CBCT Guided Markerless SBRT for Renal Cell Cancer

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.

• Evaluate the current treatment, including the benefit of online adaptive radiotherapy [Срок оценки: 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 [Срок оценки: 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 [Срок оценки: Baseline (pre-treatment) and follow-up at 3, 6, and 12 months after completion of treatment]
• Change From Baseline in Tumor Iodine Concentration on Photon-Counting CT [Срок оценки: Baseline (pre-treatment) and follow-up at 3, 6, and 12 months after completion of treatment]