetic resonance imaging on seven separate occasions: initially after the implantation of gold fiducials, the required step for Cyberknife therapy guidance, followed by MRI scans two weeks post-therapy and monthly thereafter...

General radiotherapeutic management for >10 brain metastases (BMs) totaling >100 cm3 , including multiple large lesions (>10-30 cm3 ) in close proximity, demonstrated limited efficacy and/or safety. We describe a case of 12 BMs, summating 122.2 cm3 , including a 39.6 cm3 maximum lesion and adjacent ones. The patient had an 8.1-year treatment history for recurrent/metastatic breast cancer refractory to endocrine and chemotherapy. BMs were treated with conventional whole-brain radiotherapy (WBRT) with 30 Gy/10 fractions (fr), followed by an immediate stereotactic radiosurgery (SRS) boost with 27 Gy/5 fr (52-64% isodoses) which covers the gross tumor boundaries of selected eight lesions (total 118...

Single plan techniques for multiple brain targets (MBT) stereotactic radiosurgery (SRS) are now routine. Patient specific quality assurance (QA) for MBT poses challenges due to the limited capabilities of existing QA tools which necessitates several plan redeliveries. This study sought to develop an SRS QA phantom that enables flexible MBT patient specific QA in a single delivery, along with complex SRS commissioning. PLA marble and PLA StoneFil materials were selected based on the literature and previous research conducted in our department...

Diffuse large B-cell lymphoma (DLBCL) of the skull is rare, and there are no reports of treatment using CyberKnife (CK). Here, we report the case of a patient with skull DLBCL treated with low-dose CK radiotherapy (CKR), resulting in effective local control. The patient was a 75-year-old man who was initially diagnosed with multiple skull metastases (frontal, occipital, right orbital bones) from renal pelvic cancer. We initially created a CKR treatment plan for the frontal bone lesion with a marginal dose of 35 Gy and a maximum of 64...

Objective  This article describes a novel technique for trigeminal nerve decompression in the setting of refractory trigeminal neuralgia (TN). Design  Technical note with an illustrative case example and operative video. Setting  Outpatient, inpatient, and operating room of a quaternary neurosurgical referral center. Participant  A woman in her early 70s who had previously undergone linear accelerator-based stereotactic radiotherapy (i.e., CyberKnife) and achieved 2 years of partial pain relief...