Gokula K.,Universiti Sains Malaysia |
Gokula K.,National University of Singapore |
Gokula K.,William Buckland Radiotherapy Center |
Earnest A.,Quantitative Medicine |
Wong L.C.,National University of Singapore
Radiation Oncology | Year: 2013
Background: This meta-analysis aims to ascertain the significance of early lung toxicity with 3-Dimensional (3D) conformal irradiation for breast carcinomas and identify the sub-groups of patients with increased risk.Methods: Electronic databases, reference sections of major oncological textbooks and identified studies were searched for synonyms of breast radiotherapy and radiation pneumonitis (RP). Major studies in thoracic irradiation were reviewed to identify factors frequently associated with RP. Meta-analysis for RP incidence estimation and odds ratio calculation were carried out.Results: The overall incidence of Clinical and Radiological RP is 14% and 42% respectively. Ten studies were identified. Dose-volume Histogram (DVH) related dosimetric factors (Volume of lung receiving certain dose, Vdose and Mean lung Dose, MLD), supraclavicular fossa (SCF) irradiation and age are significantly associated with RP, but not sequential chemotherapy and concomitant use of Tamoxifen. A poorly powered study in IMN group contributed to the negative finding. Smoking has a trend towards protective effect against RP.Conclusion: Use of other modalities may be considered when Ipsilateral lung V20Gy > 30% or MLD > 15 Gy. Extra caution is needed in SCF and IMN irradiation as they are likely to influence these dosimetric parameters. © 2013 Gokula et al.; licensee BioMed Central Ltd.
PubMed | University of New South Wales, William Buckland Radiotherapy Center, National Pathology Accreditation Advisory Council, Illawarra Shoalhaven Local Health District and 3 more.
Type: Journal Article | Journal: Clinical oncology (Royal College of Radiologists (Great Britain)) | Year: 2015
In many areas of health care, practice standards have become an accepted method for professions to assess and improve the quality of care delivery. The aim of this work is to present the development of practice standards for radiation oncology in Australia, highlighting critical points and lessons learned. Following a review of radiotherapy services in Australia, a multidisciplinary group with support from the Australian Government developed practice standards for radiation oncology in Australia. The standards were produced in a multistep process including a nationwide survey of radiotherapy centres and piloting of the standards in a representative subset of all Australian radiotherapy centres. The standards are grouped into three sections: Facility management (covering staffing, data management, equipment and processes); Treatment planning and delivery (providing more detailed guidance on prescription, planning and delivery); Safety and quality management (including radiation safety, incident monitoring and clinical trials participation). Each of the 16 standards contains specific criteria, a commentary and suggestions for the evidence required to demonstrate compliance. The development of the standards was challenging and time consuming, but the collaborative efforts of the professions resulted in standards applicable throughout Australia and possibly further afield.
Wein L.,The Alfred |
Dally M.,William Buckland Radiotherapy Center |
Bach L.A.,The Alfred |
Bach L.A.,Monash University
Internal Medicine Journal | Year: 2012
Stereotactic radiation therapy has emerged as an alternative to conventional radiotherapy for treatment of Cushing disease. The aim of this study was to investigate the efficacy and safety of this treatment. Records of patients with Cushing disease treated with stereotactic radiation were reviewed. Seventeen patients underwent stereotactic radiosurgery. Ten achieved remission after a mean of 23 (95% confidence interval, 15-31) months, and two developed hormone deficiencies. © 2012 The Authors. Internal Medicine Journal © 2012 Royal Australasian College of Physicians.
Ruben J.D.,William Buckland Radiotherapy Center |
Ruben J.D.,Monash University |
Lancaster C.M.,William Buckland Radiotherapy Center |
Jones P.,William Buckland Radiotherapy Center |
Smith R.L.,William Buckland Radiotherapy Center
International Journal of Radiation Oncology Biology Physics | Year: 2011
Purpose: To investigate differences in scatter and leakage between 6-MV intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT); to describe the relative contributions of internal patient scatter, collimator scatter, and head leakage; and to discuss implications for second cancer induction. Methods and Materials: Dose was measured at increasing distances from the field edge in a water bath with a sloping wall (1) under full scatter conditions, (2) with the field edge abutting but outside the bath to prevent internal (water) scatter, and (3) with the beam aperture plugged to reflect leakage only. Results: Internal patient scatter from IMRT is 11% lower than 3DCRT, but collimator scatter and head leakage are five and three times higher, respectively. Ultimately, total scattered dose is 80% higher with IMRT; however this difference is small in absolute terms, being 0.14% of prescribed dose. Secondary dose from 3DCRT is mostly due to internal patient scatter, which contributes 70% of the total and predominates until 25 cm from the field edge. For IMRT, however, machine scatter/leakage is the dominant source, contributing 65% of the secondary dose. Internal scatter predominates for just the first 10 cm from field edge, collimator scatter for the next 10 cm, and head leakage thereafter. Conclusions: Out-of-field dose is 80% higher with IMRT, but differences are tiny in absolute terms. Reductions in internal patient scatter with IMRT are outweighed by increased machine scatter and leakage, at least for small fields. Reductions from IMRT in dose to tissues within the portals and in internal scatter, which predominates close to the field edge, means that calculations based solely on dose to distant tissues may overestimate carcinogenic risks. © 2011 Elsevier Inc.
Constituent components of out-of-field scatter dose for 18-MV intensity modulated radiation therapy versus 3-dimensional conformal radiation therapy: A comparison with 6-MV and implications for carcinogenesis
Ruben J.D.,William Buckland Radiotherapy Center |
Ruben J.D.,Monash University |
Smith R.,William Buckland Radiotherapy Center |
Smith R.,RMIT University |
And 4 more authors.
International Journal of Radiation Oncology Biology Physics | Year: 2014
Conclusions: Out-of-field photon dose seems to be independent of beam energy for both techniques. Eighteen-megavolt IMRT increases out-of-field scatter 1.7-fold over 3D-CRT because of greater collimator scatter despite reducing internal/patient scatter. Out-of-field carcinogenic risk is thus increased (but improved in-field dose conformity may offset this). Potentially increased carcinogenic risk should be weighed against any benefit 18-MV IMRT may provide.Purpose: To characterize and compare the components of out-of-field dose for 18-MV intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3D-CRT) and their 6-MV counterparts and consider implications for second cancer induction.Methods and Materials: Comparable plans for each technique/energy were delivered to a water phantom with a sloping wall; under full scatter conditions; with field edge abutting but outside the bath to prevent internal/phantom scatter; and with shielding below the linear accelerator head to attenuate head leakage. Neutron measurements were obtained from published studies.Results: Eighteen-megavolt IMRT produces 1.7 times more out-of-field scatter than 18-MV 3D-CRT. In absolute terms, however, differences are just approximately 0.1% of central axis dose. Eighteen-megavolt IMRT reduces internal/patient scatter by 13%, but collimator scatter (C) is 2.6 times greater than 18-MV 3D-CRT. Head leakage (L) is minimal. Increased out-of-field photon scatter from 18-MV IMRT carries out-of-field second cancer risks of approximately 0.2% over and above the 0.4% from 18-MV 3D-CRT. Greater photoneutron dose from 18-MV IMRT may result in further maximal, absolute increased risk to peripheral tissue of approximately 1.2% over 18-MV 3D-CRT. Out-of-field photon scatter remains comparable for the same modality irrespective of beam energy. Machine scatter (C + L) from 18 versus 6 MV is 1.2 times higher for IMRT and 1.8 times for 3D-CRT. It is 4 times higher for 6-MV IMRT versus 3D-CRT. Reduction in internal scatter with 18 MV versus 6 MV is 27% for 3D-CRT and 29% for IMRT. Compared with 6-MV 3D-CRT, 18-MV IMRT increases out-of-field second cancer risk by 0.2% from photons and adds 0.28-2.2% from neutrons. © 2014 Elsevier Inc.
Roxby K.J.,William Buckland Radiotherapy Center |
Crosbie J.C.,William Buckland Radiotherapy Center |
Crosbie J.C.,Monash University
Australasian Physical and Engineering Sciences in Medicine | Year: 2010
We commissioned a commercially available portal dosimetry system for quality assurance of intensity modulated radiation therapy (IMRT) treatment plans. The system included gamma analysis software to compare the measured and predicted fluence maps from individual IMRT fields. The portal dosimetry system was tested using six head and neck IMRT patient plans, and we demonstrated that the accuracy of the alignment of measured and predicted images improved by retracting and repositioning the electronic portal imaging device (EPID) at each new gantry angle. The mean gamma score (fraction of pixels passing the gamma criteria) for the six test plans (after initial testing and using the EPID retracting and repositioning method) was 0.987 (2SD = 0.018), using gamma criteria of a dose difference of 2% of the maximum field dose and 2 mm distance to agreement. The mean gamma score was 0.989 (2SD = 0.017) for 24 head and neck IMRT patient plans carried out with portal dosimetry. Using gamma criteria of 2% maximum field dose and 2 mm distance to agreement, a gamma score tolerance of 0.980 is a useful way of highlighting only those fields requiring further analysis. Portal dosimetry is a quick way of assessing individual field fluence distributions and can be integrated into an IMRT quality assurance programme. © Australasian College of Physical Scientists and Engineers in Medicine 2010.
Ong W.L.,William Buckland Radiotherapy Center |
Ong W.L.,University of Cambridge |
Hindson B.R.,William Buckland Radiotherapy Center |
Beaufort C.,William Buckland Radiotherapy Center |
And 3 more authors.
Radiotherapy and Oncology | Year: 2014
Background and purpose: Erectile function (EF) is commonly affected following prostate cancer treatment. We aim to evaluate the long-term EF following seed brachytherapy (BT) treatment. Materials and methods: The study consisted of 366 patients treated with BT at our institution, who completed the IIEF-5 questionnaire and reported no or mild erectile dysfunction (ED) pre-BT. The probability of EF preservation post-BT was estimated using the Kaplan-Meier methods. The difference in EF preservation by patient-, tumour- and treatment-related factors was assessed using the log-rank test. Multivariate Cox regression was used to estimate the effect of each factor on EF preservation. Results: Of the 366 patients, 277 (76%) reported normal EF, and 89 (24%) reported mild ED. The patients were followed-up for a median of 41 months (range: 3-124), and the 5-year actuarial rate of EF preservation was 59%. Age at BT seed implant, presence of medical comorbidities, Gleason score and the biologically effective dose (BED) are associated with EF preservation (P < 0.005). The association for these four factors remains statistically significant in multivariate analysis, with Gleason score having the strongest effect (HR = 3.7; 95% CI = 2.6-5.4). Conclusion: The 5-year actuarial rate of EF preservation post-BT in our cohort is 59%, and is influenced by multiple factors. © 2014 Elsevier Ireland Ltd. All rights reserved.
PubMed | Princess Alexandra Hospital, William Buckland Radiotherapy Center, Auckland City Hospital, Liverpool Hospital and 3 more.
Type: Journal Article | Journal: Journal of medical imaging and radiation oncology | Year: 2016
The RANZCR Faculty of Radiation Oncology Lung Interest Cooperative (FROLIC) surveyed patterns of lung cancer radiation therapy practice for non-small cell (NSCLC) and small cell lung cancer (SCLC) to evaluate current patterns of care and potential for improvement.In October 2014, Radiation Oncologists (ROs) from all 62 departments in Australia and New Zealand were invited to a web-based survey directed at those treating lung cancer. Questions covered current radiation therapy practice as well as quality measures.Fifty-eight per cent of respondents used 4D-CT simulation. For curative treatment, 98% employed 3D-CRT and 34% intensity modulated radiotherapy (IMRT) techniques. Treatment verification was primarily performed using cone-beam CT (86%). In NSCLC, the commonest curative dose-fractionation regime was 60Gy/30# (96%) and for palliative intent, 30Gy/10# (76%). Forty-four per cent treated patients with stereotactic ablative body radiotherapy (SABR) and half treated central tumours with this technique. In fit patients with synchronous solitary brain metastases, 80% would give radical treatment. For curative-intent SCLC, 45-50.4Gy/25-28# (61%) and 45Gy/30#/1.5Gy b.d. (48%) were used. Ninety-four per cent discussed lung cancer patients at multidisciplinary meetings. Contours were peer-reviewed by 74% and 50% for conventional fractionation and SABR respectively.A significant proportion of ROs did not have access to 4D-CT. The majority used 3D image verification and consistently prescribed evidence based doses. A significant number did not participate in peer-review of contours. Practice in IMRT and synchronous oligo-metastatic disease is variable and should be an area of future research. Utilising survey findings, FROLIC is developing consensus recommendations to guide practice.
Teng K.,RMIT University |
Gagliardi F.,RMIT University |
Gagliardi F.,William Buckland Radiotherapy Center |
Alqathami M.,RMIT University |
And 2 more authors.
Medical Dosimetry | Year: 2014
Stereotactic radiotherapy (SRT) requires tight margins around the tumor, thus producing a steep dose gradient between the tumor and the surrounding healthy tissue. Any setup errors might become clinically significant. To date, no study has been performed to evaluate the dosimetric variations caused by setup errors with a 3-dimensional dosimeter, the PRESAGE. This research aimed to evaluate the potential effect that setup errors have on the dose distribution of intracranial SRT. Computed tomography (CT) simulation of a CIRS radiosurgery head phantom was performed with 1.25-mm slice thickness. An ideal treatment plan was generated using Brainlab iPlan. A PRESAGE was made for every treatment with and without errors. A prescan using the optical CT scanner was carried out. Before treatment, the phantom was imaged using Brainlab ExacTrac. Actual radiotherapy treatments with and without errors were carried out with the Novalis treatment machine. Postscan was performed with an optical CT scanner to analyze the dose irradiation. The dose variation between treatments with and without errors was determined using a 3-dimensional gamma analysis. Errors are clinically insignificant when the passing ratio of the gamma analysis is 95% and above. Errors were clinically significant when the setup errors exceeded a 0.7-mm translation and a 0.5° rotation. The results showed that a 3-mm translation shift in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions and 2° couch rotation produced a passing ratio of 53.1%. Translational and rotational errors of 1.5. mm and 1°, respectively, generated a passing ratio of 62.2%. Translation shift of 0.7. mm in the directions of SI, RL, and AP and a 0.5° couch rotation produced a passing ratio of 96.2%. Preventing the occurrences of setup errors in intracranial SRT treatment is extremely important as errors greater than 0.7. mm and 0.5° alter the dose distribution. The geometrical displacements affect dose delivery to the tumor and the surrounding normal tissues. © 2014 American Association of Medical Dosimetrists.
PubMed | William Buckland Radiotherapy Center
Type: Journal Article | Journal: ANZ journal of surgery | Year: 2016
The usual management of thyroid cancer is surgery and radioactive iodine. The role of external beam radiotherapy (EBRT) in well-differentiated thyroid carcinoma remains controversial. Indications for the use of EBRT, contained within both the American and British Thyroid Association published guidelines, include unresectable or non-iodine avid disease, extra-thyroidal extension or distant metastatic disease.A retrospective review of prospectively collected data from a single Australian institution was conducted, analysing patients referred and treated with EBRT for well-differentiated thyroid carcinoma between November 1992 and July 2013.Of 36 patients referred, 32 were treated with EBRT. Sixteen patients in total received locoregional treatment (six radical, 10 palliative), of whom 81% (13/16) had gross disease and 88% (14/16) had recurrent disease (eight with multiple recurrences). Additionally, 63% (10/16) had multiple surgical resections and 50% (8/16) had previously received multiple courses of radioactive iodine. Overall, 67% (4/6) of patients treated with radical intent had no locoregional recurrence or progression. Thirteen of the 16 patients who received locoregional EBRT remained asymptomatic from their locoregional disease at the time of last follow-up or death. The most commonly treated distant metastatic disease site was bone, with a total of 45 sites irradiated. Of these patients, 93% and 78% were symptom-free at two and four years, respectively.Our study suggests that in a select group of patients with well-differentiated thyroid carcinoma, EBRT treatment appears to provide durable tumour and symptom control.