Brachytherapy pros and cons and long term side effects

Please can you advise my partner 55 has been recently diagnosed with prostate cancer Gleason 4+3 =7 T3 confined he has been offered prostate removal or brachytherapy seeds please can anyone let me know the pros and cons for both my main concern is secondary cancer bowel and bladder is this common with brachytherapy?  Anyones experiences of both surgeries would be welcome.  Thanks