Korean J Urol.  2014 Mar;55(3):172-177. 10.4111/kju.2014.55.3.172.

Clinical Outcomes of CyberKnife Radiotherapy in Prostate Cancer Patients: Short-term, Single-Center Experience

• Koh DH
• Kim JB
• Kim HW
• Chang YS
• Kim HJ

• KMID: 1988420
• DOI: http://doi.org/10.4111/kju.2014.55.3.172

Abstract

PURPOSE
In this retrospective study, we analyzed the outcomes of prostate cancer patients treated with the CyberKnife radiotherapy system (Accuray).
MATERIALS AND METHODS
Between 2007 and 2010, 31 patients were treated for prostate cancer by use of the CyberKnife radiotherapy system. After excluding six patients who were lost to follow-up, data for the remaining 25 patients were analyzed. Patients were divided into the CyberKnife monotherapy group and a postexternal beam radiotherapy boost group. Clinicopathologic features and treatment outcomes were compared between the groups. The primary endpoint was biochemical recurrence-free survival period based on the Phoenix definition. Toxicities were evaluated by using the Radiation Therapy Oncology Group scoring criteria.
RESULTS
Of 25 patients, 17 (68%) and 8 (32%) were classified in the monotherapy and boost groups, respectively. With a median follow-up of 29.3 months, most of the toxicities were grade 1 or 2 except for one patient in the boost group who experienced late grade 3 gastrointestinal toxicity. The overall biochemical recurrence rate was 20% (5/25) and the median time to biochemical recurrence was 51.9 months. None of the patients with low or intermediate risk had experienced biochemical recurrence during follow-up. Among D'Amico high-risk populations, 16.7% (1/6) in the monotherapy group and 50.0% (4/8) in the boost group experienced biochemical recurrence.
CONCLUSIONS
Our data support that prostate cancer treatment by use of the CyberKnife radiotherapy system is feasible. The procedure can be a viable option for managing prostate cancer either in a monotherapy setting or as a boost after conventional radiotherapy regardless of the patient's risk stratification.

Keyword

Prostate cancer; Recurrence; Stereotactic radiosurgery; Toxicity

MeSH Terms

Follow-Up Studies
Humans
Lost to Follow-Up
Prostate*
Prostatic Neoplasms*
Radiosurgery
Radiotherapy*
Recurrence
Retrospective Studies

Figure

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  FIG. 1 Kaplan-Meier curves for biochemical recurrence (BCR) free survival based on Phoenix definition. (A) All cohort, (B) comparison of monotherapy and postexternal beam radiation therapy boost group. CI, confidence interval; EBRT, external beam radiation therapy; NA, not available.

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