Mechanically-Assisted and Non-Invasive Ventilation for Breathing-related Tumor Motion Mitigation.

Breathing motion still remains a major issue that jeopardizes the accuracy of photon- and proton-therapy for thoracic and upper-abdominal tumors, which represent up to 40% of curative radiotherapy treatments. Existing motion management strategies are either simple and costless but lead to futile irradiation of healthy tissues (safety margins), or complex to implement and expensive, limiting their availability in clinical routine (gating, deep-inspiration breath-hold - DIBH, real-time tracking). In addition, the accuracy and efficiency of all these techniques critically depend on tumor motion/position reproducibility over treatment time, which is often degraded by variations of the spontaneous breathing or voluntary apnea. Finally, these techniques are not easily transferrable to proton therapy (PT) in the presence of proton range uncertainties in moving anatomy. Therefore, we propose an innovative workaround to overcome these complex issues, namely, Mechanically-Assisted and Non-Invasive Ventilation (MANIV). By taking control of the patient's breathing, we previously demonstrated that MANIV can safely regularize and even reduce tumor motion using a volume-controlled ventilation mode (VC), while a slow ventilation mode (SL) can induce repeated DIBH during which the tumor motion is nearly suppressed. Although promising, we have to go a step further into the prospective clinical validation of MANIV applied to existing motion management techniques. A. Preclinical phase: 1. Clinical implementation of MANIV: development of technical solutions to integrate MANIV at each stage of a patient's clinical workflow in our radiotherapy department. 2. In-house validation and optimization of experimental mathematical models to compute the trajectory and amplitude of residual tumor motion during treatment delivery. B. Clinical phase: 1. Optimization of Respiratory Gating by reproducing repeated and stable DIBHs to fix the tumor motion for radiotherapy treatment of lung, liver and breast tumors. 2. Optimization of Tracking procedures by regularizing the breathing and tumor motion with VC mode to reduce the treatment duration for real-time lung and liver tumors tracking on Accuray Cyberknife® robotic mounted LINAC. 3. In silico delivred dose assessment of MANIV-optimized Respiratory Gating by Pencil Beam Scanning Proton Therapy (PBS-PT). At the end of this project, we will provide recommendations for the clinical implementation of a wide panel of advanced motion mitigation techniques, which would contribute to a major step forward in the management of breathing motion in both photon and proton-therapy.

Sex

All

Minimum age

18 Years

* Inclusion Criteria:

  1. Validation of the MANIV-optimized gating strategy for breasrt tumors :

     Patients with left breast tumors eligible for radiation therapy with breath hold technique.
  2. Validation of the MANIV optimized Gating strategy for lung/liver tumors:

     Patients with lung (primary or secondary) or liver (primary or secondary) tumors eligible for stereotactic radiation therapy.
  3. Validation of the MANIV-optimized Tracking strategy for liver tumors:

     Part 1: Patients with hepatic neoplasia (primary or secondary) eligible for stereotactic radiation therapy on the Cyberknife® of the Oscar Lambret center in Lille (France)..

     Part 2: Patients with hepatic neoplasia (primary or secondary) treated by respiratory tracking on the Cyberknife® of the Oscar Lambret center in Lille (France).

  4 - Evaluation of a proton therapy treatment delivered in silico to mobile tumors with MANIV in DIBH mode : Patients included in the study on the optimization of the Gating strategy.
* Exclusion Criteria:

  * history of spontaneous pneumothorax