Patterns of palliative radiotherapy fractionation for brain metastases patients in New South Wales, Australia.

BACKGROUND AND PURPOSE: There is a paucity of studies examining variation in the use of palliative radiation therapy (RT) fractionation for brain metastases. The aim of this study is to assess variation in palliative RT fractionation given for brain metastases in New South Wales (NSW), Australia, and identify factors associated with variation. MATERIALS AND METHODS: This is a population-based cohort of patients who received whole brain RT (WBRT) for brain metastases (2009-2014), as captured in the NSW Central Cancer Registry. A logistic regression model was used to identify factors associated with fractionation type. RESULTS: Of the 2,698 patients that received WBRT, 1,389 courses (51%) were < 6 fractions, 1,050 courses (39%) were 6-10 fractions, and 259 courses (10%) were > 10 fractions. Older patients were more likely to be treated with shorter courses (P < 0.0001). Patients with primary lung cancers were more likely to receive shorter courses compared with other primary cancers (P < 0.0001). Patients without surgical excision were more likely to receive < 6 fractions compared to those who underwent surgical excision. Shorter courses were more likely to be delivered to patients with the most disadvantaged socioeconomic status (SES) compared with patients with the least disadvantaged SES (P < 0.0001). There were significant fluctuations in the proportion of courses using lower number of fractions over time from 2009 to 2014, but no apparent trend (P = 0.02). There was wide variation in the proportion of shorter courses across residence local health districts, ranging from 24% to 69% for < 6 fractions, 21% to 72% for 6-10 fractions, and 4% to 20% for > 10 fractions (P < 0.0001). CONCLUSION: This study has identified significant unwarranted variations in fractionation for WBRT in NSW. Accelerating the uptake of shorter fractionation regimens, if warranted through evidence, should be prioritised to enhance evidence-based care.

Patterns of use of palliative radiotherapy fractionation for bone metastases and 30-day mortality.

BACKGROUND AND PURPOSE: Adoption of single-fraction radiation therapy (SFRT) has not been universal in the palliative treatment of bone metastases, despite evidence supporting its safety and efficacy. The aim of this study was to assess SFRT use for bone metastases in New South Wales (NSW), Australia, and the rate of 30-day mortality (30DM). MATERIALS AND METHODS: This is a population-based cohort of patients who received palliative radiation therapy (RT) for bone metastases (2009-2014), as captured in the NSW Central Cancer Registry. A logistic regression model was used to identify factors associated with fractionation type. The proportion of patients dying within 30-days from treatment start date was calculated. RESULTS: Of the 14,602 courses of palliative RT delivered for bone metastases, 30% were SFRT. SFRT was more likely to be delivered to older patients: ≥80 years (34%) versus < 60 years (28%). Patients with lower socioeconomic status (SES) (35%) were more likely to receive SFRT compared with higher SES (25%). SFRT delivered to patients from outer regional area of residence (34%) were higher compared to those from the major city (29%). The proportion of SFRT delivered to patients with comorbidities ≥2 (34%) was higher than patients with no comorbidity (29%). SFRT was associated with higher 30DM of 21% compared with 11% for multi-fraction RT (MFRT). CONCLUSION: SFRT is underused for the treatment of bone metastases in NSW. This is an impetus to develop tools making SFRT obligatory in this setting unless there is good justification not to.

Health Economic and Health Service Issues of Palliative Radiotherapy.

Palliative radiotherapy (PRT) makes up about half of all courses delivered in radiotherapy departments. It is effective in the management of common complications of cancer and is relatively inexpensive. About one third of cancer patients receive PRT within the last 2 years of life. One quarter of all patients who receive radiotherapy will undergo a second or subsequent course, mostly for palliative indications. There is considerable variation in practice, both within and between jurisdictions. This has been attributed to inconsistencies in guidelines, physician variation and differing financial incentives. Because of the widespread use of hypofractionation, variation in PRT fractionation has a lower effect on departmental capacity than variation in radical and adjuvant treatments. Excessive fractionation places an unnecessary burden on frail patients at the end of their lives and uses scarce healthcare resources. With appropriate case selection, the increased cost of fractionation or more conformal treatments can be justified where clinical benefit is expected.

Interobserver variability in clinical target volume delineation in tangential breast irradiation: a comparison between radiation oncologists and radiation therapists.

AIMS: The delineation of target volumes has been radiation oncologist led. If radiation therapists were to undertake this task, work processes may be more efficient and the skills set of radiation therapy staff broadened. This study was undertaken to quantify interobserver variability of breast target volumes between radiation oncologists and radiation therapists. MATERIALS AND METHODS: The planning computed tomography datasets of 30 patients undergoing tangential breast radiotherapy were utilised. Four radiation oncologists and four radiation therapists independently contoured the clinical target volume (CTV) of the breast on planning computed tomography using a written protocol. The mean CTV volumes and the mean distance between centres of volume (COV) were determined for both groups to determine intergroup variation. Each of the radiation oncologists' readings in turn has been used as the gold standard and compared with that of the radiation therapists. The concordance index for each patient's CTV was determined relative to the gold standard for each group. A paired t-test was used for statistical comparison between the groups. An intraclass correlation coefficient was calculated to measure the agreement between the radiation oncologist and radiation therapist groups. RESULTS: The mean concordance index was 0.81 for radiation oncologists and 0.84 for radiation therapists. The intraclass correlation coefficient for the mean volume was 0.995 (95% confidence interval 0.981-0.998) between radiation oncologist- and radiation therapist-contoured volumes. The intraclass correlation for the mean difference between radiation oncologists' and radiation therapists' COV was 0.999 (95% confidence interval 0.999-1.000). CONCLUSIONS: Interobserver variability between radiation oncologists and radiation therapists was found to be low. Radiation therapists could potentially assume the role of CTV voluming for breast radiotherapy provided a standardised contouring protocol is in place.