Irradiation du petit bassin et fonction ano-rectale.

peer reviewedLe traitement adjuvant des cancers du rectum a pour buts de stériliser la maladie résiduelle infra-clinique et d’améliorer le contrôle local. Depuis plus de 20 ans, des milliers de malades ont été inclus dans des études randomisées, visant d’abord à mettre en évidence un gain de survie et une réduction des récidives loco-régionales, en relation avec la radiothérapie pré- ou postopératoire, combinée ou non à la chimiothérapie. Les conséquences en termes de qualité de vie de ces traitements ont pourtant été peu étudiées, et la tolérance fonctionnelle du néo-rectum et de l’appareil sphinctérien à la radiothérapie restent mal connues [1]. Les difficultés liées à l’étude des effets de l’irradiation sur les tissus normaux, ainsi que la variabilité inter-individuelle de la réponse à la radiothérapie, s’ajoutent et rendent le sujet plus complexe encore. Les radiothérapeutes adaptent leur technique afin de réduire autant que possible la dose administrée aux tissus normaux avoisinant la tumeur. Dans le cas de l’irradiation du petit bassin, c’est l’intestin grêle qui a longtemps été considéré comme la structure à risque de complications, alors que l’atteinte du sphincter anal était rarement mentionnée [2]. Malgré les répercussions importantes de la dysfonction ano-rectale sur la qualité de vie des malades, l’atteinte du sphincter anal par la radiothérapie est restée un aspect négligé du traitement adjuvant des cancers du petit bassin [3]. Cet article a pour but, à travers une revue de la littérature, de mettre en évidence les effets qualitatifs et quantitatifs de la radiothérapie sur la fonction du sphincter anal, ainsi que de proposer une modification de la technique actuelle d’irradiation des cancers du bas rectum

Intracoronary Brachytherapy for Restenosis: 20 Years of Follow-Up.

Intracoronary brachytherapy (ICB) has mainly been used to treat in-stent restenosis following percutaneous coronary intervention and was virtually abandoned about 20 years ago. However, patients treated with this strategy are still alive and some teams continue to perform this therapy. We aimed to investigate the very long-term clinical outcome of patients treated with ICB. A total of 173 consecutive patients who had been treated with ICB at a large tertiary referral centre between 1998 and 2003 were included. The primary endpoint of the study was all-cause mortality. The secondary endpoints were as follows: occurrence of major adverse cardiac events (MACE, defined as all-cause death, non-fatal myocardial infarction, or target vessel revascularization), cardiac death, and presence of angina at the end of follow-up. Patients' mean age at the time of ICB was 64 ± 10 years and 77 % were male. Restenosis (bare metal stent vs. balloon angioplasty) was the only indication for ICB. Unstable angina was present in 34 % of the patients. Follow-up was available for 166 patients. After a mean follow-up of 20 ± 1.3 years, 66 % of the patients had died (including 74 patients (67 %) with cardiac death). Cumulative MACE rate at 20 years was 96 %. Very long-term follow-up of patients with in-stent restenosis treated with ICB confirmed a high all-cause mortality rate mainly due to cardiac causes and MACEs

Medical imaging professionals and related specialties : a questioning is essential!

peer reviewed: S’il y a bien un domaine où les annonces pleuvent en matière de développement de l’intelligence artificielle (IA), c’est le secteur de l’imagerie médicale au sens large du terme (regroupant la radiologie, la médecine nucléaire et la radiothérapie). Les applications, encore souvent utilisées dans des niches précises, ont tendance à devenir beaucoup plus transversales. De multiples acteurs industriels, en partenariat avec les utilisateurs, s’évertuent à construire de réelles plateformes qui offrent aux cliniciens une multitude d’applications utilisables pour combler plusieurs types de demandes et besoins (détection, diagnostic et prédiction). Il est indéniable que la capacité de l’IA dépasse largement nos capacités humaines en matière de résolution de l’image, de rapidité et d’efficience de lecture et d’analyse. Une attitude de négation ou de scepticisme de la part des professionnels du secteur n’est plus de mise. Ils doivent, sans attendre, collaborer avec les spécialistes data et les ingénieurs au développement à large échelle de l’IA en imagerie médicale et ce, au profit des patients et des payeurs.: Nowadays, we are facing an overwhelming amount of public announcements concerning the rise of artificial intelligence (AI) in the world of medical imaging (including radiology, nuclear medicine and radiotherapy). While most of the applications are still limited to specific niches, there is a general trend to build real transversal platforms. Multiple industrial players, in collaboration with the clinicians in the field, are striving to build those platforms in order to offer plenty of use cases of AI for several purposes and needs (screening/detection, diagnosis and prediction). It is already undeniable that AI far exceeds human capabilities in terms of resolution, speed of image analysis and efficiency. Negative attitudes and skepticism from concerned professionals should be banned. Collaboration with data scientists and engineers for the large scale development and implementation should be pushed forward for the benefit of both patients and payers

RENO, a European Postmarket Surveillance Registry, confirms effectiveness of coronary brachytheraypy in routine clinical practice.

Purpose: To assess, by a European registry trial, the clinical event rate in patients with discrete stenotic lesions of coronary arteries (de novo or restenotic) in single or multiple vessels (native or bypass grafts) treated with -radiation. Methods and Materials: Between April 1999 and September 2000, 1098 consecutive patients treated in 46 centers in Europe and the Middle East with the Novoste Beta-Cath System were included in Registry Novoste (RENO). Results: Six-month follow-up data were obtained for 1085 patients. Of 1174 target lesions, 94.1% were located in native vessels and 5.9% in a bypass graft; 17.7% were de novo lesions, 4.1% were restenotic, and 77.7% were in-stent restenotic lesions. Intravascular brachytherapy was technically successful in 95.9% of lesions. Multisegmental irradiation, using a manual pullback stepping maneuver to treat longer lesions, was used in 16.3% of the procedures. The in-hospital rate of major adverse cardiac events was 1.8%. At 6 months, the rate was 18.7%. Angiographic follow-up was available for 70.4% of the patients. Nonocclusive restenosis was seen in 18.8% and total occlusion in 5.7% of patients. A combined end point for late (30–180 days) definitive or suspected target vessel closure was reached in 5.4%, but with only 2% of clinical events. Multivariate analysis was performed for major adverse cardiac events and late thrombosis. Conclusion: Data obtained from the multicenter RENO registry study, derived from a large cohort of unselected consecutive patients, suggest that the good results of recent randomized controlled clinical trials can be replicated in routine clinical practice. © 2003 Elsevier Science Inc

A treatment planning intercomparison of proton and intensity modulated photon radiotherapy.

peer reviewedAbstract Purpose: A comparative treatment planning study has been undertaken between standard photon delivery techniques,b intensity modulated photon methods and spot scanned protons in order to investigate the merits and limitations of each of these treatment approaches. Methods: Plans for each modality were performed using CT scans and planning information for nine patients with varying indications and lesion sites and the results have been analysed using a variety of dose and volume based parameters. Results: Over all cases, it is predicted that the use of protons could lead to a reduction of the total integral dose by a factor three compared to standard photon techniques and a factor two compared to IM photon plans. In addition, in all but one Organ at Risk (OAR) for one case, protons are predicted to reduce both mean OAR dose and the irradiated volume at the 50% mean target dose level compared to both photon methods. However, when considering the volume of an OAR irradiated to 70% or more of the target dose, little difference could be shown between proton and intensity modulated photon plans. On comparing the magnitude of dose hot spots in OARs resulting from the proton and IM photon plans, more variation was observed, and the ranking of the plans was then found to be case and OAR dependent. Conclusions: The use of protons has been found to reduce the medium to low dose load (below about 70% of the target dose) to OARs and all non-target tissues compared to both standard and inversely planned photons, but that the use of intensity modulated photons can result in similar levels of high dose conformation to that afforded by protons. However, the introduction of inverse planning methods for protons is necessary before general conclusions on the relative efficacy of photons and protons can be drawn

Initial experience using the Palmaz Corinthian stent for right ventricular outflow obstruction in infants and small children

The original Palmaz balloon expandable stent has been used extensively for the treatment of vascular stenoses in older children and young adults. Placement of the Palmaz stent in infants and small children, however, is limited by stent inflexibility, large delivery sheath size, and concerns about creating fixed obstructions after the placement of small diameter stents in growing patients. New Palmaz Corinthian stents were placed through 6 French sheaths in four high-risk patients with postoperative right ventricular outflow obstruction. Patients were not considered candidates for surgical repair. Median patient age and weight were 17 months (range 5–32 months) and 7.7 kg (range 4.6–11.1 kg), respectively. Median fluoroscopy time was 58.2 min (range 55.2–172 min). No complications were encountered. In each case, successful stent placement was achieved, and surgery with cardiopulmonary bypass was avoided. Palmaz Corinthian stents are more flexible, require a smaller delivery sheath, have equal or increased radial strength, and can be maximally expanded to a greater cross sectional area when compared to the original Palmaz stent. These characteristics make the Palmaz Corinthian stent a reasonable alternative for use in a select group of infants and small children who are not candidates for surgical repair of postoperative right ventricular outflow obstruction. Cathet. Cardiovasc. Intervent. 51:444–449, 2000. © 2000 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35251/1/14_ftp.pd

CPT-11 and concomitant hyperfractionated accelerated radiotherapy induce efficient local control in rectal cancer patients: results from a phase II

Patients with rectal cancer are at high risk of disease recurrence despite neoadjuvant radiochemotherapy with 5-Fluorouracil (5FU), a regimen that is now widely applied. In order to develop a regimen with increased antitumour activity, we previously established the recommended dose of neoadjuvant CPT-11 (three times weekly 90 mg m−2) concomitant to hyperfractionated accelerated radiotherapy (HART) followed by surgery within 1 week. Thirty-three patients (20 men) with a locally advanced adenocarcinoma of the rectum were enrolled in this prospective phase II trial (1 cT2, 29 cT3, 3 cT4 and 21 cN+). Median age was 60 years (range 43–75 years). All patients received all three injections of CPT-11 and all but two patients completed radiotherapy as planned. Surgery with total mesorectal excision (TME) was performed within 1 week (range 2–15 days). The preoperative chemoradiotherapy was overall well tolerated, 24% of the patients experienced grade 3 diarrhoea that was easily manageable. At a median follow-up of 2 years no local recurrence occurred, however, nine patients developed distant metastases. The 2-year disease-free survival was 66% (95% confidence interval 0.48–0.83). Neoadjuvant CPT-11 and HART allow for excellent local control; however, distant relapse remains a concern in this patient population

Absence of cardiovascular manifestations in a haploinsufficient Tgfbr1 mouse model

Loeys-Dietz syndrome (LDS) is an autosomal dominant arterial aneurysm disease belonging to the spectrum of transforming growth factor β (TGFβ)-associated vasculopathies. In its most typical form it is characterized by the presence of hypertelorism, bifid uvula/cleft palate and aortic aneurysm and/or arterial tortuosity. LDS is caused by heterozygous loss of function mutations in the genes encoding TGFβ receptor 1 and 2 (TGFBR1 and -2), which lead to a paradoxical increase in TGFβ signaling. To address this apparent paradox and to gain more insight into the pathophysiology of aneurysmal disease, we characterized a new Tgfbr1 mouse model carrying a p.Y378*nonsense mutation. Study of the natural history in this model showed that homozygous mutant mice die during embryonic development due to defective vascularization. Heterozygous mutant mice aged 6 and 12 months were morphologically and (immuno)histochemically indistinguishable from wild-type mice. We show that the mutant allele is degraded by nonsense mediated mRNA decay, expected to result in haploinsufficiency of the mutant allele. Since this haploinsufficiency model does not result in cardiovascular malformations, it does not allow further study of the process of aneurysm formation. In addition to providing a comprehensive method for cardiovascular phenotyping in mice, the results of this study confirm that haploinsuffciency is not the underlying genetic mechanism in human LDS