Evaluation of the ExacTrac® Imaging Device for the Repositioning Quality of Patients Undergoing an External ENT Radiotherapy
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 45
- 试验地点
- 2
- 主要终点
- Verification of the feasibility of using the ExacTrac® system as a replacement for CBCT imaging for pre-treatment repositioning of ENT sphere cancers in adult patients receiving CRMI on a linear accelerator equipped with 2 modalities
研究概览
简要总结
Monocentric, category 2 study according to Jardé Law (minimal risks and constraints) of three prospective cohorts: Tumors located at the oropharynx, the oral cavity and the larynx-hypopharynx.
The main objective is to evaluate the 3D vector of the absolute residual positioning error observed with the CBCT reference imaging, after repositioning performed with ExacTrac®.
The secondary objectives are to evaluate: 1) the rate of residual errors ≥2mm (translations in all directions) and ≥2 ° (rotations in all directions) on CBCT imaging after repositionning with the ExacTrac® system; 2) the Evaluation of intrafraction movements amplitude by analyzing the ExacTrac® images taken during the irradiation; 3) the evolution of the relative position of the volume of the tumor at high risk of recurrence (CTVTHR) in relation to the spine over the entire duration of the treatment; 4) the impact of patient's weight loss, the advancement of RT and the realization of a chemotherapy / targeted therapy concomitant with RT, on the evolution of the relative position of the CTVTHR in relation to the column vertebral; 5) the dosimetric consequence of a strict bone registration on the CTVTHR coverage by calculating the post-treatment dose on the CBCT imaging.
详细描述
The radiotherapy treatment preparation requires performing a dosimetric scanner (CT) of the patient in the treatment position, with the compression. The repositioning of the ENT sphere can be complex, especially in cases where there is irradiation of the supraclavicular lymph node areas. Indeed, the height of the irradiated area can easily exceed 20cm and it is necessary to ensure a good reproducibility of the repositioning of the spine relative to the skull.
At the end of the dosimetric CT, the radiotherapist delineates the macroscopic tumor volume (GTV) as well as the clinical tumor target volumes (CTVT) and lymph nodes (CTVN), which take into account the infiltration risks of the tissue around the macroscopic tumor. Margins around the VCTs then make it possible to obtain the estimated PTV target volumes (T and N), defined so that the VCTs receive the prescribed dose despite the geometric uncertainties associated with the treatment. Contours of organs at risk (OAR) are also carried out on the dosimetric CT. Margins around the most critical OARs (eg: marrow, brainstem, chiasma and optic nerves) are then added to generate predictive target volumes of organs at risk (PRV), taking into account the geometric uncertainties. These uncertainties are separated into errors in the treatment execution (random) and errors in the treatment preparation (systematic).
Execution errors include repositioning errors, organ movements (overnight), patient anatomical changes, intrafraction movements.
Errors related to treatment preparation include repositioning errors related to patient's skin spotting of the treatment isocenter during the dosimetric CT (thanks to room lasers), errors related to the CT acquisition that sets the CTV in a given position, the CTV delineation errors.
Dosimetry is then carried out taking into account the dose criteria to be respected on the PRVs and PTVs. Whatever the protocol used [Shrinking Action Level (SAL), non-action-level (NAL) or e-NAL (extented NAL)], it must at least make it possible to guarantee that the delivered dose complies with the planned dose. An optimization of the imaging protocol must then be able to reduce the margins without compromising the treatment quality, while reducing its toxicity for the patient.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age ≥ 18 years old
- •Patient requiring an ENT radiotherapy with intensity modulation (IMR) in the oropharynx, oral cavity, hypopharynx or larynx with bilateral irradiation of the lymph node areas
- •Treatment planned on an accelerator equipped with a CBCT and the ExacTract® device
- •Patient affiliated to a social security system
- •Informed consent dated and signed
排除标准
- •Pregnant or breastfeeding woman
- •Patient under totorship, curatorship or legal protection
结局指标
主要结局
Verification of the feasibility of using the ExacTrac® system as a replacement for CBCT imaging for pre-treatment repositioning of ENT sphere cancers in adult patients receiving CRMI on a linear accelerator equipped with 2 modalities
时间窗: Until the end of the radiotherapy treatment
3D vector of the absolute residual positioning error observed with the CBCT reference imaging, after repositioning performed with ExacTrac®
次要结局
- Evolution of the relative position of the volume of the tumor at high risk of recurrence (CTVTHR) in relation to the spine over the entire treatment duration(Until the end of the radiotherapy treatment)
- Evaluation fo the impact of a chemotherapy / targeted therapy performed concomitantly with RT, on the evolution of the relative position of the CTVTHR in relation to the spine(Until the end of the radiotherapy treatment)
- Evaluation of residual errors rates ≥2mm (translations in all directions) and ≥2 ° (rotations in all directions) on CBCT imaging after repositionning with the ExacTrac® system(Until the end of the radiotherapy treatment)
- Evaluation of the impact of patient's weight loss on the evolution of the relative position of the CTVTHR in relation to the spine(Until the end of the radiotherapy treatment)
- Evaluation of the impact of the RT progress on the evolution of the relative position of the CTVTHR in relation to the spine(Until the end of the radiotherapy treatment)
- Evaluation of the dosimetric consequence of a strict bone repositionning on the CTVTHR coverage by calculating the post-treatment dose on the CBCT imaging(Until the end of the radiotherapy treatment)
- Evaluation of intrafraction movements amplitude by analyzing the ExacTrac® images taken during the irradiation(Until the end of the radiotherapy treatment)