$386
and inexpensive would be ideal. The acute response to any tissue injury involves a cascade of physiologic events regulated in part by acute phase reactants that include Creactive protein (CRP) and erythrocyte sedimentation rate (ESR). Measurements of CRP have correlated well with the timing of tissue injury and healing and show little elevation with non-hematological tumours. Prior studies suggest that peak levels of CRP are proportional to the degree of tissue injury, are not affected by immunologic status, red blood cell status or changes in serum protein concentrations. Materials and Methods: The patient population was comprised of head and neck cancer patients receiving radical doses of radiation with or without chemotherapy (daily platinum, 6mg/m2). Serum CRP and ESR were drawn weekly and 1 month post treatment. Tumour site, stage, total radiation dose, radiation technique (bilateral parallel opposed pair vs. ipsilateral), compliance with chemotherapy were correlated with the mucositis. Because no gold standard exists for mucositis measurements, multiple measures of mucositis severity were recorded weekly and 1 month post RT. The measures include RTOG symptom scores, a subjective mucosal assessment by two independent health care professionals and a head and neck quality of life instrument (HNRQ). Other surrogate measures such as weight loss, dependency on PEG feeds, required narcotics were also recorded. Results: Of the 38 patients, 25 received concurrent chemotherapy. The total dose ranged from 4400 to 7000cGy. 9/38 patients were treated with an ipsilateral technique. Overall, the median values of CRP and ESR steadily rose from a pretreatment level of 3.3 and 21 to a maximum median value of 10.3 and 49 by weeks 6 and 7 respectively before falling to 2.8 and 37 at 1 month post treatment. An analysis correlating -the HNRQ and other mucositis measurements to serum values has also been performed. 910 poster Testing the new ICRU 62 'planning organ at risk volume' concept for the rectum
L.P. Muren ~, .4. Karlsdotti/, Y. Kvinnsland, T. WentzelDahf ~Haukeland University Hospital, University of Bergen, Dept. of Oncology and Medical Physics, Bergen, Norway 2Haukeland University Hospital, University of Bergen, Centre for Clinical Research, Bergen, Norway Purpose: To study the impact of the new ICRU 62 'Planning organ at Risk Volume' (PRV) concept on the relationship between rectum dose-volume histogram (DVH) data and toxicity. Methods and Materials: The acute gastro-intestinal (GI) RTOG toxicity in 127 prostate cancer patients prescribed a target dose of 70 Gy with conformal irradiation to either the prostate, the prostate and seminal vesicles or the whole pelvis were analysed. DVHs were derived for the rectum only and for rectum extended with six PRV margin sets (narrow/intermediate/wide; anterior/anterior&posterior). The data was analysed using permutation testsl logistic regression and effective uniform dose (EUD) calculations. Results: Acute Grade 2 GI toxicity was seen in 22 of 127 cases (17%). Permutation tests showed that the difference between DVHs for patients with and without Grade 2 effects was significant, both for rectum only and rectum PRVs (p value range: 0.02-0.04), with generally lower p-values for the PRVs. In the logistic regressions the fractional volumes receiving more than a number of dose levels were significantly related to toxicity, with a larger number of significant levels for the PRVs. E.g., with wide anterior and
Posters
posterior margins the relation was significant at 25 different dose levels (11-12 Gy, 33-41 Gy and 58-69 Gy), compared to nine levels (36-38 Gy, 41-42 Gy and 79-82 Gy) for rectum only. A significant relationship was found at a larger number of dose levels when using both anterior and posterior margins compared to anterior only. When using both anterior and posterior margins, the number of significantly related dose levels increased with increasing margin width. EUDs were significantly different for patients with and without Grade 2 effects both for rectum only and the PRVs (95% confidence interval for EUD increase with Grade 2 effects: 0.1 - 3.1 Gy). Conclusions: All methods applied indicated a small, but definite difference in DVH parameters between patients with or without Grade 2 effects. This difference was more pronounced when wide anterior and posterior margins were applied. 911 poster Long term outcome in patients with gastrointestinal complications after pelvic or abdominal radiation therapy
A. Larsen 1, J. Reitan 2, M. Hauer-Jensen 3'4 I Haukeland University Hospital, Dept of Oncology, Bergen, Norway 2The Norwegian Radium Hosptial, Dept of Oncology, Oslo, Norway 3University of Arkansas for Medical Sciences, Departments of Surgery and Pathology, Little Rock, USA 4Central Arkansas Veterans Healthcare System, Little Rock, USA A prospective study to obtain information about the long-term prognosis of patients with severe radiation enteropathy was performed by the Norwegian Study Group for Gastrointestinal Surgery (NORGAS). Patients admitted with severe intestinal radiation injury and presumed need for surgical intervention during the period 1985-87 were enrolled on a prospective, multicenter, observational cohort study and followed up 15-17 years later. Of 59 patients enrolled, 39 had received radiation therapy for gynaecological cancers and 20 for other malignancies. Fortyfive patients (76%) required surgical intervention, 26 for intestinal obstruction, 11 for enteric fistulae, 5 for perforated bowel, and 3 for other reasons. At follow-up, 20 patients (34%) had died of their original malignancy and 17 of other unrelated disease, while 7 (12%) had died of complications from radiation enteropathy. The minimum incidence of persistent symptomatic radiation enteropathy was 58% and that of debilitating radiation enteropathy was 25%. More than half of patients who develop severe delayed radiation enteropathy have persistent symptoms, one quarter is severely debilitated, and one in ten dies as a direct result of radiation-induced bowel injury. While modern radiation therapy techniques may help reduce the incidence of delayed bowel toxicity, a stronger focus on side effects in the longterm follow-up of cancer patients is recommended. 912 poster Treatment of radiation-induced normal tissue lesions by antioxidants
M. Rezvani University of Oxford, Research Institute, Oxford, United Kingdom Recently, persistent oxidative stress has been suggested as a common pathway in the development of radiation-induced lesions that has been demonstrated in a number of tissues such as skin, kidney and spinal cord. On the basis of this