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D Couanet

Publications and source records attributed to D Couanet.

At least 19 recordsLinked to original sources
PubMed1995

[Research on bone marrow involvement in the diagnosis of solid tumors in children. Methods, results and interpretation].

The assessment of bone marrow involvement by tumor cells remains an essential problem at diagnosis in pediatric solid tumors. Besides the conventional cytological and histological methods, some modern cell density separation techniques have been described in order to improve the detection of minimal or scattered bone marrow involvement. Immunological or genetical (molecular biology) tools can be used for the recognition of separated cells. In terms of investigations, MRI and MIBG radionucleide scan, although giving no definite proof, have the ability to macroscopically study the scattering of bone marrow invasion in the particular case of neuroblastoma. In some pediatric tumors, especially neuroblastomas and non Hodgkin lymphomas, an extensive bone marrow investigation is mandatory at diagnosis. Such an investigation is only necessary in case of particular criteria at diagnosis of Hodgkin's disease, Ewing' sarcomas, rhabdomyosarcomas and retinoblastomas. All other pediatric solid tumors do not need to be investigated in terms of bone marrow involvement at diagnosis, with the exceptions of advanced disseminated disease or if an autologous bone marrow transplantation is planned.

Bone Marrow Diseases↗
PubMed1992

High-dose busulfan and thiotepa with autologous bone marrow transplantation in childhood malignant brain tumors: a phase II study.

In order to evaluate the effect of intensive combined chemotherapy in pediatric brain tumors, we designed a phase II study of high-dose busulfan and thiotepa followed by bone marrow transplantation (BMT) in children with measurable recurrent brain tumors. As alkylating agents, busulfan and thiotepa were expected to exhibit a steep dose effect and no overlapping extramedullary toxicity. Moreover, both drugs have an excellent distribution into the central nervous system in humans. Since May 1988, 20 children (median age 6 years) have been treated. Busulfan (150 mg/m2/day x 4) given orally was followed by thiotepa (350 mg/m2/day x 3), given as a 1 h i.v. infusion. Cryopreserved bone marrow was reinfused 48 h after completion of chemotherapy. Tumor response was assessed by computed tomography and magnetic resonance imaging 4 to 6 weeks after BMT. Five partial responses were observed (three of six medulloblastomas, one of five ependymomas, one of two primitive neuroectodermal tumors); two patients with medulloblastoma and one with brain stem tumor achieved an objective response. Ten patients had stable disease and one progressive disease. One patient is not evaluable because of early toxic death. Toxicity was high in terms of aplasia and cutaneous, hepatic and neurological complications. The overall response rate of 26% is encouraging since all patients had disease refractory to all conventional therapies.

Adolescent↗
PubMed1991

Childhood malignant lymphoma of bone.

From 1974 to 1987, 450 children with non-Hodgkins' lymphoma (NHL) were seen at the Institut Gustave Roussy (IGR); 14 children had malignant lymphoma of bone (MLB). Eleven of the 14 were newly diagnosed, whereas three presented in relapse. Nine patients presented with multifocal bone involvement. The median age of these eight girls and six boys was 9.5 years (range 1.25-15 years). Bone pain was present in all patients as the initial symptom. Evaluation included physical examination, routine serum chemistries, complete blood count, chest roentgenography, skeletal survey, radionuclide bone scan, lumbar puncture, bone marrow aspiration, and intravenous pyelography, and/or abdominal ultrasonography. Hypercalcemia was found in six patients. Biopsy was performed in 12 patients, revealing high-grade lymphoblastic lymphomas in all. In two patients diagnosis was made on cytological examination of bone marrow aspirate. Immunophenotyping in four cases, demonstrated non-B, non-T cell origin in three and pre-B cell origin in one. Three patients were treated prior to 1982 with Cyclophosphamide/Oncovin/Prednisone/ADriamycin (COPAD) and seven patients, seen after 1982, were treated with a modified LSA2L2 protocol (LMT). None of the previously untreated patients received radiotherapy. All patients treated with COPAD have died, whereas four out of seven treated with LMT are alive with a median follow up of 51 months (range 36-82 months). One child treated on a pilot study died. One of the three children seen at relapse is disease-free with a follow-up of 98 months after high-dose chemotherapy followed by autologous bone marrow transplantation (ABMT). Five out of six patients presenting with hypercalcemia have died. Results with LMT are encouraging and together with published results suggest that sufficiently intensive chemotherapy can result in complete remission and cure in MLB. Radiotherapy does not seem to be necessary, avoiding possible serious long-term effects. Hypercalcemia is a bad prognostic feature.

Adolescent↗
PubMed1989

Limited small cell lung cancer treated by combined radiotherapy and chemotherapy: evaluation of a grading system of lung fibrosis.

A grading system of radiological fibrosis was defined and applied by four observers for the reading of 218 posterior-anterior chest X-rays of 78 patients. These patients with limited small cell lung cancer were treated from May 1980 to July 1983 in two consecutive alternating radiotherapy-chemotherapy schedules. Chest X-rays performed at each 6-month interval were read by each observer. A second reading was performed the day after. The analysis of results showed that in spite of some systematic variations in intra- and inter-observations, the proposed grading system had a good reproducibility. The radiological lung fibrosis score progressed between 6 and 12 months but was stable after one year of follow-up. There was no difference in the score of lung fibrosis between the two protocols which delivered a total dose of 45 and 55 Gy to the mediastinum. There was no significant correlation between the radiological changes and clinical symptoms.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[Secondary metastatic neuromeningeal localization of neuroblastoma in children].

In order to evaluate the frequency, clinical and radiological aspects and prognosis of central nervous system metastases in children's neuroblastoma, the 258 children presenting with neuroblastoma, and registered from January 1982 to August 1987, were studied. Among them, 7 patients (2.7%), of which 6 had an initially metastatic neuroblastoma, presented with a secondary neuro-meningeal involvement. Parenchyma involvement (4 cases) occurred after a mean period of time of 21 months and marked the relapses. The disease recurs later on, even when locally controlled by surgical excision and local irradiation. Meningeal involvements (3 cases) occurred after a mean delay of 12.7 months, in patients with full tumoral evolutivity, and were responsible for rapid death. The clinical presentation of these metastases differs from that in adults by the rapidity of setting up of the signs and the frequency of intracranial hypertension. CT scan allows approaching diagnosis in the majority of the cases. These data are compared with those in the literature, where 30 cases were reported: they show a high patients' average age and the worse prognosis.

Brain Neoplasms↗
PubMed1988

The role of magnetic resonance imaging in the evaluation of Ewing sarcoma. A report of 27 cases.

The experience with magnetic resonance imaging (MRI) in 27 patients with Ewing sarcoma is reported and compared with computed tomography (CT) and plain films. Plain radiography proved to be the best imaging method to asses probable histological diagnosis in all cases (n = 6). For the evaluation of chemotherapeutic response (n = 4), CT and MRI gave the same information about the variation in size of the tumor. In this small series, the high signal in T2 weighted images was not altered significantly by therapy. In preoperative evaluation (n = 14), MRI gave better information than CT of soft tissue involvement and extension within the bone marrow in two cases each. The ability of MRI to accurately define extension through the epiphyseal plate in two cases permitted limb salvage which otherwise would not have been possible. In the long-term follow-up (n = 12), three patients without recurrence one year after therapy showed a low signal in the surgical area in T2 weighted images. Nine patients had a high signal in T2 weighted images: four were reactive lesions, two had obvious recurrence, and one was a hematoma. In the two remaining cases plain films and CT were normal, in the presence of both active tumor and reactive lesions. It was not possible with MRI to differentiate active tumor from reactive change, even after Gd-DTPA infusion.

Adolescent↗
PubMed1988

[Magnetic resonance imaging for bone marrow metastases of neuroblastoma].

From March 1985 to February 1987, 41 patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years (R: 6 m, 13 y). Acquisitions were done with a 1.5 t unit. Images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. Nine out of 52 examinations were excluded because of artifacts or technical failure. In 13 cases, MRI was performed for initial staging, in 30 during follow-up. Out of 24 anatomically proven medullary involvement (18 pts), MRI showed focal abnormal signals in 23 (17 pts): foci of hypersignal in T2 weighted images, compared to the normal value of bone marrow and fat tissue, were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. In our series, the sensitivity of MRI to detect BM metastases is 84% and the specificity is 88%. In comparison to the medullograms and bone marrow biopsy, MRI explores distinct sites, especially lower limbs which are often involved.

Bone Marrow↗
PubMed1988

Bone marrow metastases in children's neuroblastoma studied by magnetic resonance imaging.

Forty-one patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years. Acquisitions were done with a 1.5 tesla unit. T1 and T2 weighted images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. In 13 cases MRI was performed for initial staging, in 30 during the follow-up. 43/52 examinations were evaluable. Out of 24 anatomically proven medullary involvement (19 pts), MRI showed focal abnormal signals in 23 (18 pts): foci hypersignal in T2 weighted images and hyposignal in T1 weighted images compared to the normal bone marrow (BM) and fat tissue. The lesions were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. Nineteen examinations were performed in 15 pts with cytologically and histologically normal BM. MRI raised suspicion of BM metastases in 5 pts (7 MRI). Out of those 5 pts, 1 (2 MRI) had BM relapse 9 months later; 1 (2 MRI) had intra cranial relapse 6 months later; 1 (1 MRI) is disease free 1 1/2 year later; the follow-up is too short for 2 remaining pts (2 MRI). MRI's specificity was 88.9% and sensitivity 84.4%.

Adolescent↗
PubMed1987

Ultrasonography and computed tomography for diagnosis and follow-up of biliary duct rhabdomyosarcomas in children.

The authors report eight cases of biliary duct rhabdomyosarcoma in children, examined by US and CT. There were five boys and three girls, aged 2 to 17 years. At presentation, US demonstrates the tumor mass within the liver or the hepatic hilum; it allows measurement of it and defines the relationship with portal vessels, biliary tract and other important structures. CT complements the US evaluation and determines operability. As US and CT cannot assess the histological origin of the tumor, a biopsy is mandatory before treatment. If complete surgical excision does not seem possible, percutaneous biopsy is preferable to incomplete excision and its possible complications. During the follow-up period, US can be repeated to measure tumor regression under chemotherapy. After surgery, CT seems preferable because of gas interposition. Both US and CT proved to be valuable for the early detection of local recurrence. The prognosis of these tumors remains bad. However, with more aggressive and hopefully more efficient chemotherapy a precise evaluation of the tumor extension by US and CT is very important. Surgery will then be performed only on localized tumors or on residual masses after chemotherapy.

Adolescent↗
PubMed1987

Ultrasonography and computed tomography for diagnosis and follow-up of pelvic rhabdomyosarcomas in children.

The authors report 18 cases of pelvic rhabdomyosarcomas in children examined at presentation and followed on US and CT. There were 11 boys, 7 girls; tumor location was bladder, prostate or uterus in 12, perineum in 4, buttock in 2. US is good to define tumoral extension within the bladder CT is better to delineate the extension outside the bladder and regional spread to iliac nodes. CT is the only useful examination for perineal tumors. During chemotherapy US can be frequently repeated to appreciate tumoral regression and to give measurement of the mass. Preoperative CT should be performed when tumoral regression seems sufficient to permit complete tumoral excision without pelvic exenteration. Correlation between US and CT and surgical findings proved to be good. US and CT are also very useful in the follow-up when the child has finished treatment as it can demonstrate a local recurrence before clinical symptoms appear. However, post-surgical and post-radiation changes may be difficult to recognize. These aspects are discussed.

Adolescent↗
PubMed1987

Musculoskeletal tumors: follow-up with MR imaging after treatment with surgery and radiation therapy.

Magnetic resonance (MR) imaging was used as a follow-up technique in 60 patients who underwent surgery and/or radiation therapy for primary malignant musculoskeletal tumors. MR imaging was performed on a 1.5-T imager with T1- and T2-weighted imaging sequences; MR imaging findings were confirmed by means of posttreatment surgery and histologic analysis or follow-up for at least 1 year. If a low-signal-intensity lesion was seen on T2-weighted images in a patient who had undergone radiation therapy or surgery, the patient usually did not have active tumor (sensitivity, 96%). If a high-signal-intensity lesion was seen after a patient had undergone only surgery, the patient had active tumor (six of six such cases). In patients who had undergone only radiation therapy, however, the presence of a high-signal-intensity lesion may indicate either active tumor or radiation-induced inflammatory changes. Thus, in such cases, differential diagnosis of active tumor may be difficult, if not impossible, to make from MR images.

Bone Neoplasms↗