Time filter

Source Type

PubMed | University of Wollongong, Liverpool Cancer Therapy Center, Queensland University of Technology, University of New South Wales and 4 more.
Type: Journal Article | Journal: Medical physics | Year: 2016

The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid magnetic resonance imaging (MRI)-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-linac system. This work describes results from a prototype experimental system to demonstrate the feasibility of a high field inline MR-linac.The magnet is a 1.5 T MRI system (Sonata, Siemens Healthcare) was located in a purpose built radiofrequency (RF) cage enabling shielding from and close proximity to a linear accelerator with inline (and future perpendicular) orientation. A portable linear accelerator (Linatron, Varian) was installed together with a multileaf collimator (Millennium, Varian) to provide dynamic field collimation and the whole assembly built onto a stainless-steel rail system. A series of MRI-linac experiments was performed to investigate (1) image quality with beam on measured using a macropodine (kangaroo) ex vivo phantom; (2) the noise as a function of beam state measured using a 6-channel surface coil array; and (3) electron contamination effects measured using Gafchromic film and an electronic portal imaging device (EPID).(1) Image quality was unaffected by the radiation beam with the macropodine phantom image with the beam on being almost identical to the image with the beam off. (2) Noise measured with a surface RF coil produced a 25% elevation of background intensity when the radiation beam was on. (3) Film and EPID measurements demonstrated electron focusing occurring along the centerline of the magnet axis.A proof-of-concept high-field MRI-linac has been built and experimentally characterized. This system has allowed us to establish the efficacy of a high field inline MRI-linac and study a number of the technical challenges and solutions.

Blinman P.,University of Sydney | Alam M.,Liverpool Cancer Therapy Center | Duric V.,University of Sydney | McLachlan S.-A.,St Vincents Hospital | And 3 more authors.
Lung Cancer | Year: 2010

Background: Decisions about chemotherapy for NSCLC are complex and involve trade-offs between its benefits, harms and inconveniences. We sought to find, evaluate and summarise studies quantifying the survival benefits that cancer patients judged sufficient to make chemotherapy for NSCLC worthwhile. Methods: A search of MEDLINE identified 5 papers reporting four studies including 270 patients. Two investigators independently extracted and tabulated relevant findings from each study. Results: Most cancer patients were male, aged over 65 years, had primary lung cancer (65%) and had experienced chemotherapy (62%). Preferences were determined for chemotherapy in metastatic NSCLC (3 papers) and in locally advanced NSCLC (2 papers), but no studies determined preferences for adjuvant chemotherapy. Most cancer patients (>50%) judged moderate survival benefits sufficient to make chemotherapy worthwhile, for example, absolute increases of 10% in survival rates or 6 months in life expectancies. Individual patients' preferences varied widely: benefits judged sufficient ranged from very small (e.g. survival rate of 1%) to very large (e.g. survival rate of 50%). Smaller benefits were judged sufficient to make chemotherapy worthwhile for metastatic rather than locally advanced disease, for less toxic rather than more toxic chemotherapy, and in North American rather than Japanese studies. Four baseline characteristics were weakly associated with judging smaller benefits sufficient: younger age, having dependents, tertiary education and worse quality of life. Conclusions: The survival benefits patients judged sufficient to make chemotherapy for NSCLC worthwhile were moderate, widely variable, and difficult to predict. Doctors should encourage patients to express their preferences when facing decisions about chemotherapy for NSCLC. © 2010 Elsevier Ireland Ltd.

Carter H.E.,University of Sydney | Martin A.,University of Sydney | Schofield D.,University of Sydney | Duchesne G.,University of Melbourne | And 5 more authors.
Radiotherapy and Oncology | Year: 2014

Results IMRT was both more effective and less costly than 3DCRT over 20 years, with an additional 20 QALYs gained and over $1.1 million saved per 1000 patients treated. This result was robust to plausible levels of uncertainty.Methods A Markov decision model was developed to calculate the incremental quality adjusted life years (QALYs) and costs of IMRT compared with three dimensional conformal radiation therapy (3DCRT). Costs were estimated from the perspective of the Australian health care system.Conclusions IMRT was estimated to have a modest long term advantage over 3DCRT in terms of both improved effectiveness and reduced cost. This result was reliant on clinical judgement and interpretation of the existing literature, but provides quantitative guidance on the cost effectiveness of IMRT whilst long term trial evidence is awaited.Background Intensity modulated radiation therapy (IMRT) is a radiation therapy technology that facilitates the delivery of an improved dose distribution with less dose to surrounding critical structures. This study estimates the longer term effectiveness and cost-effectiveness of IMRT in patients post radical prostatectomy. ©2014 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology.

Boxer M.M.,Liverpool Cancer Therapy Center | Delaney G.P.,Liverpool Cancer Therapy Center | Delaney G.P.,University of New South Wales | Delaney G.P.,University of Western Sydney | And 2 more authors.
Breast | Year: 2013

Ductal carcinoma in situ (DCIS) is a heterogeneous, pre-malignant disease accounting for 10-20% of all new breast tumours. Evidence shows a statistically significant local control benefit for adjuvant radiotherapy (RT) following breast conserving surgery (BCS) for all patients. The baseline recurrence risk of individual patients varies according to clinical-pathological criteria and in selected patients, omission of RT may be considered, following a discussion with the patient. The role of adjuvant endocrine therapy remains uncertain. Ongoing studies are attempting to define subgroups of patients who are at sufficiently low risk of recurrence that RT may be safely omitted; investigating RT techniques and dose fractionation schedules; and defining the role of endocrine therapy. Future directions in the management of patients with DCIS will include investigation of prognostic and predictive biomarkers to inform individualised therapy tailored to the risk of recurrence. © 2013 .

Luckett T.,University of Sydney | Luckett T.,University of New South Wales | Goldstein D.,Prince of Wales Hospital | Goldstein D.,University of New South Wales | And 7 more authors.
The Lancet Oncology | Year: 2011

Background: Ethnic minority is associated with higher cancer incidence and poorer survival than is being in the majority group. We did a systematic review and meta-analysis to assess whether psychological morbidity and health-related quality of life (HRQoL) were affected by minority status. Methods: We searched Medline, AMED, PsycINFO, Embase, CENTRAL, CINAHL, PubMed, Sociological Abstracts, and Web of Science for English-language articles published between Jan 1, 1995, and October, 2009. Articles were eligible if they reported original data on anxiety, depression, distress (for psychological morbidity), or HRQoL in minority and majority cancer patients or survivors. Minority status was defined as being an immigrant or having an ethnic, linguistic, or religious background different to the majority of the population in the country where the research was done. We excluded African Americans and indigenous groups. Eligible articles were rated for quality of reporting, external validity, internal validity, sample size, and power. Each quality criterion was rated independently by two reviewers until inter-rater reliability was achieved. In a meta-analysis we compared mean scores adjusted for socioeconomic status and other sociodemographic and clinical variables, where available. Effect sizes greater than 0·5 and 95% CI that included 0·5 or -0·5 were deemed clinically important, with negative values indicating worse outcomes in minority patients. We assessed publication bias by estimating the number of potential unpublished studies and the number of non-signficant studies with p=0·05 required to produce a non-significant overall result. Findings: We identified 21 eligible articles that included 18 datasets collected in the USA and one in each of Canada, Romania, and the UK. Ethnic minority groups were Hispanic, Asian or Pacific Islander, or Hungarian (one dataset). Overall, we found minority versus majority groups to have significantly worse distress (mean difference -0·37, 95% CI -0·46 to -0·28; p<0·0001), depression (-0·23, -0·36 to -0·11; p=0·0003), and overall HRQoL (-0·33, -0·58 to -0·07; p=0·013). Further analyses found disparities to be specific to Hispanic patients in the USA, in whom poorer outcomes were consistent with potentially clinically important differences for distress (effect size -0·37, 95% CI -0·54 to -0·20; p<0·0001), social HRQoL (-0·45, -0·87 to -0·03; p=0·035), and overall HRQoL (-0·49, -0·78 to -0.20; p=0·0008). Results were significantly heterogeneous for overall HRQoL and all domains. Tests for interaction, for adjusted versus unadjusted and comparisons of high-quality, medium-quality, and low-quality articles, were generally non-significant, which suggests no bias. We found no evidence of any substantive publication bias. Interpretation: Hispanic cancer patients in the USA, but not other ethnic minority groups, report significantly worse distress, depression, social HRQoL, and overall HRQoL than do majority patients, of which all but depression might be clinically important. Heterogeneous results might, however, have limited the interpretation. Data for other minority groups and for anxiety are scarce. More studies are needed from outside the USA. Future reports should more clearly describe their minority group samples and analyses should control for clinical and sociodemographic variables known to predict outcomes. Understanding of why outcomes are poor in US Hispanic patients is needed to inform the targeting of interventions. Funding: Prince of Wales Hospital, Sydney, Australia. © 2011 Elsevier Ltd.

Dimoska A.,University of Sydney | Butow P.N.,University of Sydney | Lynch J.,St George and Sutherland Hospitals | Hovey E.,Liverpool Cancer Therapy Center | And 3 more authors.
Patient Education and Counseling | Year: 2012

Objective: To examine the feasibility and acceptability of routine provision of patient question prompt lists (QPLs) to promote patient participation and patient-clinician communication in medical consultations. Methods: Four cancer centres across NSW, Australia (two rural, two urban) were invited to participate, involving distribution of QPLs to patients seeing a medical or radiation oncologist, or palliative care clinician. Patients rated their satisfaction after their next consultation. Cancer specialists provided their views at the end of the study. Results: Sixty-four percent (389/606) of patients attending consultations received a QPL. Of patients offered a QPL (426), 91% accepted. Of 139 patients surveyed post-consultation, 89% reported reading the QPL and, of these, 44% referred to the QPL during the consultation at least once. All of 10 cancer specialists providing their views post-implementation reported that QPL implementation in routine practice was feasible and did not strain resources. Conclusions: Cancer patients and cancer specialists showed support for routine dissemination of the QPL. Practice implications: For successful implementation of evidence-based tools we recommend promotion by local clinical champions, negotiation with clinic staff about dissemination methods, raised patient awareness through on-site project facilitators, media, consumer and support groups, and availability of resources in hard copy and via online sources. © 2011 Elsevier Ireland Ltd.

PubMed | Liverpool Cancer Therapy Center
Type: Journal Article | Journal: Journal of medical radiation sciences | Year: 2016

To compare the differences in setup errors measured with electronic portal image (EPI) and cone-beam computed tomography (CBCT) in patients undergoing tangential breast radiotherapy (RT). Relationship between setup errors, body mass index (BMI) and breast size was assessed.Twenty-five patients undergoing postoperative RT to the breast were consented for this study. Weekly CBCT scans were acquired and retrospectively registered to the planning CT in three dimensions, first using bony anatomy for bony registration (CBCT-B) and again using breast tissue outline for soft tissue registration (CBCT-S). Digitally reconstructed radiographs (DRR) generated from CBCT to simulate EPI were compared to the planning DRR using bony anatomy in the V (parallel to the cranio-caudal axis) and U (perpendicular to V) planes. The systematic () and random () errors were calculated and correlated with BMI and breast size.The systematic and random errors for EPI (CBCT and EPI show insignificant variation in their ability to detect setup error. These findings suggest no significant differences that would make one modality considered superior over the other and EPI should remain the standard of care for most patients. However, there is a correlation with breast size, BMI and setup error as detected by CBCT-S, justifying the use of CBCT-S for larger patients.

PubMed | Liverpool Cancer Therapy Center
Type: Journal Article | Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology | Year: 2016

9622 Background: Appropriately timed cessation of chemotherapy is integral to the quality assurance of an oncology service and to patients quality of life. There is minimal data available on the use of chemotherapy in patients at the end of life. Here we evaluated the proportion of patients receiving palliative chemotherapy and determined those who received chemotherapy within 2 and 4 weeks of death and evaluated associated factor.A retrospective electronic chart review of deceased oncology patients treated with palliative intent from April 2005 to March 2007 at LCTC and MCTC was performed. Patients age, gender, country of birth, cancer types, number of lines of chemotherapy, chemosensitivity of the tumour and treating specialist were recorded to determine potential influence on commencement of palliative chemotherapy and continuation within the last 2 and 4 weeks of life. Chi square test was utilised to determine the association of individual factors with each of the three outcome variables and a logistic regression model was constructed with all the significant (p<0.05) factors to determine their independent effect on the outcome.747 oncology patients died during the study period; median age 67 years (range 20-96); female 44%. Of these, 398 patients (53%) received palliative chemotherapy, with 8% and 18% receiving chemotherapy within the last 2 and 4 weeks of life respectively. Younger age (p<0.005), female gender (p< 0.025), specific cancer type (p<0.005), and increased chemosensitivity of the tumour (p<0.005) were predictors of commencement of palliative chemotherapy. In multivariate analysis, only age (p<0.005) and cancer type (p<0.005) remained as independent predictors. None of the above factors had a significant association with chemotherapy use in the last 2 weeks of patients life. Treating specialist was the only predictor determining chemotherapy use in the last 4 weeks of life (p<0.025).Younger age and tumour type are important predictors of whether or not patients receive palliative chemotherapy. The only significant predictor of whether patients receive palliative chemotherapy in the last 4 weeks of life is individual clinicians practice. No significant financial relationships to disclose.

PubMed | Liverpool Cancer Therapy Center
Type: Journal Article | Journal: Medical physics | Year: 2016

The purpose of this project was to evaluate the performance of four commercially available dosimetry systems for Tomotherapy delivery quality assurance (DQA).Eight clinical patient plans were chosen to represent a range of treatment sites and typical clinical plans. Four DQA plans for each patient plan were created using the TomoTherapy DQA Station (Hi-Art version 4.2.1) on CT images of the ScandiDose Delta4, IBA MatriXX Evolution, PTW Octavius 4D and Sun Nuclear ArcCHECK phantoms. Each detector was calibrated following the manufacture-provided procedure. No angular response correction was applied. All DQA plans for each detector were delivered on the Tomotherapy Hi-Art unit in a single measurement session but on different days. The measured results were loaded into the vendor supplied software for each QA system for comparison with the TPS-calculated dose. The Gamma index was calculated using 3%/3mm, 2%/2mm with 10% dose threshold of maximum TPS calculated dose.Four detector systems showed comparable gamma pass rates for 3%/3m, which is recommended by AAPM TG119 and commonly used within the radiotherapy community. The averaged pass rates standard deviation for all DQA plans were (98.351.97)% for ArcCHECK, (99.9%0.87)% for Matrix, (98.5%5.09)% for Octavius 4D, (98.7%1.27)% for Delata4. The rank of the gamma pass rate for individual plans was consistent between detectors. Using 2%/2mm Gamma criteria for analysis, the Gamma pass rate decreased on average by 9%, 8%, 6.6% and 5% respectively. Profile and Gamma failure map analysis using the software tools from each dosimetry system indicated that decreased passing rate is mainly due to the threading effect of Tomo plan.Despite the variation in detector type and resolution, phantom geometry and software implementation, the four systems demonstrated similar dosimetric performance, with the rank of the gamma pass rate consistent for the plans considered.

PubMed | Liverpool Cancer Therapy Center
Type: Journal Article | Journal: Medical physics | Year: 2016

The data receive server (DRS) in the Tomotherapy Unit records planned and actually delivered plan parameters for each treatment into a log file. The purpose of this study was to develop a software tool using the log file for verification of the patient plan delivered during treatment.A software tool, TomoPQA, was developed using the Python programming language. The software was implemented using object-oriented methodology and modular design. The program has three built-in modules: Read-in module for loading the log file, analysis module for analyzing the log file and reporting module for producing a PDF report.The developed software tool can be used to monitor and check the following plan parameters during patient treatment: (1) planned and actual field width; (2) planned and actual treatment time; (3) planned and actual couch speed; (4) planned and actual gantry speed; (4) planned and actual setup position. The software shows the difference between these parameters as a graphic plot against each treatment fraction in a PDF report for easy review or these values can be exported to an excel file. The program can process a 100M byte log file and produce a report in the order of one minute and can run on Windows, Linux or Mac platforms as a standalone program. A server version of this program can also be implemented for full automation of the log file processing, generation of the PDF report and also has the potential for an automated email if given values are out of tolerance.A QA software tool has been developed for in-vivo quality assurance of treatment delivered on a Tomotherapy Unit. This tool provides an independent verification of the difference between actual delivered and planned parameters during treatment.

Loading Liverpool Cancer Therapy Center collaborators
Loading Liverpool Cancer Therapy Center collaborators