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Stereotactic body radiotherapy for localized prostate cancer: disease control and quality of life at 6 years

hopeful and opt...
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Joined: Apr 2009

Stereotactic body radiotherapy for localized prostate cancer: disease control and quality of life at 6 years

Alan J KatzMichael SantoroFred Diblasio and Richard Ashley

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Radiation Oncology 2013, 8:118 doi:10.1186/1748-717X-8-118

Published: 13 May 2013

Abstract (provisional)


Stereotactic body radiotherapy (SBRT) may yield disease control for prostate cancer in a brief, hypofractionated treatment regimen without increasing treatment toxicity. Our report presents a 6-year update from 304 low- (n = 211), intermediate- (n = 81), and high-risk (n = 12) prostate cancer patients who received CyberKnife SBRT.


The median PSA at presentation was 5.8 ng/ml. Fifty-seven patients received neoadjuvant hormonal therapy for up to one year. The first 50 patients received a total dose of 35 Gy in 5 fractions of 7 Gy. The subsequent 254 patients received a total dose of 36.25 Gy in 5 fractions of 7.25 Gy. Toxicity was assessed with the Expanded Prostate Cancer Index Composite questionnaire and the Radiation Therapy Oncology Group urinary and rectal toxicity scale. Biochemical failure was assessed using the nadir + 2 definition.


No patients experienced Grade III or IV acute complications. Fewer than 5% of patients experienced any acute Grade II urinary or rectal toxicities. Late urinary Grade II complications were observed in 4% of patients treated to 35 Gy and 9% of patients treated to 36.25 Gy. Five (2%) late Grade III urinary toxicities occurred in patients who were treated with 36.25 Gy. Late Grade II rectal complications were observed in 2% of patients treated to 35 Gy and 5% of patients treated to 36.25 Gy. Bowel and urinary quality of life (QOL) scores initially decreased, but later returned to baseline values. An overall decrease of 20% in the sexual QOL score was observed. QOL in each domain was not differentially affected by dose. For patients that were potent prior to treatment, 75% stated that they remained sexually potent. Actuarial 5-year biochemical recurrence-free survival was 97% for low-risk, 90.7% for intermediate-risk, and 74.1% for high-risk patients. PSA fell to a median of 0.12 ng/ml at 5 years; dose did not influence median PSA levels.


In this large series with long-term follow-up, we found excellent biochemical control rates and low and acceptable toxicity, outcomes consistent with those reported for from high dose rate brachytherapy (HDR BT). Provided that measures are taken to account for prostate motion, SBRT's distinct advantages over HDR BT include its noninvasiveness and delivery to patients without anesthesia or hospitalization.

VascodaGama's picture
Posts: 3227
Joined: Nov 2010


This study confirms the high ranks CK "enjoys" among the treatments for prostate cancer. Laughing

It is noticed however that the benefits differ in regards to the status of the patient at the time of treatment, varing from low (97%) to high risk (74.1%) for recurrence. These results, though good, do not vary much from IMRT when the hormonal component is added to the mix in high risk patients. In any case, the high risk cohort is only 3% of the total cases of the study. This makes CK less relevant for guys with or at risk of metastases.

I assume that the researchers have compared CK with HDR-BT only in regards to the toxicity "chart". In biochemical free matters it would be hard to compare if the HT cohort group were included. 

Good report.


VG  Wink



hopeful and opt...
Posts: 2263
Joined: Apr 2009


Vasco,....Here is the thread at cyberknife.com where I found this study. The prime presenter of this study posted this. If you wish you can post any questions or concerns to Dr. Katz.


Posts: 1013
Joined: Mar 2010

Here's a link to the full report of the study:


Results are comparable to the prior CK study reported in 2011 and to results using other treatment methods. However, the key difference in CK vs surgery and other radiation treatments is really in QOL -- quality of life -- which is reportedly (based on studies and ancedotal reports) much better for CK than other methods and is IMHO (based on my experience w/CK) is the primary reason to choose CK over other treatment methods, be they surgical or radiological. 





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