Search

Introduction: Aim of the present study is to evaluate homolateral and contralateral hippocampus (H-H, C-H, respectively) dose during Fractionated Stereotactic Radiotherapy (FSRT) or Radiosurgery (SRS) for brain metastases (BM)., Materials & Methods: Patients with BM<5, size≤30mm, KPS≥80 and a life expectancy>3months, were considered for SRS/FSRT (total dose 15-30Gy, 1-5 fractions). For each BM, a Flattening Filter Free (FFF) Volumetric Modulated Arc Therapy (VMAT) plan was generated with one or two arcs. Hippocampi were not considered during optimizations phase and were contoured and evaluated retrospectively in terms of dose: the Dmedian, Dmean, D0.1cc and the V1Gy, V2Gy, V5Gy and V10Gy were analyzed., Results: From April 2014 to December 2015, 81 BM were treated with FFF-FSRT/SRS. For the H-H, the average values of Dmedian, Dmean and D0.1cc were 1.5Gy, 1.54Gy and 2.2Gy, respectively, while the V1Gy, V2Gy, V5Gy and V10Gy values were 25%, 8.9%, 8.9% and 2.1%, respectively. For the C-H, the average Dmedian, Dmean and D0.1cc were 0.7Gy, 0.7Gy, 0.9Gy, respectively, while the average values of V1Gy, V2Gy, V5Gy and V10Gy were 18%, 10.2%, 2.8% and 1.4%, respectively. Tumor dimension, tumor cranial-caudal length and the distance between BM and H-H were correlated to Dmedian, Dmean and D0.1cc. For C-H, only the distance from PTV was correlated with a dose reduction., Conclusion: During FFF-FSRT/SRS, hippocampus received a negligible dose. Despite its clinical significance is still under evaluation, in patients with a long life expectancy, H-H should be considered during Linac-based FSRT/SRS., (Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Aim: For selected patients with brain metastases (BMs), the role of stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (SFRT) is well recognized. The recent introduction of flattening filter free (FFF) delivery during linac-based SRS or SFRT allows shorter beam-on-time, improving patients' comfort and facility workflow. Nevertheless, limited experiences evaluated the impact of FFF linac-based SRS and SFRT in BMs treatment. Aim of the current study was to analyze SRS/SFRT linac-based FFF delivery for BMs in terms of dosimetric and early clinical results., Materials and Methods: Patients with life expectancy >3 months, number of BMs <5, diameter <3 cm, and controlled or synchronous primary tumor received SRS/SFRT. The prescribed total dose and fractionation, based on BMs size and proximity to organs at risk, ranged from 15 Gy in 1 fraction to 30 Gy in 5 fractions. A FFF volumetric modulated arc therapy (VMAT) plan was generated with one or two coplanar partial arcs. Toxicity was assessed according to CTCAE v4.0., Results: From April 2014 to February 2016, 45 patients (89 BMs) were treated with SRS/SFRT linac-based FFF delivery. The mean beam-on-time was 140 s for each lesion (range 90-290 s) and the average brain Dmean was 1 Gy (range 0.1-4.8 Gy). At the time of analysis, local control was reported in 93.2% (83/89 BMs). With a median follow-up time of 12 months (range 1-27 months), the median overall survival was 14 months and the 6-month overall survival was 77%. Finally, the median intracranial disease control was 11 months. Acute and late toxicities were acceptable without severe events (no adverse events ≥G2 were recorded)., Conclusions: These preliminary results highlighted the feasibility and safety of linac-based SRS/SFRT with FFF mode for BMs patients. A longer follow-up is necessary to confirm the efficacy of this treatment modality in BM patients.

Objective: To develop a feasible volumetric modulated arc therapy (VMAT) treatment in whole brain radiotherapy (WBRT) with a simultaneous integrated boost (SIB) and hippocampal (HP) sparing in 1-5 brain metastases (BMs)., Methods and Materials: Ten patients with 20 BMs received a WBRT prescription of 20 Gy, SIB dose on BMs of 40 Gy/5 fractions. PTVWBRT was generated from brain minus BMs-PTVs (PTVSIB) and planning organ at risk volume to HP. All plans were evaluated in: homogeneity index (HI), target coverage (TC), maximum dose to prescription dose ratio (MDPD), prescription isodose to target volume ratio (PITV) and paddick conformity index (CI). We also evaluate D100%, mean and maximum doses to HP. Planning objectives were for PTVWBRT, D2% = 25 Gy with acceptable deviation of 26.7 Gy and D98% ≥ 16.7 Gy; for PTVSIB D95% ≥ 38 Gy; for HP, D100% = 6 Gy with acceptable deviation of 6.7 Gy, Dmax = 10.7 Gy with acceptable deviation of 11.3 Gy, a mean dose of 8 Gy., Results: Mean number of BMs was 2 (range 1-5). Mean values for BMs were volume of PTVSIB = 5.1 ± 4.9 cc, dose to 95% of PTVSIB 39.3 ± 0.9 Gy, HI 0.083 ± 0.03, TC 0.96 ± 0.24, CI 0.78 ± 0.17. Mean MDPD was 1.06 ± 0.02 and PITV 0.96 ± 0.24. For WBRT, mean target volume was (13.46 ± 2)*10(2) cc, mean dose to 90% of PTVWBRT 19.8 ± 0.2 Gy, mean HI 0.42 ± 0.12 and TC 0.78 ± 0.11. Mean and maximum HP doses were 7.7 ± 0.3 Gy and 10.5 ± 0.5 Gy. Mean dose to 100% of HP volume (D100%) was 6.7 ± 0.3 Gy., Conclusions: WBRT plus SIB with HP avoidance with VMAT was feasible. All dosimetric parameters were satisfied for PTVWBRT and PTVSIB.

Aim: To analyze the outcome of patients with brain oligometastases treated by radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) after whole-brain radiotherapy (WBRT)., Patients and Methods: Overall survival (OS) and local control (LC) were evaluated in patients (patients) with 1-2 brain metastases., Results: Forty-seven patients were selected. They were submitted to WBRT (median dose=3,750 cGy) followed by SRS (17 patients; median dose=1,500 cGy) or FSRT (30 patients; median dose=2,000 cGy). Median follow-up was 102 months (range=17-151); the median survival was 22 months for the SRS group and 16 months for the FSRT group. One-year and 5-year survival was 56% and 16%, respectively, in SRT and 62.1% and 3%, respectively, in FSRT. Neither treatment proved to significantly impact OS (p=0.4). The 1-year LC rates were 80% and 61.1% in the two groups, respectively (p=0.15)., Conclusion: SRS or FSRT after WBRT could offer the same outcomes in patients with brain oligometasteses. Further investigation is warranted to confirm these data and define the optimal stereotactic modality., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Objectives: Age is an unfavorable prognostic factor in glioblastoma multiforme (GBM). To assess the possibility and the advantage of radiotherapy (RT) plus concomitant/sequential temozolomide (TMZ) in patients over 65 years with GBM, we analyzed 4 prospective trials in terms of compliance and outcomes., Methods: Elderly patients with histologically proven GBM, included in 4 prospective phase II studies with a Karnofsky Performance Status (KPS) >70 and a Charlson Comorbidity Index (CCI) <3, were selected for these analyses. Patients were treated by 3D-conformal RT (60 Gy), fractionated stereotactic conformal-RT (69.4 Gy), or intensity-modulated RT with simultaneous integrated boost (63 Gy). Concomitant (standard modality, first and last week, or from the Monday to Friday) and adjuvant chemotherapy with TMZ was administered. To stratify patients, recursive partitioning analysis was used. Safety and tolerability were measured by the National Cancer Institute Common Criteria. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier method., Results: From 2001 to 2011, 201 patients were enrolled in 4 trials and 111 elderly patients were recruited for this analysis. Compliance was 96.4%: 4/111 patients discontinued treatment, prevalently for disease progression. During radiochemotherapy, acute toxicity was mild. At a median follow-up of 64 months (range, 9 to 122 mo), median PFS and OS were 10 and 13 months, respectively. Extent of surgery (P=0.009) and radiation dose (P=0.01) significantly improved survival., Conclusions: Radiochemotherapy is effective and well tolerated by elderly patients when KPS >70 and CCI <3; therefore these criterions should be considered to enroll elderly patients in combined prospective study.