Radiotherapy
Interstitial Prostate Brachytherapy
- Implantation of small radioactive sources into the prostate gland
- Recommended initial therapeutic strategy for patients with low-risk prostate cancer
- Difficult to perform in patients with very small or very large prostates, bladder outlet obstruction symptoms, or previous transurethral resection of the prostate (TURP)
- Recommended doses:
- 120 Gy (palladium)
- 140 Gy (125I) with postoperative dosimetry
Low Dose-Rate Brachytherapy
- Uses permanent low-energy seeds (Iodine-125, Palladium-103) for implantation that delivers adequate doses
- Recommended for patients with low-risk disease
- May be given to patients with intermediate risk together with external beam radiation therapy (EBRT)
- Recommended dose:
- Iodine-125: 145 Gy [110 Gy with 40-50 Gy external beam radiation therapy (EBRT)]
- Palladium-103: 125 Gy [90-100 Gy with 40-50 Gy external beam radiation therapy (EBRT)]
High Dose-Rate Brachytherapy
- Uses temporary radioactive sources (eg Iridium-192) inserted into different locations in the prostate gland
- Recommended for patients with intermediate- to high-risk localized or locally advanced prostate cancer
- Usually given together with external beam radiation therapy (EBRT) [40-50 Gy]
- Recommended dose:
- Monotherapy: 13.5 Gy x 2 fractions
- With external beam radiation therapy (EBRT): 9.5-11.5 Gy x 2 fractions; 5.5-7.5 Gy x 3 fractions; 4-6 Gy x 4 fractions
External Beam Radiation Therapy (EBRT)
- Recommended initial therapeutic strategy for patients with low-high risk prostate cancer
- Should be reconsidered in patients with very low-risk prostate cancer with life expectancy of >10-20 years
- Limited radiation fields are preferred over extended field radiotherapy for localized and locally advanced prostate cancer
- Localization of prostate with image-guided radiation therapy (IGRT) is necessary with either 3-dimensional conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) for reducing target margin and ensuring treatment accuracy
- Recommended dose for patients with low-risk prostate cancer is 75.6-79.2 Gy; intermediate- to high-risk and metastatic prostate cancer is 81.0 Gy
Radiopharmaceutical Therapy
- Eg Radium-223 dichloride, ß-emitting agents (Strontium-89, Samarium-153)
- Option for palliative treatment of patients with metastatic disease
Beta-Emitting Radioactive Agents
- Eg Strontium-89 (Sr-89, 89Sr), Samarium-153 (Sm-153, 153Sm)
- Used for treatment of painful bone metastases
Radium-223 dichloride
- An alpha particle-emitting radioactive agent used for metastatic castration-resistant prostate cancer (CRPC) with symptomatic bone metastases but without visceral involvement
- Studies have shown that patients given Radium-223 had better overall survival and time to appearance of symptomatic bone events than those given placebo
- Studies have shown that patients given Radium-223 had better overall survival and time to appearance of symptomatic bone events than those given placebo