Delineating and sparing the ileal conduit in adjuvant radiotherapy for bladder cancer with modulated radiotherapy

Purpose: We undertook a prospective planning study to describe the delineation of ileal conduit (IC) loop on radiotherapy planning computed tomography (RTP CT) scan as an organ at risk (OAR) and its sparing using volumetric modulated arc therapy (VMAT) during adjuvant irradiation of bladder malignancies.

Materials and Methods: Fifteen patients with bladder malignancy needing adjuvant radiotherapy postoperatively and having normal renal function underwent delayed phase RTP CT from June 2020 to March 2021, with certain modifications (Foley's catheter through stoma, additional delayed scans). We identified the course of ureters, external stoma, IC, and uretero-ileal (right and left) anastomotic sites. VMAT plans were generated.

Results: A step-by-step description is given. Genitourinary OARs include kidneys, ureters, uretero-ileal anastomoses, and IC. The contrast on delayed scan opacifies ureters and IC. IC can be seen three-dimensionally as a structure with two fixed ends (blind proximal end anterior to the right sacroiliac joint and the open distal end over the right anterior abdominal wall in parasagittal location) and a 15-20 cm hanging intraabdominal loop that lies adjacent to the right iliac vessels. For prescription doses (PD) of 50.4 gray and 54 gray, respectively, VMAT plan achieved IC dose maximum to less than PD and V50 lower than 10 cc. Stoma sparing traditionally used as a surrogate for IC sparing is insufficient due to the variable intraabdominal location of IC loop.

Conclusions: Delineation of IC as an OAR is feasible with slight modifications in the RTP protocols. VMAT (or other forms of intensity modulated radiation therapy) can help IC sparing and should be considered when it lies in close proximity to target volumes and the risk of additional morbidity is considerable.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:19

Enthalten in:

Journal of cancer research and therapeutics - 19(2023), 3 vom: 20. Apr., Seite 731-737

Sprache:

Englisch

Beteiligte Personen:

Goyal, Shikha [VerfasserIn]
Vias, Poorva [VerfasserIn]
Periasamy, Kannan [VerfasserIn]
Madan, Renu [VerfasserIn]
Trivedi, Gaurav [VerfasserIn]
Devana, Sudheer Kumar [VerfasserIn]
Prashar, Himani [VerfasserIn]
Khosla, Divya [VerfasserIn]

Links:

Volltext

Themen:

Cystectomy
Intensity modulated
Journal Article
Organs at risk
Radiotherapy
Urinary bladder neoplasms
Urinary diversion

Anmerkungen:

Date Completed 02.11.2023

Date Revised 02.11.2023

published: Print

Citation Status MEDLINE

doi:

10.4103/jcrt.jcrt_1843_21

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM359710581