Estimating the need for radiotherapy for lung cancer: an evidence-based, epidemiologic approach

Referral rates and trends in radiotherapy as part of primary treatment of cancer in South Netherlands, 1988–2002

BACKGROUND AND PURPOSE

To study referral rates and time trends in the use of primary radiotherapy (RT).

PATIENTS AND METHODS

The proportion and number of irradiated patients were calculated in a population-based setting among 58,436 cancer patients diagnosed between 1988 and 2002.

RESULTS

The number of patients receiving RT within 6 months of diagnosis (RT6mo) increased by about 3.3% annually, the proportion of all incident cases that received RT6mo remained stable (+/-30%). Only 20% of elderly patients (75+) received RT6mo. The proportion of cancer patients that received RT6mo increased markedly between 1988-1992 and 1998-2002 for patients with prostate cancer (15 and 28%, respectively), rectal cancer (33 and 43%) and brain tumours (48 and 67%). The absolute number of irradiated breast cancer patients increased 30% between 1988 and 2002. Among patients with rectal cancer, a shift occurred from postoperative to preoperative RT since 1995. The percentage of irradiated patients with stage I endometrial cancer decreased from 47% in 1988-1992 to 15% in 1998-2002.

CONCLUSIONS

The percentage of cancer patients who received primary RT remained stable throughout 1988-2002, being consistently lower for older patients. The increased number of irradiated patients was due mainly to earlier detection and the ageing of the population. To clarify the overall percentage of patients irradiated, population-based studies on RT given after 6 months since diagnosis are warranted.

Estimating the optimal radiotherapy utilization for carcinoma of the central nervous system, thyroid carcinoma, and carcinoma of unknown primary origin from evidence-based clinical guidelines

BACKGROUND

In this one in a series of articles, the objective was to estimate the ideal proportion of patients with cancer who should receive radiotherapy at least once during the course of their illness based on the best available evidence. This estimate should be useful in planning for future radiotherapy facilities. Optimal rates of radiotherapy for patients with central nervous system (CNS) carcinoma, thyroid carcinoma, or carcinoma of unknown primary site (CUP) have not been studied previously.

METHODS

A systematic review of evidence-based treatment guidelines for the treatment of CNS carcinoma, CUP, and thyroid carcinoma was undertaken. An optimal radiotherapy utilization tree was constructed for each of these malignancies depicting the indications for radiotherapy at various stages of disease. The proportion of patients who had clinical attributes that indicated a possible benefit from radiotherapy was calculated by adding epidemiological data to the radiotherapy utilization tree. The optimal proportion of patients who should receive radiotherapy was then calculated using specialized decision-analysis software. Sensitivity analyses using univariate analysis and Monte Carlo simulations were performed.

RESULTS

The optimal rates of radiotherapy utilization for carcinoma of the CNS, thyroid carcinoma, and CUP were 92%, 10%, and 61%, respectively. Comparison with actual rates of utilization in South Australia, Sweden, and the U.S. suggested an under-utilization of radiotherapy for CNS carcinoma and CUP. However, the actual rates of radiotherapy for thyroid carcinoma exceeded the optimal rate for some jurisdictions, although some data may have included radioactive iodine, which was not included in the current project.

CONCLUSIONS

It was possible to estimate optimal radiotherapy utilization rates based on evidence. This methodology allowed a comparison of optimal rates with actual rates to identify areas in which improvements in the evidence-based use of radiotherapy can be made, and it may provide valuable data for future radiotherapy service planning.

Estimation of the optimal brachytherapy utilization rate in the treatment of carcinoma of the uterine cervix

BACKGROUND

Brachytherapy (BT) is an integral part of cervical carcinoma treatment. There have been no attempts to estimate the optimal proportion of new cervical carcinoma cases that should be treated with BT, that is, the optimal rate of brachytherapy utilization (BTU).

METHODS

Evidence-based guidelines and primary evidence were used to construct a BTU tree for carcinoma of the uterine cervix. Searches were performed of the epidemiological literature to ascertain the proportion of patients who fulfilled criteria for BT. The robustness of the model was tested by sensitivity analyses and by peer review. A patterns of care study of BT in New South Wales for 2003 was conducted, and actual BTU for cervical carcinoma determined. The differences between optimal and actual rates of BTU were assessed.

RESULTS

The optimal cervical carcinoma BTU was 49% (range, 42% to 50%). In New South Wales in 2003, actual BTU was only 30% of 256 cervical carcinoma patients. The major discrepancy was for FIGO stage IB-IIA disease, where there was an underutilization of BT, estimated to be 15% actual use compared with 47% optimal use. In Surveillance, Epidemiology, and End Results (SEER) areas, there was underutilization for stage IB-IIA (22% actual BTU versus 47% optimal BTU) and for stage IIB-IVA (54% actual BTU versus 100% optimal BTU).

CONCLUSIONS

BT for cervical carcinoma is underutilized in New South Wales and in SEER areas. The authors' model of optimal BTU can be used as a quality assurance tool to provide an evidence-based benchmark against which actual patterns of practice can be measured. The model can also be used to help determine adequacy of BT resource allocation.

Imaging of the Patient with Non–Small Cell Lung Cancer

Lung cancer is the most common type of cancer and is the leading cause of cancer deaths in the United States for both men and women. Even though the 5-year survival rate of patients with lung cancer remains dismal at 14% for all cancer stages, treatments are improving and newer agents for lung cancer appear promising. Therefore, an accurate assessment of the extent of disease is critical to determine whether the patient is treated with surgical resection, radiation therapy, chemotherapy, or a combination of these modalities. Radiologic imaging plays an important role in the staging evaluation of the patient; however, radiologists need to be aware that there are also important differences in what each specialist needs from imaging to provide appropriate treatment. This article reviews the role of imaging in patients with non-small cell lung cancer, with an emphasis on the radiologic imaging findings relevant for each specialty.

An evidence-based estimate of the appropriate rate of utilization of radiotherapy for cancer of the cervix

PURPOSE

Current estimates of the proportion of cancer patients who will require radiotherapy (RT) are based almost entirely on expert opinion. The objective of this study was to calculate the proportion of incident cases of cervical cancer that should receive RT by application of an evidence-based approach.

METHODS AND MATERIALS

A systematic review of the literature was done to identify indications for RT for cervical cancer and to ascertain the level of evidence that supported each indication. A survey of Canadian gynecologic oncologists and radiation oncologists who treat cervical cancer was done to determine the level of acceptance of each indication among doctors who practice in the field. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of patients with cervical cancer.

RESULTS

The systematic review of the literature identified 29 different indications for RT for cervical cancer. The majority of the 75 experts who responded to the mail survey stated that they "usually" or "always" recommended RT in all but one of the clinical situations that were identified as indications for RT on the basis of the systematic review. The analysis of epidemiologic data revealed that, in a typical North American population, 65.4% +/- 2.5% of cervical cancer cases will develop one or more indications for RT at some point in the course of the illness, 63.4% +/- 2.3% will develop indications for RT as part of their initial management, and 2.0% +/- 0.9% will develop indications for RT for progressive or recurrent disease. The effects of variations in case mix on the need for RT was examined by sensitivity analysis, which suggested that the maximum plausible range for the appropriate rate of utilization of RT was 54.3% to 67.9%. The proportion of cases that required RT was stage dependent: 10.6% +/- 1.2% in Stage IA, 74.9% +/- 1.3% in Stage IB, 100% in Stages II and III, and 97.2% +/- 1.1% in Stage IV.

CONCLUSIONS

This evidence-based estimate of the appropriate rate of use of RT for cervical cancer adds to the growing pool of knowledge about the need for RT that will ultimately provide a rational basis for long-term planning for RT programs and for auditing access to RT in the general population.

The role of radiotherapy in cancer treatment: estimating optimal utilization from a review of evidence-based clinical guidelines

Radiotherapy utilization rates for cancer vary widely internationally. It has previously been suggested that approximately 50% of all cancer patients should receive radiation. However, this estimate was not evidence-based. The aim of this study was to estimate the ideal proportion of new cases of cancer that should receive radiotherapy at least once during the course of their illness based on the best available evidence. An optimal radiotherapy utilization tree was constructed for each cancer based upon indications for radiotherapy taken from evidence-based treatment guidelines. The proportion of patients with clinical attributes that indicated a possible benefit from radiotherapy was obtained by adding epidemiologic data to the radiotherapy utilization tree. The optimal proportion of patients with cancer that should receive radiotherapy was then calculated using TreeAge (TreeAge Software, Williamstown, MA) software. Sensitivity analyses using univariate analysis and Monte Carlo simulations were performed. The proportion of patients with cancer in whom external beam radiotherapy is indicated according to the best available evidence was calculated to be 52%. Monte Carlo analysis indicated that the 95% confidence limits were from 51.7% to 53.1%. The tightness of the confidence interval suggests that the overall estimate is robust. Comparison with actual radiotherapy utilization data suggests a shortfall in actual radiotherapy delivery. This methodology allows comparison of optimal rates with actual rates to identify areas where improvements in the evidence-based use of radiotherapy can be made. It provides valuable data for radiotherapy service planning. Actual rates need to be addressed to ensure better radiotherapy utilization.

Non-small cell lung cancer therapy-related pulmonary toxicity: an update on radiation pneumonitis and fibrosis

Successful treatment of non-small cell lung cancer requires adequate local and systemic disease control. Although it has been shown to have superior results, high-dose radiation therapy is not a current practice largely because of concerns of normal tissue toxicity. This article reviews and updates the possible mechanism of radiation-induced pneumonitis and fibrosis, their associations with dose intensity, and the role they may play in making treatment decisions. The commonly used clinical terminology and grading systems are summarized. Pneumonitis and fibrosis after 3-dimensional conformal high-dose radiation are reviewed, including recent updates from radiation dose escalation trials. Chemotherapy- and chemoradiation-related lung toxicities are also discussed. Individual susceptibility and potential predictive models are examined; dose and 3-dimensional dosimetric parameters are reviewed along with estimation of normal tissue complication probability and biologic predictive assays. Based on the risk levels of toxicity for each patient, future clinical trials may be designed to maximize individual therapeutic gain.

Imaging of non-small cell lung cancer

Radiologic evaluation is an important component of the clinical staging evaluation of lung cancer and can greatly influence whether the patient is treated with surgical resection, radiation therapy, chemotherapy, or a combination of these modalities. In addition to staging, the radiologic evaluation of the patient undergoing treatment and subsequent follow-up is important to the clinician for assessing treatment effects and complications. This article discusses the imaging of patients with non-small cell lung cancer and its use in management of these patients.

Towards evidence-based guidelines for radiotherapy infrastructure and staffing needs in Europe: the ESTRO QUARTS project

BACKGROUND AND PURPOSE

Adequate and equitable access to radiotherapy (RT) must be a reasonable health care goal for the EU. However, there are large variations among the EU countries and even regional variations within countries in the provision of RT. In this report, we combine the best available evidence on the indications for RT with national epidemiological data to arrive at estimates for the appropriate level of RT infrastructure in the 25 EU countries.

PATIENTS AND METHODS

Data from three systematic overviews of the best available evidence for the indication for RT in 23 main cancer types are combined with epidemiological data from the EUCAN and GLOBOCAN databases on the crude incidence of each of these cancers in the 25 EU countries. Together with published benchmarks for accelerator throughput this allows estimation of the number of linear accelerators per million people required to facilitate appropriate RT utilization rates in each country. Where possible, the estimates are compared with the detailed data available from Sweden.

RESULTS

The crude incidence of the main cancer types shows large variation among the 25 EU countries. This reflects in part differences in exposure to aetiological risk factors and partly differences among the countries in population age structure. Correspondingly, the estimate of the required number of linear accelerators per million people showed considerable variation: ranging from 4.0 in Cyprus to 8.1 in Hungary. The average for the 25 countries was 5.9 per million people. These estimates were compared with available national guidelines and actual data on RT infrastructure and large shortfalls were found in many countries. Implications for health economics and capacity planning are briefly discussed.

CONCLUSIONS

The QUARTS project has developed a model that establishes a direct and transparent link between epidemiological data and indications for RT based on the best available evidence. Comparison of the model estimates with current levels of RT infrastructure has revealed major inequalities in provision of RT in the 25 EU countries. Continuation of this study is recommended as a way of improving RT provision on rational grounds throughout the European community and as a model for health care planning in the EU.

Estimating the optimal external-beam radiotherapy utilization rate for genitourinary malignancies

BACKGROUND

Benchmark radiotherapy utilization rates for genitourinary malignancies are largely unknown, despite the finding that genitourinary cancers comprise approximately 19% of all registered malignancies in Australia.

METHODS

To develop an evidence-based benchmark of the optimal proportion of patients with genitourinary malignancies who should receive at least one course of radiotherapy at some time during their illness, the authors studied treatment guidelines and treatment reviews regarding genitourinary malignancies. Optimal radiotherapy utilization trees were constructed to show the clinical attributes that indicated possible benefit from radiotherapy based on evidence. Epidemiologic incidence data for each of these clinical attributes were obtained to calculate the optimal proportion of all patients with genitourinary cancer for whom radiotherapy was considered appropriate.

RESULTS

The proportion of patients with genitourinary malignancies for whom radiotherapy was indicated at some point in their illness, according to the best available evidence, was estimated to be 27% of patients with renal cancer, 58% of patients with bladder cancer, 60% of patients with prostate cancer, and 49% of patients with testicular cancer. The occurrence of ureteric and penile cancers among patients was too rare, and, therefore, these patients were not included in the current study.

CONCLUSIONS

There was a large discrepancy between actual radiotherapy utilization and the evidence-based optimal rate. The authors recommended strategies to implement the evidence-based guidelines. Evidence-based benchmarks for radiotherapy utilization rates such as the ones described in the current study were important in the evaluation of the appropriate use of radiotherapy.

Estimation of an optimal external beam radiotherapy utilization rate for head and neck carcinoma

BACKGROUND

Radiotherapy is used commonly in the treatment of patients with head and neck carcinoma. The benchmark radiotherapy utilization rates for head and neck carcinoma largely are unknown. The objective of the current study was to determine the optimal radiotherapy utilization rate for patients with head and neck carcinoma and to compare this optimal rate with actual utilization rates where actual utilization data were available.

METHODS

An optimal radiotherapy utilization tree was constructed that depicted all patients with head and neck carcinoma in whom radiotherapy was indicated according to evidence-based treatment guidelines. The proportions of patients with clinical attributes that indicated possible benefit from radiotherapy were obtained from epidemiological data and were inserted into the utilization tree. The optimal proportion of patients with carcinoma of the head and neck who should receive radiotherapy was calculated by merging the evidence-based recommendations with the epidemiological data in the tree. Optimal rates of radiotherapy utilization were compared with actual rates obtained from population-based studies.

RESULTS

Radiotherapy was indicated at some point during their illness in 74% of all patients with head and neck carcinoma. By subsite, the optimal radiotherapy utilization rates were oral cavity, 74%; lip, 20%; larynx, 100%; oropharynx, 100%; salivary gland, 87%; hypopharynx, 100%; nasopharynx, 100%; paranasal sinuses, 100%; and unknown squamous cell carcinoma of the head and neck, 90%. All treatment recommendations were based on Level III or IV evidence. Assessment of actual radiotherapy utilization rates indicated an increased use of radiotherapy over time for head and neck carcinoma. However, there also were some decreases in the use of radiotherapy for some carcinoma subsites over the past 20 years, despite the lower actual rates compared with the optimal rates. The reasons for these reductions in use were not identified.

CONCLUSIONS

The actual radiotherapy utilization rate for patients with head and neck carcinoma corresponded reasonably closely to the optimal rate for some populations but also identified some shortfalls for other patient groups. The results of this study provide a way of assessing shortfalls in radiotherapy.

Estimation of an optimal radiotherapy utilization rate for gynecologic carcinoma: part I--malignancies of the cervix, ovary, vagina and vulva

BACKGROUND

Radiotherapy usage rates exhibit wide variations both within and between countries. Current estimates of the proportion of cancer patients who should optimally receive radiotherapy are based either on expert opinion or on the measurement of actual usage rates rather than on the best available scientific evidence.

METHODS

With the goal of developing an evidence-based benchmark for radiotherapy use in the treatment of malignancies of the cervix, vagina, vulva, and ovary (endometrial malignancies are covered in a separate article), the authors reviewed international evidence-based treatment guidelines. Optimal radiotherapy usage trees were constructed, and proportions of patients with clinical indications for radiotherapy were obtained from epidemiologic data. These ideal usage rates were compared with actual radiotherapy utilization rates recorded in Australia and elsewhere.

RESULTS

According to the best available evidence, radiotherapy is indicated at least once for 58% of patients with cervical carcinoma, 4% of patients with ovarian carcinoma, 100% of patients with vaginal carcinoma, and 34% of patients with vulvar carcinoma. A review of the limited data available suggests that actual radiotherapy usage rates for patients with gynecologic malignancies are comparable to optimal usage rates.

CONCLUSIONS

Actual practice appears to approximate the authors' model of optimal radiotherapy use. This finding reflects the high level of agreement among treatment guidelines as well as the existence of high-quality evidence related to the management of gynecologic malignancies, and it may also be indicative of the fact that a large proportion of patients are treated in specialist units. The management of gynecologic malignancies may serve as a good example in the development of management strategies for other types of cancer.

Estimation of an optimal radiotherapy utilization rate for gynecologic carcinoma

BACKGROUND

Radiotherapy utilization rates for cancer vary widely, both within and between countries. Current estimates of the proportion of cancer patients who should optimally receive radiotherapy are based either on expert opinion or on the measurement of actual utilization rates, rather than on the best scientific evidence.

METHODS

Evidence-based treatment guidelines regarding endometrial carcinoma were reviewed to develop an evidence-based benchmark for radiotherapy utilization. An optimal radiotherapy utilization tree was constructed and the proportions of endometrial carcinoma patients with clinical indications for radiotherapy were obtained from epidemiologic data. The ideal utilization rates were compared with actual radiotherapy utilization rates for endometrial carcinoma both in Australia and internationally.

RESULTS

According to the best available evidence, radiotherapy is indicated at least once in 46% of all patients with endometrial carcinoma. A review of the limited data available concerning actual radiotherapy utilization rates revealed that the actual rates are approximately 10% lower than the optimal rates.

CONCLUSIONS

Further research into the patterns of actual treatment and the development of optimal chemotherapy and surgery utilization rates for endometrial carcinoma is recommended. The difference between the optimal and the actual utilization rates warrants investigation into the reasons for the low radiotherapy utilization rates encountered in clinical practice.

Estimation of an optimal radiotherapy utilization rate for gastrointestinal carcinoma

BACKGROUND

Radiotherapy utilization rates for cancer vary widely, both within and between countries. The optimal proportion of patients with gastrointestinal malignancies who should receive at least one course of radiotherapy at some time during their illness is an important benchmark.

METHODS

The authors studied treatment guidelines and treatment reviews to identify the indications for radiotherapy for patients with gastrointestinal malignancies. Optimal radiotherapy utilization trees were constructed to show the clinical attributes of patients with gastrointestinal carcinomas who will benefit from radiotherapy. Epidemiologic incidence data for each of these clinical attributes were obtained to calculate the optimal proportion of all patients with gastrointestinal malignancies for whom radiotherapy was considered appropriate. Optimal rates of radiotherapy use were compared with actual rates in population-based studies to assess any discrepancies between actual and optimal radiotherapy utilization rates.

RESULTS

Radiotherapy was indicated in 80% of patients with esophageal carcinoma, 68% of patients with gastric carcinoma, 57% of patients with pancreatic carcinoma, 13% of patients with carcinoma of the gallbladder, 0% of patients with hepatic carcinoma, 14% of patients with colon carcinoma, and 61% of patients with rectal carcinoma. The actual radiotherapy utilization rates for most of these gastrointestinal malignancies fell well short of optimal rates, which were derived from evidence-based treatment guidelines.

CONCLUSIONS

It is possible to model optimal radiotherapy utilization using published treatment guidelines and existing incidence data. There was a discrepancy between the optimal and actual rates of radiotherapy utilization for patients with carcinomas of the esophagus, stomach, pancreas, and rectum. Strategies to implement evidence-based clinical guidelines are recommended.

Estimation of an optimal radiotherapy utilization rate for breast carcinoma

BACKGROUND

Radiotherapy utilization rates for breast carcinoma vary widely, both within and between countries. Current estimates of the proportion of patients with carcinoma who optimally should receive radiotherapy are based either on expert opinion or on the measurement of actual utilization rates, and not on the best scientific evidence.

METHODS

To develop an evidence-based benchmark for radiotherapy utilization in patients with breast carcinoma, the authors undertook a systematic review of treatment guidelines on the use of radiotherapy for breast carcinoma. A decision tree was constructed, and the proportions of patients with clinical features that lead to a decision for radiotherapy were obtained from epidemiological data. This ideal utilization rate was compared with the utilization rates of radiotherapy over the last decade for breast carcinoma in Australia and internationally.

RESULTS

The proportion of patients with breast carcinoma in whom radiotherapy would be recommended according to the best available evidence was calculated at 83% (95% confidence interval, 82-85%) of all patients with breast carcinoma. A review of actual radiotherapy utilization rates for breast carcinoma revealed that, in clinical practice, actual utilization rates varied between 24% and 71%.

CONCLUSIONS

A substantial difference was found between the recommended optimal utilization of radiotherapy based on evidence and the actual rates reported in clinical practice. The reasons for these differences need to be examined, and a plan for addressing the suboptimal use of radiotherapy needs to be implemented. Cancer 2003.

Defining the need for radiotherapy for lung cancer in the general population: a criterion-based, benchmarking approach

BACKGROUND

We have previously used an evidence-based, epidemiologic approach to estimate the proportion of incident cases that should be treated with radiotherapy (RT) for lung cancer. The first objective of the present study was to compare this evidence-based estimate of the appropriate rate of use of RT with the rates observed in selected "benchmark" communities where there are no barriers to the appropriate use of RT and no incentives to the unnecessary use of RT. The second objective of the study was to compare the rates of use of RT in the general populations in the United States and Canada with the estimated appropriate rate.

METHODS

We established benchmark rates for the use of RT for lung cancer in Ontario, Canada, where: 1) residents make no direct payments for RT; 2) all RT is provided by site-specialized radiation oncologists in multidisciplinary cancer centers, and 3) radiation oncologists receive a salary in lieu of technical fees. Communities located close to cancer centers without long waiting lists for RT were selected to serve as benchmarks. Prospectively gathered electronic treatment records from all RT cancer centers were linked to the provincial cancer registry to describe the rate of use of RT in Ontario. The public use file of Surveillance, Epidemiology and End Results Registries (SEER) was used to describe the use of RT in the United States.

RESULTS

Overall, 41.3% (95% confidence interval [CI], 39.9%, 42.7%) of incident cases of lung cancer received RT as part of their initial management in the benchmark communities compared with the evidence-based estimate of 41.6% (95% CI, 39.2%, 44.1%). The rate of use of RT in the initial management of nonsmall cell lung cancer (NSCLC) in the benchmark communities was 49.3% (95% CI, 47.5%, 51.1%) compared with the evidence-based estimate of 45.9% (95% CI, 41.6%, 50.2%). The use of RT in the initial management of small-cell lung cancer (SCLC) in the benchmark communities was 47.0% (95% CI, 43.3%, 50.7%) compared with the evidence-based estimate of 45.4% (95% CI, 42.4%, 48.4%). In many counties of Ontario, the observed rates of RT use in the initial management of lung cancer were significantly lower than either the benchmark rate or the evidence-based estimate of the appropriate rate. In contrast, rates of use of RT in most counties in the SEER regions of the United States were close to, or higher than, the estimated appropriate rate.

CONCLUSIONS

The observed benchmark rate converged on the evidence-based estimate of the appropriate rate of use of RT for lung cancer, suggesting that either measure might reasonably be used as a "standard" against which to compare rates observed in similar populations elsewhere.

An evidence-based estimate of the appropriate radiotherapy utilization rate for colorectal cancer

PURPOSE

Current estimates of the proportion of cancer patients who will require RT are based almost entirely on expert opinion. The objective of this study was to estimate the proportion of incident cases of colorectal cancer that should receive RT using an evidence-based approach.

METHODS AND MATERIALS

A systematic review of the literature was undertaken to identify indications for RT for colorectal cancer, and to ascertain the level of evidence that supported each indication. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of colorectal cancer patients. The effect of sampling error on the estimated appropriate rate of RT was calculated mathematically, and the effect of systematic error was estimated by sensitivity analysis.

RESULTS

It was estimated that 23.7% +/- 1.0% of colorectal cancer cases develop one or more indications for RT at some point in the course of the illness: 20.9% +/- 1.1% as part of their initial treatment, and 2.8% +/- 0.5% later for recurrence or progression. We estimated that 7.1% +/- 0.8% of colon carcinoma patients will require RT at some point in the course of the illness: 4.0% +/- 0.7% as part of their initial treatment, and 3.1% +/- 0.4% later for recurrence or progression. We estimated that 72.3% +/- 1.0% of rectal carcinoma patients will require RT at some point in the course of the illness: 69.6% +/- 0.9% as part of their initial treatment and 2.7% +/- 0.2% later for recurrence or progression.

CONCLUSIONS

This method provides a rational starting point for the long-term planning of radiation services, and for the audit of access to RT at the population level. By completing such evaluations in the major cancer sites, it will be possible to estimate the appropriate RT treatment rate for the cancer population as a whole.

The appropriate rate of breast conserving surgery: an evidence-based estimate

PURPOSE

The objective of the present study was to estimate the proportion of incident cases of breast cancer that should receive breast conserving surgery (BCS), using an evidence-based approach.

METHODS

An extensive search of the literature was undertaken to identify eligibility criteria for BCS. The eligibility criteria for BCS were combined with the information about case mix and patient preference to estimate the need for BCS. An epidemiological approach was then used to estimate the incidence of each eligibility criterion for BCS in a typical North American population of breast cancer patients. The effect of sampling error on the estimated appropriate rate of BCS was calculated, and the effect of systematic error using alternative sources of information, was estimated by sensitivity analysis.

RESULTS

The analysis showed that 69.6% of breast cancer cases are eligible for BCS, and that 48.0 +/- 6.0% of breast cancer patients are both eligible for BCS and prefer it to mastectomy. Based on sensitivity analysis, the plausible range of the appropriate rate was 42.1% to 49.43%. The proportion of breast cancer cases in which BCS was appropriate was stage dependent; 63.0 +/- 11.5% in ductal carcinoma in-situ; 57.0 +/- 9.9% in stage I; 52.2 +/- 9.4% in stage II, and 27.2 +/- 5.2% in stage III.

CONCLUSIONS

This model suggests that BCS is appropriate in 48% of all breast cancer patients. This information may be useful in auditing surgical practice, and may serve as a basis for planning of ancillary services, including radiotherapy.

A model for decision making for the use of radiotherapy in lung cancer

To develop an evidence-based benchmark for the use of radiotherapy in lung cancer, we did a systematic review of treatment guidelines on radiotherapy for lung cancer. We then constructed an optimum use of radiotherapy "tree" from epidemiological data, which shows the proportion of patients with clinical attributes indicating that they would benefit from radiotherapy. We calculated that the proportion of patients with lung cancer in whom radiotherapy is indicated (according to the best available evidence) is 76%. We then compared this ideal rate with the actual rates of use of radiotherapy for lung cancer in Australia, and internationally, in the past decade. A substantial discrepancy was found between the evidence-based recommended rate of use and the actual rates reported in clinical practice. We hope this model will be used to plan efficient and cost-effective radiotherapy services.

Evidence-based estimate of appropriate radiotherapy utilization rate for prostate cancer

PURPOSE

Current estimates of the proportion of cancer patients who will require radiotherapy (RT) are based almost entirely on expert opinion. The objective of this study was to use an evidence-based approach to estimate the proportion of incident cases of prostate cancer that should receive RT at any point in the evolution of the illness.

METHODS AND MATERIALS

A systematic review of the literature was undertaken to identify indications for RT for prostate cancer and to ascertain the level of evidence that supported each indication. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of prostate cancer patients. The effect of sampling error on the estimated appropriate rate of RT was calculated mathematically, and the effect of systematic error using alternative sources of information was estimated by sensitivity analysis.

RESULTS

It was estimated that 61.2% +/- 5.6% of prostate cancer cases develop one or more indications for RT at some point in the course of the illness. The plausible range for this rate was 57.3%-69.8% on sensitivity analysis. Of all prostate cancer patients, 32.2% +/- 3.8% should receive RT in their initial treatment and 29.0% +/- 4.1% later for recurrence or progression. The proportion of cases that ever require RT is risk grouping dependent; 43.9% +/- 2.2% in low-risk disease, 68.7% +/- 3.5% in intermediate-risk disease; and 79.0% +/- 3.8% in high-risk locoregional disease. For metastatic disease, the predicted rate was 66.4% +/- 0.3%.

CONCLUSION

This method provides a rational starting point for the long-term planning of radiation services and for the audit of access to RT at the population level. By completing such evaluations in major cancer sites, it will be possible to estimate the appropriate RT rate for the cancer population as a whole.

An evidence-based estimate of appropriate radiotherapy utilization rate for breast cancer

PURPOSE

Current estimates of the proportion of cancer patients who will require radiotherapy (RT) are based almost entirely on expert opinion. We sought to use an evidence-based approach to estimate the proportion of incident cases of breast cancer that will require RT at any point in the evolution of the illness.

METHODS AND MATERIALS

We undertook a systematic review of the literature to identify indications for RT for breast cancer and to ascertain the level of evidence that supported each indication. An epidemiologic approach was then used to estimate the incidence of each indication for RT in a typical North American population of breast cancer patients. The effect of sampling error on the estimated appropriate rate of RT was calculated mathematically, and the effect of systematic error was estimated by sensitivity analysis.

RESULTS

It was estimated that 66.4% +/- 4.8% of breast cancer patients develop one or more indications for RT at some point in the course of the illness. The plausible range for this rate was 56.3%-72.4% on sensitivity analysis. Of all breast cancer patients, 57.3% +/- 4.7% require RT in their initial treatment and 9.1% +/- 1.0% do so later for recurrence or progression. The proportion of patients who ever require RT is stage dependent: 39.8% +/- 1.1% in ductal carcinoma in situ; 68.6% +/- 4.1% in Stage I invasive carcinoma; 81.5% +/- 2.3% in Stage II; 95.3% +/- 0.3% in Stage III; and 63.7% +/- 0.3% in Stage IV.

CONCLUSION

This method provides a rational starting point for the long-term planning of RT services and for the audit of access to RT at the population level. By completing such evaluations in the major cancer sites, it will be possible to estimate the appropriate RT treatment rate for the cancer population as a whole.