Inverse Relationship Between Biochemical Outcome and Acute Toxicity After Image-Guided Radiotherapy for Prostate Cancer

详细信息	查看全文 | 推荐本文 |

• 作者：Danny Vesprini ; M.D.^&lowast ; ; ^&dagger ; ; Charles Catton ; M.D.^&lowast ; ; Lindsay Jacks ; M.Sc.^&Dagger ; ; Gina Lockwood ; M.Math^&Dagger ; ; Tara Rosewall ; M.Sc.^&lowast ; ; Andrew Bayley ; M.D.^&lowast ; ; Peter Chung ; M.B.^&lowast ; ; Mary Gospodarowicz ; M.D.^&lowast ; ; Cynthia Mé ; nard ; M.D.^&lowast ; ; Michael Milosevic ; M.D.^&lowast ; ; Alan Nichol ; M.D.^&lowast ; ; Marketa Skala ; M.D.^&lowast ; ; Padraig Warde ; M.B.^&lowast ; ; Robert G. Bristow ; M.D. ; Ph.D.^&lowast ; ; ^{robert.bristow@rmp.uhn.on.ca}
• 关键词：IGRT ; Prostate cancer ; Toxicity ; Radiosensitivity
• 刊名：International Journal of Radiation Oncology*Biology*Physics
• 出版年：2012
• 期刊代码：136_03603016
• 类别：med
• 出版时间：1 June, 2012
• 卷：83
• 期：2
• 页码：608-616
• 文件大小：329 K

摘要

| Figures/TablesFigures/Tables | ReferencesReferencesml version="1.0" encoding="UTF-8"?>

Purpose

Prostate cancer patients exhibit variability in normal tissue reactions and biochemical failure. With the use of image-guided radiotherapy (IGRT), there is a greater likelihood that the differences in normal tissue and tumor response are due to biological rather than physical factors. We tested the hypothesis that prospectively scored acute toxicity is associated with biochemical failure-free rate (BFFR) in prostate cancer patients treated with IGRT.

Methods and Materials

We retrospectively analyzed BFFR in 362 patients with localized prostate cancer treated with IGRT. We compared BFFR with prospectively collected Radiation Therapy Oncology Group (RTOG) maximum acute gastrointestinal (GI) and genitourinary (GU) toxicity scores. Median follow-up for all patients was 58.3 months after total radiotherapy doses of 75.6-79.8 Gy.

Results

Patients reporting RTOG acute GU or GI toxicity scores of 鈮? were considered 鈥渟ensitive鈥?(m>nm> = 141, 39%) and patients reporting scores <2 were considered 鈥渘onsensitive鈥?(m>nm> = 221, 61%). When calculating biochemical failure (BF) using the American Society for Therapeutic Radiology and Oncology definition at 5 years, 76%(CI 70-82%) of the 鈥渘onsensitive鈥?patients were failure free, compared with only 53%(CI 43-62%) of the 鈥渟ensitive鈥?patients (log-rank test, m>pm> < 0.0001). This difference was also observed using the Phoenix definition; 鈥渘onsensitive鈥?5-year BFFR was 81%(CI 74-86%) vs. 鈥渟ensitive鈥?BFFR was 68%(CI 58-76%; log-rank test m>pm>聽= 0.0012). The difference in BF between cohorts remained significant when controlled for radiation dose (75.6 vs. 79.8 Gy), prognostic stratification (T category, prostate-specific antigen, and Gleason score), and prostate volume.

Conclusions

This study unexpectedly shows that prostate cancer patients who develop 鈮rade 2 RTOG acute toxicity during radiotherapy are less likely to remain BFF at 5 years. These results deserve further study and, if validated in other large IGRT cohorts, additional models would be required to study interaction between normal tissue and tumor biology in prostate cancer patients.