TY - JOUR
T1 - Lower urinary tract sub-structures as predictors of late urinary toxicity in concurrent chemo-radiotherapy for anal cancer
AU - Storm, Katrine S.
AU - Spindler, Karen Lise G.
AU - Persson, Gitte F.
AU - Kronborg, Camilla
AU - Serup-Hansen, Eva
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/3
Y1 - 2025/3
N2 - Background and purpose: Late toxicity is substantial after chemotherapy for anal cancer. This study aimed to investigate the relationship between radiation dose to lower urinary tract sub-structures and the risk of late urinary toxicities, in patients with anal cancer treated with chemoradiotherapy or radiotherapy. Materials and methods: From 2015 to 2021, 314 patients with localized anal cancer were included in a national prospective registration study. Urinary toxicity (CTCAE) was scored during treatment (acute toxicity) and at one- and three-years follow-up (late toxicity). Lower urinary tract sub-structures (bladder, bladder neck, bladder trigone, and urethra) were contoured post-hoc on the planning-CT and dosimetric variables extracted. Logistic regression was used to evaluate the association between clinical and dosimetric variables and registered toxicity. Results: There was an increase in late toxicity from baseline of 15 % for both urgency and frequency, and 25 % for incontinence. The most common late toxicity was urinary frequency, with 40 % of patients experiencing grade 1 and 2 % experiencing grade 2 toxicity. A dose–effect relationship was found for late urinary urgency and increasing D0.1 cm3 of the urethra (p = 0.01). Increased late urinary frequency was correlated to increasing D2cm3 of the urethra (p = 0.007), and bladder neck V30Gy (p = 0.03). Patients with acute toxicity had up to three times increased risk of corresponding late toxicity. Conclusion: We found a significant dose–effect relationship between radiation dose to urethra and bladder neck and late urinary toxicity. These findings warrant more focus on these structures when optimizing radiotherapy for anal cancer. Furthermore, a strong association between having acute toxicity and developing late toxicity was shown.
AB - Background and purpose: Late toxicity is substantial after chemotherapy for anal cancer. This study aimed to investigate the relationship between radiation dose to lower urinary tract sub-structures and the risk of late urinary toxicities, in patients with anal cancer treated with chemoradiotherapy or radiotherapy. Materials and methods: From 2015 to 2021, 314 patients with localized anal cancer were included in a national prospective registration study. Urinary toxicity (CTCAE) was scored during treatment (acute toxicity) and at one- and three-years follow-up (late toxicity). Lower urinary tract sub-structures (bladder, bladder neck, bladder trigone, and urethra) were contoured post-hoc on the planning-CT and dosimetric variables extracted. Logistic regression was used to evaluate the association between clinical and dosimetric variables and registered toxicity. Results: There was an increase in late toxicity from baseline of 15 % for both urgency and frequency, and 25 % for incontinence. The most common late toxicity was urinary frequency, with 40 % of patients experiencing grade 1 and 2 % experiencing grade 2 toxicity. A dose–effect relationship was found for late urinary urgency and increasing D0.1 cm3 of the urethra (p = 0.01). Increased late urinary frequency was correlated to increasing D2cm3 of the urethra (p = 0.007), and bladder neck V30Gy (p = 0.03). Patients with acute toxicity had up to three times increased risk of corresponding late toxicity. Conclusion: We found a significant dose–effect relationship between radiation dose to urethra and bladder neck and late urinary toxicity. These findings warrant more focus on these structures when optimizing radiotherapy for anal cancer. Furthermore, a strong association between having acute toxicity and developing late toxicity was shown.
KW - Anal cancer
KW - Concurrent radiotherapy
KW - NTCP models
KW - Predictors of toxicity
KW - Urinary toxicity
UR - http://www.scopus.com/inward/record.url?scp=85214587049&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2025.110708
DO - 10.1016/j.radonc.2025.110708
M3 - Journal article
C2 - 39761919
AN - SCOPUS:85214587049
SN - 0167-8140
VL - 204
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
M1 - 110708
ER -