Biomedical subjects
Publications and source records attributed to P Kirkbride.
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AIMS: To assess the use of lung dose-volume histogram (DVH) parameters (specifically V20Gy) in the prediction of radiation pneumonitis for non-conventional fraction sizes used in the treatment of lung cancer. MATERIALS AND METHODS: Patients requiring computed tomography planning for thoracic radiotherapy between January 1999 and January 2002 were identified. The patients receiving radical or high-dose palliative radiotherapy had DVH produced routinely during planning. These were retrospectively reviewed and the case notes accessed for additional pre-treatment parameters, demographics and evidence of radiation pneumonitis. The severity of the pneumonitis was then scored using Radiation Therapy Oncology Group criteria. Data were analysed using the SPSS computer program. RESULTS: One hundred and sixty consecutive patients were reviewed. Ninety patients received hypofractionated treatment (fraction size > 2.5 Gy) and 57 continuous hyperfractionated accelerated radiation therapy (CHART) (fraction size 1.5 Gy). Lung V20Gy values ranged from 3% to 53%, with a median value of 24%. Only six patients reported grade 2, and 16 patients grade 3 pneumonitis. Two patients developed fatal, grade 5 pneumonitis. No correlation between pneumonitis score and V20Gy or other possible predictive factors was found. CONCLUSION: The 15% grade 2-5 pneumonitis rate we document is at the lower end of the spectrum reported in other studies. This suggests that using published data on limiting V20Gy values to reduce the risk of radiation pneumonitis can be extrapolated to planning treatment with non-conventionally fractionated radiotherapy.
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AIMS: A 1-day workshop was conducted to gather interested Canadian radiation oncologists to identify priority research questions that could be answered through clinical trials under the auspices of the National Cancer Institute of Canada--Clinical Trials Group (NCIC-CTG) Symptom Control committee. MATERIALS AND METHODS: In preparation for the workshop, a survey of Canadian radiation oncologists resulted in four research areas in symptom control, including radiation-induced mucosal reactions, fatigue, radiotherapy for brain metastases and radiotherapy for bone metastases. The first half of the workshop consisted of plenary sessions where the research setting and perspective was defined for each area. This was followed by deliberations by a subgroup of researchers with special interest in the topic area. The bone-metastases subgroup deliberated the clinical context, the scientific merits and the required methodology of research questions related to the role of radiotherapy in early treatment of bone metastases, the role of re-irradiation, the role of systemic radiotherapy and patient selection for different fractionation schedules. A list of prioritised clinical studies was proposed. RESULTS: The question of single vs multi-fraction re-irradiation for symptomatic bone metastases was identified as most pertinent to the Canadian radiation oncologists present. A multi-centre, international intergroup study is undergoing protocol development. Other study concepts, such as an alternative dose-schedule of 17 Gy/2 fractions/1 week for intermediate-prognosis patients, and early referral for radiation oncologist assessment of early or mildly symptomatic bone metastases for good-prognosis patients, require further methodological development before a clinical trial can be proposed. CONCLUSION: An NCIC-CTG workshop provided an update on current evidence-based knowledge in palliative radiotherapy for bone metastases. New trial concepts were discussed among practitioners and clinical investigators to promote dialogue and collaboration. The proposal of an international intergroup randomised trial of single vs multiple fraction re-irradiation for painful bone metastases received the most support among participants.
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Whole brain radiotherapy (RT) is frequently used to palliate symptoms in patients with brain metastases, but the palliative benefit to patients has not been well documented. We conducted a longitudinal observational prospective study of patients receiving standard RT (20 Gray (Gy)/5 fractions) for symptomatic brain metastases. End-points were observer rating of neurological symptoms, patient-rated symptoms, performance status, neurological functional status, cognitive function and quality of life (QOL). Median survival for the 75 patients was 86 days (95% confidence interval (CI): 65-101 days). At 1 month, 19% of patients showed an improvement or resolution of presenting symptoms, 23% were stable and 55% had progressed or died. Patient-rated symptoms were increased at 1 month in comparison to baseline data. Only 4 patients had an improved performance status and 22 were stable. Many patients with brain metastases have a short life expectancy and may not benefit from even short duration radiation schedules. Further effort is needed to optimise patient selection and tailor treatment appropriately.
OBJECTIVES: To compare and contrast the definitions of primary treatment endpoints in randomized studies of dose-fractionation schedules for treating bone metastases and to identify basic characteristics of treatment endpoint that may require consensus among investigators. METHODS: Randomized controlled trials (RCTs) of various dose-fractionation schedules for painful bone metastases, published between 1980 and 1999, and on-going trials whose protocols were available, were systematically reviewed based on the following features of the primary treatment endpoint: (i) degree of pain relief; (ii) timing of the pain response assessment; (iii) effect of co-interventions on pain relief; (iv) the reduction of analgesic as a treatment response; and (v) quantification of response duration. RESULTS: Ten published RCTs (each sampled over 100 patients), plus two current trial protocols were reviewed. Five of the 12 studies defined any reduction in pain score as the primary endpoint. Three trials defined response at pre-determined time points, whereas eight studies attributed pain improvement at any time during follow-up to the effect of radiotherapy. No trial incorporated effect of systemic treatments on response. Only two trials incorporated analgesic scores into the primary endpoint criteria, although several trials reported results of combined pain and analgesic relief. Eight trials reported duration of response. Three provided some estimation of duration with respect to survival: two of them employing actuarial time to pain progression, and one calculated the ratio of pain response to median survival duration (percent net relief). Quality of life was measured in four of 12 studies, as secondary endpoint. CONCLUSION: Although available data suggest similarity in pain relief among various dose-fractionation schedules, accurate and consistent description of the degree of benefit from radiotherapy is lacking. While pain relief is a consistent primary treatment goal among randomized trials, a consensus on several important features of treatment endpoint is needed in order to establish common grounds for future trials in palliative radiotherapy.
BACKGROUND AND PURPOSE: Most patients with brain metastases are treated with palliative whole brain radiotherapy (WBRT). There is no established definition of palliative response. The aim of this study was to develop and test clinically useful criteria for response following palliative WBRT. MATERIALS AND METHODS: A prospective study was conducted of patients with symptomatic brain metastases treated with WBRT (20 Gy/5 fractions) and standardised steroid tapering. Assessments included observer rating of neurological symptoms, patient-completed symptom checklist and performance status (PS). Response criteria were operationally defined based on a combination of neurological symptoms, PS and steroid dose. RESULTS: Seventy-five patients were accrued. At 1 month, presenting neurological symptoms were improved in 14 patients, stable in 17, and worse in 21; 23 patients were not assessed, mainly due to death or frailty. Using response criteria defined a priori, 15% (95% CI 7-23%) of patients were classified as having a response to RT, 25% no response, and 29% progression; 27% were deceased at or soon after 1 month. A revised set of criteria was tested, with less emphasis on complete tapering of steroids: they increased the proportion of patients responding to 39% (95% CI 27-50%) but didn't change the large proportion who did not benefit (44%). CONCLUSIONS: Clinical response to RT of patients with brain metastases is multifactorial, comprising symptoms, PS and other factors. Assessment of degree of palliation depend on the exact definition used. More research is needed in this important area, to help validate criteria for assessing palliation after WBRT.
PURPOSE: The optimal management of malignant parotid gland tumours remains to be defined precisely. Specifically, a further understanding of the tumour features that influence treatment outcome is needed. MATERIALS AND METHODS: A retrospective review was conducted on 184 patients who were registered at the Princess Margaret Hospital with a diagnosis of a primary malignant parotid gland tumour. RESULTS: All patients were initially managed with a parotidectomy, and postoperative x-ray radiation therapy (XRT) was administered to 159 patients. The actuarial 5-year cause-specific survival and locoregional control rates were 76% and 81%, respectively. The survival and locoregional control rates for patients treated with surgery alone versus surgery plus postoperative XRT were not statistically different. A multiple regression analysis identified only age and tumour category to be independently significant prognostic factors for both survival and locoregional control. CONCLUSION: We would recommend that patients with malignant parotid gland tumours be managed with parotidectomy, followed by postoperative XRT for tumours with residual disease, aggressive histology, and/or positive lymph nodes.
BACKGROUND: The purpose of this study was to evaluate the effect of breast irradiation on quality of life, including cosmetic outcome, for patients enrolled in a clinical trial. METHODS: Between 1984 and 1989, a randomized trial was conducted in Ontario, Canada, in which women with lymph node negative breast carcinoma who had undergone lumpectomy and axillary lymph node dissection were randomized to either breast irradiation or no further treatment. A modified version of the Breast Cancer Chemotherapy Questionnaire (BCQ) was administered to women at baseline, 1 month (4 weeks), and 2 months (8 weeks) after randomization. Irritation of the skin of the breast, breast pain, and appearance of the breast to the patient were also assessed every 3 months for the first 2 years of the study. RESULTS: Of 837 patients, 416 were randomly allocated to radiation therapy and 421 to no further treatment. The mean change in quality of life from baseline to 2 months was -0.05 for the radiation group and +0.30 for the control group. The difference between groups was statistically significant (P = 0.0001). Longer term radiation therapy increased the proportion of patients who were troubled by irritation of the skin of the breast and breast pain. Radiation therapy did not increase the proportion of patients at 2 years who were troubled by the appearance of the treated breast; 4.8% in irradiated and nonirradiated patients (P = 0.62). CONCLUSIONS: Breast irradiation therapy had an effect on quality of life during treatment. After treatment, irradiated patients reported increased breast symptoms compared with controls. However, no difference was detected between groups at 2 years in the rates of skin irritation, breast pain, and being upset by the appearance of the breast.
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PURPOSE: To investigate the efficacy of dexamethasone as a prophylactic antiemetic for patients receiving fractionated radiotherapy to the upper abdomen in a randomized controlled trial. PATIENTS AND METHODS: One hundred fifty-four patients planned to receive fractionated radiotherapy to fields involving the upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were randomized to receive prophylactic dexamethasone (2 mg orally three times a day [tid], starting in the morning of first treatment and continuing until after their fifth treatment) or placebo. The primary end point of the study was the proportion of patients free from emesis during the study period. Secondary end points included a quality-of-life assessment using the core questionnaire of the European Organization for Research and Treatment of Cancer and side effects of dexamethasone therapy in this population of patients. RESULTS: Fifty-four (70%) out of 75 patients receiving dexamethasone had complete protection versus 37 (49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred during the initial phase of treatment. Although there was no difference in global quality of life between the two sets of patients, patients receiving dexamethasone had less nausea and vomiting and less loss of appetite but more insomnia. CONCLUSION: Dexamethasone 2 mg tid seems to be an effective prophylactic antiemetic in this situation. Side effects were acceptable, but there seemed to be no overall effect on global quality of life.
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Several studies have been conducted to assess the safety and efficacy of paclitaxel plus radiation therapy in patients with non-small cell lung cancer (NSCLC) and to assess whether the radiosensitization demonstrated by paclitaxel in vivo can translate into clinical benefit. The National Cancer Institute of Canada Clinical Trials Group conducted a phase I/II trial in patients with inoperable stage IIIA or IIIB NSCLC to determine the maximum tolerated dose and efficacy of paclitaxel, given as a 3-hour infusion every 2 weeks during radical radiotherapy. The paclitaxel maximum tolerated dose using this schedule was 135 mg/m2; the recommended phase II dose was 120 mg/m2. The dose-limiting toxicity was grade 3 neutropenia, which prevented paclitaxel re-treatment. The overall response to all paclitaxel doses was 59% (n = 17); the overall response to the recommended phase II dose was 78% (n = 9). Median survival for all patients was 1.31 years; the 1-year survival rate was 64%. Lymphocytopenia was observed in all 17 patients; four patients had associated pneumonia or other febrile episodes during treatment. Grade 3 skin toxicity within the radiation field was reported in three patients receiving paclitaxel 120 mg/m2. This combination can be safely delivered to patients with NSCLC and has demonstrated activity in this setting. This combination has been used in Canada outside of clinical trials, and its use may be expanded as additional data from ongoing clinical trials further define the role of paclitaxel-based combined modality therapy in NSCLC.
OBJECTIVES: A retrospective analysis of 550 women with pathological stage I carcinoma of the endometrium who were seen between January 1984 and December 1988 was performed in order to assess the value of adjuvant radiation therapy. METHODS: Two-hundred twenty-eight patients were treated with surgery alone (S); 97 received adjuvant external beam radiotherapy (S + EXT); 217 received external beam radiotherapy and colpostats (S + EXT + IC); and 8 patients received only colpostats (S + IC). Pelvic radiation therapy, usually 40 Gy in 20 fractions, was administered to 94% of patients whose tumors showed greater than 50% myometrial invasion and to 89% of patients with FIGO grade 3 tumors. Colpostats were used in 40% of patients, the majority of whom had lower uterine segment involvement. RESULTS: The overall survival rate for the whole group using Kaplan-Meier estimates was 84% at 5 years. The 5-year overall survival rates for each treatment group, excluding the S + IC group, were 90% for S alone, 79% for S + EXT, and 82% for S + EXT + IC. The 5-year disease-free survival rates were 84, 77, and 77%, respectively. Local control rates at 5 years were 93, 94, and 95% in the three treatment groups, but the patterns of relapse were different. Distant metastases occurred more frequently among the patients who received adjuvant radiation therapy (36/49, 73%) than among those who did not (4/19, 21%). Late toxicity was documented in 66 patients. Twelve patients had EORTC/RTOG grade 3 and 4 complications; all had been treated with S + EXT + IC. FIGO grade (P = 0.009), lower uterine segment involvement (P = 0.009), and age (P = 0.03) were significant predictors of worse disease-free survival in a multiple regression analysis. CONCLUSIONS: The addition of vaginal vault brachytherapy to external beam radiotherapy did not appear to improve local cure rates nor survival, but increased the incidence of late radiation toxicity.