Local Control Following Stereotactic Body Radiotherapy for Liver Tumors: A Preliminary Report of the AAPM Working Group for SBRT

International Journal of Radiation Oncology  Biology  Physics

S52 Oral Scientific Abstract 105; Table

Correlation between histopathological effects and treatment parameters

Parameters D33 GEM GEM

Grade Ia >  >  >

51.6 Gy 51.6 Gy 7625 mg/m2 7625 mg/m2 7625 mg/m2

 7625 mg/m Total

2

D33 D33

>  > 

51.6 51.6 51.6 51.6

Gy Gy Gy Gy

Grade Ib or higher (%)

14 42 26 30 4 22 10 20 56

mg/m2 before surgical resection more frequently achieved the effects of Ib or higher (p Z .0002). The odds-ratios were compared between the groups divided by the radiation dose and the GEM dose to disclose their interaction (Table). In addition, the effects of Grade II or higher were more frequently obtained among the lesions received GEM > 7,625 mg/m2 (22.1 % vs. 10.0 %: odds-ratio; 2.840 (1.088-8.879): p Z 0.0320). Conclusions: Dose intensity of radiation and GEM related to HE of preoperative CRT on the primary lesion of PC, and combination of them contributed to further favorable outcomes. Author Disclosure: T. Hirata: None. T. Teshima: None. K. Nishiyama: None. K. Otani: None. Y. Kawaguchi: None. K. Konishi: None. Y. Tomita: None. H. Takahashi: None. H. Ohigashi: None. O. Ishikawa: None.

106 Local Control Following Stereotactic Body Radiotherapy for Liver Tumors: A Preliminary Report of the AAPM Working Group for SBRT N. Ohri,1 A. Jackson,2 A. Mendez Romero,3 M. Miften,4 R.K. Ten Haken,5 L.A. Dawson,6 J. Grimm,7 E.D. Yorke,2 and W.A. Tome1; 1Albert Einstein College of Medicine, Bronx, NY, 2Memorial Sloan-Kettering Cancer Center, New York, NY, 3Erasmus MC Cancer Institute, Rotterdam, Netherlands, 4University of Colorado Denver, Aurora, CO, 5University of Michigan, Ann Arbor, MI, 6Princess Margaret Hospital, Toronto, ON, Canada, 7Holy Redeemer Hospital, Meadowbrook, PA Purpose/Objective(s): Numerous dosing and fractionation schedules have been used to treat hepatic tumors with stereotactic body radiation therapy (SBRT). In this report, we quantitatively evaluate published local control rates following SBRT for primary and metastatic liver tumors and examine if outcomes are affected by SBRT dosing regimen. Materials/Methods: We identified published articles that reported local control rates following SBRT for primary or metastatic liver tumors. Biologically effective doses (BEDs) were calculated for each dose regimen using the Linear Quadratic Equation. We excluded any series in which a wide range of BEDs was used. Individual patient data for local control were extracted from actuarial survival curves, and data were aggregated to form a single dataset. Actuarial local control curves were generated using the Kaplan-Meier method after grouping patients by disease type and BED (greater than 100 Gy v. less than or equal to 100 Gy). Comparisons were made using log-rank testing. Results: Thirteen papers met all inclusion criteria and formed the dataset for this analysis. Median BED was 88 Gy (range: 60 to 263 Gy). One, two, and three-year actuarial local control rates following SBRT for primary liver tumors (n Z 431) were 93%, 89%, and 86%, respectively. Lower one (90%), two (79%), and three-year (76%) actuarial local control rates were observed for liver metastases (n Z 290, log-rank p Z 0.011). Among patients treated with SBRT for primary liver tumors, there was no evidence that local control was influenced by BED within the range of doses used (BED range: 60 to 180 Gy). For liver metastases, outcomes were significantly better for patients treated with BEDs exceeding 100 Gy (3-year local control 93%) than for other patients (3-year local control 65%, p < 0.001). Conclusions: SBRT for primary liver tumors provides high rates of durable local control, with no evidence for a dose-response relationship. Excellent

43 60 78 25 34 44 9 16 103

(75.4) (58.8) (75.0) (45.5) (89.5) (66.7) (47.4) (44.4) (64.8)

p value

OR

95 % CI

0.0256

2.150

1.064-4.529

0.0002

3.600

1.815-7.273

0.0066

4.250

1.461-15.56

0.8360

1.125

0.365-3.456

local control rates are also observed following SBRT for liver metastases when biologically effective doses above 100 Gy are utilized. Author Disclosure: N. Ohri: None. A. Jackson: None. A. Mendez Romero: None. M. Miften: None. R.K. Ten Haken: None. L.A. Dawson: None. J. Grimm: None. E.D. Yorke: None. W.A. Tome: None.

107 Quality of Life Outcomes from a Phase I/II Multi-institutional, Dose-per-Fraction Escalation Trial for Prostate Cancer J.V. Brower,1 J.D. Forman,2 P.A. Kupelian,3 V. Gondi,4,1 D.G. Petereit,5 C.A. Lawton,6 N.J. Anger,1 S. Saha,1 R.J. Chappell,1 and M.A. Ritter1; 1 University of Wisconsin Carbone Cancer Center, Madison, WI, 2Wayne State University, Detroit, MI, 3UCLA Medical Center, Santa Monica, CA, 4 CDH Cancer Center, Warrenville, IL, 5John T. Vucurevich Cancer Center Institute, Rapid City, SD, 6Medical College of Wisconsin, Milwaukee, WI Purpose/Objective(s): A phase I/II clinical trial carried out by 5 institutions explored the tolerance and efficacy of increasingly hypofractionated (HPFX) radiation therapy for low/intermediate risk prostate cancer. Published quality of life (QOL) data for HPFX regimens remain limited and here we report on QOL measures recorded from this large, multiinstitutional trial. Materials/Methods: Three hundred forty-three patients were enrolled at five institutions from 2002 to 2010. Three increasing dose-per-fraction schedules were designed to yield equivalent predicted late toxicity, with EQD2 doses of 75-77 Gy, assuming an alpha/beta ratio of 3 Gy for late effects. HPFX levels were: 64.7 Gy/22 fx of 2.94 Gy, 58.08 Gy/16 fx of 3.63 Gy, and 51.6 Gy/12 fx of 4.3 Gy each. Patients were treated to the prostate  seminal vesicles utilizing IMRT with daily image guidance. Three quality of life (QOL) surveys were administered annually up to 3 years and included the Fox Chase Bowel/Bladder Toxicity, the Spitzer Quality of Life Index (SQLI) and the International Index of Erectile Function (IIEF) instruments. Results: Acute and late physician-scored toxicities were statistically nondifferent across all 3 HPFX levels. Analysis of patient-scored QOL bowel data at 3 years revealed no significant difference in average pre- to posttreatment score changes, which were modest, or in composite QOL outcomes across the 3 regimens, with scores of 86.3, 87.7, and 85.4 resp., out of a maximum 100 (p Z 0.469). Similarly, bladder outcomes at 3-years were comparable at 79.5, 82.5 and 81.1 of 100 (p Z 0.343). The SQLI data (range of 0-10) revealed excellent, similar 3-year mean scores of 9.5, 9.8 and 9.5, resp. (p Z 0.188). IIEF data also revealed no significant difference across HPFX levels at 3 years when assessing erectile function (p Z 0.07), orgasmic function (p Z 0.078), sexual (p Z 0.231), intercourse satisfaction (p Z 0.354) and overall satisfaction (p Z 0.191), although all measures except intercourse satisfaction significantly worsened post-treatment. Conclusions: Three-year QOL scores for bowel, bladder, Spitzer Quality of Life and sexual function were similar for 3 prospectively-delivered HPFX prostate cancer regimens spanning a range of 2.94 Gy to 4.3 Gy per fraction. These favorable patient-scored QOL outcome trends are consistent with physician-based toxicity scoring and provide further support for HPFX safety and tolerability. Furthermore, the predictive power of Linear Quadratic modeling for toxicity and QOL demonstrated herein for these 3