The contribution of surgical clips for optimizing highly-conformal image-guided flank irradiation in pediatric renal tumors: A single center experience

Joeri Mul; Cornelis P van de Ven; Enrica Seravalli; Annemieke S Littooij; Marc H W A Wijnen; Martine van Grotel; Marry M van den Heuvel-Eibrink; Geert O Janssens

doi:10.1016/j.radonc.2020.12.010

The contribution of surgical clips for optimizing highly-conformal image-guided flank irradiation in pediatric renal tumors: A single center experience

Radiother Oncol. 2021 Mar:156:62-68. doi: 10.1016/j.radonc.2020.12.010. Epub 2020 Dec 11.

Authors

Joeri Mul¹, Cornelis P van de Ven², Enrica Seravalli³, Annemieke S Littooij⁴, Marc H W A Wijnen², Martine van Grotel², Marry M van den Heuvel-Eibrink², Geert O Janssens⁵

Affiliations

¹ Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands; Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: j.mul-6@prinsesmaximacentrum.nl.
² Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands.
³ Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.
⁴ Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands; Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
⁵ Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands; Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.

PMID: 33310005
DOI: 10.1016/j.radonc.2020.12.010

Abstract

Background and aims: Two-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.

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. 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 (PTV_latclip), superior clips with 4D-CT technology (PTV_supclip), and both clips combined (PTV_combined), and compared to an approach without clips (PTV_noclip).

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: -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 PTV_noclip (556 mL) was statistically different from the median PTV_latclip (454 mL, p = <0.01), median PTV_supclip (373 mL, p = <0.01) and median PTV_combined (348 mL p = <0.01).

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, consequently, reduce the normal tissue volume receiving high-dose irradiation when IGRT techniques are applied.

Keywords: (Pediatric) renal tumors; 4D-CT; Fiducial marker; IGRT; Wilms tumor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Breast Neoplasms*
Child
Four-Dimensional Computed Tomography
Humans
Kidney Neoplasms* / diagnostic imaging
Kidney Neoplasms* / radiotherapy
Kidney Neoplasms* / surgery
Radiotherapy Planning, Computer-Assisted
Radiotherapy, Conformal*
Radiotherapy, Image-Guided*
Surgical Instruments