Abstract
Background and aimsTwo-opposing photon beams are considered standard of care for flank irradiation in pediatric patients with renal tumors. Nowadays, Image-Guided Radiotherapy (IGRT) techniques allow high-precision dose delivery to complex flank target volumes taking into account postoperative organ shifts and tumor bed motion. This study examines the contribution of a lateral and superior surgical clip on flank target volume delineation intended for IGRT. MethodsBetween 01-2015 and 09-2019, 30/162 newly-diagnosed pediatric patients with renal tumors, lateral/superior surgical clips (n = 30/30) and available 4D-CT-scans (n = 27/30), underwent postoperative flank irradiation. The lateral and superior clip, as respective markers for the lateral tumor extension and intrafraction motion, were analyzed. The positive and negative values depict the lateral/dorsal/cranial or the medial/ventral/caudal direction, respectively. Planning target volumes (PTV) were generated based on lateral clips (PTVlatclip), superior clips with 4D-CT technology (PTVsupclip), and both clips combined (PTVcombined), and compared to an approach without clips (PTVnoclip). ResultsIndicated by clips, the mean lateral tumor bed extension along the posterior wall was 74° (range: 50°–93°), while mean intrafraction motion was +1.2 mm (range: −1.8/+4.8 mm), +0.6 mm (range: +0.6/+4.9 mm), −0.3 mm (range: −3.8/+0.7 mm) in craniocaudal, ventrodorsal, mediolateral direction, respectively. The median PTVnoclip (556 mL) was statistically different from the median PTVlatclip (454 mL, p = <0.01), median PTVsupclip (373 mL, p = <0.01) and median PTVcombined (348 mL p = <0.01). ConclusionIn pediatric patients with renal tumors, surgical clips at the lateral and superior border of the tumor bed can optimize flank target volume delineation and, consequently, reduce the normal tissue volume receiving high-dose irradiation when IGRT techniques are applied.
Highlights
Background and aimsTwo-opposing photon beams are considered standard of care for flank irradiation in pediatric patients with renal tumors
This study aims to define the contribution of a lateral and a superior clip on the flank target volume delineation intended for Image-Guided Radiotherapy (IGRT)
The current study demonstrates that the application of surgical clips significantly reduces the target volume for highly-conformal flank irradiation by IGRT
Summary
Background and aimsTwo-opposing photon beams are considered standard of care for flank irradiation in pediatric patients with renal tumors. Image-Guided Radiotherapy (IGRT) techniques allow high-precision dose delivery to complex flank target volumes taking into account postoperative organ shifts and tumor bed motion. Methods: Between 01-2015 and 09-2019, 30/162 newly-diagnosed pediatric patients with renal tumors, lateral/superior surgical clips (n = 30/30) and available 4D-CT-scans (n = 27/30), underwent postoperative flank irradiation. Results: Indicated by clips, the mean lateral tumor bed extension along the posterior wall was 74° (range: 50°–93°), while mean intrafraction motion was +1.2 mm (range: À1.8/+4.8 mm), +0.6 mm (range: +0.6/ +4.9 mm), À0.3 mm (range: À3.8/+0.7 mm) in craniocaudal, ventrodorsal, mediolateral direction, respectively. Conclusion: In pediatric patients with renal tumors, surgical clips at the lateral and superior border of the tumor bed can optimize flank target volume delineation and, reduce the normal tissue volume receiving high-dose irradiation when IGRT techniques are applied.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
