Biomedical subjects

G P Delaney

Publications and source records attributed to G P Delaney.

7 recordsLinked to original sources

PubMed2005

Technology enhancements and changes in radiotherapy throughput in New South Wales.

AIMS: To assess the effect that the age of linear accelerators and recent changes in technology have had on linear accelerator throughput in New South Wales, Australia. MATERIALS AND METHODS: Duration was measured (time of patient entry into the treatment room to time of exit) of each radiotherapy treatment fraction delivered on each linear accelerator over a 5-day period. Patient-, treatment- and equipment-based variables were collected for all treatment fractions, and assessed for their effect on fraction duration. Comparisons were made between these data and similar productivity data collected from a study carried out in 1996. Since the sample sizes for both the study periods were large enough, the distributions of the means were assumed normal (Central Limit Theorem). Specific analyses were carried out to assess the affect that new technologies, such as automatic field-sequencing (AFS) and multi-leaf collimator (MLC), have had on fraction duration. RESULTS: A total of 12 892 treatment fields and 4316 treatment fractions were delivered on 27 linear accelerators over 135 days. Comparison between the 2003 and 1996 productivity data showed an increase in the mean number of patients treated per hour by 11% and fields treated per hour by 31%. The mean number of fields treated per fraction increased by 15%. The mean fraction duration was reduced by 13% for linear accelerators of less than the median age of 7 years that were equipped with MLC/AFS, or both, compared with older linear accelerators without AFS and MLC. This reduction was more obvious for complex techniques, such as four-field breast treatments (27% decrease in fraction duration). The mean number of fields treated per hour was 43% more on the newer machines equipped with AFS and MLC. CONCLUSIONS: An increase in productivity has been observed between the 1996 and 2003 study periods, as measured by patients or fields per hour, despite an increase in treatment complexity as measured by fields per fraction. The application of AFS and MLC, and the use of newer linear accelerators, significantly shortened the mean duration per fraction for the common treatment techniques.

Hospital Departments↗

PubMed2005

The development of a new basic treatment equivalent model to assess linear accelerator throughput.

AIMS: The basic treatment equivalent (BTE) model was developed in 1996 in an attempt to improve the measurement of linear accelerator throughput in radiotherapy. This study aimed to assess the effect of treatment set-up and patient characteristics on fraction duration, to update the BTE model and to determine the better throughput measure between fields per hour and BTE per hour. MATERIALS AND METHODS: Stopwatch measurements of the duration of each radiotherapy treatment fraction delivered on each linear accelerator in participating New South Wales radiation oncology departments over a 5-day period in 2003 were undertaken. Patient, equipment and staff data were collected to assess the effect of these variables on fraction duration. A new BTE equation was derived, including the most significant variables. Statistical comparison of fields and BTE per unit time was made to assess the better predictor of fraction duration. RESULTS: Data collected on 27 linear accelerators in 13 departments included a total of 135 days of linear accelerator operation, 4316 fractions and 12 892 treatment fields. Seventeen factors significantly influenced fraction duration (P < 0.01). These accounted for 46% of the total variance in the models. The eight most influential predictors of prolonged fraction duration were included in the BTE model. These were as follows: high number of fields, high number of port films/electronic portal imaging, absence of automatic field-sequencing and multi-leaf collimation, high number of junctions, use of bolus and first fraction of a treatment course. The BTE per hour was shown to be a better predictor of throughput than fields per hour. CONCLUSIONS: The BTE model is a better measure of linear accelerator throughput. It incorporates weightings for treatment and patient factors that significantly influenced fraction duration. This measure could be routinely collected by the radiation oncology departments and included in the electronic radiotherapy information systems.

Data Collection↗

PubMed2003

Lung cancer patterns of care in south western Sydney, Australia.

BACKGROUND: Lung cancer is the leading cause of cancer deaths in New South Wales (NSW). There is a significantly higher incidence of lung cancer in the South Western Sydney Area Health Service (SWSAHS) than the NSW average. The aim of this study was to document patterns of lung cancer care for SWSAHS residents. METHODS: SWSAHS residents diagnosed with lung cancer in 1993 and 1996 were identified from the NSW Central Cancer Registry and their medical records reviewed. RESULTS: The study population comprised 527 patients of median age 68 years. 12% did not see a lung cancer specialist, 9% did not have a pathological diagnosis, and 28% did not receive any active treatment throughout the course of their illness. The median survival was 6.7 months and the 5 year overall survival was 8% (95% CI 6 to 10). The rates of pathological diagnosis, specialist referral, and treatment decreased with older age and poorer performance status. CONCLUSIONS: The management of lung cancer patients in SWSAHS is suboptimal. A significant proportion of patients are not receiving treatment. To improve patient care and outcomes, all lung cancer patients should be referred to a specialist for management, ideally in a multidisciplinary setting. Both consumers and general practitioners need to be educated about options available for the management of lung cancers and ageist and nihilistic attitudes need to be overcome.

Adult↗

PubMed1997

Basic Treatment Equivalent (BTE): a new measure of linear accelerator workload.

The measurement of linear accelerator workload in radiation oncology departments is usually based on the number of fields treated per unit time. However, this approach ignores variations in treatment complexity. This prospective study, was designed to measure treatment workload directly, taking into account the variations in complexity of different treatment techniques. From this, a model was to be developed, which would be simple to apply and reproducible, both within and between radiation oncology departments in Australasia. It would provide a realistic basis for assessing treatment costs and enable the comparison of patient throughput between departments. This paper describes the derivation of the model. Over a 4-week period in the Radiation Oncology Department of Westmead Hospital, all fractions of radiotherapy were timed. The data collected included: tumour site; treatment intent; number of fields; number of wedges, compensators and shielding blocks; fraction number; patient age; performance status; and need for general anaesthesia. Multivariate modelling was performed to identify factors that significantly affected fraction duration, so that these could be used to develop a model of resource utilization. The durations of 2371 fractions were measured in 219 patients. Seventy-five per cent of fractions were given with radical intent. The factors found to influence fraction duration on multivariate modelling were: number of fields; number of shielding blocks; first treatment fraction; need for anaesthesia; and performance status. The number of wedges and compensators were also found to be significant but were not included in the model in order to maintain simplicity. This was felt to be necessary if the model is to be applied to the widest possible variety of machines. A model of resources utilization called 'Basic Treatment Equivalent' (BTE) was derived, which incorporated these factors. When tested at Westmead Hospital, this model accurately reflected the predicted BTE value over a further 1-week study period. This model of linear accelerator use, which incorporates complexity has been derived and evaluated in one radiation oncology department. This requires further prospective testing before its widespread use. The model appears to reflect linear accelerator workload better than previous measures. An Australasian study to validate the model further will be undertaken. If adopted, this model has implications for comparative workload reports, diagnostic-related groups, waiting list calculations, and patient scheduling.

Efficiency↗

PubMed1997

An assessment of the Basic Treatment Equivalent (BTE) model as measure of radiotherapy workload.

Current methods of linear accelerator workload analysis in radiation oncology use patients per hour or fields per hour as the basic unit of measurement but fail to take account of the variations in complexity of different treatment techniques. The Basic Treatment Equivalent (BTE) model of productivity assessment has been derived as a potentially better measure of workload because it includes a complexity factor. This model has now been tested prospectively in ten radiation oncology departments in New South Wales and compared with the numbers of fields and patients per hour. Over a 4-week period there were 50,115 fields administrated in 18,466 fractions in 441 hours of machine time in ten radiation oncology departments. The average productivity results for all departments were 4.18 patients, 11.25 fields and 5.66 BTE per hour. When compared with patients per hour and fields per hour, there was less variability of BTE per patient per hour in all departments, suggesting that most departments deliver radiation therapy in a consistent way, which is not appropriately reflected in the numbers of fields or patients per hour. Departments that were able to treat a high number of patients or fields per hour were able to do so because they used less complicated techniques or had a less complicated casemix of patients. The BTE model allows for variations in the complexity of treatment techniques, is simple to apply, and is reproducible under different conditions in different departments. Following revision of the model, an Australasian study is now proposed. The confirmation of our findings will have significant implications for resource utilization comparisons, patient time allocations, waiting list estimates and cost-benefit analysis.

Efficiency↗

PubMed1997

The equivalent simple treatment visit (ESTV) model does not measure radiation oncology productivity under Australian conditions.

The measurement of workload in radiation oncology departments has been based on the number of patients treated per linear accelerator per unit time, or on the number of fields treated per linear accelerator per unit time. The Equivalent Simple Treatment Visit (ESTV) model was proposed to allow for the incorporation of a factor for complexity of treatment techniques, to permit more detailed comparisons than those offered by previous measures. This prospective study was designed to assess the suitability of the ESTV model as a measure of radiation oncology productivity within an Australian radiation oncology department. A calculated ESTV value was assigned to all treatment fractions delivered in our department over a 4-week period. Treatment fractions were then timed using a stopwatch, and average treatment times for simple, intermediate and complex techniques were calculated and analysed by multiple t-tests for statistical significance. Average treatment times were 8.1 minutes (standard deviation (SD) = 4.2) for 'simple' techniques, 14.1 minutes (SD = 4.4) for 'intermediate' techniques, and 11.8 minutes (SD = 5.6) for 'complex' techniques. These times were significantly different from each other (P < 0.05). Although ESTV attempts to allow for the incorporation of a complexity factor into productivity reporting, a revision of the model is necessary, given the inconsistency by which a 'complex' technique takes significantly less time than an 'intermediate' technique.

Adolescent↗

PubMed1995

Split-course accelerated therapy in head and neck cancer: an analysis of toxicity.

PURPOSE: To retrospectively assess a protocol of split-course accelerated radiation therapy (SCAT) for selected head and neck cancers. METHODS AND MATERIALS: SCAT consisted of 1.8 Gy per fraction administered twice daily with a minimum gap between fractions of 6 h. The treatment protocol prescribed an initial 16 fractions followed by a planned 5 to 12 day break, and then a further 20 to 22 fractions for a total dose ranging from 64.8 to 72 Gy delivered in 5 to 6 weeks. RESULTS: Twenty-eight patients received SCAT for histologically confirmed head and neck cancer between January 1987 and August 1991. All patients were followed up until December 1, 1993. The mean potential follow-up time was 4.2 years (range: 2.9-6.2 years). All patients completed the treatment protocol. Thirteen tumors were laryngeal in origin, eight hypopharyngeal, four paranasal sinus, and three oropharyngeal. There were no Stage I, three Stage II, nine Stage III, and 12 Stage IV tumors. Four tumors were not staged (two paranasal sinus cancers and two surgical recurrences). Early and late toxicities were moderate to severe. Confluent mucositis was experienced by 27 of the 28 patients (96%). One patient required a prolonged midtreatment break of 24 days. Nine patients (32%) required narcotic analgesia for pain relief. Eleven patients (39%) required hospitalization for nasogastric feeding or pain control. The median length of hospital stay was 14 days (range 7-98 days). The actuarial rate of severe late toxicity at 3 years was 47% (standard error (SE) = 13%). A complete tumor response was achieved in 86% of patients. The actuarial local control rate at 3 years was 43% (SE = 11%) and the actuarial survival rate at 3 years was 25% (SE = 8%). CONCLUSION: Given the encouraging complete response rate and local control for such advanced tumors, SCAT for locoregionally advanced tumors merits further investigation. However, because of the significant late toxicity observed, the total dose, interfraction interval, and fractionation technique used should be reconsidered.

Actuarial Analysis↗