Stereotactic radiosurgery and radiotherapy for resected brain metastases: current pattern of care in the Radiosurgery and Stereotactic Radiotherapy Working Group of the German Association for Radiation Oncology (DEGRO).

PURPOSE: Preoperative stereotactic radiosurgery (SRS) of brain metastases may achieve similar local control and better leptomeningeal control rates than postoperative fractionated stereotactic radiotherapy (FSRT) in patients treated with elective metastasectomy. To plan a multicentre trial of preoperative SRS compared with postoperative FSRT, a survey of experts was conducted to determine current practice. METHODS: A survey with 15 questions was distributed to the DEGRO Radiosurgery and Stereotactic Radiotherapy Working Group. Participants were asked under what circumstances they offered SRS, FSRT, partial and/or whole brain radiotherapy before or after resection of a brain metastasis, as well as the feasibility of preoperative stereotactic radiosurgery and neurosurgical resection within 6 days. RESULTS: Of 25 participants from 24 centres, 22 completed 100% of the questions. 24 respondents were radiation oncologists and 1 was a neurosurgeon. All 24 centres have one or more dedicated radiosurgery platform and all offer postoperative FSRT. Preoperative SRS is offered by 4/24 (16.7%) centres, and 9/24 (37.5%) sometimes recommend single-fraction postoperative SRS. Partial brain irradiation is offered by 8/24 (33.3%) centres and 12/24 (50%) occasionally recommend whole-brain irradiation. Two centres are participating in clinical trials of preoperative SRS. SRS techniques and fractionation varied between centres. CONCLUSION: All responding centres currently offer postoperative FSRT after brain metastasectomy. Approximately one third offer single-fraction postoperative SRS and four already perform preoperative SRS. With regard to potential co-investigators, 18 were identified for the PREOP­2 multicentre trial, which will randomise between preoperative SRS and postoperative FSRT.

Impact of regular magnetic resonance imaging follow-up after stereotactic radiotherapy to the surgical cavity in patients with one to three brain metastases.

BACKGROUND: Administering stereotactic radiotherapy to the surgical cavity and thus omitting postoperative whole brain radiotherapy (WBRT) is a favored strategy in limited metastatic brain disease. Little is known about the impact of regular magnetic resonance imaging follow-up (MRI FU) in such patient cohorts. The aim of this study is to examine the impact of regular MRI FU and to report the oncological outcomes of patients with one to three brain metastases (BMs) treated with stereotactic radiosurgery (SRS) or hypo-fractionated stereotactic radiotherapy (HFSRT) to the surgical cavity. METHODS: We retrospectively analyzed patients who received SRS or HFSRT to the surgical cavity after resection of one to two BMs. Additional, non-resected BMs were managed with SRS alone. Survival was estimated by the Kaplan-Meier method. Prognostic factors were examined with the log-rank test and Cox proportional hazards model. Regular MRI FU was defined as performing a brain MRI 3 months after radiotherapy (RT) and/or performing ≥1 brain MRI per 180 days. Primary endpoint was local control (LC). Secondary endpoints were distant brain control (DBC), overall survival (OS) and the correlation between regular MRI FU and overall survival (OS), symptom-free survival (SFS), deferment of WBRT and WBRT-free survival (WFS). RESULTS: Overall, 75 patients were enrolled. One, 2 and 3 BMs were seen in 63 (84%), 11 (15%) and 1 (1%) patients, respectively. Forty (53%) patients underwent MRI FU 3 months after RT and 38 (51%) patients received ≥1 brain MRI per 180 days. Median OS was 19.4 months (95% CI: 13.2-25.6 months). Actuarial LC, DBC and OS at 1 year were 72% (95% CI: 60-83%), 60% (95% CI: 48-72%) and 66% (95% CI: 53-76%), respectively. A planning target volume > 15 cm3 (p = 0.01), Graded Prognostic Assessment (GPA) score (p = 0.001) and residual tumor after surgery (p = 0.008) were prognostic for decreased OS in multivariate analysis. No significant correlation between MRI FU at 3 months and OS (p = 0.462), SFS (p = 0.536), WFS (p = 0.407) or deferment of WBRT (p = 0.955) was seen. Likewise, performing ≥1 MRI per 180 days had no significant impact on OS (p = 0.954), SFS (p = 0.196), WFS (p = 0.308) or deferment of WBRT (p = 0.268). CONCLUSION: Our results regarding oncological outcomes consist with the current data from the literature. Surprisingly, regular MRI FU did not result in increased OS, SFS, WFS or deferment of WBRT in our cohort consisting mainly of patients with a single and resected BM. Therefore, the impact of regular MRI FU needs prospective evaluation. TRIAL REGISTRATION: Project ID: 2017-00033, retrospectively registered.

Postoperative (Chemo)Radiotherapy for Oral Cavity Squamous Cell Carcinomas: Outcomes and Patterns of Failure.

AIMS: To determine outcomes after adjuvant radiotherapy for squamous cell carcinoma of the oral cavity and to correlate locoregional recurrence patterns with radiotherapy target volumes. MATERIALS AND METHODS: All patients receiving adjuvant radiotherapy±chemotherapy after surgery with curative intent for oral cavity squamous cell carcinoma between 2007 and 2012 were retrospectively analysed. Locoregional recurrences were reconstructed on the planning computed tomography scan by both deformable image co-registration and by visual assessment. Recurrences were categorised as in-field, marginal or out-of-field if >95%, 20-95%, and <20% of the recurrence volume was encompassed by 95% of the prescription isodose, respectively. RESULTS: In total, 106 patients with a median follow-up of 42 months were included. Oral cavity subsites included oral tongue (54%) and floor of mouth (32%). Thirty (28%) patients received concurrent chemotherapy. Fifty-five (52%) patients received bilateral neck radiotherapy. Two year overall, disease-free, local disease-free, regional disease-free and distant metastases-free survival were 72, 83, 92, 89, 94%, respectively. On multivariate analysis, extracapsular nodal spread was the only factor significantly associated with inferior overall survival. Fourteen (13%) patients have experienced locoregional failure. Of the eight local recurrences at the primary tumour site, four, three and one were classified as in-field, marginal and out-of-field, respectively. Of 10 regional recurrences, one, one and eight were in-field, marginal and out-of-field. There were 7/21 (33%) contralateral regional recurrences in patients with pN2a/b disease who did not receive contralateral neck irradiation; there were 0/21 (0%) and 0/9 (0%) contralateral regional recurrences in patients with pN0 or pN1 disease, respectively, who did not receive contralateral neck irradiation. CONCLUSION: Marginal recurrences highlight the need for generous target volume delineation. Based upon rates of contralateral regional recurrences, a comprehensive approach to target volume selection should be advised for tumour subsites with bilateral lymphatic drainage in the presence of pN2a/b disease.

A method for coincidence timing resolution enhancement.

A method including the coincidence time resolution improvement for a TOF/positron emission tomography system was suggested. The spectrometer for this aim was composed of two NaI(Tl) and two plastic scintillation detectors. Experimental results were supported by FLUKA Monte Carlo simulation program by constructing the detector setup in software medium. Present experimental results verified our previous results and conclusions obtained from the suggested method. It was concluded that better resolutions would help the improvement not only on the TOF gain but also on the spatial resolution, leading to better images and helping the Physician in his/her diagnosis and treatment.

Evaluation of heart rate variability and night-time blood pressure measurements in patients with idiopathic sudden sensorineural hearing loss.

OBJECTIVE: The aim of this study is to investigate the role of the autonomic nervous system in the etiology of idiopathic sudden sensorineural hearing loss (ISSHL) by measuring heart rate variability (HRV) and night-time blood pressure levels. PATIENTS AND METHODS: A total of 58 patients, 31 ISSHL patients (group 1) and 27 healthy volunteers (control group; group 2), were included in this study. Clinical and ambulatory blood pressure measurements and Holter electrocardiography were performed in both groups. After these evaluations, HRV parameters and night-time blood pressure values were determined. RESULTS: Mean systolic blood pressure (SBP) and mean diastolic blood pressure (DBP) measured at night-time were higher in group 1 compared to group 2 (p < 0.05). Heart rate variability parameters were lower in group 1 than in group 2. CONCLUSIONS: In patients with ISSHL, elevated blood pressure at night-time and reduced heart rate variability suggest that autonomic nervous system dysfunction might play a role in the etiopathogenesis of the disease. The measurements of ambulatory blood pressure and heart rate variability can reveal more enlightening data in the determination of the etiology of ISSHL and guiding the treatment.

Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated.