Retrospective analysis of linac-based radiosurgery for arteriovenous malformations and testing of the Flickinger formula in predicting radiation injury

The aim of the study was to validate the use of linac-based radiosurgery in arteriovenous malformation (AVM) patients and to predict complications using an integrated logistic formula (ILF) in comparison with clinical outcomes. The results of radiosurgery in 92 AVM patients were examined. All patients were treated with linac-based radiosurgery. Of these, 70 patients were followed for 12-45 months (median, 24 months) and were analyzed. The treated volume varied from 0.09 to 26.95 cm(A3) (median, 2.3 cm(A3)) and the median marginal dose was 20 Gy (range, 10.4-22). The median 12-Gy volume was 9.94 cm(A3) (range, 0.74-60.09 cm(A3)). Patients and lesion characteristics potentially affecting nidus obliteration and excellent outcome were evaluated by performing a log-rank test and univariate and multivariate analyses. The risk for radiation injury (RRI) was calculated with an integrated logistic formula. The predictive power of the RRI was assessed by calculating the area under the receiver operating characteristic (ROC) curve. Follow-up magnetic resonance (MR) angiography revealed complete AVM obliteration in 56 of 70 patients. The MR angiography confirmed an obliteration rate of 80%. The annual hemorrhage rate was 1.4% for the first 2 years after radiosurgery and 0% thereafter. The number of patients with an excellent outcome was 48 (68%). Factors associated with better obliteration were higher radiation dose to the lesion margins [12-Gy volume (V12) > 10 cm(A3)], small volume, and a Pollock-Flickinger score less than 1.49; those predicting excellent outcomes were V12 10 cm(A3) (p=0.03) and volume greater than 2 cm(A3) (p=0.001), as determined by a univariate analysis. The analyses showed an ROC of 0.66. These data suggest that linac-based radiosurgery is effective. In terms of obliteration, excellent outcomes, and especially radiation injury, V12 and volume should be considered. The Flickinger formula seems to be applicable to Novalis-treated patients, but long-term follow-up is necessary for definite conclusions

Dosimetric comparison of anterior posterior-posterior anterior 2-field three-dimensional conformal radiotherapy, 4-field three-dimensional conformal radiotherapy and forward plan intensity modulated radiotherapy techniques in female lymphoma patients irradiated to neck and mediastinum

Aim: Dosimetric comparison of three different techniques in female lymphoma patients who had radiotherapy (RT) to the neck and mediastinum. Setting and Design:: Retrospective clinical study. Materials and Methods: Computerized tomography-simulator images of eight patients were obtained retrospectively. Using 6 MV-X photon energy, RT plans were formed with three different techniques (anterior posterior-posterior anterior 2-field three-dimensional conformal RT [AP-PA 2-field 3D-CRT], 4-field 3D-CRT and forward plan intensity modulated RT [FPIMRT]). Comparisons were in terms of homogeneity index (HI), conformity index (CI), and inhomogeneity coefficient for planning target volume (PTV); mean lung dose, V-5Gy, V-10Gy, V-20Gy, V-30Gy for lung; D-mean, V-7.5Gy, V-15Gy, V-25Gy for heart; D-mean, V-3.5Gy, V-10Gy, V-20Gy for breast; D-max for spine; D-mean, V-10Gy, V-18Gy, V-25Gy, V-30Gy for thyroid. Statistical Analysis Used: Since nonparametric tests had to be used due to the study population being When FPIMRT was compared with AP-PA and 4-field techniques with respect to, HI (AP-PA/FPIMRT P: 0.017; 4-field/FPIMRT P: 0.03) and CI (AP-PA/FPIMRT P: 0.018; 4-field/FPIMRT P: 0.042), FPIMRT was more advantageous. In addition, FPIMRT was found more useful in terms of D-max (AP-PA/FPIMRT P: 0.012; 4-Field/FPIMRT P: 0.012) for spinal cord and D-mean (AP-PA/FPIMRT P: 0.012; 4-field/FPIMRT P: 0.012) for thyroid. Conclusion: FPIMRT was superior in terms of PTV homogeneity and conformity. However, it was observed that for normal tissues, FPIMRT was advantageous only for spinal cord and thyroid; but it was not the most advantageous technique for some of the dose-volume parameters of the breast, lung, and heart

PSA bouncing after external beam radiation for prostate cancer with or without hormonal treatment

OBJECTIVES: The purpose of this study was to find out the frequency of PSA bouncing and the factors effecting PSA bounce after external beam radiation treatment (EBRT) with or without hormonal treatment (HT) for prostate cancer and to identify any possible relationship with biochemical control. METHODS: Between March 1997 and November 2000, 72 consecutive patients with clinically localised prostate cancer were treated by EBRT with or without HT. All patients had a pretreatment PSA level, at least six post-treatment PSA levels and minimum two years of follow-up. Median follow-up for all patients was 51 months (range 25-69 months). Median radiation dose given to the center of the prostate was 70Gy (range 63-74Gy). Fifty-nine patients (82%) received adjuvant HT with median duration of six months. PSA bounce was defined as a minimal rise of 0.4ng/ml over six months (monthly rise > or =0.07 ng/ml), followed by any decrease. Biochemical failure was defined in accordance with the ASTRO consensus guidelines. RESULTS: Seventeen patients (24%) experienced at least one PSA bounce. PSA bounces were more frequent in patients with T1-2 stage, pretreatment PSA or =0.2 ng/ml and without HT. PSA bounce occurred in 54% of patients treated by EBRT only, and 17% of patients treated by EBRT and HT. Logistic regression model for multivariate analysis revealed the radiation field size as the only independent predictive factor for PSA bounce. Five-year biochemical control rates were 82% for non-bouncers and 88% for bouncers (p=0.5). CONCLUSIONS: PSA bouncing occurs in approximately a quarter of patients treated with EBRT with or without HT. It is associated with pretreatment and treatment characteristics, but we did not observe any relationship with biochemical failure

Prostate-specific antigen nadir within 1 year of radiotherapy combined with hormone therapy predicts cancer-specific mortality and biochemical recurrence-free survival in prostate cancer patients

Background In this study, we investigated the ability of prostate-specific antigen (PSA) 12 months after (nPSA12) external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT) to predict biochemical recurrence-free survival (BRFS), overall survival (OS), and prostate cancer-specific mortality (PCSM) in intermediateand high-risk prostate cancer patients. Methods We retrospectively reviewed the clinical data of 338 intermediate- and high-risk prostate cancer patients treated with EBRT with ADT at our institution between 2000 and 2018. The median radiation dose was 76 Gy, the median initial PSA level was 17 ng/mL (range, 1–228 ng/mL), and the median duration of ADT was 24 months (range, 6–167 months). The median PSA level 1 months after EBRT was 0.06 ng/mL (range, 0–25.6 ng/mL). Univariate and multivariate analyses were performed. Patient survival was assessed using the Kaplan-Meier method and Cox proportional hazards regression analyses. Results The median follow-up time was 5 years (range, 1–20 years). Multivariate analysis revealed that nPSA was an independent and significant factor associated with OS, PCSM, and BRFS (P = 0.008, P = 0.001, P = 0.04). Furthermore, the time to nPSA12 was an independent predictor of PCSM and BRFS (P = 0.042, P = 0.021). Pelvic irradiation was also significantly associated with worse OS and PCSM (P = 0.004, P = 0.01). Additionally, age (≤ 70 or > 70 years) and hormone therapy duration (6 months, 1–3 years, or > 3 years) were significantly associated with OS and PCSM, respectively (P = 0.004, P = 0.02). For high risk, nPSA and nPSA12 were an independent predictor for BRFS. (P = 0.021, P = 0.029) Conclusion The nPSA12 level of > 0.06 ng/mL may independently predict worse PCSM and BRFS in intermediateand high-risk prostate cancer patients undergoing EBRT and ADT. Additionally, for high risk, nPSA > 0.06 ng/mL and nPSA12 > 0.06 ng/mL may independently predict worse BRFS