Impact of prostate position-based image-guidance in intensity-modulated radiation therapy for localized prostate cancer

• Published in: International journal of clinical oncology Vol. 29; no. 3; pp. 325 - 332
• Main Authors: Aizawa, Rihito, Inokuchi, Haruo, Ikeda, Itaru, Nakamura, Kiyonao, Ogata, Takashi, Akamatsu, Shusuke, Goto, Takayuki, Masui, Kimihiko, Sumiyoshi, Takayuki, Kita, Yuki, Kobayashi, Takashi, Mizowaki, Takashi
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.03.2024; Springer Nature B.V
• Subjects: Bleeding; Cancer Research; Clinical outcomes; Computed tomography; Disease control; Humans; Male; Medicine; Medicine & Public Health; Oncology; Original Article; Prostate; Prostate cancer; Prostatic Neoplasms - radiotherapy; Radiation therapy; Radiotherapy, Image-Guided - adverse effects; Radiotherapy, Intensity-Modulated - adverse effects; Rectum; Retrospective Studies; Surgical Oncology; Intensity-modulated radiation therapy; Biochemical tumor control; Image-guided radiotherapy; Late toxicity; Prostate cancer
• ISSN: 1341-9625; 1437-7772; 1437-7772
• DOI: 10.1007/s10147-023-02456-1

Background/purpose The long-term clinical impact of prostate position-based image-guided radiotherapy (IGRT) for localized prostate cancer remains unclear. Materials and methods We retrospectively compared clinical outcomes following intensity-modulated radiation therapy (IMRT) with cone-beam computed tomography-based prostate position-based IGRT (P-IGRT) or without P-IGRT (non-P-IGRT). From June 2011, we applied P-IGRT in IMRT for intermediate-risk (IR) prostate cancer (PCa) (D’Amico risk classification) (76 Gy in 38 fractions, with smaller margins). Clinical outcomes of patients who received P-IGRT between June 2011 and June 2019 were retrospectively compared with those of patients with IR PCa who received IMRT without P-IGRT between October 2002 and May 2011 in our institution (74 Gy in 37 fractions). Results A total of 222 consecutive patients were analyzed: 114 in the P-IGRT cohort and 108 in the non-P-IGRT cohort. The median follow-up period after IMRT was 7.1 years for the P-IGRT cohort and 10.8 years for the non-P-IGRT cohort. The biochemical failure-free rate was significantly better in the P-IGRT cohort (94.9% for the P-IGRT cohort vs 82.7% for the non-P-IGRT cohort at 10 years, p  = 0.041). The rate of rectal bleeding which needs intervention including the use of suppositories was significantly lower in the P-IGRT cohort ( p  < 0.001). Conclusions The use of P-IGRT with higher doses and smaller margins was correlated with significantly better biochemical control, and a lower incidence of rectal bleeding in IMRT for intermediate-risk prostate cancer. The enhanced accuracy using P-IGRT has the potential to independently improve disease control and reduce late rectal bleeding.