[en] Background and purpose: No standard dose fractionation has been defined for metastatic spinal cord compression. This retrospective analysis was undertaken to explore the impact of hypo fractionated treatment compared to conventional multi fraction treatment. Materials and methods: One hundred and two consecutive patients referred to Mount Vernon Cancer Centre with metastatic spinal canal compression confirmed on MR scan in 95% with median age 68 years (range 32-90) and main primary tumour types breast (28%), prostate (28%) and lung (20%); 51% of patients were fully ambulant at diagnosis, 41% ambulant but with paraparesis and 9% had complete paraplegia. Spinal radiotherapy was given delivering a single dose in 32% and 20 Gy in five fractions in 64%. Results: The median survival was 3.5 months; survival was significantly related to primary site and motor function at presentation. Normal ambulation was achieved in 58% at 2 weeks and 71% up to 2 months after treatment. No patient who presented with paraplegia regained function. At presentation 59% of patients had severe pain, which fell to 8% at 2 weeks. Comparing those patients who received one or two dose treatments with those who received protracted fractionation, the two groups were matched for age, sex, primary site and site of compression. Relatively more patients treated with one or two doses had paraplegia; 19% vs. 3%. Despite this outcome in the two groups was equivalent for motor and sphincter function and pain control. Conclusions: Metastatic spinal canal compression carries a poor prognosis. Urgent treatment will maintain and improve motor function in patients presenting ambulant but those who have paraplegia at presentation do not improve and have a very short survival. In this series no difference in outcome was seen between patients treated with one or two radiation doses compared to multi fraction treatment; a randomised trial comparing fractionation schedules would be justified

[en] Background and purpose: This paper compares the quality control checks performed in departments in the United Kingdom with those recommended by the Institute of Physics and Engineering in Medicine (IPEM) in Report 81. Method: The data were gathered by the quality assurance team for the START trial, during visits to individual departments. Data are compared with the frequencies suggested in IPEM report 81. Where applicable, data are also analyzed with respect to machine manufacturer. Results: All departments with linear accelerators check the output at least weekly for both photons and electrons, however 11% of departments do not perform a constancy check of the output on a daily basis. The majority of departments check flatness at gantry zero on a monthly basis. However 27% of departments never check at non-zero gantry angles. In 51% of departments no fluoroscopy checks are performed on simulators on a daily basis. Conclusion: The majority of departments are following the frequencies suggested in IPEM report 81 although there are a number of discrepancies particularly for simulators. Accelerator type needs to be considered when designing quality assurance checks. In many departments more time than is currently allocated is needed on equipment, particularly simulators, to complete all of the checks suggested in Report 81

[en] Fractionated high dose rate afterloading brachytherapy for prostate cancer requires a robust means of catheter fixation with good quality assurance. Catheter position and dosimetry has been formally evaluated in 20 consecutive patients representing a total of 332 catheters undergoing two HDR afterloading brachytherapy fractions over 36 h. The mean inter fraction movement of catheters as measured by external length was less than 1 mm, but within the prostate on consecutive CT scans there was a mean inter fraction movement of 11.5 mm away from the prostate base. This has a significant impact on implant dosimetry as measured by D90 and the COIN index, unless corrected by repositioning the catheters

[en] Aim: To assess the effect of combining oral nicotinamide, oral pentoxifylline and carbogen gas (2% CO₂, 98% O₂) breathing on human tumour red cell flux. Methods and materials: Microregional red blood cell flux was measured in accessible tumour nodules using laser Doppler microprobes in 11 patients with histologically proven malignancy. Patients received single oral doses of nicotinamide 40 mg kg^-1 and pentoxifylline 1200 mg 2 h before a 10-min period of carbogen gas breathing, corresponding to peak plasma concentrations of these drugs. Red cell flux in up to six microregions in each tumour was measured for 30 min, recording pre-, during and post-carbogen breathing for 10 min each. Results: Data from ten of the 11 patients could be assessed. The red cell flux in 48 microregions was analysed and the mean red cell flux was calculated. A mean relative increase in red cell flux of 1.18 (±0.09, 95% confidence interval (CI)) was observed after 6 min of carbogen breathing, 2 h after the administration of nicotinamide and pentoxifylline. This compares to relative increases of 1.4 (±0.39, 95%CI) after nicotinamide with carbogen and 1.15 (±0.10, 95%CI) after pentoxifylline with carbogen. These differences are not statistically significant (P>0.05). The increased red cell flux persisted after the cessation of carbogen gas breathing. Conclusions: A combination of pentoxifylline, nicotinamide and carbogen produces an increase in human tumour red cell flux, similar to that observed when each of the drugs are used alone with carbogen breathing

[en] Purpose: To assess the efficacy and toxicity of continuous hyperfractionated accelerated radiotherapy (CHART) in locoregional control compared with a historical group of patients treated with conventionally fractionated radical radiotherapy. Methods and Materials: Between 1985 and 1994, 54 patients with localized esophageal cancer were treated with CHART. Twenty-eight patients received CHART alone (54 Gy in 36 fractions over 12 consecutive days) and 15 were given intravenous mitomycin C and cisplatin on days 10 and 13, respectively. Eleven patients received 40.5 Gy in 27 fractions over 9 days, followed by a single high-dose-rate intraluminal brachytherapy insertion of 15 Gy at 1 cm. Results: Acute toxicity was well tolerated and dysphagia was improved in 35 patients (65%), with 28 (52%) eating a normal diet by week 12. This compares with an improvement in dysphagia score in 72% of the conventionally treated group. The median duration of relief of dysphagia was 7.8 months (range 0-41.4) in the CHART group compared with 5.5 months (range 0-48) in the controls. Strictures developed in 29 patients (61%) and 18 were confirmed on biopsy to be due to recurrent disease. Median survival was 12 months (range 0.5-112) in the CHART group and 15 months (range 3.6-56) in the control patients. Conclusion: CHART is well tolerated and achieves a high rate of local control. Palliation in the short overall treatment time of esophageal cancer is an advantage in these patients whose median survival is only 12 months

[en] Purpose: To examine the ability of computer planning systems to calculate the dose to the breast correctly in three dimensions. Both the absolute dose at the center of the breast and the accuracy of the isodose distributions were investigated. Methods and Materials: Measurements were performed in a water-filled breast phantom using an ionization chamber. Thirty-six sets of data obtained during the Standardization of Breast Radiotherapy breast fractionation trial quality assurance program were included in the analysis. The planning systems were grouped according to the algorithms used on the basis of the definitions given in International Commission on Radiation Units and Measurements Report No. 24. Results: Thirty-two of the 36 planning systems overestimated the dose to the center of the breast, with a mean measured/calculated dose ratio of 0.979 (SD 0.013). The relative dose within 2 cm of the lung was also overestimated. Conclusion: Only one algorithm (collapsed cone) investigated in this study was able to calculate the dose at the center of the breast correctly in tangential breast radiotherapy. With modern algorithms, it is important to include a correction for the lower density of the lung, because the dose close to the interface between breast and lung tissue will also be lower than anticipated

[en] Background and purpose: Carbogen is currently being re-evaluated as a radiosensitiser. It acts primarily by increasing tissue pO₂, although there is evidence to suggest that enhanced tumour blood flow may also be a component of its action. Materials and methods: Ten tumours in eight patients with advanced malignant disease were studied. Up to six microprobes, each with an estimated sampling volume of 10^-2 mm³, were inserted into the tumours. Ten min of baseline readings were taken prior to a 10 min carbogen (95% (O₂(5%)) CO₂) breathing period, measurements were continued for a further 10 min. Results: The results show that in 34 microregions analysed no overall change in tumour perfusion was seen with carbogen breathing. Individual tumour analysis demonstrated variation in response between patients to carbogen - after 6 min of carbogen four tumours showed an increase in blood flow by more than 10% of the pre-breathing value, two a decrease and four no change. The magnitude of change was small, with only two tumours fluctuating by more than 25%. Conclusions: These findings confirm the presence of transient fluctuations in microregional blood flow in human tumours but suggest that the radiosensitising action of carbogen lies primarily in its effect on increasing the oxygen capacity of blood. This supports the addition of agents such as nicotinamide with carbogen in order to overcome both diffusion and perfusion limited hypoxia

No abstract available

[en] Background: To evaluate early urinary (GU) and gastrointestinal (GI) adverse events (AEs) after two or one fraction of high-dose rate brachytherapy (HDR-BT) in advanced prostate cancer. Patients and methods: 165 patients were treated with 2 × 13 Gy (n = 115), or a single dose of 19 Gy (n = 24) or 20 Gy (n = 26) HDR-BT. Early AEs were assessed using the RTOG scoring system and the International Prostate Symptom Score (IPSS). Results: Week-2 prevalence of severe IPSS symptoms was higher after 20 Gy than after 26 or 19 Gy but by 12 weeks all groups were at pre-treatment levels or less. Grade-3 GU toxicity was observed ⩽9% of patients. No Grade 4 GU and no Grade 3 or 4 GI complications were observed. However, there was a significant increase in catheter use in the first 12 weeks after implant after 19 and 20 Gy compared with 2 × 13 Gy. Conclusion: Single dose HDR-BT is feasible with acceptable levels of acute complications; tolerance may have been reached with the single 19 Gy schedule

[en] Background: To evaluate late urinary (GU) and gastrointestinal (GI) adverse events (AEs) and biochemical control of disease after high-dose rate brachytherapy (HDR-BT) in locally advanced prostate cancer. Patients and methods: 227 consecutive patients were treated with 3 × 10.5 Gy (n = 109) or 2 × 13 Gy (n = 118) HDR-BT alone. Biochemical failure was assessed using the Phoenix definition of PSA nadir + 2 μg/l and late AEs using the RTOG scoring system and the International Prostate Symptom Score (IPSS). Results: Kaplan–Meier estimates and prevalence of late events indicate that urinary, bowel and IPSS symptoms are higher after 31.5 Gy than after 26 Gy, however differences are significant only for Grade 1 and 2 urinary toxicity. Kaplan–Meier estimates of morbidity are consistently and considerably higher than time-point estimates of prevalence; which reflects the transient nature of most symptoms. At 3 years 93% and 97% of patients treated with 26 and 31.5 Gy, respectively, were free from biochemical relapse (p = 0.5) and 91% for the latter regimen at 5 years. In univariate and multivariate analysis risk-category was the only significant predictor of relapse (p < 0.03). Conclusion: These HDR-BT schedules achieved high levels of biochemical control of disease in patients with advanced prostate cancer with few severe complications seen throughout the first 3 years