Biochemical Recurrence after CyberKnife Treatment of Localized Prostate Cancer

1
Biochemical Recurrence after CyberKnife Treatment
of Localized Prostate Cancer
ChulKoo Cho, SeongYul Yoo, MiSook Kim, HyungJun
Yoo, KwangMo Yang, ChulWon Choi, YoungSeok Seo,
DongHan Lee, JaeHong Park, Geonhun Kim.
KwanJin Park, MoonKi Jo, ChongWook Lee
Departments of Radiation Oncology, CyberKnife
Center and Urology, Korea Institute of
Radiological Medical Sciences
Biochemical failure free survival rate by
clinical risk
PURPOSE
CK treatment planning
Low 100

• Herein is reported our experience of the
  CyberKnife (CK) to show its safety and
  feasibility as a treatment modality for localized
  prostate cancer.

Intermediate 100
High 75.9
MATERIAL METHODS

• Between August 2002 and July 2006, 37 patients,
  with biopsy-proven prostate cancers, who treated
  with CyberKnife were enrolled in this study. The
  patients were divided into three risk groups low
  (pretreatment PSA lt 10 ng/ml and Gleason score
  6 and Stage T1b T2a) high (pretreatment PSA
  20ng/ml or Gleason score 8) and intermediate
  (all other patients). Ten patients of 44 were
  low, 9 were intermediate, and remaining 25
  patients were high risk group. The median age was
  70 years (range 53 79) and the median follow-up
  duration was 20 months (range 8 50 months). All
  patients had received CK treatment with total
  doses of 32 36 Gy in 4 fractions. The
  biochemical failure free survival rate and
  overall survival rate were analyzed according to
  Kaplan-Meier method. The biochemical failure was
  defined as a rise by 2 ng/ml or more above the
  nadir with the date of failure be determined at
  call. The acute toxicities of rectum and urinary
  bladder were also evaluated using the acute
  toxicity score of the Radiation Therapy Oncology
  Group (RTOG).

p 0.197
Comparison with other results
RESULTS
Patient characteristics
biochemical free survival rate by modified ASTRO
definition treated with stereotactic RT, all
patients had low-risk disease
3-year result
Aug 2002 July 2006 (total 37 patients)

• Overview of biochemical failure free survival
  rates as reported in recent studies using IMRT,
  3-D conformal RT, or stereotactic RT
• The Results of CK treatment were comparable with
  those of IMRT or 3-D CRT

Characteristics
No. of patients
OSR 100
8 50 (Median 20)
Follow-up duration (months)
53 79 (Median 70)
Age (years)
DFSR 97.1
Clinical risk
bNED 84.7
7
Low
7
Intermediate
23
High
Low risk group pretreatment PSA lt 10 ng/ml and
Gleason score 6 and Stage T1b T2a, high risk
group pretreatment PSA 20 ng/ml or Gleason
score 8, intermediate group all other patients
The acute toxicities were scored using RTOG
acute toxicity criteria
Doses of CyberKnife
CONCLUSIONS

• The results of CK treatment for localized
  prostate cancer were comparable with those of
  IMRT or 3D CRT based upon biochemical analysis
• No severe complications
• Short treatment period would provide much
  convenience to patients
• CK could be recommended as an alternative
  treatment option for localized prostate cancer
• Longer follow-up duration is needed

Overall survival rate, disease free survival
rate, no evidence of biochemical disease
Normalized total doses in 2-Gy fractions