Current and projected gaps in the availability of radiotherapy in the Asia-Pacific region: a country income-group analysis

BACKGROUND

Cancer incidence and mortality is increasing rapidly worldwide, with a higher cancer burden observed in the Asia-Pacific region than in other regions. To date, evidence-based modelling of radiotherapy demand has been based on stage data from high-income countries (HIC) that do not account for the later stage at presentation seen in many low-income and middle-income countries (LMICs). We aimed to estimate the current and projected demand and supply in megavoltage radiotherapy machines in the Asia-Pacific region, using a national income-group adjusted model.

METHODS

Novel LMIC radiotherapy demand and outcome models were created by adjusting previously developed models that used HIC cancer staging data. These models were applied to the cancer case mix (ie, the incidence of each different cancer) in each LMIC in the Asia-Pacific region to estimate the current and projected optimal radiotherapy utilisation rate (ie, the proportion of cancer cases that would require radiotherapy on the basis of guideline recommendations), and to estimate the number of megavoltage machines needed in each country to meet this demand. Information on the number of megavoltage machines available in each country was retrieved from the Directory of Radiotherapy Centres. Gaps were determined by comparing the projected number of megavoltage machines needed with the number of machines available in each region. Megavoltage machine numbers, local control, and overall survival benefits were compared with previous data from 2012 and projected data for 2040.

FINDINGS

57 countries within the Asia-Pacific region were included in the analysis with 9·48 million new cases of cancer in 2020, an increase of 2·66 million from 2012. Local control was 7·42% and overall survival was 3·05%. Across the Asia-Pacific overall, the current optimal radiotherapy utilisation rate is 49·10%, which means that 4·66 million people will need radiotherapy in 2020, an increase of 1·38 million (42%) from 2012. The number of megavoltage machines increased by 1261 (31%) between 2012 and 2020, but the demand for these machines increased by 3584 (42%). The Asia-Pacific region only has 43·9% of the megavoltage machines needed to meet demand, ranging from 9·9-40·5% in LMICs compared with 67·9% in HICs. 12 000 additional megavoltage machines will be needed to meet the projected demand for 2040.

INTERPRETATION

The difference between supply and demand with regard to megavoltage machine availability has continued to widen in LMICs over the past decade and is projected to worsen by 2040. The data from this study can be used to provide evidence for the need to incorporate radiotherapy in national cancer control plans and to inform governments and policy makers within the Asia-Pacific region regarding the urgent need for investment in this sector.

FUNDING

The Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology for Asia and the Pacific (RCA) Regional Office (RCARP03).

Predicting 2-year survival in stage I-III non-small cell lung cancer: the development and validation of a scoring system from an Australian cohort

Background

There are limited data on survival prediction models in contemporary inoperable non-small cell lung cancer (NSCLC) patients. The objective of this study was to develop and validate a survival prediction model in a cohort of inoperable stage I-III NSCLC patients treated with radiotherapy.

Methods

Data from inoperable stage I-III NSCLC patients diagnosed from 1/1/2016 to 31/12/2017 were collected from three radiation oncology clinics. Patient, tumour and treatment-related variables were selected for model inclusion using univariate and multivariate analysis. Cox proportional hazards regression was used to develop a 2-year overall survival prediction model, the South West Sydney Model (SWSM) in one clinic (n = 117) and validated in the other clinics (n = 144). Model performance, assessed internally and on one independent dataset, was expressed as Harrell’s concordance index (c-index).

Results

The SWSM contained five variables: Eastern Cooperative Oncology Group performance status, diffusing capacity of the lung for carbon monoxide, histological diagnosis, tumour lobe and equivalent dose in 2 Gy fractions. The SWSM yielded a c-index of 0.70 on internal validation and 0.72 on external validation. Survival probability could be stratified into three groups using a risk score derived from the model.

Conclusions

A 2-year survival model with good discrimination was developed. The model included tumour lobe as a novel variable and has the potential to guide treatment decisions. Further validation is needed in a larger patient cohort.

Trends in the use of short-course radiation therapy for rectal cancer in New South Wales, Australia

INTRODUCTION

Trends in the use of short-course radiation therapy (RT) for rectal cancer in Australia are unknown. The purpose of this study was to compare short-course RT and long-course chemoradiation (CRT) utilisation in the neoadjuvant treatment of rectal cancer in New South Wales (NSW).

METHODS

Patients who received neoadjuvant RT (2009-2014) for rectal cancer were identified from the NSW Central Cancer Registry. Univariate and multivariable analyses were performed to investigate factors associated with receipt of short-course RT.

RESULTS

A total of 1196 (81%) patients received long-course CRT, and 274 (19%) patients received short-course RT. Receipt of short-course RT was associated with older age: 54% in patients ≥80 years, and 11% in patients <50 years (P < 0.0001). Patients with T2 disease (30%) were more likely to receive short-course RT, compared with T3 (19%) or T4 (8%) disease (P = 0.002). Patients with N0 (23%) disease were more likely to be treated with short-course RT, compared with N+ (16%) (P = 0.03). The proportion of short-course RT delivered to patients with Charlson Comorbidity Index (CCI) ≥ 2 (28%) was higher than patients with CCI = 0 (17%) (P = 0.002). There was wide variation in the proportion of short-course RT used across residence local health districts (5-29%) (P < 0.0001).

CONCLUSION

In rectal cancer patients treated with neoadjuvant RT in NSW, 19% received short-course RT. The use of short-course RT was associated with older age, comorbidities and less advanced disease. Wide variation across NSW was identified and future research investigating factors for the variation will be useful.

Surgical and radiotherapy patterns of care in the management of breast cancer in NSW and ACT Australia

INTRODUCTION

This study aims to report on the surgical and radiotherapy patterns of breast cancer care in New South Wales (NSW) and Australian Capital Territory (ACT) in Australia, to identify factors that impact on utilisation of evidence-based treatment and to report on the overall survival (OS) rate and the influencing factors on OS.

METHODS

Cancer registry data linked to hospital records for all patients with breast cancer diagnosis in NSW and ACT between 2009 and 2014 were used to calculate rates of breast conserving surgery (BCS), mastectomy, sentinel lymph node biopsy (SLNB), axillary lymph node dissection (ALND) and radiotherapy. Multivariate analysis used to identify factors that led to variations in care. 5-year OS was calculated and cox regression model assessed factors that influenced survival.

RESULTS

Data for 30,337 patients were analysed. BCS and mastectomy rates were 64% and 36%, respectively. The SLNB, ALND and ALND after SLNB rates were 61.5%, 32.1% and 6.4%, respectively. Radiotherapy was utilised in 63%. Younger age, socio-economic disadvantage, longer distance to a radiotherapy facility and overseas place of birth were factors that predicted for increased rates of mastectomy and ALND. Radiotherapy was more likely to be utilised in later years of diagnosis, patients between 40-69 years old, and those who lived in major cities and closer to a radiotherapy facility. 5-year OS was 80.5%. Older patients, the socioeconomically disadvantaged and those advanced tumours had worse survival.

CONCLUSION

Variations in breast cancer care continue to exist in certain patient groups that we identified. Targeted strategic planning and further research to identify other drivers of existing disparities remain a priority.

Translation of oncology multidisciplinary team meeting (MDM) recommendations into clinical practice

Background

Multidisciplinary team meeting (MDM) processes differ according to clinical setting and tumour site. This can impact on decision making. This study aimed to evaluate the translation of MDM recommendations into clinical practice across solid tumour MDMs at an academic centre.

Methods

A retrospective audit of oncology records was performed for nine oncology MDMs held at Liverpool Hospital, NSW, Australia from 1/2/17–31/7/17. Information was collected on patient factors (age, gender, country of birth, language, postcode, performance status, comorbidities), tumour factors (diagnosis, stage) and MDM factors (number of MDMs, MDM recommendation). Management was audited up to a year post MDM to record management and identify reasons if discordant with MDM recommendations. Univariate and multivariable regression analyses were performed to assess for factors associated with concordant management.

Results

Eight hundred thirty-five patients were discussed, median age was 65 years and 51.4% were males. 70.8% of patients were presented at first diagnosis, 77% discussed once and treatment recommended in 73.2%. Of 771 patients assessable for concordance, management was fully concordant in 79.4%, partially concordant in 12.8% and discordant in 7.8%. Concordance varied from 84.5% for lung MDM to 97.6% for breast MDMs. On multivariable analysis, breast and upper GI MDMs and discussion at multiple MDMs were significantly associated with concordant management. The most common reason for discordant management was patient/guardian decision (28.3%).

Conclusion

There was variability in translation of MDM recommendations into clinical practice by tumour site. Routine measurement of implementation of MDM recommendations should be considered as a quality indicator of MDM practice.

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.

Variation in the use of radiotherapy fractionation for breast cancer: Survival outcome and cost implications

•

We evaluated the use of hypofractionation in breast radiotherapy in an Australian population-based cohort.

•

Hypofractionation appears underused for breast radiotherapy in Australia over time.

•

Variation in practice were observed by patient, tumour, sociodemographic and geographical factors.

•

This study highlights that evidence-based practice will translate to reduced health care treatment costs.

Background and purpose

Substantial variation in the adoption of hypofractionation for breast radiation therapy has been observed, despite the availability of consensus guidelines. This study aimed to investigate the variation in radiation therapy fractionation in breast cancer patients in New South Wales (NSW), Australia, and to estimate survival outcome and cost implications.

Materials and methods

This is a population-based cohort of patients who received radiation therapy for breast cancer (2009–2013), as captured in the NSW Central Cancer Registry. A logistic regression model was used to identify factors associated with fractionation type. Survival outcome was estimated using multivariable Cox proportional hazards model. Cost per treatment and potential cost saving associated with evidence-based fractionation was estimated.

Results

A total of 10,482 patients were available for analysis, divided into 3 cohorts (breast alone: N = 7000; breast + nodes: N = 1119; all chestwall: N = 2363). In multivariable analysis, increasing age, laterality (right), year of treatment (2013), early stage, lower socioeconomic status, and regional area of residence were independent predictors of hypofractionation for breast alone radiation therapy. For the breast + nodes and chest wall cohorts, common factors that predicted the use of hypofractionation were increasing age. In multivariable survival analysis, there was no difference between the fractionation regimens at 5 years. Estimated radiation therapy cost of this cohort approximated $52.1 million, compared with $38.5 million had these patients been treated with evidence-based fractionation. This demonstrated a potential saving of $13.6 million.

Conclusion

Hypofractionation appears underused for breast radiation therapy in NSW over time. This study highlights that evidence-based practice will translate to reduced health care treatment costs.

Quality management in radiation therapy: A 15 year review of incident reporting in two integrated cancer centres

•

Fifteen years of reported incidents were reviewed.

•

Overall reduction in incident severity overtime identified.

•

New technology associated to reduced incident severity.

•

Reporting culture associated to reporting rates.

•

Taxonomy changes required to improve ISL and incident classification.

Fifteen years of reported incidents were reviewed to provide insight into the effectiveness of an Incident Learning System (ISL). The actual error rate over the 15 years was 1.3 reported errors per 1000 treatment attendances. Incidents were reviewed using a regression model. The average number of incidents per year and the number of incidents per thousand attendances declined over time. Two seven-year periods were considered for analysis and the average for the first period (2005–2011) was 6 reported incidents per 1000 attendances compared to 2 incidents for the later period (2012–2018), p < 0.05. SAC 1 and SAC 2 errors have reduced over time and the reduction could be attributed to the quality assurance aspect of IGRT where the incident is identified prior to treatment delivery rather than after, reducing the severity of any potential incidents. The reasoning behind overall reduction in incident reporting over time is unclear but may be associated to quality and technology initiatives, issues with the ISL itself or a change in the staff reporting culture.

Radiotherapy underutilisation and its impact on local control and survival in New South Wales, Australia

BACKGROUND AND PURPOSE

This study aimed to identify the actual radiotherapy utilisation rate (A-RUR) in New South Wales (NSW) Australia for 2009-2011 and compare that to the published evidence-based optimal radiotherapy utilisation rate (O-RUR) and to previously reported A-RUR in NSW in 2004-2006. It also aimed to estimate the effect of underutilisation on 5-year local control (LC) and overall survival (OS) and identify factors that predict for underutilisation.

MATERIALS AND METHODS

All cases of registered cancer diagnosed in NSW between 2009 and 2011 were identified from the NSW Central Cancer Registry and linked with data from all radiotherapy departments. The A-RUR was calculated and compared with O-RURs for all cancers. The difference for each indication was used to estimate 5-year OS and LC shortfall. Univariate and multivariate analyses were performed to identify factors that correlated with reduced radiotherapy utilisation.

RESULTS

110,645 cancer cases were identified. 25% received radiotherapy within one year of diagnosis compared to an estimated optimal rate of 45%. This has marginally improved from previously reported rate of 22% in NSW in 2004-2006. We estimated that 5-year OS and LC were compromised in 1162 and 5062 patients respectively. Factors that predicted for underuse of radiotherapy were older age, male gender, lower socioeconomic status, increasing distance to nearest radiotherapy centre and localised disease.

CONCLUSION

The identified deficit in radiotherapy use has a significant negative impact on patient outcomes. Strategies to overcome such shortfalls need to be developed to improve radiotherapy use and patient outcomes.

Estimating the cost of radiotherapy for 5-year local control and overall survival benefit

BACKGROUND AND PURPOSE

Escalating health care costs have led to greater efforts directed at measuring the cost and benefits of medical treatments. The aim of this study was to estimate the costs of 5-year local control and overall survival benefits of radiotherapy for the cancer population in Australia.

MATERIALS AND METHODS

The local control and overall survival benefits of radiotherapy at 5-years and optimal number of fractions per course have been estimated for 26 tumour sites for which radiotherapy is indicated. For this study, a hybrid approach that merges features from activity based costing (ABC) and relative value units costing (RVU) were used to provide cost estimates. ABC methodology was used to allocate costs to all radiotherapy activities associated with each patient's treatment course, while the RVUs represent the cost of each radiotherapy activity relative to the average cost of all activities and were used to achieve a weighted cost allocation. A patient's journey for the financial year was constructed by consolidating all the radiotherapy activities and their associated costs, and the average cost per activity (fraction) was determined. The cost of radiotherapy per 5-year overall survival and local control was then estimated.

RESULTS

The estimated population 5-year local control and overall survival benefits of radiotherapy for all cancer were 23% and 6%, respectively. The optimal number of fractions per treatment course if guidelines were followed was 19.4 fractions. The average cost per fraction for all cancer was AU$276. The estimated cost of radiotherapy was AU$23,585 per 5-year local control and AU$86,480 per 5-year overall survival (equivalent to 5 life years) for all cancer.

CONCLUSION

The cost of AU$86,480 per 5-year overall survival would translate to AU$17,296 1-year overall survival. Therefore, the cost of radiotherapy is inexpensive if delivered optimally. Policy implications from this study include knowledge about cost to deliver radiotherapy to allow one to quantify the expected benefit at a population level.

Radiotherapy patterns of care for stage I and II non-small cell lung cancer in Sydney, Australia

INTRODUCTION

Curative radiotherapy is guideline treatment for inoperable patients of good performance status with Stage I & II Non-Small Cell Lung Cancer (NSCLC). The aim of this study was to evaluate radiotherapy patterns of care in these patients, the reasons for palliative treatment and the proportion of patients suitable for curative stereotactic ablative body radiotherapy (SABR).

METHODS

Electronic oncology databases at three institutions were queried to retrieve data on patients with inoperable Stage I & II NSCLC seen in radiation oncology clinics between 1/1/2008 and 31/12/2014. Suitability for SABR was defined as peripheral tumours less than 5 cm in size. Factors associated with curative treatment were determined using univariate and multivariate analyses.

RESULTS

Three-hundred-and-twelve patients were identified of whom 178 (57%) received curative radiotherapy, 58 (19%) palliative radiotherapy and 76 (24%) no radiotherapy. The main reason for receiving palliative rather than curative treatment was COPD or poor pulmonary function (26%). Method of diagnosis (P = 0.031), Simplified Comorbidity Score (P = 0.003), ECOG performance status (P = 0.016), FEV1% (P = 0.040), treating institution (P < 0.0001) and time period (P = 0.016) were associated with curative radiotherapy on multivariate analysis. In patients with T1-2N0M0 NSCLC, 19 (31%) who did not receive treatment and 7 (21%) who underwent palliative radiotherapy were technically and clinically suitable for SABR.

CONCLUSION

Only 57% of patients with Stage I-II NSCLC were treated with curative radiotherapy. Patient factors were the predominant reason for palliative treatment, however, treating institution also played a role. A considerable proportion of patients who underwent palliative or no radiotherapy were suitable for SABR treatment.

The population benefit of evidence-based radiotherapy: 5-Year local control and overall survival benefits

BACKGROUND

To describe the population benefit of radiotherapy in a high-income setting if evidence-based guidelines were routinely followed.

METHODS

Australian decision tree models were utilized. Radiotherapy alone (RT) benefit was defined as the absolute proportional benefit of radiotherapy compared with no treatment for radical indications, and of radiotherapy over surgery alone for adjuvant indications. Chemoradiotherapy (CRT) benefit was the absolute incremental benefit of concurrent chemoradiotherapy over RT. Five-year local control (LC) and overall survival (OS) benefits were measured. Citation databases were systematically queried for benefit data. Meta-analysis and sensitivity analysis were performed.

FINDINGS

48% of all cancer patients have indications for radiotherapy, 34% curative and 14% palliative. RT provides 5-year LC benefit in 10.4% of all cancer patients (95% Confidence Interval 9.3, 11.8) and 5-year OS benefit in 2.4% (2.1, 2.7). CRT provides 5-year LC benefit in an additional 0.6% of all cancer patients (0.5, 0.6), and 5-year OS benefit for an additional 0.3% (0.2, 0.4). RT benefit was greatest for head and neck (LC 32%, OS 16%), and cervix (LC 33%, OS 18%). CRT LC benefit was greatest for rectum (6%) and OS for cervix (3%) and brain (3%). Sensitivity analysis confirmed a robust model.

INTERPRETATION

Radiotherapy provides significant 5-year LC and OS benefits as part of evidence-based cancer care. CRT provides modest additional benefits.

The Benefits of Providing External Beam Radiotherapy in Low- and Middle-income Countries

More than half of all cancer diagnoses worldwide occur in low- and middle-income countries (LMICs) and the incidence is projected to rise substantially within the next 20 years. Radiotherapy is a vital, cost-effective treatment for cancer; yet there is currently a huge deficit in radiotherapy services within these countries. The aim of this study was to estimate the potential outcome benefits if external beam radiotherapy was provided to all patients requiring such treatment in LMICs, according to the current evidence-based guidelines. Projected estimates of these benefits were calculated to 2035, obtained by applying the previously published Collaboration for Cancer Outcomes, Research and Evaluation (CCORE) demand and outcome benefit estimates to cancer incidence and projection data from the GLOBOCAN 2012 data. The estimated optimal radiotherapy utilisation rate for all LMICs was 50%. There were about 4.0 million cancer patients in LMICs who required radiotherapy in 2012. This number is projected to increase by 78% by 2035, a far steeper increase than the 38% increase expected in high-income countries. National radiotherapy benefits varied widely, and were influenced by case mix. The 5 year population local control and survival benefits for all LMICs, if radiotherapy was delivered according to guidelines, were estimated to be 9.6% and 4.4%, respectively, compared with no radiotherapy use. This equates to about 1.3 million patients who would derive a local control benefit in 2035, whereas over 615 000 patients would derive a survival benefit if the demand for radiotherapy in LMICs was met. The potential outcome benefits were found to be higher in LMICs. These results further highlight the urgent need to reduce the gap between the supply of, and demand for, radiotherapy in LMICs. We must attempt to address this 'silent crisis' as a matter of priority and the approach must consider the complex societal challenges unique to LMICs.

Comparison of Magnetic Resonance Imaging and Computed Tomography for Breast Target Volume Delineation in Prone and Supine Positions

PURPOSE

To determine whether T2-weighted MRI improves seroma cavity (SC) and whole breast (WB) interobserver conformity for radiation therapy purposes, compared with the gold standard of CT, both in the prone and supine positions.

METHODS AND MATERIALS

Eleven observers (2 radiologists and 9 radiation oncologists) delineated SC and WB clinical target volumes (CTVs) on T2-weighted MRI and CT supine and prone scans (4 scans per patient) for 33 patient datasets. Individual observer's volumes were compared using the Dice similarity coefficient, volume overlap index, center of mass shift, and Hausdorff distances. An average cavity visualization score was also determined.

RESULTS

Imaging modality did not affect interobserver variation for WB CTVs. Prone WB CTVs were larger in volume and more conformal than supine CTVs (on both MRI and CT). Seroma cavity volumes were larger on CT than on MRI. Seroma cavity volumes proved to be comparable in interobserver conformity in both modalities (volume overlap index of 0.57 (95% Confidence Interval (CI) 0.54-0.60) for CT supine and 0.52 (95% CI 0.48-0.56) for MRI supine, 0.56 (95% CI 0.53-0.59) for CT prone and 0.55 (95% CI 0.51-0.59) for MRI prone); however, after registering modalities together the intermodality variation (Dice similarity coefficient of 0.41 (95% CI 0.36-0.46) for supine and 0.38 (0.34-0.42) for prone) was larger than the interobserver variability for SC, despite the location typically remaining constant.

CONCLUSIONS

Magnetic resonance imaging interobserver variation was comparable to CT for the WB CTV and SC delineation, in both prone and supine positions. Although the cavity visualization score and interobserver concordance was not significantly higher for MRI than for CT, the SCs were smaller on MRI, potentially owing to clearer SC definition, especially on T2-weighted MR images.

A Population-based Model of Local Control and Survival Benefit of Radiotherapy for Lung Cancer

AIMS

To estimate the population-based locoregional control and overall survival benefits of radiotherapy for lung cancer if the whole population were treated according to evidence-based guidelines. These estimates were based on a published radiotherapy utilisation (RTU) model that has been used to estimate the demand and planning of radiotherapy services nationally and internationally.

MATERIALS AND METHODS

The lung cancer RTU model was extended to incorporate an estimate of benefits of radiotherapy alone, and of radiotherapy in conjunction with concurrent chemotherapy (CRT). Benefits were defined as the proportional gains in locoregional control and overall survival from radiotherapy over no radiotherapy for radical indications, and from postoperative radiotherapy over surgery alone for adjuvant indications. A literature review (1990-2015) was conducted to identify benefit estimates of individual radiotherapy indications and summed to estimate the population-based gains for these outcomes. Model robustness was tested through univariate and multivariate sensitivity analyses.

RESULTS

If evidence-based radiotherapy recommendations are followed for the whole lung cancer population, the model estimated that radiotherapy alone would result in a gain of 8.3% (95% confidence interval 7.4-9.2%) in 5 year locoregional control, 11.4% (10.8-12.0%) in 2 year overall survival and 4.0% (3.6-4.4%) in 5 year overall survival. For the use of CRT over radiotherapy alone, estimated benefits would be: locoregional control 1.7% (0.8-2.4%), 2 year overall survival 1.7% (0.5-2.8%) and 5 year overall survival 1.2% (0.7-1.9%).

CONCLUSIONS

The model provided estimates of radiotherapy benefit that could be achieved if treatment guidelines are followed for all cancer patients. These can be used as a benchmark so that the effects of a shortfall in the utilisation of radiotherapy can be better understood and addressed. The model can be adapted to other populations with known epidemiological parameters to ensure the planning of equitable radiotherapy services.

Estimating the population benefit of radiotherapy: using demand models to estimate achievable cancer outcomes

The measurement of population benefits is important for priority setting, economic evaluation and quality improvement. It also informs advocacy. In this article, the use of demand models to estimate the achievable benefit of cancer therapy is reviewed. Achievable benefit refers to the treatment benefit achievable under optimal conditions. The population benefit of radiotherapy has been used as an example. Demand models provide a means of estimating the optimal proportion of patients with treatment indications when guidelines are followed. They may be used to estimate achievable benefit. The choice of end point should reflect the range of benefits associated with the treatment of interest. In some cases, further model development is needed if a pre-existing demand model is used. The benefit of treatment for each indication is estimated using a systematic review process. The highest level of evidence is used to define the benefit for each indication. In cases where multiple sources of the same level and quality of evidence exist, a meta-analysis is carried out. Population-based effectiveness data sources are considered, but three major challenges to their use are: (i) generalisability of the observed outcomes, (ii) data resolution and (iii) confounding and bias. The population benefit determined from this process describes the population proportion achieving a benefit due to the use of guideline-based treatment, compared with no use of that treatment. Sensitivity analysis provides a means for modelling the effect of model uncertainties. The predominant uncertainty is most often due to uncertainty in indication proportion. Preference-sensitive treatment decisions are a common example. The described approach to estimating the achievable benefit of cancer therapy is robust to model uncertainties, rapidly adaptable and is transparent. However, estimates rely on the quality of model data sources and may be affected by model assumptions. Models should be developed for a broader range of modalities of cancer therapy and relevant end points.

Abstract P3-11-11: A Comparison of Breast Cancer Treatment Rates in British Columbia, Scotland, and Western Australia, and a Comparison with Models of “Optimal” Therapy

Background: Evidence-based optimal utilization models provide estimates of optimal radiotherapy, chemotherapy and hormonal therapy utilization by stage and other clinically relevant patient sub-groups. We therefore compared predicted utilization with actual utilization of radiotherapy, hormone therapy and chemotherapy in 3 jurisdictions with population-based stage and treatment data: British Columbia, Canada; Dundee, Scotland; and Perth, Western Australia.

Methods: Previously published optimal radiotherapy, chemotherapy, and endocrine therapy treatment utilization trees for an Australian population were modified to incorporate epidemiological data from British Columbia, Dundee, and Perth, such that the optimal trees for each region reflected the casemix for each region. Frequency data on patient, tumour, and surgical factors were used to calculate optimal treatment rates for each region. Optimal rates were then compared with actual rates of surgery, radiotherapy, chemotherapy, and endocrine therapy use obtained from 2 population-based and 1 institution-based cancer registries for patients diagnosed with breast cancer between 2000 to 2004. Information on region-specific treatment guidelines was also collected.

Results: Region-specific optimal treatment utilization rates at diagnosis varied between 80% and 81% for radiotherapy (62 to 64% when patient preference is taken into account), 53% to 56% for chemotherapy, and 49% to 54% for endocrine therapy. The predicted ranges were due to local variations in demographics, and tumour stage. Actual radiotherapy utilization was 57%, 49%, and 52%; chemotherapy utilization was 32%, 24%, and 29%; and endocrine therapy utilization was 56%, 64%, and 52% for British Columbia, Dundee, and Perth, respectively. Conclusion: There are significant differences in actual treatment utilisation rates between the study populations. It is unlikely that all of this variation is due to differences in tumour characteristics alone. Actual utilization rates were lower than the calculated optimal rates for radiotherapy and chemotherapy, and higher for endocrine therapy. Differences between actual regional rates of treatment utilization were seen, and were associated with differences in mastectomy rates, and guideline recommendations for treatment use in that region. This methodology allows comparison of the treatment that occurs in a jurisdiction against what would be considered optimal based on evidence.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-11-11.

Management of skin toxicity during radiation therapy: a review of the evidence

Acute skin toxicity occurs in the majority of the patients undergoing radical radiotherapy. While a variety of topical agents and dressing are used to ameliorate side effects, there is minimal evidence to support their use. The aims of this study were to systematically review evidence on acute skin toxicity management and to assess the current practices in ANZ. A systematic review of the literature was conducted on studies published between 1980 and 2008. A meta-analysis was performed on articles on clinical trials reporting grade II or greater toxicity. Analyses were divided into breast (the most common site) and other sites. A survey of Radiation Oncology departments across ANZ was conducted to identify patterns of practices and compare these with the published evidence. Twenty-nine articles were reviewed. Only seven articles demonstrated statistically significant results for management of side-effects. These were for topical corticosteroids, hyaluronic acid, sucralfate, calendula, Cavilon cream (3M, St Paul, Minnesota, USA) and silver leaf dressing. Meta-analysis demonstrated statistical significance for the prophylactic use of topical agents in the management acute toxicity. The survey of departments had a low response rate but demonstrated variation in skin care practices across ANZ. A considerable number of these practices were based only on anecdotal evidence. Lack of evidence in the literature for the care of radiation skin reactions was associated with variation in practice. Only a limited number of studies have demonstrated a significant benefit of specific topical agents. There is a need for objective and prospective recording of skin toxicity to collect meaningful comparative data on which to base recommendations for practice.

Dosimetric implications of the addition of 18 fluorodeoxyglucose-positron emission tomography in CT-based radiotherapy planning for non-small-cell lung cancer

Summary The aim of this study was to assess the impact of F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) CT on radiotherapy planning parameters for patients treated curatively with radiotherapy for non-small-cell lung cancer (NSCLC). Five patients with stages I-III NSCLC underwent a diagnostic FDG-PET CT (dPET CT), planning FDG-PET CT (pPET CT) and a simulation CT (RTP CT). For each patient, three radiation oncologists delineated a gross tumour volume based on RTP CT alone, and fused with dPET CT and pPET CT. Standard expansions were used to generate PTVs, and a 3D conformal plan was created. Normal tissue doses were compared between plans. Coverage of pPET CT PTV by the plans based on RTP CT and dPET CT was assessed, and tumour control probabilities were calculated. Mean PTV was similar between RTP CT, dPET CT and pPET CT, although there were significant inter-observer differences in four patients. The plans, however, showed no significant differences in doses to lung, oesophagus, heart or spinal cord. The RTP CT plan and dPET CT plan significantly underdosed the pPET PTV in two patients with minimum doses ranging from 12 to 63% of prescribed dose. Coverage by the 95% isodose was suboptimal in these patients, but this did not translate into poorer tumour control probability. The effect of fused FDG-PET varied between observers. The addition of dPET and pPET did not significantly change the radiotherapy planning parameters. Although FDG-PET is of benefit in tumour delineation, its effect on normal tissue complication probability and tumour control probability cannot be predicted.

Patients' and health care professionals' evaluation of health-related quality of life issues in bone metastases

The objective of this study was to examine the agreement between health care professionals' (HCPs) and patients' evaluation of health-related quality of life (HRQOL) issues for cancer patients with bone metastases. A total of 413 patients and 152 HCPs were interviewed across five centres worldwide. Mean scores were almost always higher for HCPs than for patients. Patients and HCPs agreed that four issues affect HRQOL of bone metastases patients profoundly: 'long-term (chronic) pain', 'difficulty in carrying out usual daily tasks', 'able to perform self-care' and 'able to perform role functioning'. A substantial difference was found with respect to the perceived importance of psychosocial and somatic issues. Patients emphasised psychosocial issues with a particular focus on 'worry' about loss of mobility, dependence on others and disease progression, HCPs however rated 'symptom' issues as more important, specifically those related to 'pain'. In conclusion, patients and HCPs agreed that pain and physical/role functioning are important to the HRQOL of cancer patients with bone metastases, but patients also emphasized the importance of psychosocial issues to HRQOL. This information has been an important component in the development of a health-related quality of life questionnaire for patients with bone metastases (EORTC QLQ-BM 22).

An evidence-based estimation of local control and survival benefit of radiotherapy for breast cancer

BACKGROUND AND PURPOSE

Survival benefits from radiotherapy for breast cancer described in randomised trials represent only those patients eligible for trials. We estimated the benefit of radiotherapy as an adjuvant treatment for the entire population of breast cancer patients if evidence-based treatment guidelines were followed.

MATERIALS AND METHODS

Evidences on 10-year local control and overall survival gain (radiotherapy vs no radiotherapy) were identified from review of literature. The data were incorporated into the optimal radiotherapy utilization tree that we previously reported for all categories of breast cancer patients and overall local control and survival benefits were estimated.

RESULTS

The gains in 10-year local control and overall survival from optimal treatment of all breast cancer patients were 11.1% (95% CI 10.8-11.2%) and 3.1% (95% CI 3.0-3.4%), respectively. The stage-based estimates in local control and survival benefit were: 8% and 0% for Ductal Carcinoma in situ (DCIS), 12% and 2% for stage I-II cancers and 13% and 20% for stage III cancers.

CONCLUSIONS

Our model was able to estimate the contribution of radiotherapy in breast cancer treatment if all patients were treated according to the recommended guidelines. These estimates could be used to benchmark population-based survival reports and to assess the cost-effectiveness of radiotherapy for breast cancer treatment.

Role of radiotherapy in cancer control in low-income and middle-income countries

More than half the cases of cancer in the world arise in people in low-income and middle-income countries. This proportion will rise to 70% by 2020. These are regions where the annual gross national income per person is less than 9386 US dollars. Radiotherapy is an essential part of the treatment of cancer. In high-income countries, 52% of new cases of cancer should receive radiotherapy at least once and up to 25% might receive a second course. Because of the different distribution of tumour types worldwide and of the advanced stage at presentation, patients with cancer in low-income and middle-income regions could have a greater need for radiotherapy than those in high-income countries. Radiotherapy for cure or palliation has been shown to be cost effective. Many countries of low or middle income have limited access to radiotherapy, and 22 African and Asian countries have no service at all. In Africa in 2002, the actual supply of megavoltage radiotherapy machines (cobalt or linear accelerator) was only 155, 18% of the estimated need. In the Asia-Pacific region, nearly 4 million cases of cancer arose in 2002. In 12 countries with available data, 1147 megavoltage machines were available for an estimated demand of nearly 4000 megavoltage machines. Eastern Europe and Latin America showed similar shortages. Strategies for developing services need planning at a national level and substantial investment for staff training and equipment. Safe and effective development of services would benefit from: links with established facilities in other countries, particularly those within the same region; access to information, such as free online journal access; and better education of all medical staff about the roles and benefits of radiotherapy.

Polyclonal expansion of peripheral gamma delta T cells in human Plasmodium falciparum malaria

Plasmodium falciparum malaria in humans is associated with an increase in the percentage and absolute number of gamma delta T cells in the peripheral blood. This increase begins during the acute infection phase and persists for at least 4 weeks during convalescence. In the present study, 25 to 30% of the gamma delta T cells expressed HLA-DR antigens in vivo and in some patients they proliferated in response to further stimulation by purified human interleukin 2 in vitro. However, there was no in vitro proliferative response to various malarial antigens, including a 75-kDa heat shock protein and a 72-kDa glucose-regulated protein of P. falciparum during the acute infection phase. Cytofluorographic studies showed that although an increase of V delta 1- gamma delta T cells was largely responsible for the expansion of the total number of gamma delta T cells, there was also a proportional increase in V delta 1+ cells. These results were confirmed with anchored PCR and by DNA sequencing to characterize at the molecular level the set of T-cell receptor (TCR) delta mRNAs expressed in the peripheral blood of two patients with high levels of gamma delta T cells. In each case, most of the TCR delta mRNA transcripts corresponded to nonproductively rearranged delta genes (unrearranged J delta or near J delta spliced to C delta). In those sequences which did represent productively rearranged genes, most of the transcripts originated from a V delta 2/J delta 1 joining, as in normal individuals. A minority of transcripts originated from a V delta 1/J delta 1 rearrangement, and one originated from a V alpha 4/J delta 1 rearrangement. Polyclonal activation of gamma delta T cells was inferred from the extensive junctional diversity seen in the delta mRNAs analyzed. Expansion of a heterogeneous set of both V delta 1(-)- and V delta 1(+)-bearing T cells suggests that the elevated levels of gamma delta T cells seen during acute P. falciparum malaria arose from immune responses to multiple distinct parasite antigens or unidentified host factors.

Effects of a newly synthesized K+ channel opener, Y-26763, on noradrenaline-induced Ca2+ mobilization in smooth muscle of the rabbit mesenteric artery

1. The mechanisms underlying the vasodilatation induced by (-)-(3S,4R)-4-(N-acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2, 2-dimethyl-2H-1-benzopyran-3-ol (Y-26763) were investigated by measuring membrane potential, intracellular Ca2+ concentration ([Ca2+]i) and isometric force in smooth muscle cells of the rabbit mesenteric artery. 2. Y-26763 (0.03-1 microM) concentration-dependently hyperpolarized the membrane and glibenclamide (1-10 microM) inhibited this hyperpolarization. Noradrenaline (NA, 10 microM) depolarized the membrane and generated spike potentials. Y-26763 (1 microM) inhibited these NA-induced electrical responses. 3. In thin smooth muscle strips in 2.6 mM Ca2+ containing (Krebs) solution, 10 microM NA produced a large phasic, followed by a small tonic increase in [Ca2+]i and force with associated oscillations. In Ca(2+)-free solution (containing 2 mM EGTA), NA produced only phasic increases in [Ca2+]i and force. In ryanodine-treated strips, NA could not produce the phasic increases in [Ca2+]i and force even in the presence of 2.6 mM Ca2+, suggesting that ryanodine functionally removes the NA-sensitive intracellular storage sites. 4. Nicardipine (1 microM) partly inhibited the NA-induced tonic increases in [Ca2+]i and force but had no effect on either the resting [Ca2+]i or the NA-activated phasic increases in [Ca2+]i and force. By contrast, Y-26763 (10 microM) lowered the resting [Ca2+]i and also inhibited both the phasic and the tonic increases in [Ca2+]i and force induced by NA. All these actions of Y-26763 were inhibited by glibenclamide (10 microM). 5. In ryanodine-treated strips, nicardipine partly, but Y-26763 completely inhibited the NA-induced increases in [Ca2+]i, suggesting that Y-26763 inhibits both the nicardipine-sensitive and -insensitive Ca2+ influxes activated by NA. Y-26763 attenuated the phasic increase in [Ca2+]i and force in a Ca(2+)-free solution containing 5.9 mM K+, but not in one containing 50 mM K+, suggesting that Y-26763 inhibits NA-induced Ca2+ release, probably as a result of its membrane hyperpolarizing action. 6. In Beta-escin-skinned strips, Y-26763 (10 MicroM) had no effect on either the NA-induced Ca2+ release or the Ca2+-tension relationship in the presence and absence of NA (10 MicroM) with guanosine 5'-triphosphate(GTP, 10 MicroM), suggesting that Y-26763 has no direct action on either NA-induced Ca2+ release or the contractile proteins.7. It is concluded that Y-26763 inhibits NA-activated Ca2+ release and Ca2+ influx and thus inhibits the NA-contraction. Y-26763 also lowers the resting [Ca2+]i through an inhibition of the nicardipine insensitive Ca2+ influx. These actions of Y-26763 may be linked with the membrane hyperpolarization it produces by activation of the ATP-sensitive K+ channels.

Use of restriction fragment length polymorphisms resolved by pulsed-field gel electrophoresis for subspecies identification of mycobacteria in the Mycobacterium avium complex and for isolation of DNA probes

Mycobacterial strains from the Mycobacterium avium complex were compared with each other and with Mycobacterium phlei isolates by restriction endonuclease digestion of chromosomal DNA with SspI and analysis by pulsed-field gel electrophoresis. Characteristic profiles were observed for known typed strains, and five groups were identified. Primary bovine isolates identified as Mycobacterium paratuberculosis by classical methods were shown to fall into both the M. paratuberculosis- and M. avium-like groups. M. paratuberculosis 18 was in the latter category. Two Mycobacterium intracellulare strains of different Schaefer serotypes had different digestion profiles. In addition, this system was exploited for the preparation of DNA probes by the isolation, digestion, and subcloning of DNA fragments separated by pulsed-field gel electrophoresis. Probe JC12 hybridized only to M. avium complex strains, but not to M. phlei, showing characteristic hybridization profiles for each of the groups previously identified by pulsed-field gel electrophoresis. The approach taken in the study lends itself to the comparative analysis of members of the M. avium complex and to the isolation and characterization of DNA probes with specificity for these mycobacteria.

Mechanisms of vasodilation induced by NKH477, a water-soluble forskolin derivative, in smooth muscle of the porcine coronary artery

To study the mechanism of vasodilation induced by 6-(3-dimethylaminopropionyl) forskolin (NKH477), a water-soluble forskolin derivative, its effects on the acetylcholine (ACh)-induced contraction of muscle strips of porcine coronary artery were examined. [Ca2+]i, isometric force, and cellular concentrations of cAMP and inositol 1,4,5-trisphosphate were measured. NKH477 (0.1-1.0 microM), isoproterenol (0.01-0.1 microM), or forskolin (0.1-1.0 microM) increased cAMP and attenuated the contraction induced by 128 mM K+ or 10 microM ACh in a concentration-dependent manner. These agents, at concentrations up to 0.3 microM, did not change the amount of cGMP. NKH477 (0.1 microM) attenuated the contraction induced by 128 mM K+ without corresponding changes in the evoked [Ca2+]i responses. ACh (10 microM) produced a large phasic increase followed by a small tonic increase in [Ca2+]i and produced a sustained contraction. The ACh-induced phasic increase in [Ca2+]i, but not the tonic increase, disappeared after application of 0.1 microM ionomycin. NKH477 (0.1 microM) attenuated both the increase in [Ca2+]i and the force induced by 10 microM ACh in muscle strips that were not treated with ionomycin and inhibited the ACh-induced contraction without corresponding changes in [Ca2+]i in ionomycin-treated muscle strips. These results suggest that NKH477 inhibits ACh-induced Ca2+ mobilization through its action on ionomycin-sensitive storage sites. In ionomycin-treated and 128 mM K(+)-treated muscle strips, 0.1 microM NKH477 shifted the [Ca2+]i-force relation to the right in the presence or absence of 10 microM ACh. In beta-escin-skinned smooth muscle strips, 0.1 microM NKH477 shifted the pCa-force relation to the right but had no effects on Ca(2+)-independent contraction. We conclude that in smooth muscle of porcine coronary artery, NKH477 inhibits ACh-induced contraction by both attenuating ACh-induced Ca2+ mobilization and reducing the sensitivity of the contractile machinery to Ca2+, possibly by activating cAMP-dependent mechanisms.