I. Azinovic

Ethnic difference in risk of toxicity in prostate cancer patients treated with dynamic arc radiation therapy

Aims and background The objective of this study was to assess the influence of ethnicity on toxicity in patients treated with dynamic arc radiation therapy (ART) for prostate cancer (PC). Methods From June 2006 to May 2012, 162 cT1-T3 cN0 cM0 PC patients were treated with ART (primary diagnosis, n = 125; post-prostatectomy/brachytherapy biochemical recurrence, n = 26; adjuvant post-prostatectomy, n = 11) at 2 institutions. Forty-five patients were Latin Americans and 117 were Europeans. The dose prescribed to the prostate ranged between 68 Gy and 81 Gy. Results The median age was 69 years (range 43-87 years). The median follow-up was 18 months (range 2-74 months). Overall, only 3 patients died, none due to a cancer-related cause. Biochemical recurrence was seen in 7 patients. The rates of acute grade 2 gastrointestinal (GI) and genitourinary (GU) toxicities were 19.7% and 17%, respectively. Only 1 patient experienced acute grade 3 GI toxicity, whereas 11 patients (6.7%) experienced acute grade 3 GU toxicity. Multivariate analysis showed that undergoing whole pelvic lymph node irradiation was associated with a higher grade of acute GI toxicity (OR: 3.46; p = 0.003). In addition, older age was marginally associated with a higher grade of acute GI toxicity (OR: 2.10; p = 0.074). Finally, ethnicity was associated with acute GU toxicity: Europeans had lower-grade toxicity (OR: 0.27; p = 0.001). Conclusions Our findings suggest an ethnic difference in GU toxicity for PC patients treated with ART. In addition, we found that ART is associated with a very low risk of severe toxicity and a low recurrence rate.

Image-Guided Radiation Therapy Based on Helical Tomotherapy in Prostate Cancer: Minimizing Toxicity

Background: We report the clinical results and prognostic factors of image-guided radiation therapy (RT) with helical tomotherapy (HT) for localized and recurrent prostate cancer (PC). Patients and Methods: We evaluated 70 patients with PC (primary diagnosis, n = 48; adjuvant, n = 5; salvage, n = 17) treated with HT from May 2006 through January 2011. The dose prescribed to the prostate/surgical bed ranged between 60 and 78 Gy. Potential risk factors for genitourinary (GU) and gastrointestinal (GI) toxicity were assessed. Results: The median age was 68 years (range 51-87 years). The median follow-up was 37 months (range 3-74 months). The rates of acute grade 2 GI and GU toxicities were 10 and 13%, respectively. Only 1 patient experienced acute grade 3 GU toxicity. The rates of late grade ≥ 2 GI and GU toxicities were 1% each. Multivariate analysis showed an association between rectum mean dose > median (39 Gy) and bladder median dose > median (46 Gy) with a higher grade of acute GI (p = 0.017) and GU (p = 0.019) toxicity, respectively. Additionally, older age was associated with late GU toxicity (p = 0.026). Conclusion: Toxicity with HT is low and is associated with higher median/mean doses in organs at risk as well as with older age. A prospective validation would be necessary to confirm these results.

High dose rate brachytherapy for prostate cancer: A prospective toxicity evaluation of a one day schedule including two 13.5 Gy fractions

BACKGROUND AND PURPOSE High dose-rate (HDR) brachytherapy (BT) provides a highly conformal method of dose delivery to the prostate. The purpose of this study is to prospectively determine the toxicity of the treatment protocol of 13.5 Gy × 2 fractions. MATERIALS AND METHODS From 2010 through 2017, 119 patients with low (71%) or intermediate-risk prostate cancer were prospectively treated in a single institute with HDR-BT at 13.5 Gy × 2 fractions within one day. Median follow-up time was 4.4 years. RESULTS Actuarial rates of no biochemical evidence of disease, overall survival and metastasis-free survival for all patients were 96%,98% and 98%, respectively. The cumulative incidence of acute grade 2 and 3 genitourinary (GU) toxicity was 9% and 2%, respectively. The corresponding incidences of late GU toxicity were 18% and 1%. No grade ≥4 of either type of toxicity was detected. Multivariate analysis showed that having higher international prostate symptom score (IPSS; P = 0.041) or higher V200 (P = 0.013) was associated with a higher risk of experiencing any grade of acute GU toxicity. In addition, patients having a higher IPSS (P = 0.019) or a higher V150 (P = 0.033) were associated with a higher grade >1 acute GU toxicity. CONCLUSIONS The findings of this study show that HDR-BT 13.5 Gy × 2 as monotherapy was safe and effective for prostate cancer patients with low-intermediate risk.

Stereotactic radiosurgery in patients with multiple intracranial meningiomas

PURPOSE Stereotactic radiosurgery (SRS) delivers a potent, highly focused dose of radiation to the tumor while sparing the surrounding normal tissues. The purpose of this study was to assess the outcome of patients with intracranial meningiomas treated with SRS. METHODS A total of 73 patients with 221 benign meningiomas treated between 1991 and 2005 with SRS and followed up for more than a year were reviewed. Fifty patients (68%) were treated with SRS to the primary meningioma while 23 (32%) received SRS to relapsing tumors adjacent or distant from the site of the initial meningioma that was previously treated with surgery alone. Mean tumor margin dose was 14 Gy (range 10-16). SRS was delivered after surgery in 117 meningiomas (55 patients). RESULTS The median age at diagnosis was 47 years (range 16-74) and the median follow-up 5.8 years (range 1-13.6). The 3- and 5-year overall survival (OS) rates for all patients were 95% and 90%, respectively. The mean gross tumor volume decreased from 4.17 cm3 to 3.23 cm(3) after SRS (p=0.057). Twenty-two (10%) meningiomas increased after SRS. In addition, clinical symptoms improved in 36% and remained stable in 45% of the patients. With regard to morbidity of SRS, only 7 patients (9.6%) had late complications, including edema (N=4), brain necrosis (N=4), gliosis (N=1), and paresis of the III pair nerve (N=1). There was no treatment-related mortality. CONCLUSION SRS for patients with multiple intracranial meningiomas is effective yielding a high rate of local tumor control, whereas treatment-related morbidity remains low.