[Role of stereotactic radiotherapy in the treatment of oligometastatic colorectal cancer]. / Place de la radiothérapie (cancer primitif, métastases) dans la prise en charge des patients atteints d'un cancer oligométastatique : cancer colorectal.

Stereotactic radiotherapy is used for patients with oligometastases from colorectal cancer. It results in good local tumour control, especially for hepatic and pulmonary metastases, subject to a sufficiently high biologically effective dose, and is well-tolerated. It can be associated with other local treatments such as surgery or radiofrequency as part of combined treatments, in order to increase patient survival.

Quantitative mathematical modeling of clinical brain metastasis dynamics in non-small cell lung cancer.

Brain metastases (BMs) are associated with poor prognosis in non-small cell lung cancer (NSCLC), but are only visible when large enough. Therapeutic decisions such as whole brain radiation therapy would benefit from patient-specific predictions of radiologically undetectable BMs. Here, we propose a mathematical modeling approach and use it to analyze clinical data of BM from NSCLC. Primary tumor growth was best described by a gompertzian model for the pre-diagnosis history, followed by a tumor growth inhibition model during treatment. Growth parameters were estimated only from the size at diagnosis and histology, but predicted plausible individual estimates of the tumor age (2.1-5.3 years). Multiple metastatic models were further assessed from fitting either literature data of BM probability (n = 183 patients) or longitudinal measurements of visible BMs in two patients. Among the tested models, the one featuring dormancy was best able to describe the data. It predicted latency phases of 4.4-5.7 months and onset of BMs 14-19 months before diagnosis. This quantitative model paves the way for a computational tool of potential help during therapeutic management.

[Adaptive radiotherapy in routine: The radiation oncologist's point of view]. / Radiothérapie adaptative en routine : point de vue de l'oncologue radiothérapeute.

Adaptive radiotherapy is defined as all processes leading to the modification of a treatment plan on the basis of patient-specific variations observed during the course of a treatment. This concept is currently of particular relevance due to the development of onboard volumetric imaging systems, which allow for daily viewing of variations in both tumour and organs at risk in terms of position, shape or volume. However, its application in routine clinical practice is limited due to the demanding nature of the processes involved (re-delineation and replanning) and increased dependence on available human resources. Even if "online" strategies, based on deformable image registration (DIR) algorithms, could lead to a reduction in both work and calculation time, for the moment their use is limited to the research field due to uncertainties surrounding the validity of results gathered. Other strategies without DIR can be used as "offline" or "hybrid offline-online" strategies that seem to offer a compromise between time consumption and therapeutic gain for the patient.