A phase I trial of stereotactic body radiation therapy (SBRT) for liver metastases.
OBJECTIVE
To determine the maximum tolerated dose (MTD) of stereotactic body radiation therapy (SBRT) for liver metastases.


METHODS
A multicenter Phase I clinical trial was conducted. Eligible patients had one to three liver metastases, tumor diameter <6 cm, and adequate liver function. The first cohort received 36 Gy to the planning target volume (PTV) in three fractions (F). Subsequent cohorts received higher doses up to a chosen maximum of 60 Gy/3F. At least 700 mL of normal liver had to receive a total dose <15 Gy. Dose-limiting toxicity (DLT) included acute Grade 3 liver or intestinal toxicity or any acute Grade 4 toxicity. The MTD was exceeded if 2/6 patients in a cohort experienced DLT.


RESULTS
Eighteen patients were enrolled (10 male, 8 female): median age, 55 years (range, 26-83 years); most common primary site, colorectal (6 patients); median aggregate gross tumor volume, 18 ml (range, 3-98 ml). Four patients had multiple tumors. No patient experienced a DLT, and dose was escalated to 60 Gy/3F without reaching MTD.


CONCLUSIONS
Biologically potent doses of SBRT are well tolerated in patients with limited liver metastases. Results of this study form the basis for an ongoing Phase II SBRT study of 60 Gy over three fractions for liver metastases.
Schefter
Tracey E
TE
Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO 80045-0510, USA. Tracey.Schefter@uchsc.edu
Kavanagh
Brian D
BD
Timmerman
Robert D
RD
Cardenes
Higinia R
HR
Baron
Anna
A
Gaspar
Laurie E
LE
D000328:Adult; D000368:Aged; D000932:Antiemetics / Q000627:therapeutic use; D015331:Cohort Studies; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D007668:Kidney; D008099:Liver; D008113:Liver Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods*; D013116:Spinal Cord
D000932:Antiemetics