Stereotactic body radiotherapy versus Surgery for treatment of isolated adrenal metastases: a
matched pair analysis including 62 patients
Background:
The adrenal gland is a common site for metastasic disease, however, isolated adrenal metastases
(IAM) are rare and their management remains unclear. Surgery (adrenalectomy) continues to be the
treatment of choice for this matter, especially in renal cell carcinoma. Stereotactic body radiotherapy
(SBRT) is gaining acceptance in the field but there is an evident lack of studies to support it. Here we
present a matched Case Control study comparing outcomes and survival after SBRT or Laparoscopic
Adrenalectomy (LA).
Methods:
A retrospective study including 62 patients (controlled primary tumor) treated with curative intent
between May 2002 and December 2010 for IAM, with LA (n=41) or SBRT (n=11). Patients were
matched-pair (3 for 1 or 4 for 1) according to their age, primary site tumor (p=0.257; chi2) and stage.
Results:
The median age was 62.7 years (inter quartile range IQR: 43 – 77 years; p=0.762; Mann-Whitney).
The primary site included kidney (n=28), lung (n=17), colon/rectum (n=6) and bladder (n=1). Mean
follow up was 18 months (Interval of confidence: IC 95%: 7 – 24). For SBRT, the prescribed dose was
36 Gy (IQR: 30 – 42) in 5 fractions (IQR: 4 – 6), (80 % isodose, 8 Gy per fraction (IQR: 6 – 10) at the
isocenter). The 6 month and 1 year median survival rates were not statistically different, being for
SBRT: 77% (IC 95%: 49 – 100) and 62% (26 – 97) and for LA: 87% (75 – 98) and 77% (64 – 91) (p=
0.145, Kaplan Meier method). Multivariate analysis showed that primary site tumor influenced
independently on survival (p=0.025; Cox model) but not the type of management, LA vs, SBRT
(p=0,290; Cox Model).
Conclusion:
SBRT could represent a less invasive alternative of surgery for isolated adrenal metastases with
curative intent. A prospective study should be done to compare the efficacy of SA and SBRT on long
term survival outcome.