Image-guided radiation therapy produces lower acute and chronic gastrointestinal and genitourinary toxicity in prostate cancer patients.

Purpose: This paper compares individual radiation therapy techniques used for prostate cancer and their benefits in clinical practice.

Methods: We retrospectively analyzed 921 patients with localized prostate tumors treated between 1997 and 2012. We divided the patients into four groups according to the selected treatment technique (conformal radiation therapy [3DCRT], intensity-modulated radiation therapy [IMRT], image-guided radiation therapy [IGRT], and volumetric-modulated arc therapy [VMAT]) and evaluated the incidence of acute and chronic gastrointestinal (GI) and genitourinary (GU) toxicity.

Results: The incidence of grade 2 or greater acute GU and GI toxicity was significantly higher among techniques other than IGRT (p˂0.001). We found the same results in the case of grade 3 or greater acute GU toxicity (p˂0.001). Grade 3 or higher acute GI toxicity occurred only in one patient treated by 3DCRT. Cumulative late GI toxicity of grade 2 or higher and grade 3 or higher was recorded over 3 years significantly more frequently among non-IGRT techniques as compared to IGRT (p˂0.001). As regards GU toxicity, we found significantly higher incidence only for grade 2 or higher (p˂0.001), not for grade 3 or higher. No occurrence of grade 4 toxicity was recorded. The greatest incidence of patients without acute and chronic GI/GU toxicity was recorded in connection with VMAT.

Conclusion: IGRT demonstrated a pronounced reduction in acute and chronic GU and GI toxicity as compared to non-IGRT techniques in the treatment of localized prostate cancer.