Preoperative radiosurgery for brain metastases (PREOP-1): A feasibility trial.

Purpose: Preoperative radiosurgery (SRS) of brain metastases (BM) aims to achieve cavity local control with a reduction in leptomeningeal relapse (LMD) and without additional radionecrosis compared to postoperative SRS. We present the final results of a prospective feasibility trial of linac-based stereotactic radiosurgery (SRS) prior to neurosurgical resection of a brain metastasis (PREOP-1). Methods: Eligibility criteria included a BM up to 4 cm in diameter for elective resection. The primary endpoint was the feasibility of delivering linac-based preoperative SRS in all patients prior to anticipated gross tumour resection. Secondary endpoints included rates of LMD, local control and overall survival. Exploratory endpoints were the level of expression of immunological and proliferative markers. Results: Thirteen patients of median age 65 years (range 41-77) were recruited. Twelve patients (92 %) received preoperative radiosurgery and metastasectomy and one patient went directly to surgery and received postoperative SRS, thus the primary endpoint was not met. The median time between referral and preoperative SRS was 6.5 working days (1-10) and from SRS to neurosurgery was 1 day (0-5). The median prescribed dose was 16 Gy (14-19) to a median planning target volume of 12.7 cm3 (5.9-26.1). Five patients completed 12-month follow-up after preoperative SRS without local recurrence or leptomeningeal disease. The patient who received postoperative FSRT developed LMD after six months. There was one transient toxicity (grade 2 alopecia) and nine patients have died from extracranial causes. Patients reported significant improvement in motor weakness at 6 months (P = 0.04). No pattern in changes of marker expression was observed. Conclusion: In patients with large brain metastasis without raised intracranial pressure, linac-based preoperative SRS was feasible in 12/13 patients and safe in 12/12 patients without any surgical delay or intracranial complications.

Conversational artificial intelligence: the interface with the patient concerns inventory.

The patient concerns inventory (PCI) allows patients to highlight the issues they would like to discuss at their outpatient consultation. It improves patient-clinician communication and has proven benefits. While the PCI is effective, patient experiences could be improved with better access to it and the ability to more easily and frequently express their concerns. This, of course, is in the context of ever-increasing healthcare challenges and limited resources. Use of conversational artificial intelligence (CAI) represents an opportunity to improve information flow between patients and professionals remote from the consultation. This paper highlights the potential for CAI to provide an 'always-on' platform, using natural language interface technology and based on the PCI, which patients can access via their mobile devices. We also discuss potential pitfalls and concerns, along with outlining a current clinical trial assessing, in the first instance, usability of this technology.

The experiences of new mothers accessing feeding support for infants with down syndrome during the COVID-19 pandemic.

Infants with Down syndrome are more likely to experience feeding problems and mothers are likely to require more feeding support than mothers of typically developing infants. During the COVID-19 pandemic, many feeding support services changed from face-to-face to online, which impacted some maternal feeding experiences negatively, but no studies to date have explored the impact for mothers of infants with Down syndrome. Thematic analysis was conducted on semi-structured interviews from thirteen new mothers of infants (aged 8-17 months) with Down syndrome in the UK. Three superordinate themes were generated: (1) Every baby with Down syndrome has a unique journey, (2) There's no point asking, they won't know, (3) Lack of in-person support. Many mothers expressed frustrations over health professionals' lack of Down syndrome specific knowledge resulting in unmet needs, further magnified due to the nature of the virtual support being offered. Moreover, mothers struggled with reduced social support from other mothers when encountering feeding problems. These results hold real-world implications for health professionals who could provide more specialised face-to-face feeding support to mothers of infants with Down syndrome. This should be prioritised for children's overall development and mothers' wellbeing.

Visual hallucinations after resection of cerebral metastases: two patients with complex phantom images.

PURPOSE: Complex visual hallucinations are rarely seen in neurooncology. They are commonly observed alongside psychotic symptoms in schizophrenia or dementia, in Parkinson's or Lewy-body disease, after opioid medications or anesthesia, and, in particular, they appear with visual impairments. METHODS: Here we report two normal-sighted and mentally healthy patients with unusual visual hallucinations after the resection and irradiation of brain metastases, the main features of which were persistent colorful and meaningful images with hallucinatory perseveration. RESULTS: These cases demonstrate the occurrence of complex visual hallucinations after resection of visual cortices as an effect of deafferentation, so-called visual release hallucinations or phantom images, similar to phantom pain after amputation of a limb. CONCLUSION: This case serves to heighten awareness in the radiooncology practitioner of the occurrence of visual release hallucinations (Charles Bonnet syndrome) related to multidisciplinary treatment of brain metastases.

The Lucy Thermal Emission Spectrometer (L'TES) Instrument.

The Lucy Thermal Emission Spectrometer (L'TES) will provide remote measurements of the thermophysical properties of the Trojan asteroids studied by the Lucy mission. L'TES is build-to-print hardware copy of the OTES instrument flown on OSIRIS-REx. It is a Fourier Transform spectrometer covering the spectral range 5.71-100 µm (1750-100 cm-1) with spectral sampling intervals of 8.64, 17.3, and 34.6 cm-1 and a 7.3-mrad field of view. The L'TES telescope is a 15.2-cm diameter Cassegrain telescope that feeds a flat-plate Michelson moving mirror mounted on a linear voice-coil motor assembly to a single uncooled deuterated l-alanine doped triglycine sulfate (DLATGS) pyroelectric detector. A significant firmware change from OTES is the ability to acquire interferograms of different length and spectral resolution with acquisition times of 0.5, 1, and 2 seconds. A single ∼0.851 µm laser diode is used in a metrology interferometer to provide precise moving mirror control and IR sampling at 772 Hz. The beamsplitter is a 38-mm diameter, 1-mm thick chemical vapor deposited diamond with an antireflection microstructure to minimize surface reflection. An internal calibration cone blackbody target, together with observations of space, provides radiometric calibration. The radiometric precision in a single spectrum is ≤2.2 × 10-8 W cm-2 sr-1 /cm-1 between 300 and 1350 cm-1. The absolute temperature error is <2 K for scene temperatures >75 K. The overall L'TES envelope size is 37.6 × 29.0 × 30.4 cm, and the mass is 6.47 kg. The power consumption is 12.6 W average. L'TES was developed by Arizona State University with AZ Space Technologies developing the electronics. L'TES was integrated, tested, and radiometrically calibrated on the Arizona State University campus in Tempe, AZ. Initial data from space have verified the instrument's radiometric and spatial performance.

Induction of cancer neoantigens facilitates development of clinically relevant models for the study of pancreatic cancer immunobiology.

Neoantigen burden and CD8 T cell infiltrate are associated with clinical outcome in pancreatic ductal adenocarcinoma (PDAC). A shortcoming of many genetic models of PDAC is the lack of neoantigen burden and limited T cell infiltrate. The goal of the present study was to develop clinically relevant models of PDAC by inducing cancer neoantigens in KP2, a cell line derived from the KPC model of PDAC. KP2 was treated with oxaliplatin and olaparib (OXPARPi), and a resistant cell line was subsequently cloned to generate multiple genetically distinct cell lines (KP2-OXPARPi clones). Clones A and E are sensitive to immune checkpoint inhibition (ICI), exhibit relatively high T cell infiltration, and have significant upregulation of genes involved in antigen presentation, T cell differentiation, and chemokine signaling pathways. Clone B is resistant to ICI and is similar to the parental KP2 cell line in terms of relatively low T cell infiltration and no upregulation of genes involved in the pathways noted above. Tumor/normal exome sequencing and in silico neoantigen prediction confirms successful generation of cancer neoantigens in the KP2-OXPARPi clones and the relative lack of cancer neoantigens in the parental KP2 cell line. Neoantigen vaccine experiments demonstrate that a subset of candidate neoantigens are immunogenic and neoantigen synthetic long peptide vaccines can restrain Clone E tumor growth. Compared to existing models, the KP2-OXPARPi clones better capture the diverse immunobiology of human PDAC and may serve as models for future investigations in cancer immunotherapies and strategies targeting cancer neoantigens in PDAC.

Follow-up arrangements in head and neck cancer clinics during the COVID-19 pandemic: results from two tertiary UK head and neck cancer centres.

INTRODUCTION: The aim of this paper is to report the pattern of follow-up that occurred for a cohort of head and neck cancer (HNC) patients across two large centres in the UK (Aintree and Leeds), as a consequence of the COVID-19 pandemic. METHODS: Patients had been treated for HNC with curative intent between April 2017 and October 2019 by 14 oral and maxillofacial (OMFS) and ear nose and throat (ENT) oncology surgeons in the Patient Concerns Inventory intervention trial. In October 2020, hospital records were reviewed, and information collected on the timing and mode (face-to-face/telephone/video) of follow-up consultations. In addition, recurrence, second primary tumours and deaths were recorded. RESULTS: At the start of 'lockdown', 212 members of the cohort were known to be alive. During the post-lockdown period (follow-up appointment data comprised 5 months in Aintree and 7 months in Leeds) 7 died and 13 were identified as palliative/recurrence/new primary/metastases ('new event'). In Aintree, the first ENT/OMFS consultations after lockdown were 51 (67%) telephone and 25 (33%) face-to-face appointments. In Leeds, 46 (78%) consultations were by telephone and 13 (22%) were face-to-face. The second ENT/OMFS consultations post lockdown included 11 (44%) telephone and 14 (56%) face-to-face in Aintree, and 21 (75%) telephone and 7 (25%) face-to-face in Leeds. CONCLUSIONS: These data suggest that clinicians favoured remote consultations. Variations in practice were observed but reached a point of a 'hybrid follow-up approach' that included both face-to-face and remote consultations. With the emergence of telemedicine, clinicians may consider a follow-up model tailored to risk stratification. The development of the mode of such a consultation model needs further evaluation.

Feasibility and Accuracy of Measuring Carotid Plaque Volume (Burden) With Contrast-Enhanced Tomographic 3D Ultrasound and Ultrasound Image Fusion.

BACKGROUND: Stenosis severity has been the indication for carotid endarterectomy (CEA) for 4 decades, but the annual stroke risk in asymptomatic carotid stenosis >70% is under 2%. Atherosclerotic volume has emerged as a risk factor for future stroke, but needs to be measured noninvasively. Tomographic ultrasound (tUS) is a novel technology that assembles 3D images in seconds. We evaluated accuracy of measuring Carotid Plaque Volume (CPV) with tUS in patients undergoing CEA. METHOD: Consecutive patients were imaged immediately before CEA by tUS and contrast-enhanced tUS (CEtUS). CPV was measured using tUS, CEtUS, and a fused images incorporating both tUS and CEtUS by trained vascular scientists. Precise volume of the endarterectomy specimen was measured using Archimedes technique. RESULTS: Mean ± sd (range) CPV in 129 endarterectomy specimens was 0.75 ± 0.43 cm3 (0.10-2.47 cm3). Mean ± sd CPV measured by tUS (n = 114) was 0.87 ± 0.51 cm3, CEtUS (n = 104) was 0.75 ± 0.45 cm3 and with fusion (n = 95) was 0.83 ± 0.49 cm3. Differences between specimen volume and CPV measured by tUS (0.13 ± 0.24 cm3), CEtUS (-0.01 ± 0.21 cm3) or fusion (-0.08 ± 0.20) were clinically insignificant. Intra-/interobserver differences were minimal. CONCLUSIONS: tUS accurately measures CPV with excellent intra-/interobserver agreement. CEtUS improves accuracy if precise CPV measurement is needed for research but tUS alone would be sufficient for population screening.

Optimized workflow to minimise intra-fractional motion during stereotactic body radiotherapy of spinal metastases.

Background and purpose: This study evaluated translational and rotational intra-fractional patient movement during spinal stereotactic body radiotherapy (SBRT) using 6D positioning based on 3D cone beam computerized tomography (CBCT) and stereoscopic kilovoltage imaging (ExacTrac). The aim was to determine whether additional intra-fractional image verification reduced intra-fractional motion without significantly prolonging treatment time, whilst maintaining acceptable imaging related dose. Materials and methods: A retrospective analysis of 38 patients with 41 primary tumour volumes treated with SBRT between September 2018 and May 2021 was performed. Three different image-guided radiotherapy (IGRT) workflows were assessed. The translational and rotational positioning errors for the different imaging workflows, 3D translational vectors and estimates of imaging dose delivered for the different imaging workflows were evaluated. Results: As the frequency of intra-fractional imaging increased from workflow 1 to 3, the mean intra-fraction 3D translational vector improved from 0.91 mm (±0.52 mm), to 0.64 (±0.34 mm). 85 %, 83 % and 97 % of images were within a tolerance of 1 mm/1° for workflows 1, 2 and 3 respectively, based on post treatment CBCT images. The average treatment time for workflow 3 was 13 min, as compared to 12 min for workflows 1 and 2. The effective dose per treatment for IGRT workflows 1, 2 and 3 measured 0.6 mSv, 0.95 mSv and 1.8 mSv respectively. Conclusion: The study demonstrated that the use of additional intra-fractional stereoscopic kilovoltage image-guidance during spinal SBRT, reduced the number of measurements deemed "out of tolerance" and treatment delivery could be optimized within a standard treatment timeslot without applying substantial additional radiation dose.

Stereotactic radiosurgery and radiotherapy for resected brain metastases: current pattern of care in the Radiosurgery and Stereotactic Radiotherapy Working Group of the German Association for Radiation Oncology (DEGRO).

PURPOSE: Preoperative stereotactic radiosurgery (SRS) of brain metastases may achieve similar local control and better leptomeningeal control rates than postoperative fractionated stereotactic radiotherapy (FSRT) in patients treated with elective metastasectomy. To plan a multicentre trial of preoperative SRS compared with postoperative FSRT, a survey of experts was conducted to determine current practice. METHODS: A survey with 15 questions was distributed to the DEGRO Radiosurgery and Stereotactic Radiotherapy Working Group. Participants were asked under what circumstances they offered SRS, FSRT, partial and/or whole brain radiotherapy before or after resection of a brain metastasis, as well as the feasibility of preoperative stereotactic radiosurgery and neurosurgical resection within 6 days. RESULTS: Of 25 participants from 24 centres, 22 completed 100% of the questions. 24 respondents were radiation oncologists and 1 was a neurosurgeon. All 24 centres have one or more dedicated radiosurgery platform and all offer postoperative FSRT. Preoperative SRS is offered by 4/24 (16.7%) centres, and 9/24 (37.5%) sometimes recommend single-fraction postoperative SRS. Partial brain irradiation is offered by 8/24 (33.3%) centres and 12/24 (50%) occasionally recommend whole-brain irradiation. Two centres are participating in clinical trials of preoperative SRS. SRS techniques and fractionation varied between centres. CONCLUSION: All responding centres currently offer postoperative FSRT after brain metastasectomy. Approximately one third offer single-fraction postoperative SRS and four already perform preoperative SRS. With regard to potential co-investigators, 18 were identified for the PREOP­2 multicentre trial, which will randomise between preoperative SRS and postoperative FSRT.

A 31-year review of composite radial forearm free flaps for head and neck reconstruction.

The aim of this study was to report the patient characteristics and radial fracture rates in a consecutive series of composite radial forearm free flap (CRFFF) for head and neck reconstruction over a 31-year period. The patients were identified from between 1990 to 2020 inclusive from theatre records and records from previous analyses at the Unit on free flap outcomes. Electronic case notes were accessed where available, to gather information on the operation, histopathology, and radiographs. Patients were categorised into three groups for analysis: (1) new oral cancers with a composite radial being the first choice of flap, (2) new oral cancers with a composite radial being the choice of flap following compromise of another bony flap, (3) osteoradionecrosis (ORN) cases. There were 103 CRFFF cases, median (IQR) age 69 (59-80) years, comprising 78 (Group 1), 5 (Group 2) and 20 (Group 3). The CRFFF failure rate was 6% (6/103) and the radius fracture rate was also 6% (6/103), both with 95% confidence interval 2.2-12.2%. Of the 6 radius fractures, 1 underwent surgical management (rush nailing), 1 died in hospital and the others managed with cast immobilisation. Two-year overall survival after surgery for the103 patients was 54% (SE 5%), while 5-year survival was 40% (SE 5%). In conclusion, in spite of the familiarity with other bone flaps such as fibular free flap, DCIA, scapula, and the limited bone stock and potential fracture related morbidity associated with the CRFFF, this flap still has a place in the surgical reconstructive armamentarium.

A survey to ascertain peer support models available in Head and Neck cancer across the United Kingdom.

In cancers and chronic conditions, peer support (PS) has been shown to improve quality of life (QOL) and provide an important coping mechanism for patients, however there is little evidence for this intervention in Head and Neck cancer (HNC). Peer support allows individuals to come together and share information, encouragement, and experiences. It is delivered in a variety of ways including one-to-one, online, and support groups. There is limited literature regarding the timing, barriers, and types of PS available for individuals with HNC across the United Kingdom (UK). The aim of this project was to survey healthcare professionals with respect to their experience regarding types, timings, and barriers to PS in HNC. The survey was developed based on the literature, feedback and advice from a HNC patient research group and healthcare professionals. It was conducted online and consisted of twelve questions. Eighty-eight individuals responded covering twenty-four of twenty-six cancer alliances across the UK. Three main themes with subthemes were identified: patient barriers (emotional barriers and patient limitations), organisational barriers (administrative problems, limited time and resources and COVID-19), and staff barriers (lack of departmental support, concerns with PS and matching and timing of support). The survey demonstrated the different types of PS available across the UK and the barriers faced when implementing this support. It highlighted the complexity of being able to satisfactorily deliver appropriate and effective PS in HNC and the challenges involved.

Immediate postoperative care on high dependency unit or ward following microvascular free tissue transfer: lessons learnt from a change in practice imposed during the COVID-19 pandemic.

The COVID-19 pandemic resulted in sudden changes to the established practice of using the high dependency unit (HDU) for the first night of postoperative care following microvascular free tissue transfer. Patients were managed instead on the head and neck ward. This retrospective case-note review aimed to report outcomes in consecutive patients treated before and during the pandemic, and to reflect on the implications of ward-based rather than HDU care. A total of 235 patients had free tissue transfer between 3 January 2019 and 25 February 2021: 125 before (lockdown 23 March 2020), and 110 during the pandemic (52 ward-managed and 58 HDU-managed). There were subtle case-mix differences during the pandemic, with 92% of ward-treated patients having oral cancers compared with 64% of HDU patients, and 73% of ward patients having a tracheostomy compared with 40% of HDU patients. Ward patients were less likely to receive electrolyte replacement (45% HDU vs 0% ward) and inotropes (12% HDU vs 2% ward). There were fewer returns to theatre for evacuation of a haematoma or re-anastomosis during the pandemic than there were before it. Other than fewer haematoma complications during the pandemic, the nature of complications was similar. In conclusion, the dramatic changes imposed by the pandemic have shown that the ward is a safe place for patients to be cared for immediately postoperatively, and it alleviates the bed pressures experienced in HDU. Careful case selection and clear criteria are required to identify patients who need the HDU.

Risk stratification for poor health-related quality of life following head and neck cancer through the aid of a one-page item prompt list.

The aim of this work was to evaluate the usability of a single-page, patient-completed, condition-specific prompt list, the Patient Concerns Inventory (PCI-HN), to risk-stratify for poor health-related quality of life (HRQOL). Data were collected between 2008 and 2017. The main dataset comprised 310 patients first completing the PCI-HN and University of Washington Quality of Life questionnaire (UW-QOLv4) between 2012 and 2017. Another 201 patients first completing the PCI-HN between 2008 and 2011 provided a second dataset for independent validation. Subsequent completions of the PCI-HN in both groups and the distress thermometer (DT) were also used as further validation datasets. Associations between PCI-HN items selected by patients and a range of UW-QOLv4 outcomes were explored using conventional logistic regression and Chi-squared automated interaction detection (CHAID) analyses. One quarter of patients reported less than good HRQOL, range 26-29% across the four datasets. Several individual items from within the PCI-HN were predictive of adverse outcomes. The total number of items selected was also predictive. The single-sheet prompt list enables clinicians to identify patients at high risk of poor HRQOL. This simple approach has the potential to be integrated into routine clinical practice.

Patients' views of physical activity whilst living with and beyond head and neck cancer.

Exercise is an important component of recovery following cancer. Head and neck cancer (HNC) patients typically report low levels of engagement in exercise initiatives. The aim of this study was to give insight into HNC patients' reflections on how and why they would be interested in participating in an exercise programme. A stratified sample of 51 patients based on age, gender and initial interest in an exercise programme was selected from 430 postal survey respondents. Twenty-five took part in a semi-structured telephone interview. There was responder bias with females, younger patients, and those already participating in or interested in an exercise programme being over-represented. The responders in this study highlighted issues related to physical activity levels, perceived ability to meet physical activity guidelines for cancer survivors, perceived exercise benefits, perceived exercise barriers, and advice to others diagnosed with cancer. The findings support the premise of personalized interventions tailored towards the specific needs of the patient, supported by patient peers to emphasize the benefits and help motivate patients to take part. In order to promote engagement in exercise there needs to be collaborative, culturally sensitive and individualized approaches, in order to address the specific barriers experienced by HNC patients.

Patient characteristics and refusal to participate in a head and neck cancer intervention trial: experience of two tertiary UK head and neck cancer centres.

INTRODUCTION: Randomised clinical trials are an essential component for robust clinical evaluation. They are expensive to deliver but can fail to achieve the required outcomes. This paper reports details of trial recruitment in a head and neck Patient Concerns Inventory intervention trial from two UK head and neck tertiary centres. MATERIALS AND METHODS: Data were collected for a pragmatic cluster preference randomised control trial with 15 consultants recruiting patients treated with curative intent after a diagnosis of head and neck cancer (all sites, disease stages, treatments). Ethical approval was given to report on those not recruited by the following characteristics: trial site, trial arm, age, sex, tumour site, overall stage, index of multiple deprivation quintile, timeframe. RESULTS: There were 368 patients approached who remained eligible and 80 (22%) declined to participate. Logistic regression suggested that age group (p = 0.008) and index of multiple deprivation quintile group (p = 0.003) were independent predictors of refusal. CONCLUSIONS: Although recruitment to the trial was very good, it raised the issue of lower recruitment in the more deprived older group and lower social economic strata. Innovative ways need to be explored to facilitate the 'hard to reach' group contributing to, and benefiting from, clinical trials.

Jumping in lantern bugs (Hemiptera, Fulgoridae).

Lantern bugs are amongst the largest of the jumping hemipteran bugs, with body lengths reaching 44 mm and masses reaching 0.7 g. They are up to 600 times heavier than smaller hemipterans that jump powerfully using catapult mechanisms to store energy. Does a similar mechanism also propel jumping in these much larger insects? The jumping performance of two species of lantern bugs (Hemiptera, Auchenorrhyncha, family Fulgoridae) from India and Malaysia was therefore analysed from high-speed videos. The kinematics showed that jumps were propelled by rapid and synchronous movements of both hind legs, with their trochantera moving first. The hind legs were 20-40% longer than the front legs, which was attributable to longer tibiae. It took 5-6 ms to accelerate to take-off velocities reaching 4.65 m s-1 in the best jumps by female Kalidasa lanata. During these jumps, adults experienced an acceleration of 77 g, required an energy expenditure of 4800 µJ and a power output of 900 mW, and exerted a force of 400 mN. The required power output of the thoracic jumping muscles was 21,000 W kg-1, 40 times greater than the maximum active contractile limit of muscle. Such a jumping performance therefore required a power amplification mechanism with energy storage in advance of the movement, as in their smaller relatives. These large lantern bugs are near isometrically scaled-up versions of their smaller relatives, still achieve comparable, if not higher, take-off velocities, and outperform other large jumping insects such as grasshoppers.

Five fraction stereotactic radiotherapy after brain metastasectomy: a single-institution experience and literature review.

PURPOSE: The outcomes of five fraction stereotactic radiotherapy (hfSRT) following brain metastasectomy were evaluated and compared with published series. METHODS: 30 Gy in 5 fractions HfSRT prescribed to the surgical cavity was reduced to 25 Gy if the volume of 'brain-GTV' receiving 20 Gy exceeded 20 cm3. Endpoints were local recurrence, nodular leptomeningeal recurrence, new brain metastases and radionecrosis. The literature was searched for reports of clinical and dosimetric outcomes following postoperative hfSRT in 3-5 fractions. RESULTS: 39 patients with 40 surgical cavities were analyzed. Cavity local control rate at 1 year was 33/40 (82.5%). 3 local failures followed 30 Gy/5 fractions and 4 with 25 Gy/5 fractions. The incidence of leptomeningeal disease (LMD) was 7/40 (17.5%). No grade 3-4 toxicities, particularly no radionecrosis, were reported. The incidence of distant brain metastases was 15/40 (37.5%). The median overall survival was 15 months. Across 13 published series, the weighted mean local control was 83.1% (adjusted for sample size), the mean incidence of LMD was 14.9% (7-34%) and the mean rate of radionecrosis was 10.3% (0-20.6%). CONCLUSION: Postoperative hfSRT can be delivered with 25-30 Gy in 5 fractions with efficacy in excess of 82% and no significant toxicity when the dose to 'brain-GTV' does not exceed 20 cm3.