Intra-rectal use of epinephrine in radiotherapy of prostate cancer

Abstract

Shang-Bin Qin,1 Xian-Shu Gao,1 Hong-Zhen Li,1 Chao-Xing Liu,2 Dong-Liang Hou,3 Wei-Dong Nian,4 Xue-Ying Li,5 Dian Wang61Department of Radiation Oncology, Peking University First Hospital, Beijing, People’s Republic of China; 2Department of Radiation Oncology, Shijiazhuang City First Hospital, Shijiazhuang, People’s Republic of China; 3Department of Radiation Oncology, Beijing Shijitan Hospital, Beijing, People’s Republic of China; 4Department of General Surgery, Peking University First Hospital, Beijing, People’s Republic of China; 5Department of Medical Statistics, Peking University First Hospital, Beijing, People’s Republic of China; 6Department of Radiation Oncology, Rush University Medical Center, Chicago, IL, USAPurpose: The aim of the study was to evaluate the feasibility and toxicity of intra-rectal epinephrine during prostatic radiotherapy.Materials and methods: A total of 34 patients with prostate cancer were randomized to receive daily intra-rectal epinephrine (4 mg in 40 mL, n=16) or placebo (40 mL normal saline, n=18) 5 min before daily radiotherapy. Physical examination including systolic blood pressure (SBP) and heart rate (HR) was performed before, 5 min after, and 20 min after intra-rectal use. Toxicities were graded using the Radiation Therapy Oncology Group standard. A two-sided Fisher’s exact test was used to compare proportions between groups. A mixed-effects model was used to analyze multiple measurements of SBP and HR. Survival curves were calculated using the Kaplan–Meier method and compared between groups using the log-rank test.Results: All patients completed the protocol treatment and reported no cardiovascular symptoms after intra-rectal administration. There were no differences in SBP and HR between these two groups at any time point (before, 5 min after, and 20 min after epinephrine). At 5 weeks after the start of radiotherapy, the incidence of rectal toxicity≥grade 2 was 27.8% (5/18) for the control group versus 12.5% (2/16) for the epinephrine group, but was not statistically significant (p=0.4). There was no rectal toxicity≥grade 2 in these two groups beyond 2-year follow-up. The 5-year biochemical relapse-free survival was 75.0% and 72.2% for the epinephrine and control group, respectively.Conclusion: Results of this pilot randomized trial have demonstrated that intra-rectal administration of epinephrine is feasible and safe in prostatic radiotherapy. Its radio-protective effect warrants further investigation.Keywords: radiation proctitis, epinephrine, radiotherapy

Keywords

• Radiation Proctitis
• Epinephrine
• Radiotherapy