Total-body irradiation and cataract incidence: a randomized comparison of two instantaneous dose rates.

PURPOSE: To assess the influence of instantaneous total-body irradiation dose rate in hematological malignancies, we randomized 157 patients according to different instantaneous dose rates. METHODS AND MATERIALS: Between December 10, 1986 and December 31, 1989 157 patients have undergone a total-body irradiation before bone-marrow transplantation according to two different techniques: either in one fraction (1000 cGy given to the midplane at the level of L4, and 800 cGy to the lungs) or in six fractions (1200 cGy over 3 consecutive days to the midplane at the level of L4, and 900 cGy to the lungs). Patients were randomized according to two instantaneous dose rates, called LOW and HIGH, in single-dose (6 vs. 15 cGy/min) and fractionated (3 vs. 6 cGy/min) TBI groups; there were 77 cases for the LOW and 80 for the HIGH groups, with 57 patients receiving single-dose (28 LOW, 29 HIGH) and 100 patients receiving fractionated total-body irradiation (49 LOW, 51 HIGH). RESULTS: As of July 1992, 16 (10%) of 157 patients developed cataracts after 17 to 46 months, with an estimated incidence of 23% at 5 years. Four (5%) of 77 patients in the LOW group, 12 (15%) of 80 patients in the HIGH group developed cataracts, with 5-year estimated incidences of 12% and 34%, respectively (p = 0.03). Ten (18%) of 57 patients in the single-dose group, and 6 (6%) of 100 patients in the fractionated group developed cataracts, with 5-year estimated incidences of 39% and 13%, respectively (p = 0.02). When the subgroups were considered, in the single-dose group, 3 (11%) of 28 LOW patients, and 7 (24%) of 29 HIGH patients developed cataracts, with 5-year estimated incidences of 24% and 53%, respectively; in the fractionated group, 1 (2%) of 49 LOW patients, and 5 (10%) of 51 HIGH patients developed cataracts, with 5-year estimated incidences of 4% and 22%, respectively (single-dose LOW vs. single-dose HIGH vs. fractionated LOW vs. fractionated HIGH, p = 0.006). There was no statistically significant difference in terms of 5-year estimated cataract incidence between the patients receiving steroids and those not (30% vs. 25%, p = 0.22). Multivariate analyses revealed that the instantaneous dose rate was the only independent factor influencing the cataractogenesis (p = 0.04). CONCLUSION: We conclude that the total-body irradiation regimen (instantaneous dose rate and/or fractionation) may have an influence on the development of cataracts following bone-marrow transplantation.

Radiosensitivity, blood perfusion and tumour oxygenation after perflubron emulsion injection.

The effect of 90% and/or 100% w/v perflubron (perfluorooctyl bromide (PFOB); Alliance Pharmaceutical Corp.) emulsions on radiosensitivity, tumour relative perfusion and oxygenation was studied using EMT6 tumours in nude mice. Perflubron (2-15 ml/kg) emulsion was injected. The mice inhaled carbogen for 30 min and 60 min prior to irradiation. The radiosensitizing effect of the 90% w/v emulsion was maximal at 4 ml/kg. The tumour relative perfusion diminished after injection of both 100% and 90% w/v emulsions in carbogen-breathing mice at a dose of 15 ml/kg. This drop could explain the lack of efficiency of these treatments at this high concentration. Lastly, tumour oxygenation was increased after administration of perflubron emulsion plus carbogen.

[Review of results and clinical analysis of conservative partial surgery associated with postoperative radiotherapy in operable breast cancers stages I amd II]. / Revue des résultats et étude critique de la chirurgie partielle conservatrice associée à une radiothérapie postopératoire dans les cancers du sein opérables d'emblée stades I et II.

Over the last 25 years, conservative forms of treatment have been used for the locoregional treatment of early breast cancer, stages I and II (< 3 cm in diameter). At present, the same carcinological results are obtained with conservative surgery and radiation therapy as with radical surgery, and the aesthetic and functional results have improved. Several parameters should be taken into account, ie tumour volume, breast volume, multifocal nature and histologic type. A number of questions still remain unanswered namely: what is the most appropriate conservative surgery (quadrantectomy, tumourectomy or local excision)? What is the most appropriate total irradiation dose (50 Gy over 5 weeks: or 45 Gy over 4.5 weeks)? What is the value of radiation boost in patients with negative resection margins? What is the value of radiation boost in patients with a high local risk of recurrence? What is the most appropriate radiation technique for boost in the primary tumour bed (electrons or iridium implants)? Does the external irradiation of regional lymph nodes improve survival rate? Is it possible to extend conservative treatment to a 4-cm diameter tumour? What is the impact of adjuvant systemic chemotherapy and/or hormonotherapy on the risk of isolated breast cancer recurrence?