Biomedical subjects
Publications and source records attributed to L Chauveinc.
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No criteria are currently available to determine the spontaneous or radiation-induced origin of a malignant tumor occurring in a previously irradiated area. This study presents the dosimetric and cytogenetic analysis of meningiomas diagnosed in irradiated brain areas from a single patient and a discussion of the karyotypes of spontaneous meningiomas and radiation-induced tumors published in the literature.
Thirty one patients previously treated with surgery, radiation therapy and chemotherapy with a nitrosourea for malignant supratentorial gliomas received a combination of carboplatin (CBDCA) and etoposide (VP16) at tumor progression. Carboplatin and etoposide (CE) were given, each at a dose of 100 mg/m2/day from day 1 to 3. The response was evaluated at each course and a minimum of three course was required to definite stable patient. Tolerance was evaluated in 31 patients. None had renal or auditory toxicity. Side effects consisted of grade III hematologic toxicity in 6 patients (19%), and grade III hepatic toxicity in one patient. No grade IV WHO toxicity was observed. All 31 patients could be evaluated for therapeutic response. A partial response was noted in 4 patients during 13, 34 +, 35 + and 51 + weeks. Ten patients had stable disease after a minimum of 3 courses (19 to 37 weeks). The rate of partial response (PR) and stabilisation (S) was 45% (14/31). The median time to tumor progression (MTTP) for responding and stable patients was 28 weeks. The median survival time (ST) for the entire group was 45 weeks and over 51 weeks for PR and S patients.
For the non-operable malignant glioma patients, prognosis remains poor, with a survival of 8 months for the glioblastomas (G), and 15 months for anaplastic astrocytomas (AA). 27 histologic proven malignant gliomas (17 AA and 10 G) were treated between April 1991 and June 1992. Median age was 48 years. The therapeutic protocol consisted of three courses of intra arterial chemotherapy (IAC) with ACNU, at intervals of six weeks, and a localised 60 Gy radiotherapy between the first and the second IAC course. 72 courses of IAC were delivered (2.4 per patient). Response rate was 51.8%. Median survival (MS) was 13 months, with a survival rate of 28% at 24 months. For the AA, MS was 21 months, with a survival rate of 37% at 24 months. For the G, median survival was 10 months. Responders were 65% for AA, 30% for G. Non responders all died before 24 months had relapsed with a MS of 9 months. 54% of responding patients had a 2 years survival. Toxicity were acceptable with 7% of haematological toxicity and partial loss of visual acuity in 11% of the case. No chronic neurological sequellae were noted. We compare theses results with two previous trials, concerning inoperable patients, treated by association of radiotherapy and systemic chemotherapy. Survival seems to be equivalent with HeCNU and with this treatment, but toxicity decrease with ACNU. Early radiotherapy does not increase complications. This treatment can be used for patients with inoperable malignant gliomas.
Two types of "severe accidental irradiation" can be schematically described: high dose localized irradiations and accidental total body overexposure. Actually, these two pathologies may coexist, and may be associated with external or internal radioactive contamination, and with all the "catastrophe medicine" syndromes. For high dose localized irradiation, physicians must manage as well as possible complex surgical procedures which unfortunately cannot always avoid being mutilating. For total body overexposure, haematological problems are at the forefront. In according with various situations, hematological growth factors or even allogeneic bone marrow transplantation will be discussed in specialized haematology (and transplant) units. The optimal management of severe accidental irradiation victims implies a close--and rapidly organized--cooperation between general practitioners, firemen, intensive care units, radiopathologists, specialist surgeons (hand and burns) and haematologists.
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In 1994, late effects of radiotherapy should be limited to an acceptable rate of benign and non-disabling complications. In almost all cases, this goal can be presently reached, owe to recent technological and radiobiological advances. The precise adaptation of irradiated volume, dose, fractionation and total duration of treatment should avoid severe post-radiotherapeutic toxicity. The identification of subgroups of patients with high susceptibility to ionizing radiations should soon allow the radiotherapists to take up the challenge of a both efficient and non-toxic irradiation.
A cytogenetic analysis was performed on 19 recurrent gliomas all of which had been treated by radiotherapy. All cases exhibited clonal chromosomal anomalies, the tumors were classified into four categories in relation to their mono- or polyclonality and to the presence or absence of a clonal evolution. Polyclonal tumors without clonal evolution had a delay of recurrence significantly longer than monoclonal or polyclonal tumors with clonal evolution. This difference could be related to the presence of clones with different malignant potential, which could be differentiated by their pattern of chromosomal aberrations. The malignant potential of "highly malignant" clones resulted from the juxtaposition of imbalances, such as monosomy 10, as in high-grade primary gliomas, and presumably radiation-induced structural rearrangements. That of clones of low malignancy was almost limited to the presence of multiple balanced structural rearrangements, probably induced by radiation.
From December 1981 to October 1990, 28 patients with prior irradiation of the oropharynx underwent salvage brachytherapy for a squamous cell carcinoma of the tonsil and/or the soft palate. The patients were free of cervical nodes and without metastatic disease. There were 4 immediate failures of radiotherapy, 14 local recurrences, and 10 new malignancies. The mean size of the lesion was 2.7 +/- 1.7 cm (range, 0.5 to 7 cm). The initial irradiation had delivered 40 to 80 Gy (mean, 69 Gy) to the oropharynx with a mean interval between external therapy and salvage treatment of 22 +/- 28 months. Salvage brachytherapy consisted of two split course implants done 1 month apart, delivering 35 and 30 Gy, respectively. Fifteen patients (46.5%) were clinically disease-free before the second implant and 23 (82%) were clinically disease-free at the end of treatment. Five local failures have been observed without any influence of the tumor size, the topographic site of the tumor, or the histological differentiation. Of the 4 patients who previously had failed with external beam therapy, 3 were disease-free after salvage brachytherapy. Among the 23 patients in complete remission, 4 (17%) presented a local recurrence within a mean time of 5 months. The overall local control rate was 68% with a mean follow-up of 41 +/- 29 months. The overall actuarial survival was 25% and 19% at 2 and 5 years, respectively; it was 30% at 5 years for the patients presenting with lesions less than or equal to 3 cm. Tolerance was acceptable. Among the 23 patients who achieved complete remission, subsequent soft-tissue necrosis was observed in 4 cases. For these 4 patients, the interval between previous radiation therapy and salvage treatment was short (mean, 7 months). Interstitial split course brachytherapy offers an effective and reasonable option for salvage therapy in patients with recurrent and second cancers occurring in the tonsillar region and in the soft palate, even when the tumor arises in a zone that has previously received high-dose irradiation.
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The mechanism of the transient encephalopathy induced by high dose systemic administration of methotrexate (HDMTX) is unknown. Metabolic and vascular hypothesis have been formulated but convincing evidence is lacking. We report the first case of vascular disturbances (thinness of cortical arteries on angiography, reversible fall down of cerebral flow and increase of carotid resistance) in a young Algerian patient treated for an osteogenic osteosarcoma. This observation might lead to the exploration by non invasive and easily repeatable techniques of the cerebral vascular dynamic in patients submitted to HDMTX and thus contributed to the elucidation of the mechanism and to the prevention of these neurological side effect.
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We report three examples of toxic acute colitis which occurred after ingestion of colocynth (Citrullus colocynthis) for ritual purposes. The prominent clinical feature was dysenteric diarrhoea; colonoscopic changes included congestion and hyperaemia of the mucosa with abundant exudates but no ulceration or pseudopolyp formation. A causal relationship between colonic injury and the intake of colocynth was supported by the following features: (1) the pharmacology of the colocynth extract ingested; (2) the temporal relationship between colocynth intake and clinical onset (eight to 12 h); (3) the rapid recovery within three to six days, with normal endoscopy at day 14; (4) the absence of other possible causes for the observed patterns, except in one case, in which a concomitant intestinal infection with Clostridium perfringens Type A was discovered; (5) the specific pathological features. Colonic biopsies taken 27, 44, and 72 h after colocynth intake showed: erosions with fibrino-purulent exudate, early fibrosis of the lamina propria, hyaline thickening of the superficial epithelial basal membrane. These pathological features completely disappeared within 14 days in all three cases.
Forty-six cases of non-surgical malignant glioma were treated by several repeated infusion of non-superselective intra-arterial chemotherapy using HECNU, followed by conventional radiotherapy. Chemotherapy was well tolerated immediately. Good responses rate was 46% for the whole group, but was higher in anaplastic astrocytomas (71%) than in glioblastomas (43%). The median survival for responders was 17 months, and clinical improvement was observed in a large majority of them. Later, neurological or ophthalmological ipsilateral complications of varying severity were observed in 8.7% and 15% of the cases respectively. Despite these complications the treatment was generally well tolerated and gave in responders a longer survival with better comfort.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.