Nicole Causse

Fractionated radiation therapy in the treatment of intracranial meningiomas: Local control, functional efficacy, and tolerance in 91 patients☆

PURPOSE To evaluate efficacy and tolerance of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. METHODS AND MATERIALS From January 1981 to September 1993, 91 patients with intracranial meningiomas were treated with fractionated RT. Indications were as follows: (a) incomplete surgical resection, 29 patients; (b) tumor recurrences without considering the amount of the second resection, if performed, 14 patients; (c) completely excised angioblastic, aggressive benign, and anaplastic tumors, 8 patients; (d) medically inoperable and basilar tumors where operation would involve considerable danger or permanent neurological damage, 44 patients. Most patients were irradiated with 6 to 9 MV photon beams. A three- to four-field technique with coned-down portals was used. Doses were calculated on the 95% isodose and were given 5 days a week for a median total dose of 52 Gy (1.80 Gy/fraction). RESULTS Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent, but there were six late delayed injuries. Tumor recurrences occurred in six cases. Six patients died from their tumor or RT complications, 19 from nontumoral reasons. Three, 5- and 10-year survival rates were 82, 71, and 40%, respectively. The most significant prognostic factor was age: 5-year survival rate was 86% for patients less than 65 years and 37% for patients more than 65. However, there were no differences in recurrence-free survival rates between patients younger than 65 and the oldest ones. Of 60 symptomatic patients with neurological deficits, 43 had neurological improvement (72%), beginning in some cases within 15 to 20 days after starting RT. CONCLUSION These results reassess the role of fractionated RT in the treatment of meningiomas, and stress on its efficacy, especially on cranial nerves palsies, without severe toxicity in most cases.

Effet volume en radiothérapie [II]. Deuxième partie : volume et tolérance des tissus sains

The first part of our work has focused on the relationship between tumor volume and tumor control. Indeed, it is well known that the importance of irradiated volume could be a main parameter of radiation-induced complications. Numerous mathematical models have described the correlation between the irradiated volume and the risk of adverse effects. These models should predict the complication rate of each treatment planning. At the present time late effects have been the most studied. In this report we firstly propose a review of different mathematical models described for volume effect. Secondly, we will discuss whether these theoretical considerations can influence our view of radiation treatment planning optimization.Resume Dans la premiere partie, nous avons evoque la relation entre la taille tumorale et les effets de l’irradiation. Par ailleurs, le volume de tissu sain irradie peut conditionner le risque de complications en radiotherapie. De nombreux modeles mathematiques ont ete appliques a la relation dose–volume–effet afin de predire le risque de complications d’un schema d’irradiation donne. Les modeles les plus developpes concernent les effets tardifs de l’irradiation. Dans un premier temps, pour une meilleure comprehension des mecanismes incrimines dans la relation dose–volume, nous allons faire la revue de la litterature concernant un certain nombre de modeles predictifs. Dans un second temps nous tenterons d’evaluer l’impact de la prise en compte de cet effet volume sur l’optimisation de la planification des traitements par radiations ionisantes.

Radiothérapie fractionnée des méningiomes intracrâniens : 15 ans d'expérience au centre hospitalier universitaire de Bordeaux

PURPOSE: To evaluate the long-term results of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas. PATIENTS AND METHODS: From January 1981 to December 1996, 156 patients with intracranial meningiomas were treated with external fractionated RT. Median age was 57. Indications for radiation therapy were as follows: (1) completely excised histologically aggressive tumors (12 patients); (2) incomplete surgical resection (37 patients); (3) medically inoperable or basilar tumors where operation would involve considerable danger or permanent neurological damage (77 patients); and, (4) tumor recurrences (30 patients). Most patients were irradiated with 6 to 9 MV photon beams. A three to four-field technique with coned-down portals was used. Since 1993, 71 patients had a three dimensional dosimetry. Doses were calculated on the 95% or 98% isodoses, all fields were treated every day, five days a week, for a median total dose of 50 Gy (1.8 Gy/Fraction). RESULTS: Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent; an early clinical improvement during radiation therapy was noted in 19 patients (17.8%). Clinical improvement or stabilization was observed in 130 patients (83.4%). Radiologically, local control was obtained in 124 cases (79.4%) and tumor recurrences occurred in 21 cases (ten progressions in the treated volume, five borderline, six new locations). Overall and cause specific-survival rates were 75% and 89% at five years, and 45 and 76% at 10 years, respectively. CONCLUSION: These results reassess the role of fractionated RT in the treatment of intracranial meningiomas. Long-term tolerance is excellent for a majority of patients. The study of recurrences confirms the importance of the definition of the target volume, and asks questions about total given doses.

Fractionated Radiation Therapy in the Treatment of Cerebello-Pontine Angle Neurinomas: 12 Years of Experience in 29 Cases

The purpose of this research was to reevaluate long-term results of frationated radiation therapy (RT) in two previously published series of cerebello-pontine angle (CPA) neurinomas. From January 1986 to October 1995, 29 patients with stage III and IV CPA neurinomas were treated with external fractionated RT. One patient was irradiated on both sides and indications for radiotherapy were as follows: (a) poor general condition or old age contraindicating surgery, 16 cases; (b) hearing preservation in bilateral neurinomas after contro-lateral tumor removal, 6 cases; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 5 cases; (d) nonsurgical relapse, 3 cases. Most patients were irradiated with 6 to 10 MV photons. A three- to four-field technique with coplanar static beams and conformal blocks was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 51 Gy (1.80 Gy/fraction). Median follow-up from RT was 66 months (7 to 120); 7 patients died, 2 with progressive disease, 5 from nontumoral causes. Two patients underwent total tumor removal after RT (1 stable and 1 growing tumor). On the whole, tumor shrinkage was observed in 13 patients (43.3%), stable disease in 14 (46.6%), and tumor progression in 3. Hearing was maintained in 4 out of 6 hearing patients. No patient experienced facial or trigeminal neuropathy. Long-term efficacy of fractionated RT is well documented in this series. Acute and delayed tolerance was excellent. Hearing can be preserved for a long time.

L'effet volume en radiothérapie première partie : effet volume et tumeur

Volume is an important parameter of radiation therapy. Local control is inversely related to tumor size and the complication rate increases with the importance of the irradiated volume. Although the effect of irradiated volume has been widely reported since the beginning of radiotherapy, it has been less studied than other radiation parameters such as dose, fractionation, or treatment duration. One of the first organ system in which the adverse effect of increased volume was well defined is the skin. Over the last twenty years, numerous mathematical models have been developed for different organs. In this report we will discuss the relation between irradiated volume and tumor control. In a second article we will study the impact of irradiated volume on radiation adverse effects.

Whole Brain Irradiation is not necessary for the Treatment of Malignant Supra-Tentorial Gliomas

Compared with other cancers, supra-tentorial astrocytoma malignancy is not a result of metastatic diffusion but of local recurrence: this suggests that local treatment might be effective. Nevertheless, long term survivors do not exceed 5 to 10% at 3 to 5 years.