Long duration of immunotherapy before radiosurgery might improve intracranial control of melanoma brain metastases

PURPOSE

Despite significant advances that have been made in management of metastatic melanoma with immune checkpoint therapy, optimal timing of combination immune checkpoint therapy and stereotactic radiosurgery is unknown. We have reported toxicity and efficiency outcomes of patients treated with concurrent immune checkpoint therapy and stereotactic radiosurgery.

PATIENTS AND METHODS

From January 2014 to December 2016, we analyzed 62 consecutive patients presenting 296 melanoma brain metastases, treated with gamma-knife and receiving concurrent immune checkpoint therapy with anti-CTLA4 or anti-PD1 within the 12 weeks of SRS procedure. Median follow-up time was 18 months (mo) (13-22). Minimal median dose delivered was 18 gray (Gy), with a median volume per lesion of 0.219 cm³.

RESULTS

The 1-year control rate per irradiated lesion was 89% (CI 95%: 80.41-98.97). Twenty-seven patients (43.5%) developed distant brain metastases after a median time of 7.6 months (CI 95% 1.8-13.3) after gamma-knife. In multivariate analysis, positive predictive factors for intracranial tumor control were: delay since the initiation of immunotherapy exceeding 2 months before gamma-knife procedure (P=0.003) and use of anti-PD1 (P=0.006). Median overall survival (OS) was 14 months (CI 95%: 11-NR). Total irradiated tumor volume<2.1 cm³ was a positive predictive factor for overall survival (P=0.003). Ten patients (16.13%) had adverse events following irradiation, with four grade≥3. Predictive factors of all grade toxicity were: female gender (P=0.001) and previous treatment with MAPK (P=0.05).

CONCLUSION

A long duration of immune checkpoint therapy before stereotactic radiosurgery might improve intracranial tumor control, but this relationship and its ideal timing need to be assessed in prospective trials.

Radiation guidelines for gliomas

Gliomas are the most frequent primary brain tumour. The proximity of organs at risk, the infiltrating nature, and the radioresistance of gliomas have to be taken into account in the choice of prescribed dose and technique of radiotherapy. The management of glioma patients is based on clinical factors (age, KPS) and tumour characteristics (histology, molecular biology, tumour location), and strongly depends on available and associated treatments, such as surgery, radiation therapy, and chemotherapy. The knowledge of molecular biomarkers is currently essential, they are increasingly evolving as additional factors that facilitate diagnostics and therapeutic decision-making. We present the update of the recommendations of the French society for radiation oncology on the indications and the technical procedures for performing radiation therapy in patients with gliomas.

Guidelines for external radiotherapy and brachytherapy procedures: 3rd edition

The purpose of the first two editions of the guidelines for external radiotherapy procedures, published in 2007 and 2016 respectively, was to issue recommendations aimed at optimising, harmonising and standardising practices. The purpose of this third edition, which includes brachytherapy, is identical while also taking into account recent technological improvements (intensity modulation radiation therapy, stereotactic radiotherapy, and three-dimension brachytherapy) along with findings from literature. Part one describes the daily use of general principles (quality, security, image-guided radiation therapy); part two describes each treatment step for the main types of cancer.

[The 30th anniversary of SFRO, the French society of oncological radiotherapy]

The French society of oncological radiotherapy (Société française de radiothérapie oncologique, SFRO) was created in 1990. On the occasion of its thirtieth annual congress, in October 2019, a session was devoted to it, with the objective of exposing its functioning, its actions and its productions during these three decades during which radiotherapy and oncology have undergone unprecedented transformations. We propose in this article to outline the content of this session.

Radiotherapy of non-tumoral refractory neurological pathologies

Intracranial radiotherapy has been improved, primarily because of the development of stereotactic approaches. While intracranial stereotactic body radiotherapy is mainly indicated for treatment of benign or malignant tumors, this procedure is also effective in the management of other neurological pathologies; it is delivered using GammaKnife® and linear accelerators. Thus, brain arteriovenous malformations in patients who are likely to experience permanent neurological sequelae can be managed by single session intracranial stereotactic body radiotherapy, or radiosurgery, in specific situations, with an advantageous benefit/risk ratio. Radiosurgery can be recommended for patients with disabling symptoms, which are poorly controlled by medication, such as trigeminal neuralgia, and tremors, whether they are essential or secondary to Parkinson's disease. This literature review aims at defining the place of intracranial stereotactic body radiotherapy in the management of patients suffering from non-tumoral refractory neurological pathologies. It is clear that the multidisciplinary collaboration of experienced teams from Neurosurgery, Neurology, Neuroradiology, Radiation Oncology and Medical Physics is needed for the procedures using high precision radiotherapy techniques, which deliver high doses to locations near functional brain areas.

[Guidelines for the radiotherapy of gliomas]

Gliomas are the most frequent primary brain tumours. Treating these tumours is difficult because of the proximity of organs at risk, infiltrating nature, and radioresistance. Clinical prognostic factors such as age, Karnofsky performance status, tumour location, and treatments such as surgery, radiation therapy, and chemotherapy have long been recognized in the management of patients with gliomas. Molecular biomarkers are increasingly evolving as additional factors that facilitate diagnosis and therapeutic decision-making. These practice guidelines aim at helping in choosing the best treatment, in particular radiation therapy.

[Radiotherapy for gliomas in adults: What are the stakes of the follow-up?]

Linked to the difference of prognosis, the terms and conditions of the follow-up of low-grade and high-grade gliomas treated by irradiation differ highly. Patients treated for a low-grade glioma have prolonged survival. In this case, monitoring of toxicities linked to the treatment is a major objective. Opportunistic infections and depression are corticosteroids side effects widely underestimated. Radionecrosis search and differentiation with recurrent disease are done by MRI. Perfusion and spectroscopy showing a choline/creatine ratio increase are in favour of disease recurrence. Cognitive status and quality of life must be evaluated during the follow-up. They have to be evaluated by adapted scales. Cognitive rehabilitation improves interestingly the post-treatment cognitive status. Pseudoprogression rates for high-grade gliomas are near 20%. MRI is the benchmark imaging for its diagnosis. Diffusion weight imaging and spectroscopy are actually the most interesting techniques.

[Management of gliomas]

Gliomas are the most frequent primary brain tumors. Their care is difficult because of the proximity of organs at risk. The treatment of glioblastoma includes surgery followed by chemoradiation with the protocol of Stupp et al. The addition of bevacizumab allows an increase in progression-free survival by 4 months but it does not improve overall survival. This treatment is reserved for clinical trials. Intensity modulation radiotherapy may be useful to reduce the neurocognitive late effects in different types of gliomas. In elderly patients an accelerated radiotherapy 40 Gy in 15 fractions allows a similar survival to standard radiotherapy. O(6)-methylguanine-DNA methyltransferase (MGMT) status may help to choose between chemotherapy and radiotherapy. There is no standard for the treatment of recurrent gliomas. Re-irradiation in stereotactic conditions allows a median survival of 8 to 12.4 months. Anaplastic gliomas with 1p19q mutation have a greater sensibility to chemotherapy by procarbazine, lomustine and vincristine. Chemoradiotherapy in these patients has become the standard treatment. Many studies are underway testing targeted therapies, their place in the therapeutic management and new radiotherapy techniques.

[Chordoma]

PURPOSES

To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.

MATERIALS

The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine.

METHODS

In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups.

RESULTS

In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection.

CONCLUSIONS

Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

[Radiotherapy in central neurocytoma and review of literature]

Central neurocytoma is a rare primary central nervous system tumour of young adults with good prognosis. Typical and atypical forms are described according to various histologic and histopathologic parameters. Central neurocytoma develops in the periventricular areas and is revealed by increased intracranial pressure. The tumour exhibits typical characteristics on CT scan and MRI and a characteristic peak of glycine on spectroscopy-MRI. The main treatment is total resection, which is achievable only in half of the cases. External beam therapy improves local control of partially resected and/or atypical central neurocytoma. Many studies show that stereotactic radiotherapy can be used in the therapeutic management as exclusive treatment, in postoperatives residues and in case of distant recurrence. Chemotherapy is the last line of treatment in refractory forms, especially in the forms with extracranial and/or neuromeningeal spread and in recurrent forms after treatment with surgery and/or radiotherapy.

[Radiation therapy of sinonasal natural killer/T-cell lymphoma]

Natural killer (NK)/T-cell lymphoma are part of lymphoproliferative diseases, they are rare in Europe and the United States but relatively common in Asia and South America. Natural killer (NK)/T-cell lymphoma present clinically as destructive lesions of the upper aerodigestive tract with perforation of deep structures of the face, destruction of the palate or an invasion of orbits. Treatment modalities of these lymphomas are still discussed because of the lack of available studies and the rarity of this disease. Radiotherapy provides a rapid control of the disease and is positioned as a major treatment of localized stages of NK/T-cell lymphoma of the nasal cavity. We therefore studied the different forms of radiation therapy in the early stages of nasal NK/T-cell lymphoma.

Stereotactic radiotherapy for large solitary brain metastases

PURPOSE

To assess effectiveness and toxicity levels of stereotactic radiation therapy without whole brain radiation therapy in patients with solitary brain metastases larger than 3cm.

PATIENTS AND METHODS

Between June 2007 and March 2009, 12 patients received fractionated stereotactic radiation therapy and 24 patients underwent stereotactic radiosurgery. For the fractionated stereotactic radiation therapy group, 3×7.7Gy were delivered to the planning target volume (PTV); median volume and diameter were 29.4 cm(3) and 4.4cm, respectively. For the stereotactic radiosurgery group, 14Gy were delivered to the PTV; median volume and diameter were 15.6 cm(3) and 3.7cm, respectively.

RESULTS

Median follow-up was 218 days. For the fractionated stereotactic radiation therapy group, local control rates were 100% at 360 days and 64% at 720 days; for the stereotactic radiosurgery group, rates were 58% at 360 days and 48% at 720 days (P=0.06). Median survival time was 504 days for the fractionated stereotactic radiation therapy group and 164 days for the stereotactic radiosurgery group (P=0.049). Two cases of grade 2 toxicity were observed in the fractionated stereotactic radiation therapy group, and 6 cases of grade 1-2 toxicity, in the stereotactic radiosurgery group.

CONCLUSIONS

This study provides data to support that fractionated stereotactic radiation therapy without whole brain radiation therapy with a margin dose of 3 fractions of 7.7Gy for treatment of solitary large brain metastases is efficient and well-tolerated. Because of the significant improvement in overall survival, this schedule should be assessed in a randomized trial.

[Radiotherapy and implantable medical device: example of infusion pumps]

Indication for radiotherapy is often questioned for patients equipped with implantable medical devices like infusion pumps as the radiation tolerance is poor or not known. We report here on the case of a patient who we treated with pelvic radiotherapy for cervical cancer and who had an infusion pump in iliac fossa. We conducted a series of tests on five identical pumps that insured that the treatment protocol is harmless to the implanted device.

Comparison of organs' shapes with geometric and Zernike 3D moments

The morphological similarity of organs is studied with feature vectors based on geometric and Zernike 3D moments. It is particularly investigated if outliers and average models can be identified. For this purpose, the relative proximity to the mean feature vector is defined, principal coordinate and clustering analyses are also performed. To study the consistency and usefulness of this approach, 17 livers and 76 hearts voxel models from several sources are considered. In the liver case, models with similar morphological feature are identified. For the limited amount of studied cases, the liver of the ICRP male voxel model is identified as a better surrogate than the female one. For hearts, the clustering analysis shows that three heart shapes represent about 80% of the morphological variations. The relative proximity and clustering analysis rather consistently identify outliers and average models. For the two cases, identification of outliers and surrogate of average models is rather robust. However, deeper classification of morphological feature is subject to caution and can only be performed after cross analysis of at least two kinds of feature vectors. Finally, the Zernike moments contain all the information needed to re-construct the studied objects and thus appear as a promising tool to derive statistical organ shapes.

[Radiobiology in brachytherapy]

Low-dose rate brachytherapy has some radiobiological advantages compared to external beam radiotherapy: subletal damages repair during irradiation leading to a relative protection of healthy tissues; no tumor cell repopulation, cell cycle redistribution and a low oxygen enhancement ratio. High dose rate and pulsed dose rate modalities allow an optimization of dose distribution by varying the dwell times over the different dwell positions. Because of the use of afterloaders, they also offer a better radioprotection of the staff. High dose rate and pulsed dose rate treatments seem to offer the same results as low-dose rate brachytherapy, particularly in cervix carcinoma. For high dose rate brachytherapy, schedules must be designed according to the linear-quadratic model. In pulsed dose rate brachytherapy, pulse dose and time intervals must also be derived from the linear-quadratic model, but half-time repair must be taken into account.

[Difficulties encountered and solutions found when implementing stereotactic radiotherapy of non-small cell lung cancer]

The aim of this paper is to describe the difficulties encountered when implementing stereotactic radiotherapy of non-small cell lung cancer (T1-T2, N0, M0) using a voluntary breath-hold technique. From 25/03/2010 to 22/02/2011, eight patients with a non-small cell lung cancer were selected for treatment. CT images were obtained with the patient maintaining breath-hold using a spirometer. Treatment was delivered when the patient maintains this level of breath-hold. Treatment was performed with a 4 MV and 10 MV photon beams from a linear accelerator Varian 2100CS, equipped with a 120 leaves collimator. 60 Gy or 48 Gy were delivered, in four sessions, to the 80% isodose. The planning target volume (PTV) was defined by adding a 5mm margin to the internal target volume (ITV), the ITV corresponding to the gross tumour volume (GTV) plus a 3mm margin. CTV is considered equal to GTV. The non-understanding of the gating technique, the great number of beams and the limited breath-hold times led to the failure of some treatments. It can be explained by some patients insufficient respiratory abilities and the low dose rate of one of the beams used for treatment, thus forcing some radiation fields to be delivered in two or three times. Implementing such a technique can be limited by the patients' physical abilities and the materials used. Some solutions were found: a training phase more intense with a coaching of the breath-hold technique more precise, or the use of an abdominal compression device.

[Ballistic quality assurance]

This review describes the ballistic quality assurance for stereotactic intracranial irradiation treatments delivered with Gamma Knife® either dedicated or adapted medical linear accelerators. Specific and periodic controls should be performed in order to check the mechanical stability for both irradiation and collimation systems. If this step remains under the responsibility of the medical physicist, it should be done in agreement with the manufacturer's technical support. At this time, there are no recent published guidelines. With technological developments, both frequency and accuracy should be assessed in each institution according to the treatment mode: single versus hypofractionnated dose, circular collimator versus micro-multileaf collimators. In addition, "end-to-end" techniques are mandatory to find the origin of potential discrepancies and to estimate the global ballistic accuracy of the delivered treatment. Indeed, they include frames, non-invasive immobilization devices, localizers, multimodal imaging for delineation and in-room positioning imaging systems. The final precision that could be reasonably achieved is more or less 1mm.

[Malignant gliomas]

Glial tumors represent 2000 to 3000 new cases per year in France and 75% of them are of high grade. Recent understanding of the molecular biology of these tumors revealed the importance of 1p19q codeletion and mgMT promotor methylation. Radiotherapy also recently evolved with the progress in medical imaging which allows a better definition of the target volumes. Even modest, therapeutic progress is based on chemoradiotherapy with temozolomide and on the development of non-coplanar conformational radiotherapy. Knowledge and precise evaluation of potential late effects of our treatments is necessary due to actual improvement of survival with chemoradiotherapy in glioblastoma.

[Management of Merkel cell carcinoma: Role of radiotherapy in elderly patients]

PURPOSE

Merkel cell carcinoma carcinoma (MCC) or primary cutaneous neuroendocrine carcinoma is a rare and aggressive malignancy affecting elderly. Optimal therapeutic strategy has not yet been established in elderly patients.

PATIENTS AND METHODS

From March 1996 to March 2007, 29 patients with Merkel cell carcinoma of were treated at the University Hospital of Amiens, France. Adjuvant radiotherapy (RT) was performed for 14 patients (50%) on the tumor bed with margins of 3 to 5cm, an average dose of 46Gy (30-60Gy), by 2Gy per fraction. Ten of them also received RT to the lymph node area at mean dose of 44.3Gy (26-50Gy). Duration of RT was 35 days. A retrospective analysis was conducted to better evaluate survival and prognostic factors.

RESULTS

Median overall survival (OS) was 18.9 months (3-122) and the median time to progression (MTP) 5.5 months (1-26). At 5 years, OS for irradiated patients was 47% (IC95: 12-82%) versus 27% (IC95: 5-49%) in cases of surgery alone (p=0.032). The most frequent sites of recurrence were nodal (34.5%), local (24.1%) and metastatic (17.2%). For patients over 70 years, eight (36.5%) were free of disease at last news, 8 (36.5%) had died from cancer and six from other causes (27%). In this subgroup, MTP was 6 months (2-19) and median OS of 19 months (4-87). There was no acute toxicity greater than grade 2.

CONCLUSION

Although limited by a retrospective analysis, this report suggests an advantage of postoperative RT for patients with MCC. It combined low toxicity and improvement of survival. Prospective multicenter trials are needed to clarify and validate the optimal strategy.

[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.

[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.