[Intensity modulation in breast radiotherapy: development of an innovative field-in-field technique at Institut Gustave-Roussy]. / Modulation d'intensité en radiothérapie mammaire : développement d'une méthode innovante de champ dans le champ à l'institut Gustave-Roussy.

PURPOSE: To assess the potential dosimetric gain of presegmentation modulated radiotherapy (OAPS, DosiSoft™) of breast, compared to routine 3D conformal radiotherapy. PATIENTS AND METHODS: Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm(3); range [100-1049 cm(3)]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the presegmentation algorithm of DosiSoft™ (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V30 Gy for the heart, and mean dose, V20 Gy and V30 Gy for lungs. RESULTS: Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P<0,0001). For heart and lung, OAPS decreased irradiation (mean cardiac dose 1,3 vs 1,6 Gy [P<0,0001] and pulmonary V20 Gy 6,6 vs 7,1 [P<0,0001]). CONCLUSION: OAPS (DosiSoft™) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk.

[Early breast cancer without axillary lymph node involvement]. / Cancer du sein sans atteinte ganglionnaire axillaire.

Breast cancer is the most common cancer in women. In France, breast cancer incidence was 88.9 per 100,000 women in 2000. Early detection of breast tumours by screening mammography allows a breast conserving treatment, i.e., breast irradiation preceded by a lumpectomy and a sentinel node biopsy. The standard irradiation of early breast cancers consists in delivering 50 Gy to the whole breast in 2 Gy fractions over a five-week period followed by an additional dose targeting the tumour bed of 16 Gy in eight fractions. The 3D-conformal treatment planning optimizes dose distribution to the whole breast and to the tumour bed and lessens the normal tissue irradiation (heart and ipsilateral lung). The aim of this article is to describe epidemiologic, radio anatomic and prognostic features of early stage breast cancer and to propose guidelines for 3D-conformal treatment planning in early breast cancers. This review is illustrated by a case report.

[Breast cancer with axillary lymph node involvement]. / Cancer du sein avec atteinte ganglionnaire axillaire.

Breast cancer is the most frequent cancer of women in western countries. There are one million new cases per year in the world which represents 22% of all female cancers, and more than 370,000 deaths due to breast cancer per year (14% of cancer mortality). More than half of breast cancers are associated with axillary nodal involvement. Post-operative radiation therapy (XRT) is a crucial part of locoregional treatment in axillary nodal involvement breast cancer owing to a 15-years risk reduction of locoregional recurrence of 70% and to a 5.4% risk reduction of specific mortality. In 3D-conformal irradiation in such breast cancers, target volumes are chest wall when mastectomy was performed or breast and boost of tumor bed in case of breast conservative surgery, and supra-clavicular and/or axillary and/or internal mammary node areas. The main organs at risk are ipsilateral lung, heart and brachial plexus. The aim of this article is to describe epidemiologic, radio anatomic and prognostic features of axillary nodal involvement breast cancer and to propose guidelines for 3D-conformal treatment planning in locally advanced breast cancers. This review is illustrated by a case report.

[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.

[Intensity modulated radiotherapy for cancers of the upper aerodigestive tract]. / Radiothérapie conformationnelle avec modulation d'intensité pour les cancers des voies aérodigestives supérieures.

Intensity-modulated radiotherapy (IMRT) is a new high precision radiotherapy technique, allowing to protect some normal tissues without compromising the tumour cure probability. This is a more complex and more costly technique, compared to conventional radiotherapy, which needs increased quality assurance programs. The early results obtained in head-and-neck carcinomas have been very promising but would need to be confirmed in randomised trials to determine whether these results can be transposed to the majority of these cancers and especially to locally advanced cases, which are the most frequently occurring forms of these cancers.