Risk for second bladder and rectal malignancies from cervical cancer irradiation

Abstract

The objective of this study was to estimate the risk of developing second malignancies to partially in-field organs from volumetric modulated arc therapy (VMAT) of cervical cancer and to compare the above risks with those from the conventional three-dimensional conformal radiotherapy (3D-CRT). Seventeen consecutive patients with uterine cervix carcinoma were selected. VMAT and 3D-CRT plans were generated with 6 and 10 MV photons, respectively. The prescribed tumor dose was 45 Gy given in 25 fractions. Differential dose-volume histogram data from the treatment plans were obtained for the partially in-field organs such as bladder and rectum. These data were used to estimate the patient-specific lifetime attributable risk (LAR) for bladder and rectal cancer induction with a non-linear model based on a mixture of plateau and bell-shaped dose-response relationships. The estimated risks per 10000 people were compared with the baseline risks for unexposed population.The patient-specific rectal cancer risk estimates from VMAT were significantly lower than those from 3D-CRT (P = 0.0144). The LARs for developing bladder malignancies from VMAT were significantly high compared to those from conventional irradiation (P = 0.0003). The mean difference between the patient-specific LARs for radiation-induced bladder and rectal malignancies as derived from 3D-CRT and VMAT plans was 6.6% and 2.0%, respectively. The average LAR for developing bladder and rectal malignant diseases due to VMAT was 9.2 × 10 -4 and 43.7 × 10 -4 , respectively. The corresponding risks following 3D-CRT were 8.6 × 10 -4 and 44.6 × 10 -4 . These average risks showed that pelvic irradiation increases the baseline probability for cancer induction by 12.6-19.1%. The differences in the second cancer risks associated with the VMAT and 3D-CRT for cervical cancer were found to be small. Both treatment techniques resulted in considerable increased probabilities for developing bladder and rectal malignancies relative to those of unirradiated population.

Efeitos Colaterais Sofridos Por Pacientes Submetidas À Radioterapia Por Câncer De Colo De Útero: Uma Revisão De Literatura

“…Outro ponto encontrado foi o desenvolvimento de tumores induzidos por radiação, tardios em relação ao período de exposição à radiação, com destaque às neoplasias de reto e de bexiga, porém com informações ainda escassas relacionadas ao assunto (MAZONAKIS et al, 2021;NADOVA et al, 2021).…”

Advanced Bladder Cancer: Changing the Treatment Landscape

“…Arsenic in drinking water has been associated with bladder cancer in several geographic regions. Radiotherapy for pelvic organs (prostate, rectum, and uterus) has been demonstrated to increase the risk of BC [ 3 , 4 ]. Chronic bladder irritation and infection such as the presence of bladder stones, continuously indwelled bladder catheter, and schistosomiasis (mainly in Africa and the Middle East) have been associated with the increased risk of bladder squamous cell cancer.…”