This study aims to improve the treatment of kidney tumors using radiotherapy, by investigating whether kidney cancer can be more effectively irradiated with the help of new imaging techniques
In total 40 patients will be treated for RCC using SBRT. For 15 patients, additional breath-hold CBCT scans will be made during SBRT to investigate the intra- and inter-fraction uncertainty in breath-hold positions as well as assessing the feasibility of using surface guidance as a surrogate for target position. Subsequently, 25 patients will be treated using the new motion management technique developed using the extra imaging data obtained from the first cohort of patients. It is hypothesized that either breath-hold or gating in combination with surface guidance will result in a reproducible (stable) position of the target and therefore minimal margins.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
40
Additional imaging will be done using CT, therefore the patient will receive additional radiation dose
Reduction of renal dose
The primary aim of this project is to minimize treatment margins, reducing the PTV, to optimally preserve renal function, while ensuring adequate tumor coverage as well as adhering to dose constraints of OARs. Primary endpoint of this study is the reduction of dose to the healthy ipsilateral kidney, defined as the ipsilateral renal volume receiving 50% of the prescribed dose (V50%).
Time frame: At day 1 planning CTs are acquired for treatment planning. These scans will be used to make a treatment planning with standard motion management and a treatment planning will be made using novel motion management. Both plans will be compared.
Evaluate the current treatment, including the benefit of online adaptive radiotherapy
The possible benefit of online adaptive radiotherapy will be assessed by doing an offline analysis by comparing target coverage in % between adapted and non-adapted, original plans
Time frame: Day 1 planning CTs. Approximately day 14: start radiotherapy (3 times per week). At each fraction: CBCT. At completion of treatment (at approximately day 30) planning for adapted and non-adapted plans
Investigate treatment fraction reduction
the feasibility of transitioning from a 5×8 Gy schedule to 3×14 Gy or 1×26 Gy will be investigated by simulating the difference in the mean number of fractions when using SoC motion management and the novel motion management
Time frame: At day 1 planning CTs are acquired for treatment planning. These will be used for treatment planning for simulated fraction schedules using standard and novel motion management
Change From Baseline in Tumor Contrast Enhancement on Photon-Counting CT
Tumor contrast enhancement measured on contrast-enhanced photon-counting CT scans. Enhancement values will be quantified within the treated lesion and reported as change from baseline.
Time frame: Baseline (pre-treatment) and follow-up at 3, 6, and 12 months after completion of treatment
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Change From Baseline in Tumor Iodine Concentration on Photon-Counting CT
Iodine concentration quantified within the treated lesion using material decomposition from contrast-enhanced photon-counting CT scans. Values will be reported as change from baseline.
Time frame: Baseline (pre-treatment) and follow-up at 3, 6, and 12 months after completion of treatment