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R Ferrand

Publications and source records attributed to R Ferrand.

At least 19 recordsLinked to original sources
PubMed2005

[Chordomas of the base of the skull and upper cervical spine. 100 patients irradiated by a 3D conformal technique combining photon and proton beams].

OBJECTIVE: To define prognostic factors for local control and survival in 100 consecutive patients treated by fractionated photon and proton radiation for chordoma of the skull base and upper cervical spine. PATIENTS AND METHODS: Between December 1995 and August 2002, 100 patients (median age: 53 years, range: 8-85, M/F sex-ratio: 3/2), were treated by a combination of high-energy photons and protons. The proton component was delivered by the 201 MeV proton beam of the Centre de Protonthérapie d'Orsay (CPO). The median total dose delivered to the gross tumour volume was 67 Cobalt Gray Equivalent (CGE) (range: 60-71). A complete surgery, incomplete surgery or a biopsy was performed before the radiotherapy in 16, 75 and 9 cases, respectively. RESULTS: With a median follow-up of 31 months (range: 1-87), 25 tumours failed locally. The 2 and 4-year local control rates were 86.3% (+/-3.9%) and 53.8% (+/-7.5%), respectively. According to multivariate analysis, less than 95% of the tumour volume encompassed by the 95% isodose line (P=0.048; RR: 3.4 IC95% [1.01-11.8]) and a minimal dose less than 56 CGE (p=0.042; RR: 2.3 IC95% [1.03-5.2]) were independent prognostic factors of local control. Ten patients died. The 2 and 5-year overall survival rates were 94.3% (+/-2.5%) and 80.5% (+/-7.2%). According to multivariate analysis, a controlled tumour (P=0.005; RR: 21 IC95% [2.2-200]) was the lonely independent favourable prognostic factor for overall survival. CONCLUSION: In chordomas of the skull base and upper cervical spine treated by surgical resection followed by high-dose photon and proton irradiation, local control is mainly dependent on the quality of radiation, especially dose-uniformity within the gross tumour volume. Special attention must be paid to minimise underdosed areas due to the close proximity of critical structures and possibly escalate dose-constraints to tumour targets in future studies, in view of the low toxicity observed to date.

Adolescent↗
PubMed2003

[Treatment with charged particles beams: hadrontherapy part I: physical basis and clinical experience of treatment with protons].

Protons have physical characteristics, which differ from those of photons used in conventional radiotherapy. Better shielding of critical organs is obtained by using their particular ballistic (Bragg peak and lateral narrow penumbra). Some indications as ocular melanoma, chordoma and chondrosarcoma of the base of skull are now strongly accepted by the radiation oncologist community. Others are still in evaluation: meningioma, locally advanced nasopharynx tumor and paediatric tumors. The aim of this review is to present the clinical results of a technic which seems "confidential" because of the rarety and the cost of equipments.

Adult↗
PubMed2003

[Treatment with neutrons: hadrontherapy part II: physical basis and clinical experience].

Neutrons have radiobiological characteristics, which differ from those of conventional radiotherapy beams (photons) and which offer a theoretical advantage over photons to fight radioresistance by the differential relative biological effect of them between normal and tumour tissues. Neutron therapy beneficed of great interest between 1975 and 1985. Many of phase III trials were conducted and indications have been definitively deducted of them. After briefly describing the properties of neutron beams, this review discusses the indication of neutron therapy on the basis of the clinical results. Salivary, prostate tumours and sarcomas are the main indications of neutron therapy. In concern to the prostate cancers, other alternative treatments reduce the neutron therapy field. For sarcomas, the lack of randomised trials limits the impact of the interest of neutrons. For other tumours, the ratio benefice/risk of neutron therapy is inferior to these obtained with photons and they could not be considered like classical indications.

Clinical Trials, Phase III as Topic↗
PubMed2003

[Automatization and robotics of the set-up and treatment of patients irradiated for brain and base ot the skull tumors].

Progresses of the three-dimensional imageries and of the software of planning systems makes that the radiotherapy of the tumours of brain and the base of skull is increasingly precise. The set-up of the patients and the positioning of the beams are key acts whose realization can become extremely tiresome if the requirement of precision increases. This precision very often rests still on the visual comparison of digital images. In the near future, the development of the automated systems controlled by robots should allow a noticeable improvement of the precision, safety and speed of the patient set-up.

Automation↗
PubMed2002

[Comparison with dose-volume histograms of two conformal irradiation techniques used for the treatment of T2N0M0 nasopharyngeal cancer, one with association of photons and protons and another with photons alone].

Purpose- There is a relationship between the local control rate of the nasopharyngeal cancer and the total dose delivered within the tumoral volume. In contrast, the relation between the dose and the irradiated volume and the risk of complication is not clearly defined. That is why, in patients presenting with a locally advanced nasopharyngeal cancer, we compared the dose-volume distribution of irradiated tissues, obtained from two 3D conformal irradiation techniques. Patients and methods- Between January 2000 and June 2001, 5 patients, 3 males and 2 females, with a median age of 32 years and presenting with a T4N0M0 nasopharyngeal cancer received a chemoradiotherapy. Radiotherapy combined photons and protons beams and the platin-based chemotherapy was delivered in three intravenous injections at d1, 22, 43 of the irradiation. To calculate the dosimetry, a CT scan and a MRI were performed in all the patients. The gross tumor volume (GTV) was delineated from the imagery, three clinical tumor volumes were defined, the CTV1 was the GTV and the whole nasopharynx, the CTV2 was the CTV plus a 10 mm-margin and the CTV3 was the CTV2 and the nodes areas (cervical and subclavicular). Prophylactic dose within node areas was 44 Gy. Prescribed doses within CTV2 and GTV or CTV1 were 54 Gy/CGE (Cobalt Gy Equivalent, for an EBR = 1,1) and 70 Gy/CGE, respectively. Irradiation was delivered with fractions of 1.8 or 2.0 Gy/CGE, with 44 Gy or 54 Gy by photons and with 16 or 26 CGE by protons. According to dose-volume histograms obtained from the dosimetry planning by protons and photons and from the theoretical dosimetry by photons lonely, for the different volumes of interest, GTV, CTV2, and organs at risk (optic nerves, chiasm, internal ears, brainstem, temporal lobes), we compared the averages of the maximum, minimum and mean doses and the averages of the volumes of organs of interest encompassed by different isodoses.Results- Calculated averages of minimum, maximum and mean doses delivered within GTV were superior for the treatment with combined photons and protons than with photons alone. The average GTV encompassed by the 70 Gy/CGE isodose was larger by 65% with the association compared to photons alone. The conformation ratio (tissue volume encompassed by the 95% isodose/GTV encompassed by the 95% isodose) was 3.1 with the association compared to 5.7 with photons alone. For the CTV2, there were no differences in different criteria according to the both irradiation techniques. For the critical, radiosensitive organs, the comparison of the majority of the criteria was in favour of the association of protons and photons. Overall, 78% of the criteria were in favour of the association.Conclusion- For locally advanced nasopharyngeal cancer without clinical adenopathy, irradiation by photons and protons increases the tumor volume irradiated at the prescribed dose and decreases the volume or critical organs irradiated and the total dose delivered within them.

Adult↗
PubMed2002

[Results of proton beam irradiation for treatment of choroidal melanoma].

PURPOSE: To evaluate the results of proton beam irradiation of choroidal melanomas on a large series of patients. PATIENTS AND METHODS: Retrospective analysis of a series of patients treated with proton beam irradiation between 1991 and December 1998. The data were analyzed to evaluate the local tumor control as well as the general progression and metastatic rate of the patients. Statistical analysis served to isolate risk factors for relapse or metastasis. RESULTS: We treated 1062 patients during the study period, with a median follow-up of 38 months. Local control was obtained for 97.1% of the patients. Tumors anterior to the equator were at risk for relapse. The survival rate was 92% at 2 years and 78% at 5 years. 73.1% of the 1062 patients died from metastasis, 6.1% of living patients presented with metastatic disease. The risk factors for death were the initial diameter, the age of the patient, and large tumor volume at diagnosis. Metastasis were essentially hepatic (94.6%). Risk factors for metastasis were: a large tumor volume, a lesion anterior or straddling the equator and the age of the patient. Ocular complications may induce a visual loss of 0.1 and less in 47% of the patients, due to optic nerve head and macular ischemia. 6% of the patients required secondary enucleation due to local complications (neovascular glaucoma). CONCLUSION: Proton beam irradiation of choroidal melanoma allows good tumor control and eye retention. The survival prognosis is associated with the initial volume of the tumor. The functional results may be improved and new therapeutics are needed to treat metastatic disease.

Adolescent↗
PubMed2001

Combination of photon and proton radiation therapy for chordomas and chondrosarcomas of the skull base: the Centre de Protonthérapie D'Orsay experience.

PURPOSE: Prospective analysis of local tumor control, survival, and treatment complications in 44 consecutive patients treated with fractionated photon and proton radiation for a chordoma or chondrosarcoma of the skull base. METHODS AND MATERIALS: Between December 1995 and December 1998, 45 patients with a median age of 55 years (14-85) were treated using a 201-MeV proton beam at the Centre de Protonthérapie d'Orsay, 34 for a chordoma and 11 for a chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented two-thirds of the total dose and protons one-third. The median total dose delivered within the gross tumor volume was 67 cobalt Gray equivalent (CGE) (range: 60-70). RESULTS: With a mean follow-up of 30.5 months (range: 2-56), the 3-year local control rates for chordomas and chondrosarcomas were 83.1% and 90%, respectively, and 3-year overall survival rates were 91% and 90%, respectively. Eight patients (18%) failed locally (7 within the clinical tumor volume and 1 unknown). Four patients died of tumor and 2 others of intercurrent disease. In univariate analysis, young age at time of radiotherapy influenced local control positively (p < 0.03), but not in multivariate analysis. Only 2 patients presented Grade 3 or 4 complications. CONCLUSION: In skull-base chordomas and chondrosarcomas, the combination of photons with a proton boost of one-third the total dose offers an excellent chance of cure at the price of an acceptable toxicity. These results should be confirmed with a longer follow-up.

Adolescent↗
PubMed2001

Experimental determination and verification of the parameters used in a proton pencil beam algorithm.

We present an experimental procedure for the determination and the verification under practical conditions of physical and computational parameters used in our proton pencil beam algorithm. The calculation of the dose delivered by a single pencil beam relies on a measured spread-out Bragg peak, and the description of its radial spread at depth features simple specific parameters accounting individually for the influence of the beam line as a whole, the beam energy modulation, the compensator, and the patient medium. For determining the experimental values of the physical parameters related to proton scattering, we utilized a simple relation between Gaussian radial spreads and the width of lateral penumbras. The contribution from the beam line has been extracted from lateral penumbra measurements in air: a linear variation with the distance collimator-point has been observed. Analytically predicted radial spreads within the patient were in good agreement with experimental values in water under various reference conditions. Results indicated no significant influence of the beam energy modulation. Using measurements in presence of Plexiglas slabs, a simple assumption on the effective source of scattering due to the compensator has been stated, leading to accurate radial spread calculations. Dose measurements in presence of complexly shaped compensators have been used to assess the performances of the algorithm supplied with the adequate physical parameters. One of these compensators has also been used, together with a reference configuration, for investigating a set of computational parameters decreasing the calculation time while maintaining a high level of accuracy. Faster dose computations have been performed for algorithm evaluation in the presence of geometrical and patient compensators, and have shown good agreement with the measured dose distributions.

Algorithms↗
PubMed2001

Intraocular inflammation after proton beam irradiation for uveal melanoma.

AIM: To describe the inflammatory reaction that can occur following proton beam irradiation of uveal melanomas based on a large series of patients and to try to determine the risk factors for this reaction. METHODS: Data from a cohort of patients with uveal melanoma treated by proton beam irradiation between 1991 and 1994 were analysed. The presence of inflammation was recorded and evaluated. Kaplan-Meier estimates and statistical analysis of general and tumour related risk factors were performed. RESULTS: 28% of patients treated during this period presented with ocular inflammation (median follow up 62 months). Risks factors were essentially tumour related and were correlated with larger lesions (height > 5 mm, diameter > 12 mm, volume > 0.4 cm(3)). Multivariate analysis identified initial tumour height and irradiation of a large volume of the eye as the two most important risk factors. Ocular inflammation usually consisted of mild anterior uveitis, resolving rapidly after topical steroids and cycloplegics. The incidence of inflammation after proton beam irradiation of melanomas seems higher than previously reported and is related to larger lesions. Evidence of inflammation associated with uveal melanoma has been described and seems to be associated with tumour necrosis (spontaneous or after irradiation). The appearance of transient inflammation during the follow up of these patients may be related to the release of inflammatory cytokines during tumour necrosis. CONCLUSION: Inflammation following proton beam irradiation is not unusual. It is correlated with larger initial tumours and may be related to tumour necrosis.

Analysis of Variance↗
PubMed2001

[Neovascular glaucoma following proton-beam therapy. Case report].

A 52-year-old-male patient was treated for a posterior choroid melanoma of the right eye. When it was diagnosed, it measured 6mm in thickness and 11.9mm for the largest diameter and had a typical mushroom shape. General investigations found no metastatic disease. It was treated with proton-beam irradiation. Seven years later, the patient experienced increased intraocular pressure associated with cataract and pain. The patient finally accepted enucleation, as the vision of this eye was completely lost and the eye had become painful. Histologic analysis of the eye showed changes affecting both the anterior and the posterior segments of the eye, mostly related to the tumor and the consequences of treatment. Neovascular glaucoma is a major complication that very often leads to enucleation.

Cataract↗
PubMed2000

[Optic neuropathy after proton-beam therapy for malignant choroidal melanoma].

Proton-beam irradiation is a conservative therapy commonly used for the treatment of uveal malignant melanomas. Some adverse effects such as optic neuropathy can compromise the visual outcome. We were interested in determining the risk factors for radiation papillopathy. Since there is currently no effective therapy, this is an interesting way to improve prevention of optic neuropathy. Six hundred sixty-two eyes had more than 24 month follow-up after proton-beam irradiation for uveal melanoma. In five hundred twenty-two cases, the clinical examination of the optic nerve head by ophthalmoscopy was possible. One-hundred eleven optic discs were pathologic, whereas 411 remained disease-free. Retrospective study of these two groups allowed to quantify the risk factors for optic neuropathy. The irradiation of more than 2mm of optic nerve at 30 Grays-equivalents appeared to be the major risk factor for optic neuropathy. For a given irradiation dose, the observed pattern of clinical responses was heterogeneous. These results are discussed and compared to the previous published reports. Visual results and life prognosis are also discussed, considering the optic nerve head status. Proton-beam therapy can preserve the optic nerve when the tumor location allows to keep it away from the irradiation-field. Patients must be informed about the risk of optic neuropathy after proton-beam irradiation.

Choroid Neoplasms↗
PubMed1999

Proton beam therapy (PT) in the management of CNS tumors in childhood.

At the Centre de Protontherapie d'Orsay, nine children with intra-cranial malignancies were treated between July 1994 and January 1998. Immediate and late tolerances were excellent in all cases (follow-up 2 to 50 months). Two patients recurred locally (marginal failures), seven are alive and doing well. At Loma Linda, 28 children were treated between 1991 and 1994, 16 for a benign tumor of the brain and twelve for a malignant one. With a follow-up of seven to 49 months, three patients died (grade 2 to 4 gliomas), one is living with a persistent disease. Four children had treatment-related toxicity (one cataract, two hormonal failures and two seizures). The other children are doing well. At MGH Boston, 18 children with skull base-cervical spine chordomas have been reported. At five years, actuarial survival and disease-free survival have been 68 and 63%, respectively. Children with cervical sites had a worse prognosis (p = 0.008). Four children had radiation-related morbidity: two pituitary failures, one temporal lobe necrosis, one temporal muscle fibrosis. In this experience, such rare tumors seemed to behave in children like in adults.

Adolescent↗
PubMed1998

A preliminary comparative treatment planning study for radiotherapy of age-related maculopathy.

PURPOSE: We present a comparative planning of different approaches for external radiotherapy in age-related maculopathies. MATERIALS AND METHODS: Calculated dose distributions and dose-volume histograms for (a) bilateral irradiation with 6 MV photons, (b) a single lateral-oblique beam using either photons, electrons or protons and (c) an anterior circular proton beam. RESULTS: For lateral photon or electron beams the dose to the lens is usually lower than 10% of the dose to the macula. The entrance doses for bilateral photon beams are about 50% which increase up to 100% at the orbital bone. About 5 mm of optic nerves are irradiated at the maximal dose while the optic chiasma is spared. A single photon beam gives 50% of the dose to the fellow eye. The electron beam spares the fellow eye but gives a rather inhomogeneous dose to the target volume. For a lateral proton beam, 4 mm of optic nerve receives 90% of the dose, the skin dose is at least 70% of the dose to the macula and the lens and the fellow eye are spared. An anterior proton beam gives 90% of the dose to 1 mm of optic nerve and the 50% isodose approaches the periphery of the lens. CONCLUSION: Doses to the critical structures can be dramatically diminished for all the techniques by reducing the beam size, but only if very precise set-up techniques are used. Proton beams are an attractive solution, but the impact of such a choice on the use of proton facilities and on the national health system should be carefully evaluated, as well as the risk of radio-induced secondary neoplasias.

Humans↗
PubMed1997

[Initial results of proton therapy in choroidal melanoma at the d'Orsey Center for Proton Therapy; the first 464 cases].

PURPOSE: Retrospective analysis of the treatment of choroidal melanoma with protontherapy at the Centre de protonthérapie d'Orsay, France. PATIENTS AND METHODS: Between September 1991 and September 1995, 612 patients presenting with choroidal melanoma were treated by protontherapy in Orsay. Following initial management of the first 464 patients, results were analyzed, as were results after a 1-year follow-up for 305 patients, a 2-year follow-up for 169 patients, and a 3-year follow-up for 59 patients. RESULTS: Univariate analysis showed that the actuarial local recurrence rate was 5%, the 3-year survival rate 88%, and the overall metastasic rate 5%. The initial tumor volume was the most significant predictive factor for visual results and metastases. Multivariate analysis revealed that visual results were significantly related to the initial tumor volume, initial retinal detachment, and total dose delivered to the optic nerve and macula. CONCLUSION: Protontherapy of choroidal melanoma allows in most cases conservation of the eye without modification of survival. Visual results mainly depend on the site and size of the tumor.

Choroid Neoplasms↗
PubMed1997

A model for the lateral penumbra in water of a 200-MeV proton beam devoted to clinical applications.

An experimental approach for modeling the lateral penumbra of a proton beam has been investigated. Measurements were made with a silicon diode in a water tank. Several geometrical configurations (phantom position, collimator-to-surface distance, collimator diameter, bolus thickness, air gap, etc.) and beam characteristics (range, modulation, etc.) have been studied. The results show that the lateral penumbra is almost independent of the beam modulation and the diameter of the collimator. The use of scaled variables for depth and penumbra allows us to represent the increase in penumbra with depth for any configuration with a second order polynomial function, provided that the penumbra at the entrance of the medium and at the depth of the range are known.

Biophysical Phenomena↗
PubMed1997

Lack of correlation between the location of choroidal melanoma and ultraviolet-radiation dose distribution.

Ocular melanomas arise from the choroid. The results of our study of a total of 92 ocular melanomas would indicate that there is no preferential location for tumors on the eye. We estimated the ultraviolet (UV) radiation dose distribution using data available in the literature. We then compared tumor location and UV-radiation dose distribution. UVC and UVB do not reach the choroid, and UVA is filtered by the cornea and the lens. Only a small percentage of the incoming rays reach the posterior and inferior part of the retina, but none reach the superior and anterior part of the eye. We concluded that it is therefore very unlikely that UV-radiation exposure is responsible for choroidal melanoma.

Choroid Neoplasms↗