CyberKnife for Prostate Cancer Patients Aged 70 y or More

Robotic Stereotactic Radiation treatment of prostatic adenocarcinoma of the elderly.

Rationale : Half of the prostatic adenocarcinoma are diagnosed in the elderly but until now curative treatments were not proven to increase overall survival rates. Therefore, very short, comfortable and safe treatments have to be designed to increase the pelvic control of the disease. Moreover, the alpha/beta ratio of the disease ≤3Gray is in favour of using hypofractionation schemes.

Primary objective : acute and late toxicity evaluation at 36 months. Secondary objectives : PSA and MRI response and quality of life evaluation.

Inclusion criteria

T1-T3b, MRI pelvic nodes negative, M0, any Gleason Score, PSA<30ng/ml.

Dose : 36.25 Gray in 5 fractions, in 10 days, considering CAPRA Score≤5 AND 37.5 Gray in 5 fractions, in 10 days, considering CAPRA Scores>5.

Doses to the Organs At Risk (OAR) : Rectum wall : V36.25<2%, V27<20%, V23<30%, V20<35%. Bladder wall : V36.25<2%, V27<20%, V20<35%. Considering specifically the prescription of 37.5 Gray, the rectum and bladder wall: V37.5<2%. Anytime, hot spots of 105 % of the prescription dose must avoid the urethra.

Evaluation criteria : CTCAEV4 (Common Toxicity Criteria for Adverse Events, version4), PSA, multiparametric MRI, IPSS (International Prostate Score Symptom) and IIEF5 (International Index of Erectile Function).

Methodolgy : this is a three step prospective, observational study of 20 patients each step. Before moving to the next step, the severe acute or late toxicity at a median follow-up of 1 year must remain below 5% each.

Inclusion criteria

• T1-T3b,
• MRI pelvic nodes negative,
• M0,
• any Gleason Score,
• PSA<30ng/ml,
• WHO (World Health Organisation) score<2, IPSS≤15,
• maximal urinary flow rate ≥15ml/s,
• mean urinary flow rate ≥5ml/s,
• multiparametric prostatic and pelvis MRI

Exclusion criteria

• Prostatic volume > 100cc,
• TURP (transurethral prostatectomy) <3 y,
• any recurrent prostatitis within the last 3 years,
• collagenose diseases,
• ulcero-haemorrhagic rectocolitis or
• crohn diseases