[The 30th anniversary of SFRO, the French society of oncological radiotherapy]. / Les 30 ans de la SFRO.

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.

[Hypofractionation and radiotherapy: "the eternal return"]. / Hypofractionnement en radiothérapie : l'éternel retour.

Hypofractionation is not a new idea in radiotherapy. The use of a few high-dose fractions has been proposed by some pioneers of our specialty in the early years of the 20th century. Hypofractionation then reappeared several times in the next decades, based on successive radiobiological concepts, a number of them having been shown to be wrong. The nominal single dose (NSD), for example, so fashionable in the 1970's, dramatically underestimated the late toxicity of the high-dose fractions. Consequently, the NSD was directly responsible for a significant increase of the incidence and of the severity of late complications in large cohorts of patients. The linear-quadratic model (LQ) unequivocally improved our understanding of fractionation sensitivity, but one has to keep in mind its limitations, both in the areas of low and high doses per fraction. For more than a decade, prostate cancer has been the subject of fierce discussions about its sensitivity to fractionation. A number of studies have suggested an unusually low (for a malignant tumor) alpha/beta ratio. However, the available data do not allow a precise evaluation of this ratio; "very low" (1.5 Gy), with an advantage of hypofractionation in terms of local control? Or simply "low" (3-4 Gy), only allowing a reduction of the total number of fractions (with a dose adequately reduced)? While waiting for complementary data, it is advised to remain very careful when modifying the classical schemes towards hypofractionation.

[Role of French teams in the development of clinical and translational research in radiation oncology]. / Implications récentes des équipes françaises en oncologie radiothérapie et radiobiologie clinique.

Many clinical studies have showed the key role of radiotherapy in anticancer treatment strategy. Radiations are delivered alone or in combination with systemic therapies. In recent years, the main goal of all clinical developments has focused on improving clinical benefit, with an increased tumour control and a higher normal tissue protection. This research was designed to reduce local recurrences, to increase recurrence-free or overall survival and to decrease acute and late effects. Technological and biological evolutions (or revolutions) accompanied clinicians to improve clinical benefit, namely with strong progress in radiology and better understanding of radiobiology, particularly at the molecular level. Differences in tumour and normal tissues radiosensitivity are nowadays integrated in daily clinical practice of radiation oncologists. The current report details the last 5-year developments of clinical and translational research in radiation oncology, especially the role of French teams in the development of personalized treatment.

Early PSA decrease is an independent predictive factor of clinical failure and specific survival in patients with localized prostate cancer treated by radiotherapy with or without androgen deprivation therapy.

BACKGROUND: The aim was to identify predictors of outcome in patients with localized prostate cancer treated with external beam radiotherapy (EBRT), with or without androgen deprivation therapy (ADT). MATERIALS AND METHODS: A total of 448 patients with prostate cancer received EBRT alone (n = 361, group 1) or ADT followed by EBRT (n = 87, group 2). In group 2, ADT was initiated 3 months before EBRT. After baseline prostate-specific antigen (PSA) determination (PSA(preRT)), PSA was assessed during the 6th week of the EBRT course (PSA(6wRT)) in group 1. In group 2, PSA was measured again 3 months after the start of ADT, before EBRT (PSA(ADT-preRT)). RESULTS: In group 1, median PSA(6wRT)/PSA(preRT) was 0.72 and median prostate-specific antigen velocity (PSAV) was -1.5 ng/ml/month. In the multivariate analysis, prognostic groups and PSA(6wRT)/PSA(preRT) (or PSAV) independently predicted biochemical failure (BF), clinical failure (CF), and prostate cancer-specific survival. In group 2, the median PSA(ADT-preRT) was 1.3 ng/ml. In the high-risk group, an undetectable PSA(ADT-preRT) (< or =0.2 ng/ml) predicted BF (P < 0.01) and CF (P = 0.007). CONCLUSION: A PSA decline 6 weeks after the start of EBRT when used as monotherapy and 3 months after the start of ADT in patients treated with combined ADT and EBRT is predictive of progression and specific survival.

[French radiotherapy database: results of a survey of French radiation oncology centers in 2007]. / Observatoire national de la radiothérapie: rapport de l'enquête conduite en 2008 sur l'année 2007.

For the second year, the French Radiotherapy Database presents information from French radiation oncology centers. Among 179 centers, 159 have participated (90 %). The number of accelerators increased from 371 to 384 between 2006 and 2007, 11 % of these machines are more than 15 years old. On average, centers are open 50 hours per week for treatment and 9.5 % more for maintenance. The lack of dedicated CT remains a difficulty: 158 from 159 centers have an access to a CT, but only 50 % have a dedicated scanner. There is no progress compared to 2006. The proportion of centers having a MU double calculation system has increased from 51 to 58 %. Two thirds of centers do not implement in vivo dosimetry. The activity is stable around 190 000 treatments per year. Three-dimension conformal radiotherapy is used for more than half of treatments in 77.2 % of private centers and 50 % of public hospitals. Intensity modulated radiotherapy remains rarely used. The number of radiation oncologists and technologists remains stable. The number of radiophysicists has increased from 7.6 %. Despite some progress, the difficulties of this speciality persist in France and are equally distributed across all regions, and between private and public centers. In 2009, the French Society for Radiation Oncology and the associated partners will continue this survey, which interest is recognized by both professionals and health administrations.

[Increasing quality and safety of external radiation treatments: actions of the French Society of Radiation Oncology (SFRO)]. / Qualité en radiothérapie: les actions de la société française de radiothérapie oncologique (SFRO).

Accidents which recently occured in external radiotherapy led the French Ministry of Health to implement a programme aimed at increasing quality and safety of treatments. We report the actions of the French society of radiation oncology in the field of this programme called Feuille de route.

[Epinal radiotherapy accident: passed, present, future]. / L'accident d'Epinal: passé, présent, avenir.

The accident of radiation oncology at the Public General Hospital in Epinal, Vosges, is the highest in France. It is classified level 6 on a 10 degrees scale of the ASN/SFRO (Autorité de sûreté nucléaire/Société française de radiothérapie oncologique). It is linked to errors in the process of treatment, and a mistake in the use of dynamic wedges, with an overdosage of 20%. The clinical consequences are severe, for the patients treated for a prostate cancer and exposed to this overdosage, between May 2005 and August 2006. Sequelae were classified grade 2 to 5 on the CTCAE 3.0 scale. A second cohort of 397 was identified, which received an overdose of 10% linked to the daily use of portal imaging, which explained a higher risk of gr 2-3 rectitis. The treatments were interrupted in this hospital for several months, to organize a new management of the department, based on quality and safety. The preventive actions to avoid such an accident necessitate to evaluate standard and innovative treatments, to develop an internal and external quality control program.

[The actions of the French Society of Radiation Oncology (SFRO), within the frame of Plan cancer and the recent events of radioprotection]. / 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.

[External ionizing radiation on the prosthesis-arterial anastomosis for the prevention of intimal hyperplasia and study of biomechanical resistance. Experiments and results]. / Radiations ionisantes délivrées par voie externe sur l'anastomose prothéto-artérielle pour limiter l'hyperplasie intimale et étude de la résistance biomécanique. Expérimentations et résultats.

PURPOSE: To evaluate the use of external ionizing radiation for the prevention of intimal hyperplasia in anastomosis between PTFE and artery. METHODS: Bypass using a 6 mm PTFE was performed on a swine subrenal aorta with a distal conventional anastomosis (N = 35) associated (test group; N = 17) or not (control group; N = 18) with post-operative external radiation (20 Gy) on this anastomosis. At 45 days, histological studies and morphometric studies were performed on the aorta receiving the anastomosis. Two protocols were performed, the first protocol with standard analysis and the animals were randomly assigned to either group (test group; N = 11 and control group; N = 13) and the second protocol with test of extraction comparing the biomechanical resistance between the irradiated group (N = 6) and the control group (N = 5). RESULTS: Twenty-one animals survived the procedure in the first protocol, 11 in the second. The endothelium was restored in either group. Histological recasting was observed in the media after radiation with fibrosis and areas of necrosis. Intimal thickness was significantly lower after irradiation in the heel (P < 0.01), the head (P < 0.01) and the suture line (P < 0.001) of the artery in the first protocol. The intimal thickness was also significantly lower in the second protocol after radiation in the heel (P < 0.05) and the head of the artery (P < 0.05). There was no difference between the two groups comparing the resistance. CONCLUSION: After external irradiation, the thickness parameter of the intima decreased significantly in comparison with the control group with similar resistance. Media fibrosis and necrosis need to be confirmed by further investigation.

[Hyperplasia of the arterial intima due to smooth muscle cell proliferation. Current data, experimental treatments and perspectives]. / Hyperplasie intimale artérielle par prolifération de cellules musculaires lisses dans la paroi: données actuelles, traitements expérimentaux et perspectives.

Restenosis after vascular surgery using bypasses or endovascular techniques for dilatation or recanalisation remains the major Achilles' heel for these techniques. The progressive decrease of vessel lumen in an anastomose leading to graft failure or after arterial transluminal angioplasty is due to a complex process: intimal hyperplasia. This process can be compared to an hypertrophic healing into the intimal layer, reducing the lumen of the vessel. This process appears shortly after surgery or dilatation, between the 3rd and the 18th month. Mechanisms leading to this process are particularly complex, involving several cells and many regulatory processes still unclear. Smooth muscle cells are the main actor by their ability to proliferate and to secrete matrix into the media layer but stimulation and control of this process appear nevertheless complicated. The present review focuses on the pathophysiology of intimal hyperplasia, on different cells acting and on their regulation. Also, we reviewed the experimental and clinical trials evaluating approaches to the prevention of intimal hyperplasia in arteries.

[High-dose external ionizing radiation prevents intimal hyperplasia and limits secretion of growth factors PDGFbb, bFGF, and TGFb1. Experiments and results]. / Les radiations ionisantes externes à doses élevées limitent l'hyperplasie intimale et diminuent la sécrétion des facteurs de croissance PDGF-bb, bFGF et TGFb1. Expérimentation et résultats.

PURPOSE: To evaluate the ionizing radiation for intimal hyperplasia prevention and to assess the production of growth factors. METHODS: An oversized injury using an embolectomy catheter was performed on a rabbit distal aorta (N=23), associated (test group; N=12) or not (control group; N=11) with a post-operative external radiation (25 Gy). At t=45 days, histological studies and morphometric studies were performed on the aorta. Smooth muscular cells and endothelial cells were stained using immuno-histologic revelation. Immuno-histological analysis was performed on arteries for growth factors PDGFbb, bFGF and TGFb1. RESULTS: Twenty-one animals survived the procedure, 11 were in the test group and 10 in the control group. Intimal thickness and ratio intima/media were significantly lower after radiation (respectively p=0.008, p=0.008). There was no difference for the medial thickness (p=0.155). Immuno-histochemical positive staining for PDGF and TGFb1 was lower after radiation (respectively 18.44 +/- 2.963% versus 47.64 +/- 6.86%, p<0.001 and 10.11 +/- 3.18% versus 29.45 +/- 4.156%, p<0.001). There was no difference for the expression of bFGF growth factor. After radiation, the media was found to be reduced and replaced by interstitial fibrosis. CONCLUSION: After external radiation the thickness parameter of the intima and the ratio intima/media decreased significantly in comparison with the control group. PDGF and TGFb1 were also less expressed in the artery irradiated. Fibrosis recasting needs to be confirmed by further investigation.

[Influence of thermoplastic masks on the absorbed skin dose for head and neck tumor radiotherapy]. / Influence des masques thermoformés de contention sur la dose à la peau en radiothérapie des tumeurs des voies aérodigestives supérieures.

The influence of thermoplastic masks used in clinical routine for patient immobilization in head and neck radiotherapy treatment on the absorbed skin dose has been investigated at Gustave-Roussy Institute. The measurements were performed in 60Co gamma-rays, 4 and 6MV X-rays and in 8 and 10MeV electron beams. Initially, the measurements were performed with thermoluminescent dosimeters (LiF) and a NACP chamber on a polystyrene phantom in order to study the influence of physical parameters (distance, field size, energy...) on first millimeters depth variation dose. The study was completed with in vivo measurements on 14 patients using various dosimeters (thermoluminescent detectors, diodes) in order to assess the increase of dose on first millimeters depth and to verify the delivered dose during treatment sessions (quality control). In treatment conditions, masks lead to an important increase of dose on the first millimeter in 60Co gamma-rays beams (dose value normalized to maximum of dose increase from 57.1% to 77.7% for 0.5 mm-water depth and from 78.5% to 88% for 1 mm-water depth); its contribution is less important in 4 and 6 MV X-rays beams (dose value normalized to maximum of dose increase from 49.5% to 63.2% for 0.5 mm-water depth and from 59% to 70.1% for 1 mm-water depth). Concerning 8 and 10 MeV electron beams, the normalized dose value increase respectively from 78.4% to 81.7% and from 82.2% to 86.1% for 0.5 mm-water depth. In vivo dosimetry enabled the quality control of delivered dose during treatment. Measured dose is in agreement within +/- 5% with the prescribed dose for 92.3% of cases. In routine, in vivo dosimetry allowed to quantify the increase of skin dose induced by thermoplastic masks for various energies of photon and electron beams as well as quality control.

Influence of high-energy photon beam irradiation on pacemaker operation.

In this paper, we determine the influence of high-energy photon beam irradiation used for external radiotherapy on pacemakers, at different doses and dose rates. Ninety-six pacemakers of various origins and ages underwent in vitro high-energy photon irradiation under technical conditions close to external radiotherapy, using a linear accelerator delivering photons of high energy (18 MV). Various dose levels (up to 200 Gy for certain particularly resistant pacemakers) were delivered to pacemakers located in a water-equivalent phantom with several dose rates (from 0.05 to 8 Gy min(-1)). Observed failures were sorted into eight classes of progressive harmfulness, some of them possibly lethal. One irradiated pacemaker exhibited an important defect at a dose rate of 0.2 Gy min(-1), for a cumulative dose of 0.15 Gy. Two pacemakers showed an important defect at a cumulative dose of 1 Gy, while nine pacemakers failed at a cumulative dose lower than or equal to 2 Gy and 13 failed at a cumulative dose lower than or equal to 5 Gy. The most important failure probability (70% of irradiated pacemakers) is observed for 8 Gy min(-1), whereas no pacemakers failed at a dose rate lower than or equal to 0.2 Gy min(-1). In conclusion, warnings given by manufacturers about the maximum tolerable cumulative radiation doses for safe operation of irradiated pacemakers (5 Gy), even reduced to 2 Gy, are not reliable. The spread of cumulative doses inducing failures is very large since our observations show an important failure at 0.15 Gy, while ten pacemakers withstood more than 140 Gy of cumulative dose. The safe operation of pacemakers under irradiation depends mainly on type and model. It depends also on dose rate. From our observations, for the safe operation of pacemakers, a recommendation of a maximum dose rate of 0.2 Gy min(-1) rejecting direct irradiation of the pacemaker at a standard dose rate for tumour treatment (2 Gy min(-1)) is made.

[Localized cancer of the prostate. What to tell the patient?]. / Cancer de prostate localisé. Que dire au patient?

Answering the question from patients with adenocarcinoma of the prostate is always difficult; choice of radiation therapy (versus prostatectomy), indications of brachytherapy frequency and severity of acute and late effects as rate of survival, local control, are among the most frequent inquiries. A part of the answers are not evident of due lack, consensus and the physicians need to speak honestly and give the most appropriate responses without improving anxiety and fears of the patient.

[Method of radiotherapy planning for head and neck tumors using simulated CT images and radiographic data, developed at the Gustave Roussy Institute]. / Méthode utilisée à l'institut Gustave Roussy pour l'établissement des plans de traitement des cancers ORL à partir des images de simulateur-scanneur et du film radiographique de profil.

The paper deals with the recent improvements introduced in the most usual method applied in the Institut Gustave Roussy radiotherapy department for obtaining the anatomical data of patients treated for head and neck tumors. For each of these patients, five to seven transverses slices and a lateral radiographic film are taken from a Mecaserto simulator-CT. The anatomical representation of the patient sagittal plane is carried out from the digitalisation of the radiographic film on a Vidar Vxr-12 Plus film scanner and integrated into the Dosigray dose calculation programme in order to be used as a support for the laying out of the dose distribution in reference to the treatment. The sagittal anatomical representation obtained from the radiographic film digitalisation is compared with the one resulting from the interpolation between a limited number of irregularly-spaced transverse slices taken on the simulator-CT. The method using the simulator-scanner transverse slices and the radiographic film digitalisation represents an interesting alternative for obtaining an anatomy simulation representative of the patient in hospitals where a scanner is not available full-time for the needs of the radiotherapy process.