Michael Good

Stereotactic body radiation therapy for patients with heavily pretreated liver metastases and liver tumors.

We present our initial experience with CyberKnife stereotactic body radiation therapy (SBRT) in a heavily pretreated group of patients with liver metastases and primary liver tumors. From October 2007 to June 2009, 48 patients were treated at the Philadelphia CyberKnife Center for liver metastases or primary liver tumors. We report on 30 patients with 41 discrete lesions (1–4 tumors per patient) who received an ablative radiation dose (BED ≥ 79.2 Gy10 = 66 Gy EQD2). The treatment goal was to achieve a high SBRT dose to the liver tumor while sparing at least 700 cc of liver from radiation doses above 15 Gy. Twenty-three patients were treated with SBRT for metastatic cancer to the liver; the remainder (n = 7) were primary liver tumors. Eighty-seven percent of patients had prior systemic chemotherapy with a median 24 months from diagnosis to SBRT; 37% had prior liver directed therapy. Local control was assessed for 28 patients (39 tumors) with 4 months or more follow-up. At a median follow-up of 22 months (range, 10–40 months), 14/39 (36%) tumors had documented local failure. A decrease in local failure was found with higher doses of SBRT (p = 0.0237); 55% of tumors receiving a BED ≤ 100 Gy10 (10/18) had local failure compared with 19% receiving a BED > 100 Gy10 (4/21). The 2-year actuarial rate of local control for tumors treated with BED > 100 Gy10 was 75% compared to 38% for those patients treated with BED ≤ 100 Gy10 (p = 0.04). At last follow-up, 22/30 patients (73%) had distant progression of disease. Overall, seven patients remain alive with a median survival of 20 months from treatment and 57 months from diagnosis. To date, no patient experienced persistent or severe adverse effects. Despite the heavy pretreatment of these patients, SBRT was well tolerated with excellent local control rates when adequate doses (BED > 100 Gy10) were used. Median survival was limited secondary to development of further metastatic disease in the majority of patients.

SBRT: an opportunity to improve quality of life for oligometastatic prostate cancer

Objective Oligometastatic prostate cancer is a limited metastatic disease state in which potential long-term control is still possible with the use of targeted therapies such as surgery or stereotactic body radiation therapy (SBRT). SBRT may as well potentially prolong the time before the initiation of androgen deprivation therapy (ADT) and docetaxel chemotherapy for oligometastatic prostate cancer. The goal of this study is to outline prognostic factors associated with improved outcome with SBRT for metastatic prostate cancer and to quantify the effect of prior systemic treatments such as ADT and docetaxel on survival after SBRT. Methods Twenty-four prostate cancer patients were treated with SBRT at the Philadelphia CyberKnife Center between August 2007 and April 2014. Retrospective data collection and analysis were performed for these patients on this Institutional Review Board approved study. Kaplan–Meier methodology was utilized to estimate and visually assess overall survival (OS) at the patient level, with comparisons accomplished using the log-rank test. Unadjusted hazard ratios were estimated using Cox proportional hazards regression modeling. Results An improved median survival was noted for patients with oligometastatic disease defined as ≤4 lesions with median survival of >3 years compared with 11 months for polymetastases (p = 0.02). The use of docetaxel at some time in follow-up either before or after SBRT was associated with decreased survival with median survival of 9 months vs. >3 years (p = 0.01). Conclusion Prognosis was better for men with recurrent prostate cancer treated with SBRT if they had ≤4 metastases (oligometastases) or if docetaxel was not necessary for salvage treatment. The prolonged median OS for men with oligometastases in this population of heavily pretreated prostate cancer patients following SBRT may allow for improved quality of life because of a delay of more toxic salvage therapies.

Survival and Control Prognosticators of Recurrent Gynecological Malignancies of the Pelvis and Para-aortic Region Treated with Stereotactic Body Radiation Therapy

Purpose To define prognostic factors associated with improved survival and local control (LC) for gynecologic cancer recurrences limited to the pelvis and para-aortic (PA) region using stereotactic body radiation therapy (SBRT). Methods Between 2/2008 and 7/2014, 30 women (35 targets) with pelvic or PA recurrence of endometrioid (n = 12), cervical (n = 11), ovarian (n = 3), uterine-serous (n = 2), or carcinosarcoma (n = 2) cancer were treated with SBRT. Eleven recurrences were located in the central pelvis, 11 along the pelvic sidewall (PSW), and 13 in the PA region. Results Five-year survival for all patients was 42% with a median survival of 43.4 months. Multivariate analysis revealed better performance status (PS), and smaller clinical tumor volume was significant for improved survival (p < 0.05). Conclusion SBRT is a local therapy for recurrent gynecological malignancies in the pelvis and PA region with curative potential. SBRT is especially effective for LC when targeting PSW or PA recurrence and for patients with a cervical/endometrioid uterine primary. Survival is improved for patients with better PS and smaller recurrence volume prior to SBRT.

SBRT for the primary treatment of localized prostate cancer: the effect of Gleason score, dose and heterogeneity of intermediate risk on outcome utilizing 2.2014 NCCN risk stratification guidelines

Purpose: To report an update of our previous experience using stereotactic body radiation therapy (SBRT) for the primary treatment of prostate cancer, risk stratified by the updated National Comprehensive Cancer Network (NCCN) version 2.2014, reporting efficacy and toxicity in a community hospital setting. Methods: From 2007 to 2012, 142 localized prostate cancer patients were treated with SBRT using CyberKnife. NCCN guidelines Version 2.2014 risk groups analyzed included very low (20%), low (23%), intermediate (35%), and high (22%) risk. To further explore group heterogeneity and to comply with new guidelines, we separated our prior intermediate risk group into favorable intermediate and unfavorable intermediate groups depending on how many intermediate risk factors were present (one vs. > one). The unfavorable intermediate group was further analyzed in combination with the high risk group as per NCCN guidelines Version 2.2014. Various dose levels were used over the years of treatment, and have been categorized into low dose (35 Gy, n = 5 or 36.25 Gy, n = 107) and high dose (37.5 Gy, n = 30). All treatments were delivered in five fractions. Toxicity was assessed using radiation therapy oncology group criteria. Results: Five-year actuarial freedom from biochemical failure (FFBF) was 100, 91.7, 95.2, 90.0, and 86.7% for very low, low, intermediate and high risk patients, respectively. A significant difference in 5 year FFBF was noted for patients with Gleason score (GS) ≥8 vs. 7 vs. 5/6 (p = 0.03) and low vs. high dose (p = 0.05). T-stage, pretreatment PSA, age, risk stratification group, and use of ADT did not affect 5-year FFBF. Multivariate analysis revealed GS and dose to be the most predictive factors for 5-year FFBF. Conclusion: Our experience with SBRT for the primary treatment of localized prostate cancer demonstrates favorable efficacy and toxicity comparable to the results reported for IMRT in literature. GS remains the single most important pretreatment predictor of outcome.