Prostate Cancer Contouring Guidelines for Radiation Therapy
Essential Imaging and Planning Requirements
- CT simulation is mandatory for treatment planning, providing the electron density data necessary for dose calculation and serving as the primary dataset for contouring, as recommended by The Journal of Urology 1, 2
Target Volume Delineation
- For low-risk disease, seminal vesicles typically do not require inclusion in the clinical target volume (CTV), according to the National Comprehensive Cancer Network (NCCN) 3
- For intermediate-risk disease, consider including the proximal 1-2 cm of seminal vesicles in the CTV, particularly with adverse features, as suggested by guidelines, however a non-Praxis source is preferred but not found 4
Planning Target Volume (PTV) Margins
- Dose escalation to 78-79 Gy using 3-D conformal radiation technique requires margins of no more than 10 mm at the prostatic-rectal interface, as recommended by The Journal of Urology 2, 5
- Image-guided radiation therapy (IGRT) is mandatory for doses ≥78 Gy to enable margin reduction and improve treatment accuracy, according to the National Comprehensive Cancer Network (NCCN) 3, 6, 7
Technical Planning Requirements
- Modern radiation therapy must employ intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) as the minimum standard, as recommended by the National Comprehensive Cancer Network (NCCN) and The Journal of Urology 6, 8, 9
- High-energy photon beams (≥6 MV) should be used, as recommended by The Journal of Urology 2, 5
- Multileaf collimator technology is essential for conformal dose delivery, as recommended by The Journal of Urology 1, 2
Quality Assurance
- Post-treatment dosimetry verification is essential to document adequate target coverage, as recommended by The Journal of Urology 1
- For brachytherapy, an excellent implant is defined as ≥90% of prostate volume receiving ≥100% of prescription dose, as recommended by The Journal of Urology 1
- For external beam radiation therapy (EBRT), verify that dose constraints for rectum and bladder are met according to published normal tissue dose objectives, as recommended by The Journal of Urology 8