The role of image-guided radiotherapy in prostate cancer: A systematic review and meta-analysis

Image-guided radiotherapy (IGRT) has gradually been widely promoted in clinical procedure. However, there has been no consensus on the effects of IGRT on toxicity and survival, and no clear level 1 evidence has even been promulgated.

Medline, EMBASE, PubMed, Cochrane databases and ClinicalTrials.gov were searched for studies comparing IGRT vs non-IGRT or higher frequency IGRT vs lower frequency IGRT during prostate radiotherapy, indexed from database inception to April 2022.

The review included 18 studies (3 randomized clinical trial and 15 cohort studies) involving 6521 men, with a median duration of patient follow-up of 46.2 months in the IGRT group vs 52.7 months in the control group. The meta-analysis demonstrated that IGRT significantly reduced acute GU (risk ratio [RR], 0.78; 95 % confidence interval [CI], 0.69-0.88; P < 0.001 [9 studies]) and GI toxicity (RR, 0.49; 95 % CI, 0.35-0.68; P < 0.001 [4 studies]) and late GI toxicity (HR, 0.25; 95 % CI, 0.07-0.87; P = 0.03 [3 studies]) compared with non-IGRT. Meanwhile, compared with prospective studies, retrospective studies showed that IGRT had a more significant effect in reducing the late GI toxicity. Compared with non-daily IGRT, daily IGRT significantly improved 3-year PRFS (HR, 0.45; 95 % CI, 0.28-0.72; P = 0.001 [2 studies]) and BFFS (HR, 0.57; 95 % CI, 0.39-0.83; P = 0.003 [3 studies]). Furthermore, high-frequency daily IGRT could lead to greater 3-year BFFS benefit in prostate cancer patients than weekly IGRT. However, no significant effects of IGRT on acute rectal toxicity, late GU toxicity, 5-year OS and SCM were found.

For men receiving prostate radiotherapy, IGRT was associated with an improvement in biochemical tumor control and a reduction in GI and acute GU toxicity, but did not significantly improve 5-year OS or increase 5-year SCM.