Single community-based institutional series of stereotactic body radiation therapy (SBRT) for treatment of liver metastases.

BACKGROUND: Stereotactic body radiation therapy (SBRT) is a safe and effective option for treatment of liver metastases. However, existing data are mostly reported by high-volume centers. There have been reports that advanced radiotherapy techniques performed at low-volume centers result in inferior outcomes. Our goal was to assess the implementation of SBRT for the treatment of liver metastases at a low-volume center by studying the efficacy and toxicity of this technology through retrospective database review at a single, community-based institution. METHODS: We performed an IRB approved patient registry study. Patients had a median age of 65, KPS of at least 70 (median 90) and primary tumor controlled. All patients underwent fiducial marker placement under CT-guidance 1-2 weeks prior to planning scans. Gross tumor volume (GTV) was delineated using contrast enhanced CT scans, as well as fusion with PET and/or MRI scans. GTV was expanded by 5 mm to create the planning target volume (PTV). Treatment was delivered by image guided stereotactic robotic radiosurgery with respiratory motion tracking. Lesions were treated with 3 fractions to a median total dose of 54 Gy. Overall survival, progression-free survival (PFS) and local failure-free survival were estimated using the Kaplan-Meier method. Log-rank statistic was used to compare local control based on GTV volume. RESULTS: Between 2006 and 2016, 42 consecutively treated patients with 81 metastatic liver lesions were treated with SBRT. Median follow-up was 25 months. Major primary tumor sites were colon (n=18) and lung (n=7). Synchronous extrahepatic disease was present in 15% of the treated lesions and 46% had prior local treatment of liver metastases. The number of lesions treated concurrently ranged from 1 to 4. Lesions had a median maximum diameter of 2.5 cm (range, 0.5-9.5 cm), and a mean volume of 53 cc (range, 0.5-363.0 cc). Kaplan-Meier estimated 1- and 2-year overall survival was 72% and 62%. Estimated 1- and 2-year progression free survival was 32% and 23%. Estimated 1- and 2-year local control was 86% and 80%. Two-year local control was worse for lesions >50 cc compared to lesions ≤50 cc (62% vs. 84%, P=0.04). Toxicity occurred in 26% of treatment courses and included grade 1 (n=12) and grade 2 toxicity (n=3). CONCLUSIONS: These results are comparable to available published data regarding the safety and efficacy of liver metastasis SBRT on trial at high volume institutions. Our findings, therefore, demonstrate the successful implementation of a liver metastasis SBRT program in the low-volume, community-hospital setting. These findings suggest that low-volume and high-volume centers are both options for liver metastasis SBRT.

Associations Between Functional Movement Screening, the Y Balance Test, and Injuries in Coast Guard Training.

Tests that have the ability to predict injuries in various military and athletic populations are important because of the role they could play in primary prevention. Functional Movement Screen (FMS) and Y Balance Tests (YBT) may provide this prognostic ability. This study examined the association between injuries and age, physical characteristics, FMS, and upper and lower body YBTs among Coast Guard Maritime Security Response Team (MSRT) candidates. Thirty-one male Coast Guard Maritime Security Response Team candidates were administered the 7 FMS tests and lower- and upper-body YBTs before their intense 2-month training course. Age, height, weight, and body mass index were also obtained. Physical training-related injuries were recorded during the course. Injury incidence was 41%. Older age and lower scores on either FMS or the upper-body YBT were associated with higher injury risk. Performance of the lower-body YBT was not associated with injury risk. This is the first investigation showing that lower scores on the upper-body YBT were associated with higher injury risk and is in consonance with previous investigations demonstrating associations between lower FMS scores and higher injury risk. Certain limitations need to be addressed. Future studies should determine if FMS and the YBTs have prognostic ability in other populations.

Efficacy of functional movement screening for predicting injuries in coast guard cadets.

Functional movement screening (FMS) examines the ability of individuals to perform highly specific movements with the aim of identifying individuals who have functional limitations or asymmetries. It is assumed that individuals who can more effectively accomplish the required movements have a lower injury risk. This study determined the ability of FMS to predict injuries in the United States Coast Guard (USCG) cadets. Seven hundred seventy male and 275 female USCG freshman cadets were administered the 7 FMS tests before the physically intense 8-week Summer Warfare Annual Basic (SWAB) training. Physical training-related injuries were recorded during SWAB training. Cumulative injury incidence was calculated at various FMS cutpoint scores. The ability of the FMS total score to predict injuries was examined by calculating sensitivity and specificity. Determination of the FMS cutpoint that maximized specificity and sensitivity was determined from the Youden's index (sensitivity + specificity - 1). For men, FMS scores ≤ 12 were associated with higher injury risk than scores >12; for women, FMS scores ≤ 15 were associated with higher injury risk than scores >15. The Youden's Index indicated that the optimal FMS cutpoint was ≤ 11 for men (22% sensitivity, 87% specificity) and ≤ 14 for women (60% sensitivity, 61% specificity). Functional movement screening demonstrated moderate prognostic accuracy for determining injury risk among female Coast Guard cadets but relatively low accuracy among male cadets. Attempting to predict injury risk based on the FMS test seems to have some limited promise based on the present and past investigations.

Stereotactic Body Radiotherapy for Clinically Localized Prostate Cancer: Toxicity and Biochemical Disease-Free Outcomes from a Multi-Institutional Patient Registry.

OBJECTIVES: To report on initial patient characteristics, treatment practices, toxicity, and early biochemical disease-free survival (bDFS) of localized prostate cancer treated with stereotactic body radiotherapy (SBRT) and enrolled in the RSSearch(®) Patient Registry. METHODS:  A retrospective analysis was conducted on patients with clinically localized prostate cancer enrolled in RSSearch(®) from June 2006 - January 2015. Patients were classified as low-risk (PSA ≤ 10 ng/ml, T1c-T2a, Gleason score ≤ 6), intermediate-risk (PSA 10.1 - 20 ng/ml, T2b-T2c, or Gleason 7), or high-risk (PSA > 20 ng/ml, T3 or Gleason ≥ 8). Toxicity was reported using Common Toxicity Criteria for Adverse Events, version 3. Biochemical failure was assessed using the Phoenix definition (nadir + 2 ng/ml). The Kaplan-Meier analysis was used to calculate bDFS and association of patient and tumor characteristics with the use of SBRT. RESULTS:  Four hundred thirty-seven patients (189 low, 215 intermediate, and 33 high-risk) at a median of 69 years (range: 48-88) received SBRT at 17 centers. Seventy-eight percent of patients received 36.25 Gy/5 fractions, 13% received 37 Gy/5 fractions, 6% received 35 Gy/5 fractions, 3% received 38 Gy/4 fractions, and 5% received a boost dose of 19.5-29 Gy following external beam radiation therapy. Median follow-up was 20 months (range: 1-64 months). Genitourinary (GU) and gastrointestinal (GI) toxicities were minimal, with no acute or late Grade 3+ GU or GI toxicity. Late Grade 1 and 2 urinary frequency was 25% and 8%. Late Grade 1 and 2 proctitis was 3% and 2%. Median PSA decreased from 5.8 ng/ml (range: 0.3-43) to 0.88, 0.4, and 0.3 ng/ml at one, two, and three years. Two-year bDFS for all patients was 96.1%. Two-year bDFS was 99.0%, 94.5%, and 89.8% for low, intermediate, and high-risk patients (p < 0.0001). Two-year bDFS was 99.2%, 93.2%, and 90.4% for Gleason ≤ 6, Gleason 7, and Gleason ≥ 8 (p < 0.0001). Two-year bDFS was 96.4%, 97.2%, and 62.5% for PSA ≤ 10 ng/ml, PSA 10.1 - 20 ng/ml, and PSA > 20 ng/ml (p < 0.0001). Clinical T Stage was not significantly associated with bDFS.  CONCLUSIONS:  Early disease outcomes of SBRT for the treatment of clinically localized prostate cancer from a multicenter patient registry compare favorably with reports from single institutions. Acute and late GU and GI toxicities were minimal, and PSA response to SBRT was highly encouraging. Continued accrual and follow-up will be necessary to confirm long-term results.

Comparison of planned dose distributions calculated by Monte Carlo and Ray-Trace algorithms for the treatment of lung tumors with cyberknife: a preliminary study in 33 patients.

PURPOSE: To compare dose distributions calculated using the Monte Carlo algorithm (MC) and Ray-Trace algorithm (effective path length method, EPL) for CyberKnife treatments of lung tumors. MATERIALS AND METHODS: An acceptable treatment plan is created using Multiplan 2.1 and MC dose calculation. Dose is prescribed to the isodose line encompassing 95% of the planning target volume (PTV) and this is the plan clinically delivered. For comparison, the Ray-Trace algorithm with heterogeneity correction (EPL) is used to recalculate the dose distribution for this plan using the same beams, beam directions, and monitor units (MUs). RESULTS: The maximum doses calculated by the EPL to target PTV are uniformly larger than the MC plans by up to a factor of 1.63. Up to a factor of four larger maximum dose differences are observed for the critical structures in the chest. More beams traversing larger distances through low density lung are associated with larger differences, consistent with the fact that the EPL overestimates doses in low-density structures and this effect is more pronounced as collimator size decreases. CONCLUSIONS: We establish that changing the treatment plan calculation algorithm from EPL to MC can produce large differences in target and critical organs' dose coverage. The observed discrepancies are larger for plans using smaller collimator sizes and have strong dependency on the anatomical relationship of target-critical structures.

Dosimetric verification of intensity modulated radiation therapy of 172 patients treated for various disease sites: comparison of EBT film dosimetry, ion chamber measurements, and independent MU calculations.

Three independent dose verification methods for intensity modulated radiation therapy (IMRT) were evaluated. Planar IMRT dose distributions were delivered to EBT film and scanned with the Epson Expression 1680 flatbed scanner. The measured dose distributions were then compared to those calculated with a Pinnacle treatment planning system. The IMRT treatments consisted of 7 to 9 6-MV beams for different treatment sites. The films were analyzed using FilmQA (3cognition LLC, Great Neck, NY) software. Comparisons between measured and calculated dose distributions are reported as dose difference (DD) (pixels within +/- 5%), distance to agreement (DTA) (3 mm), as well as gamma values (gamma) (dose = +/- 3%, distance = 2 mm). Point dose measurements with an ion chamber at isocenter were compared to dose calculated at that point. An independent monitor units (MUs) calculation program was also used for verification. For the film dose distributions, DD values varied from 92% to 97%, with head-and-neck and lung treatments showing lower values. Gamma varied from 93% to 98%, and DTA was well above 99%. The isocenter dose measurements deviated from 0.008 to 0.028 from the calculated dose. The larger deviations were attributed to high-dose gradients at the isocenter. RadCalc MU calculations gave differences from 0.027 to 0.079. The larger differences observed were for beams crossing large areas of heterogeneous tissue and were attributed to the limitations of the simple path-length correction method employed in RadCalc. In conclusion, the 3 independent verification methods for each IMRT patient at our institution demonstrated very good agreement between measurements and calculations and gave us the confidence that our IMRT treatments are delivered accurately.