[Radiation therapy for glial tumors: technical aspects and clinical indications]

Radiotherapy of glial tumors is rapidly evolving with the recent technical and therapeutic progress. About technical aspects, progress in technical imaging and development of non-coplanar conformal and IMRT techniques provide new possibilities for sparing healthy tissue while increasing dose in tumoral volume. Furthermore, functional and molecular imaging are helpful for delineation and for prediction of relapse. Even modest, the actual improvement of survival with radiochemotherapy leads now to new and important developments for clinical research according to clinical data (age, general status), biological data (MGMT promotor methylation and cytogenetic modifications) and technical data (quality of surgery and radiotherapy). Understanding of molecular mechanisms allows for rational targeting or specific pathways of repair, signaling angiogenesis associated with surgery and radiotherapy in a multidisciplinary approach.

[Should elderly patients with glioblastoma be proposed to radiotherapy?]

In glioblastoma multiform-patients, advanced age has been associated with poor prognosis and decreased tolerance to treatments. The optimal management, especially with irradiation, was not definitively determined in the eighth and ninth decades. The Association of French-speaking neuro-oncologists (Anocef) has recently conducted a randomized clinical trial comparing radiotherapy plus supportive care versus supportive care alone in such patients. Patients aged 70-years and older with newly diagnosed glioblastoma and a Karnofsky performance score of 70 or above were randomly assigned to receive focal irradiation in daily fraction of 1.8 Gy given five days per week for a total dose of 50 Gy plus supportive care or supportive care only. Radiotherapy resulted in a modest but significant improvement in overall survival without reducing quality of life or cognition. However, the optimal regimen of radiotherapy in this fragile population remains uncertain. Abbreviated course of radiotherapy (40 Gy in 15 fractions over 19 days) has been proposed. Analysis of preliminary results showed that efficacy and safety of this hypofractionated accelerated regimen compared favourably with those of classically fractionated treatments. Finally, the potential contribution of surgery and chemotherapy should be evaluated in prospective clinical trials.

Les actions de la Société française de radiothérapie oncologique (SFRO), dans le contexte du Plan cancer et des événements récents de radioprotection

Within the frame of Plan cancer and events of radioprotection which occurred since 2005, the community of radiation oncologists is aware under the umbrella of SFRO of the technologic, structural and cultural mutation that our discipline is going through, with the support of the tutelages. We report on the actions the SFRO has participated with, or initiated these last 2 years.

La curiethérapie en France en 2002: résultats de l'enquête PCBE de l'ESTRO

The authors report the results of the Patterns of Care for Brachytherapy in Europe (PCBE) throughout France. Responses were obtained for 91% of the Radiation Oncology departments, which have declared using brachytherapy for 67, and gave detailed data for 49 ones. The equipments and treated tumours were recorded. LDR brachytherapy remained the most often used (53.5%), followed by HDR (28%). PDR represented 5.5% and permanent implants 11%. The authors discuss the development of new equipment, with an aggregation of the structures, and an increase of the PDR and prostate implants use.

Chimiothérapie néoadjuvante suivie d'une radiothérapie adaptée à la réponse tumorale dans les tumeurs germinales séminomateuses du système nerveux central: expérience de l'hôpital de la Pitié-Salpêtrière et revue de la littérature

PURPOSE

Retrospective analysis of ten cases of germinoma of the central nervous system treated in Pitié-Salpêtrière Hospital, Paris.

PATIENTS AND METHODS

Ten male patients were treated from 1997 to 2005 for histologically verified primary seminoma of the central nervous system. The median age was 27 years (range 18-40 years). Our option for the treatment was the association of 3-4 cycles of neoadjuvant chemotherapy (cisplatin and etoposide) to radiotherapy. Five patients received a craniospinal radiotherapy of 30 Gy (for one patient 36 Gy) followed by a tumoral boost from 20 to 24 Gy. For five patients, irradiated volume was limited to the tumour, total dose from 24 to 54 Gy (for three patients the total dose was from 24 to 30 Gy). Surgery was used for five patients, but only in one case was macroscopic complete.

RESULTS

Six patients were in situation of complete remission after neoadjuvant chemotherapy. All the patients were in situation of complete remission after the irradiation. All the patients were alive free of disease with a median follow-up 46 months (range 13-90 months).

CONCLUSION

In spite of the fact that the intracranial germinal tumours are not the subject of a consensual treatment strategy, this retrospective analysis pleads in favour of chemotherapy followed by limited dose and volume irradiation.

[Giant cell tumor of the base of the skull: a report of two cases and review of the literature]

Giant cell tumors of the skull base are rare neoplasms. This report reviews two cases of patients presenting with aggressive giant cell tumors that were irradiated by a combination of photons and protons. Two females 29 and 14 years old were initially managed with one and three extensive surgical resections respectively. Radiation therapy was recommended in respect to tumor aggressiveness. Combined proton and photon radiation therapy was performed based on a three-dimensional planning, and delivered a total dose of 59.4 CGE to 65.2 CGE respectively, administered in 5 sessions per week of 1.8-2 Gy/CGE (Cobalt Gray Equivalent). With 8 and 83 months follow-up, respectively, the youngest patient relapsed marginally 4 months post irradiation, while the second remained with NED. No complication developed in any of them. In conclusion, we have reviewed a total of 116 cases (114 previously published cases+2 new cases) and discuss the role and modalities of radiation therapy in the management of giant cell skull base tumors.

Preliminary analysis of the resources in brachytherapy in Europe and its variability of use

PURPOSE

The main objective of the program <<Patterns of Care for Brachytherapy in Europe (PCBE)>> is to establish a group with detailed information on brachytherapy throughout Europe.

METHODS

The data was compiled by the general coordinator, the ESTRO, and the <<National Cancer Services Analysis>> through a website.

RESULTS

A total of 32 countries reported data from at least 50% of their centres (criteria of inclusion). Countries were grouped in three categories based on the time of incorporation to the European Union. The majority of treatments belonged to gynaecological tumours. A large spread was found regarding workload of specialists depending on centre and group.

CONCLUSION

Collection of information by a website is a feasible methodology. An increase in brachytherapy treatment was observed in all 3 groups by a rate of more than 20% (year 2002 versus year 1997). These results advocate for the continuation of the PCBE study to demonstrate the development in the field, such as an increase or decrease of patient numbers per tumour category.

Radiothérapie des glioblastomes : de la radiobiologie à la chimiothérapie concomitante

The prognosis of glioblastoma remains extremely poor. Clinical research has been very active for thirty years, and has explored all the concepts developed in the laboratories of radiobiology. Radiosensitisation of hypoxic tumours, hyperfractioned radiotherapy, external beam radiotherapy plus stereotactic radiosurgery or brachytherapy boost, and intensity modulated radiation therapy failed to improve the results of the treatment of these patients. Concomitant chemoradiotherapy has just obtained a new success in the treatment of glioblastoma. The addition of temozolomide to radiotherapy resulted in a statistically significant survival benefit with minimal acute additional toxicity. The challenge remains to improve clinical outcomes further, and some new research pathways are open.

Les chordomes de la base du crâne et du rachis cervical haut. À propos d'une série de 100 patients irradiés selon une technique conformationnelle 3D par une association de faisceaux de photons et de protons

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.

Partial breast irradiation: revolution or evolution?

INTRODUCTION

It is well established that there is no significant difference in terms of overall survival between mastectomy and radio-surgical conservative treatment (RSCT). Ten to fifteen years have been needed to change from the "standard" to the "new" breast cancer treatment. At the end of the 1990s, a few authors published preliminary results of phase II trials using partial breast irradiation (PBI) as sole post-operative treatment based on interstitial low or high dose rate brachytherapy techniques. Currently, phase III randomized trials comparing whole breast irradiation versus PBI are ongoing in the USA and in EU.

MATERIALS AND METHODS

The authors reviewed the literature regarding issues in the irradiation of breast cancer and the potential role of PBI to prevent local recurrence in the ipsilateral breast. Furthermore, potential advantages of PBI were discussed as well as the limits of such a procedure. Finally, we tried to determine the characteristics of a subgroup of patients who would receive benefit from this radiation technique.

RESULTS

Phase II and III trials have been analyzed concerning feasibility, efficacy and toxicity. PBI may be delivered through low or high dose rate brachytherapy or intraoperative/external beam radiation therapy. PBI satisfies the control quality criteria. The majority of the teams provide PBI recurrence rates lower than 5% (0-4.4%) with a median follow-up varying between 8 and 72 months, and associated with cosmetic results comparable to those achieved with conventional external beam.

CONCLUSION

RSCT does not replace mastectomy; mastectomy and RSCT are used together to treat different subgroups of patients. PBI furnished encouraging preliminary results in terms of local control and cosmetic results. However, caution in interpreting the results is required along with longer follow-up. PBI should not replace CT, but could be considered as a new therapeutic strategy for breast cancer dedicated to a very well defined subgroup of patients with a low risk of local recurrence.

Résultats de l’irradiation en conditions stéréotaxiques de rattrapage de 14 patients atteints d’un gliome de grade III ou IV

AIMS

To determine local control and overall survival rates of 14 patients treated for a grade III or IV glioma relapsing in a previously irradiated area and re-irradiated by stereotactic radiosurgery.

PATIENTS AND METHODS

From January 1997 to October 2001, 14 patients (median age 52 Years, age range 49-58 Years, Karnofski performance score 80 to 100) received radiosurgery for a relapse of grade III (3 patients) and or grade IV (10 patients) malignant gliomas. Before relapse, all patients had undergone surgery and had been given with a classical radiation protocol. Median maximum diameter and Volume of the tumors were 38.5mm (24-86mm) and 7cm3 (2-35cm3), respectively.

RESULTS

Median maximal dose at the isocenter and median minimal dose at the periphery of the lesion were 21Gy (16-38Gy) and 13Gy (9-17Gy), respectively. Mean follow-up was 8.5 Months (1-29). Median overall survival was 11.6 Months; 6-Month, 1- and 2-Year overall survival rates were 85p.100, 36p.100 and 12p.100, respectively. At univariate analysis, only histological grade was a significant prognostic factor of overall survival (p=0.03). Median disease-free survival was 8.2 Months while 6-Month and 1-Year disease-free survival rates were 69p.100 and 14p.100, respectively. According to univariate analysis, histological grade (p=0.033) and minimal dose delivered at the margin of the target Volume (p=0.02) were prognostic factors for disease-free survival. Two patients developed a symptomatic radionecrosis.

CONCLUSION

Radiosurgery of relapsed primitive high-grade brain tumors is efficient and overall survival rates were encouraging.

Irradiation stéréotaxique de première intention des métastases cérébrales

BACKGROUND

The minimal radiosurgical dose required to control cerebral metastases remains unknown. The aim of this study was to test whether a lower peripheral dose than usually delivered could effectively control these lesions or not.

PATIENTS AND METHODS

One hundred and eighty patients presenting 356 lesions were give first-line radiosurgery between 1995 and 2001 in Pitié-Salpêtrière hospital using a 10 MV LINAC. Mean age was 59 years, sex-ratio was 1.65, mean KI was 70. The lung was the most frequent primary site (n=85), followed by melanoma (n=29), kidney (n=21), digestive tract (n=14), breast (n=11), and others (n=20). Seventy-six percent of the patients presented 1 or 2 lesions. Mean tumor Volume was 5.5 cm3. Mean peripheral dose was 14.8Gy, mean isocenter dose was 21.6Gy.

RESULTS

Median survival was 7.6 months, local control rate was 90% at 6 months, 76% at 1 Year and 70% at 2 years. Median "neurological disease free" survival was 15 months. Multivariate analysis demonstrated the influence of two parameters on survival: number of lesions (p=0.001) and KI (p=0.04). The only parameter significantly correlated with disease-free survival was the number of isocenters (p=0.005). Morbidity (grade 2 RTOG) was 7.2% with no perimortality.

CONCLUSIONS

Low peripheral doses delivered by radiosurgery may control brain metastases with the same efficacy and fewer side-effects as the doses usually reported in the literature.

[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.

[Epstein-Barr virus associated central nervous system leiomyosarcoma occurring after renal transplantation: case report and review of the literature]

Central nervous system leiomyosarcomas are extremely rare, however, they became more frequent among immunodeficient patients, either in a patients infected with human immunodeficiency virus (HIV), or after organ transplantation. The data of the literature indicate that the infection by Epstein-Barr virus (EBV) plays a causal role in the development of these tumours but its precise role in the oncogenesis remains unresolved. We report a new case of EBV associated leiomyosarcoma of the left cavernous sinus occurring after renal transplantation. The epidemiological, clinical, pathological and therapeutic characteristics of these tumours are discussed.

[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.

Le traitement par neutrons : hadronthérapie partie II : bases physiques et expérience clinique

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.