[Accelerated partial breast irradiation for early breast cancer]. / Irradiation partielle accélérée du cancer du sein : aspect théorique.

Hypofractionated and accelerated partial breast irradiation are more and more widely used for early breast cancer. Here, this short communication would expose the role of hypofractionated radiotherapy in adjuvant breast radiotherapy, rational, techniques and indications of accelerated partial breast irradiation.

[Debate about breast cancer: "Cons: Intraoperative radiotherapy"]. / Débats autour du cancer du sein : « contre ¼ la radiothérapie peropératoire.

Early breast cancer incidence increases owing to mammography screening. Hypofractionated radiotherapy is more and more proposed in women with low local relapse risk breast cancer, especially accelerated partial breast irradiation. Various irradiation modalities have been reported: brachytherapy, intraoperative irradiation, 3D-conformal accelerated partial breast irradiation. We describe limitations of intraoperative irradiation and the advantages of alternative techniques.

[Accelerated partial breast irradiation: bifractionated 40Gy in one week. A French pilot phase II study]. / Étude pilote française de phase II d'irradiation partielle accélérée du sein conformationnelle tridimensionnelle bi-fractionnée hebdomadaire de 40Gy.

PURPOSE: Since 2009, accelerated partial breast irradiation (APBI) in North America has been allowed to be used for selected group of patients outside a clinical trial according to the ASTRO consensus statement. In France, accelerated partial breast irradiation is still considered investigational, several clinical trials have been conducted using either intraoperative (Montpellier) or Mammosite(®) (Lille) or brachytherapy modality (PAC GERICO/FNCLCC). Here, we report the original dosimetric results of this technique. PATIENTS AND METHODS: Since October 2007, Institut Gustave-Roussy has initiated a phase II trial using 3D-conformal accelerated partial breast irradiation (40 Gy in 10 fractions BID in 1 week). Twenty-five patients with pT1N0 breast cancer were enrolled and were treated by two minitangent photons beams (6MV) and an "en face" electron beam (6-22 MeV). RESULTS: The mean clinical target volume and planning target volume were respectively 15.1cm(3) (range: 5.2-28.7 cm(3)) and 117 cm(3) (range: 52-185 cm(3)). The planning target volume coverage was adequate with at least a mean of 99% of the volume encompassed by the isodose 40 Gy. The mean dose to the planning target volume was 41.8 Gy (range: 41-42.4 Gy). Dose inhomogeneity did not exceed 5%. Mean doses to the ipsilateral lung and heart were 1.6 Gy (range: 1.0-2.3 Gy) and 1.2 Gy (range: 1.0-1.6 Gy), respectively. CONCLUSION: The 3D conformal accelerated partial breast irradiation using two minitangent and "en face" electron beams using a total dose of 40 Gy in 10 fractions BID over 5 days achieves appropriate planning target volume coverage and offers significant normal-tissue sparing (heart, lung). Longer follow-up is needed to evaluate the tissue tolerance to this radiation dose.

[Conformal radiotherapy of brain tumors]. / La radiothérapie conformationnelle des tumeurs cérébrales.

Conformal irradiation of brain tumours is based on the three-dimensional reconstruction of the targeted volumes and at-risk organ images, the three-dimensional calculation of the dose distribution and a treatment device (immobilisation, beam energy, collimation, etc.) adapted to the high precision required by the procedure. Each step requires an appropriate methodology and a quality insurance program. Specific difficulties in brain tumour management are related to GTV and CTV definition depending upon the histological type, the quality of the surgical resection and the medical team. Clinical studies have reported dose escalation trials, mostly in high-grade gliomas and tumours at the base of the skull. Clinical data are now providing a better knowledge of the tolerance of normal tissues. As for small tumours, the implementation of beam intensity modulation is likely to narrow the gap between conformal and stereotaxic radiotherapy.

rhBMP-collagen sponges as osteoinductive devices: effects of in vitro sponge characteristics and protein pI on in vivo rhBMP pharmacokinetics.

Osteoinductive devices, comprised of biodegradable collagen scaffolds and recombinant human Bone Morphogenetic Proteins (rhBMPs), are being currently pursued for local bone induction. To better understand the biological performance of such devices, we have carried out a series of studies to investigate the effects of sponge properties and protein structural features on the pharmacokinetics of implanted rhBMPs. The results indicated little dependence of the rhBMP-2 pharmacokinetics on the in vitro determined sponge properties. The protein isoelectric point (pI), on the other hand, was found to significantly affect the initial implant retention of rhBMPs, but not the subsequent pharmacokinetics. A 100-fold difference in the implant-retained dose could be observed depending on the type of rhBMP implanted. We conclude that protein structural features are important variables controlling in vivo pharmacokinetics of rhBMPs, and possibly the osteoinductive potency of the devices.