Between September 1990 and March 1995, 189 patients were treated with high-dose-rate endobronchial brachytherapy. Most patients (70%) presented with either recurrent or persistent symptomatic endobronchial tumor after standard therapy. A minority of the patients (12%) had small endobronchial tumor and were unfit for surgical resection or radiotherapy. Treatment was delivered weekly and consisted of three to four 8- to 10-Gy radiotherapy fractions applied at 10 mm from the source. Major symptomatic improvement was obtained on hemoptysis (74%), dyspnea (54%), and cough (54%). Complete endoscopic response occurred in 54.5% of the cases. Median survival was 7 months for the entire group. For small strictly endobronchial tumors, complete response rate was 95.5%, median survival was 17 months, and 30-month survival was 46%, with a plateau starting at 18 months. The rate of late grade 3 to 4 toxicity was 17%, including hemoptysis (n = 13), stenosis (n = 12), local necrosis (n = 8), and bronchial fistula (n = 3). By univariate analysis, no factor was found to be predictive of late toxicity. Our study confirms the benefit of endobronchial brachytherapy in the palliative treatment of endobronchial recurrences and in the curative intent treatment of small endobronchial tumors in patients not suitable for other forms of therapy.
Proton therapy is widely acknowledged as one of the most effective methods in the selective destruction of cancer cells. Its development has, however, been hampered by the complexity, the size and the cost of the necessary equipment, which were up to now not adapted to the hospital environment. Things are changing in this regard. At the beginning of 1994, the Massachusetts General Hospital (MGH) of the Harvard Medical School in Boston, MA, USA, a pioneer in proton therapy since 1959, selected a team led by IBA to supply the proton therapy equipment of its new Northeast Proton Therapy Centre (NPTC). The present paper presents the integrated system being build for the NPTC. This equipment includes a compact 235 MeV isochronous cyclotron, a short energy selection system transforming the fixed energy beam extracted from the cyclotron into a variable energy beam, one or more isocentric gantries fitted with a nozzle, one or more horizontal beam lines, a global control system including an accelerator control unit and several independent but networked therapy control stations, a global safety management system, and a robotic patient positioning system.
The purpose of this study was to determine the benefit of high dose rate endobronchial brachytherapy in the treatment of obstructive lung cancer. Between September 1990 and March 1995, 189 patients with bronchogenic carcinoma were treated with high dose rate endobronchial brachytherapy. Most patients (69.3%) had received prior treatment and presented with symptomatic bronchial obstruction due to either recurrent or residual endobronchial disease. A small group (12%) was medically unfit for either surgical resection or thoracic radiotherapy and benefited from endobronchial brachytherapy alone for small endobronchial tumours. The remainder of the patients had not been treated previously and endobronchial brachytherapy was performed for life-threatening symptoms requiring emergency obstruction relief before other therapy. Treatment was performed weekly and consisted of three to four 8 to 10 Gy fractions at a radius of 10 mm from the centre of the source. Major symptomatic relief was obtained for haemoptysis (74%), dyspnoea (54%), and cough (54%). Complete endoscopic response was observed in 54% of cases. Median survival was 7 months for the entire group. For small, strictly endobronchial tumours, complete response rate was 96%, median survival 17 months, and 30 month survival 46%, with a plateau starting at 18 months. Grade 3 to 4 toxicities occurred at a rate of 17% and included massive haemoptysis (n=13), bronchial stenosis (n=12), soft tissue necrosis (n=8), and bronchial fistula (n=3). By univariate analysis, no factor was found to be predictive of late pulmonary toxicity. The present study confirms the usefulness of endobronchial brachytherapy in alleviating symptoms caused by endobronchial recurrence of bronchogenic carcinoma. In addition, this therapy can be tried with curative intent in patients who present with small endobronchial tumours and are not candidates for other forms of therapy.
Si le pronostic des formes precoces des cancers du col uterin est maintenant favorable grâce aux associations radiochirurgicales, le pronostic des formes localement evoluees reste sombre. Nous rapportons les resultats preliminaires d'une etude retrospective portant sur 29 patientes porteuses de tumeurs localement evoluees traitees entre decembre 1987 et janvier 1990 par une association de radiotherapie et de cisplatine. L'âge median est de 47 ans. Il s'agit de 1 stade ib, 5 stades ila, 6 stades ilb, 7 stades illa, 9 stades illb et 1 stade IVa
Les irradiations par capture de neutrons visent à détruire sélectivement et efficacement les cellules tumorales au moyen de réactions nucléaires produites sélectivement en leur sein. Pour ce faire, du 10B est apporté préférentiellement à l'intérieur des tumeurs au moyen d'une molécule vectrice, puis l'ensemble des tissus est irradié par des neutrons thermalisés (E = 0,025 eV). Lors des réactions de capture de neutrons sur 10B, le noyau final se scinde en une particule α et un ion 7Li qui emportent une énergie de 2,79 MeV et qui détruiront tout sur leurs parcours d'une dizaine de micromètres. Ces captures sont utilisées soit exclusivement lors d'une irradiation par neutrons ≪lents≫, c'est la thérapie par capture de neutrons, soit en potentialisation d'une irradiation par neutrons ≪rapides≫, c'est la potentialisation par capture de neutrons. Les premiers essais cliniques américains des années 1951 à 1961 pour le traitement des gliomes de haut grade ont été un échec en raison d'une localisation préférentielle de 10B à l'intérieur des vaisseaux et des capillaires sanguins intracérébraux. Actuellement, un certain nombre d'éléments nouveaux permettent de penser que la méthode peut être utilisée en clinique pour le contrôle local de tumeurs radiorésistantes: des molécules vectrices plus performantes; des faisceaux de neutrons mieux calibrés; une meilleure connaissance de la radiobiologie liée à ce type d'irradiation. Parmi les tumeurs pouvant bénéficier de ce type d'irradiation, il y a les gliomes de haut grade, les mélanomes cutanés et sans doute oculaires, et peut-être les sarcomes des tissus mous.
Neutron capture irradiation aims to selectively destroy tumor cells using 10B(n,α)7 Li nuclear reactions produced within themselves. Following the capture reaction, an α particle and a, 7Li ion are emitted. Carrying an energy of 2.79 MeV, they destroy all molecular structures along their path close to 10μm. These captures, used exclusively with a ‘slow’ neutron irradiation, provide a neutron capture therapy (BNCT). If they are used in addition to a fast neutron beam irradiation, they provide a neutron capture potentiation (NCP). The Centre Antoine-Lacassagne in Nice is actively involved in the European Demonstration Project for BNCT of grade IV glioblastomas (GBM) after surgical excision and BSH administration. Taking into account the preliminary results obtained in Japan, work on an ‘epithermal’ neutron target compatible with various cyclotron beams is in progress to facilitate further developments of this technique. For NCP, thermalized neutron yield has been measured in phantoms irradiated in the fast neutron beam of the biomedical cyclotron in Nice. A thermal peak appears after 5cm depth in the tissues, delayed after the fast neutron peak at 1.8cm depth. Thus, a physical overdosage of 10% may be obtained if 100 ppm of 10B are assumed in the tissues. Our results using CAL 58 GBM cell line demonstrate a dose modification factor (DMF) of 1.19 when 100 ppm of boric acid are added to the growth medium. Thus for the particles, issued from neutron capture, a biological efficiency at least twice that of fast neutrons can be derived. These results, compared with historical data on fast neutron irradiation of glioblastoma, suggest that a therapeutic window may be obtained for GBM.
The French National Agency for Medical Evaluation (ANDEM) was requested to assess the effectiveness of proton and neutron beam therapy in cancer treatment compared to conventional radiotherapy. This task was accomplished by a critical appraisal of the clinical and economic literature. According to the published economic literature and the capital and staffing cost analysis, it appears that the costs of proton therapy are likely to be two or three times greater than those of photon conformal therapy. According to the published clinical literature, proton beam therapy should be proposed as a routine treatment only for uveal melanoma and skull base cancers. Neutron beam therapy should be proposed as a routine treatment for inoperable salivary gland tumors; its use may be also discussed in cases of stage C-Dl prostate cancers and soft tissue sarcomas. Based on the current scientific evidence and given the incidence rate of these tumors, the time and material requirements, the current French proton/neutron beam facilities are able to meet the current demand. For other cancers the medical and economic potential of proton therapy is still an open question.
De 1981 à 1985, 428 patients présentant un carcinome épidermoïde de l'hypopharynx et/ou du larynx ont été traités avec intention curative par exérèse chirurgicale et irradiation postopératoire. Les deux-tiers des tumeurs étaient classés T3 et 60 % avaient un envahissement ganglionnaire clinique. Le taux d'échec local est respectivement de 8 %, 18 % et 13 % respectivement pour les cancers du larynx, du sinus piriforme et de la paroi postérieure, les échecs régionaux étant respectivement de 8 %, 23 % et 13 %. Il n'y a pas de site cervical à haut ou faible risque de rechute après curage mais la rupture capsulaire reste un facteur de mauvais pronostic. Le taux de survie à 5 ans de l'ensemble de la série est de 38 %, pour la localisation laryngée il atteint 62 %. Le risque de métastases est lié à l'envahissement ganglionnaire et à l'intervalle de temps entre la chirurgie et l'irradiation.
