Peter Dixon

Waiting for radiotherapy in Ontario

PURPOSE Waiting lists for radiotherapy are a fact of life at many Canadian cancer centers. The purpose of this study was to provide a detailed description of the magnitude of the problem in Ontario. METHODS AND MATERIALS The interval between diagnosis and initiation of radiation treatment was calculated for all patients receiving primary radiotherapy for carcinoma of the larynx, cervix, lung, and prostate at seven Ontario cancer centers between 1982 and 1991. The interval between surgery and initiation of postoperative radiotherapy for breast cancer was also calculated over the same period. The intervals between diagnosis and referral (t1), between referral and consultation (t2), and between consultation and initiation of radiotherapy (t3), were analyzed separately to determine where delay occurred. RESULTS Median waiting times between diagnosis and initiation of radical treatment for carcinoma of the larynx, carcinoma of the cervix, nonsmall cell lung cancer, and carcinoma of the prostate were 30.3 days, 27.2 days, 27.3 days, and 93.3 days, respectively. The exceptional interval between diagnosis and treatment of prostate cancer was due to much longer delays between diagnosis and referral. The median waiting time between diagnosis and initiation of postoperative radiotherapy for breast cancer was 61.4 days and the median time between the completion of surgery and initiation of postoperative radiotherapy was 57.8 days. There were significant intercenter variations in median waiting times, but in every situation the median waiting time in Ontario as a whole increased steadily between 1982 and 1991. Median waiting times from diagnosis to the start of curative treatment for laryngeal cancer, cervical cancer, nonsmall cell lung cancer, and prostate cancer increased by 178.7%, 105.6%, 158.3%, and 62.9%, respectively. Waiting time from completion of surgery to initiation of postoperative radiotherapy for breast cancer increased by 102.7%. Most of the increase in treatment delay was found in the interval between consultation and initiation of radiotherapy. CONCLUSIONS The Committee on Standards of the Canadian Association of Radiation Oncologists recommends that the interval between referral and consultation should not exceed 2 weeks and that the interval between consultation and initiation of radiotherapy should also not exceed 2 weeks. The majority of patients treated in Ontario met both those standards in 1982, but by 1991 few patients received care within the prescribed intervals.

Randomized phase III trial of single versus fractionated thoracic radiation in the palliation of patients with lung cancer (NCIC CTG SC.15)

PURPOSE This multi-institutional Phase III randomized study compared 10 Gy single-fraction radiotherapy (RT) with 20 Gy in five fractions in the palliation of thoracic symptoms from lung cancer. METHODS AND MATERIALS The primary end point was palliation of thoracic symptoms at 1 month after RT, evaluated by a patient-completed daily diary card. Secondary end points included quality of life, toxicity, and survival. RESULTS Most (69%) of 230 patients randomized had locally advanced disease unsuitable for curative treatment. The treatment arms were well balanced with respect to the known prognostic factors. At 1 month after RT, no difference was found in symptom control between the two arms, as judged by the daily diary scores. The changes in the scores on the Lung Cancer Symptom Scale indicated that the fractionated RT (five fractions) group had greater improvement in symptoms related to lung cancer (p = 0.009), pain (p = 0.0008), ability to carry out normal activities (p = 0.037), and better global quality of life (p = 0.039). The European Organization for Research and Treatment of Cancer QLQ-C30 scores showed that patients receiving five fractions had a greater improvement in scores with respect to pain (p = 0.04). No significant difference was found in treatment-related toxicity. Patients who received five fractions survived on average 2 months longer (p = 0.0305) than patients who received one fraction. CONCLUSION Although the two treatment strategies provided a similar degree of palliation of thoracic symptoms, the difference in survival between the two study arms was of a clinically relevant magnitude.

Does a centralized radiotherapy system provide adequate access to care

PURPOSE In the Canadian province of Ontario, all radiotherapy is provided by a centrally managed provincial network of nine cancer centers. The primary goal of this study was to determine whether this highly centralized radiotherapy system provides adequate and equitable access to care for the provinces dispersed population. METHODS The Ontario Cancer Registry (OCR) was used to identify 295,386 cases of invasive cancer, excluding nonmelanoma skin cancer, which were diagnosed in Ontario between 1984 and 1991. Electronic radiotherapy records from each of the provinces radiotherapy centers were linked to the registry at the level of the individual case. RESULTS The proportion of incident cases treated with radiotherapy was 18.8% at 4 months after diagnosis, 23.7% at 1 year, 25.8% at 2 years, 28.2% at 5 years, and 29.1% at 8 years. These rates of radiotherapy use are much lower than the accepted national and international targets, and lower than rates reported from other jurisdictions. The rate of radiotherapy use at 1 year varied significantly from county to county across Ontario (range, 18.6% to 32.4%; P < 10(-6)), and the highest rates were recorded in communities close to radiotherapy centers. There was a common geographic pattern of rate variations among several disease groups, including breast cancer, lung cancer, the genitourinary malignancies, and the gastrointestinal malignancies. CONCLUSION The low and uneven rates of radiotherapy use across the province indicate that Ontarios centralized radiotherapy system does not, at present, provide adequate or equitable access to care.

Intensity-modulated radiotherapy in the treatment of prostate cancer

Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses beams with multiple intensity levels for any single beam, allowing concave dose distributions and tighter margins than those possible using conventional radiotherapy. IMRT is ideal for treating complex treatment volumes and avoiding close proximity organs at risk that may be dose limiting and provides increased tumour control through an escalated dose and reduces normal tissue complications through organ at risk sparing. Given the potential advantages of IMRT and the availability of IMRT-enabled treatment planning systems and linear accelerators, IMRT has been introduced in a number of disease sites. This systematic review examined the evidence for IMRT in the treatment of breast cancer to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. Providing that avoidance of acute adverse effects associated with radiation is an outcome of interest, then IMRT is recommended over tangential radiotherapy after breast-conserving surgery, based on a review of six published reports including 2012 patients. There were insufficient data to recommend IMRT over standard tangential radiotherapy for reasons of oncological outcomes or late toxicity. Future research should focus on studies with longer follow-up and provide data on late toxicity and disease recurrence rates.

Changes in the use of radiotherapy in Ontario 1984–1995

PURPOSE To describe changes in the use of radiotherapy in the management of cancer in Ontario between January 1, 1984 and December 31, 1995. METHODS A retrospective review of prospectively gathered electronic records of all radiotherapy for cancer at nine provincial cancer treatment centres. RESULTS Over the 12 years of the study, the incidence of cancer increased by 33%. The number of curative and adjuvant courses per incident case increased by 39.3% and the number of palliative courses per incident case decreased by 15.8%. The mean number of fractions per curative and adjuvant course increased by 13%, and the mean number of fractions per palliative course decreased by 22%. The number of curative fractions per incident case increased by 63%, and the number of palliative fractions per incident case decreased by 32%. The increase in curative workload was mainly due to an increase in the incidence of prostate cancer, to an increase in the number of courses per incident case in breast and prostate cancer, and to an increase in the number of fractions per curative course in every disease group. The decrease in palliative workload was due to a decrease in the number of courses per incident case in most disease groups, and to a decrease in the number of fractions per course in most disease groups. CONCLUSIONS In Ontario, between 1984 and 1995, there was a large shift in workload from palliative radiotherapy to curative radiotherapy. Potential causes for this phenomenon are discussed.

Using TNM staging to predict survival in patients with squamous cell carcinoma of head & neck†

There is a need for a classification system for prognosis based on the TNM system for patients with squamous cell carcinoma of the head and neck such that patient groupings are homogeneous within and heterogeneous between.

Management and outcome differences in supraglottic cancer between Ontario, Canada, and the Surveillance, Epidemiology, and End Results areas of the United States.

PURPOSE We compared the management and outcome of supraglottic cancer in Ontario, Canada, with that in the Surveillance, Epidemiology, and End Results (SEER) Program areas in the United States. METHODS Electronic, clinical, and hospital data were linked to cancer registry data and supplemented by chart review where necessary. Stage-stratified analyses compared initial treatment and survival in the SEER areas (n = 1,643) with a random sample from Ontario (n = 265). We also compared laryngectomy rates at 3 years in those patients 65 years and older at diagnosis. RESULTS Radical surgery was more commonly used in SEER, with absolute differences increasing with increasing stage: I/II, 17%; III, 36%; and IV, 45%. The 5-year survival rates were 74% in Ontario and 56% in SEER for stage I/II disease (P =.01), 55.7% in Ontario and 46.8% in SEER for stage III disease (P =.40), and 28.5% in Ontario and 29.1% in SEER for stage IV disease (P =.28). Cancer-specific survival results mirrored the overall survival results with the exception of stage IV disease, for which 34.6% of Ontario patients survived their cancer compared with 38.1% in SEER (P =.10). This stage IV difference was more pronounced when we further controlled for possible cause of death errors by restricting the comparison to patients with a single primary cancer (P =.01). Three-year actuarial laryngectomy rates differed. In stage I/II, these rates were 3% in Ontario compared with 35% in SEER (P < 10(-3)). In stage III disease, the rates were 30% and 54%, respectively (P =.03), and in stage IV disease they were 33% and 64% (P =.002). CONCLUSION There are large differences in the management of supraglottic cancer between the SEER areas of the United States and Ontario. Long-term larynx retention was higher in Ontario, where radiotherapy is widely regarded as the treatment of choice and surgery is reserved for salvage. In stages I to III, survival was similar in the two regions despite the differences in treatment policy. In stage IV, there may be a small survival advantage in the U.S. SEER areas related to the higher use of primary surgery.

The role of computed tomography in the T classification of laryngeal carcinoma

The objectives of this study were 1) to describe patterns of use of computed tomography (CT) in laryngeal carcinoma, and 2) to characterize the contribution of CT to the T classification of laryngeal carcinoma.

Could changes in clinical practice reduce waiting lists for radiotherapy

OBJECTIVES To describe variation in the practice of radiation oncology among the nine cancer centres in Ontario, and to explore the impact of variations in the number of treatments prescribed per case on the overall demand for radiotherapy in the province. METHODS Prospectively collected, electronic records of all courses of radiotherapy given at the nine radiotherapy centres in Ontario between 1 January 1996 and 31 December 1997 were analysed to describe inter-centre variations in the number of radiation treatments (fractions) prescribed per case. The effect of the observed inter-centre variations in practice on the total provincial workload was modelled. RESULTS During the two-year study, 672,292 fractions were administered as 44,096 courses of treatment. On average there were 63.6 high-energy treatment machines operating in the province over this period. The mean number of fractions per course for the province as a whole was 15.3, and ranged from 10.9 at centre D to 16.0 at centre F. The inter-centre variation in the number of fractions per course was higher when radiotherapy was used palliatively than curatively. The range of variation in the number of treatments per curative course was disease-specific; it was highest for breast cancer, and lowest for the gynaecological malignancies. If each clinical problem had been treated everywhere in the province as it was at the centre which treated it with the fewest treatments, 77,274 fewer radiation treatments each year would have been required to treat the same number of cases. This is equivalent to the capacity of 14.6 treatment machines, and exceeds the estimated shortfall in the current supply of radiotherapy in the province. Province-wide adoption of more parsimonious approaches to the use of palliative radiotherapy, or to the use of curative (adjuvant) radiotherapy in breast cancer, would produce dramatic decreases in the overall demand for radiotherapy machine time. In these particular situations, the literature indicates that shorter courses of treatment are just as effective, and as well tolerated, as longer courses. CONCLUSIONS Variation in the way that oncologists prescribe radiotherapy is an important determinant of overall radiotherapy machine workload. Modest changes in prescribing by radiation oncologists, even within the range of current practice in Ontario, and within the range of fractionation schemes that have been shown to produce optimal results, have the potential to reduce waiting lists for radiotherapy.

A treatment trade-off based decision aid for patients with locally advanced non-small cell lung cancer

Purpose To describe the structure and use of a decision aid for patients with locally advanced non‐small cell lung cancer (LA‐NSCLC) who are eligible for combined‐modality treatment (CMT) or for radiotherapy alone (RT).