SU-GG-T-535: The Impact of Imaging Frequency on Intrafraction Setup Corrections in Frameless Image Guided Stereotactic Radiosurgery

2010 ◽  
Vol 37 (6Part24) ◽  
pp. 3310-3310
Author(s):  
D Westerly ◽  
K Stuhr ◽  
C Altunbas ◽  
Q Diot ◽  
B Kavanagh ◽  
...  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiaojing Shi ◽  
Caiguang Cao ◽  
Zeyu Zhang ◽  
Jie Tian ◽  
Zhenhua Hu

AbstractCerenkov luminescence imaging (CLI) is a novel optical imaging technique that has been applied in clinic using various radionuclides and radiopharmaceuticals. However, clinical application of CLI has been limited by weak optical signal and restricted tissue penetration depth. Various fluorescent probes have been combined with radiopharmaceuticals for improved imaging performances. However, as most of these probes only interact with Cerenkov luminescence (CL), the low photon fluence of CL greatly restricted it’s interaction with fluorescent probes for in vivo imaging. Therefore, it is important to develop probes that can effectively convert energy beyond CL such as β and γ to the low energy optical signals. In this study, a Eu3+ doped gadolinium oxide (Gd2O3:Eu) was synthesized and combined with radiopharmaceuticals to achieve a red-shifted optical spectrum with less tissue scattering and enhanced optical signal intensity in this study. The interaction between Gd2O3:Eu and radiopharmaceutical were investigated using 18F-fluorodeoxyglucose (18F-FDG). The ex vivo optical signal intensity of the mixture of Gd2O3:Eu and 18F-FDG reached 369 times as high as that of CLI using 18F-FDG alone. To achieve improved biocompatibility, the Gd2O3:Eu nanoparticles were then modified with polyvinyl alcohol (PVA), and the resulted nanoprobe PVA modified Gd2O3:Eu (Gd2O3:Eu@PVA) was applied in intraoperative tumor imaging. Compared with 18F-FDG alone, intraoperative administration of Gd2O3:Eu@PVA and 18F-FDG combination achieved a much higher tumor-to-normal tissue ratio (TNR, 10.24 ± 2.24 vs. 1.87 ± 0.73, P = 0.0030). The use of Gd2O3:Eu@PVA and 18F-FDG also assisted intraoperative detection of tumors that were omitted by preoperative positron emission tomography (PET) imaging. Further experiment of image-guided surgery demonstrated feasibility of image-guided tumor resection using Gd2O3:Eu@PVA and 18F-FDG. In summary, Gd2O3:Eu can achieve significantly optimized imaging property when combined with 18F-FDG in intraoperative tumor imaging and image-guided tumor resection surgery. It is expected that the development of the Gd2O3:Eu nanoparticle will promote investigation and application of novel nanoparticles that can interact with radiopharmaceuticals for improved imaging properties. This work highlighted the impact of the nanoprobe that can be excited by radiopharmaceuticals emitting CL, β, and γ radiation for precisely imaging of tumor and intraoperatively guide tumor resection.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii186-ii186
Author(s):  
O’Dell Patrick ◽  
H Nickols ◽  
R LaRocca ◽  
K Sinicrope ◽  
D Sun ◽  
...  

Abstract BACKGROUND Patients who have recurrent glioblastoma have limited treatment options. We conducted a retrospective review of patients with recurrent glioblastoma treated with standard initial radiation and temozolomide with tumor treating fields to investigate whether reirradiation using radiosurgery would be associated with improved outcomes. METHODS We reviewed the records of 54 consecutively treated patients with recurrent glioblastoma with ECOG 0 or 1 at recurrence and conducted Kaplan-Meier analysis with Log-rank testing to determine significance between groups. RESULTS We identified 24 patients who were treated without radiation therapy (control) while 30 patients underwent re-irradiation using radiosurgery (ReSRS) with a median total dose of 25Gy in five fractions. All patients had completed standard initial therapy, and there was no difference in the time to recurrence between the two groups (10 months for control, 15 months for ReSRS, [P = 0.17, HR for progression 0.65 (95% CI 0.38-1.13)]. A larger proportion of patients in the control arm (54%) had subtotal or gross total resection of the recurrence compared with the ReSRS group (44%, P < 0.05). The majority of patients had recurrence confirmed with biopsy (18/22 in control group, 25/31 in the ReSRS group). MGMT methylation status did not differ between control vs ReSRS (29% vs. 27%). ReSRS was associated with improved median survival from the time of first recurrence of 11.6 months versus 3.8 months in the control arm [P< 0.0001, HR for death 0.33 (95% CI 0.18-0.6)]. CONCLUSIONS In a group of patients with high performance status diagnosed with recurrent glioblastoma, reirradiation with stereotactic radiosurgery was associated with nearly one year median survival after recurrence. Additional analyses are warranted to determine the impact of concurrent systemic therapies with irradiation and underlying tumor or patient factors to predict outcomes.


Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3926
Author(s):  
Yuan-Mao Lin ◽  
Iwan Paolucci ◽  
Kristy K. Brock ◽  
Bruno C. Odisio

Image-guided ablation can provide effective local tumor control in selected patients with CLM. A randomized controlled trial suggested that radiofrequency ablation combined with systemic chemotherapy resulted in a survival benefit for patients with unresectable CLM, compared to systemic chemotherapy alone. For small tumors, ablation with adequate margins can be considered as an alternative to resection. The improvement of ablation technologies can allow the treatment of tumors close to major vascular structures or bile ducts, on which the applicability of thermal ablation modalities is challenging. Several factors affect the outcomes of ablation, including but not limited to tumor size, number, location, minimal ablation margin, RAS mutation status, prior hepatectomy, and extrahepatic disease. Further understanding of the impact of tumor biology and advanced imaging guidance on overall patient outcomes might help to tailor its application, and improve outcomes of image-guided ablation.


2017 ◽  
Vol 31 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Rossella Di Franco ◽  
Valentina Borzillo ◽  
Vincenzo Ravo ◽  
Sara Falivene ◽  
Francesco Jacopo Romano ◽  
...  

Objective The aim of this work was to evaluate the impact of stereotactic radiosurgery/fractionated stereotactic radiotherapy with the Cyberknife system on local disease control, clinical outcome and toxicity in patients with meningioma, according to the site and histological grade of lesion. From January 2013 to April 2017, 52 patients with intracranial meningiomas were treated with the Cyberknife system. Twenty-four patients had undergone previous surgery: 38% gross total resection, 10% subtotal resection; 27 patients underwent no surgery; 22 patients had a recurrence of meningioma. Methods Radiosurgery was used for lesions smaller than 2 cm, stereotactic radiotherapy for lesions larger than 2 cm, or smaller but close to a critical site such as the optical chiasm, optic pathway or brainstem. Results Local control and clinical outcomes were analysed. Median follow-up was 20 months: six patients died, one after re-surgery died from post-surgical sepsis, three from heart disease. Progression-free survival had a mean value of 38.3 months and overall survival of 41.6 months. We evaluated at 12 months 28 patients (100% local control); at 24 months 19 patients (89% local control); at 36 months nine patients (89% local control). At baseline, 44/52 patients (85%) were symptomatic: 19 visual disorders, 17 motor disorders, six hearing disorders, 10 headache and six epilepsy. Visual symptoms remained unchanged in 52%, improved in 32%, resolved in 16%. Headache was improved in 40%, resolved in 10%, unchanged in 50%. Epilepsy was resolved in 17%, unchanged in 33%, worsened in 33%. Conclusions Stereotactic radiosurgery/fractionated stereotactic radiotherapy with Cyberknife provides a good local disease control, improving visual, hearing and motor symptoms.


2021 ◽  
pp. 1-9
Author(s):  
I. Jonathan Pomeraniec ◽  
Zhiyuan Xu ◽  
Cheng-Chia Lee ◽  
Huai-Che Yang ◽  
Tomas Chytka ◽  
...  

OBJECTIVE Stereotactic radiosurgery (SRS) provides a safe and effective therapeutic modality for patients with pituitary adenomas. The mechanism of delayed endocrine deficits based on targeted radiation to the hypothalamic-pituitary axis remains unclear. Radiation to normal neuroendocrine structures likely plays a role in delayed hypopituitarism after SRS. In this multicenter study by the International Radiosurgery Research Foundation (IRRF), the authors aimed to evaluate radiation tolerance of structures surrounding pituitary adenomas and identify predictors of delayed hypopituitarism after SRS for these tumors. METHODS This is a retrospective review of patients with pituitary adenomas who underwent single-fraction SRS from 1997 to 2019 at 16 institutions within the IRRF. Dosimetric point measurements of 14 predefined neuroanatomical structures along the hypothalamus, pituitary stalk, and normal pituitary gland were made. Statistical analyses were performed to determine the impact of doses to critical structures on clinical, radiographic, and endocrine outcomes. RESULTS The study cohort comprised 521 pituitary adenomas treated with SRS. Tumor control was achieved in 93.9% of patients over a median follow-up period of 60.1 months, and 22.5% of patients developed new loss of pituitary function with a median treatment volume of 3.2 cm3. Median maximal radiosurgical doses to the hypothalamus, pituitary stalk, and normal pituitary gland were 1.4, 7.2, and 11.3 Gy, respectively. Nonfunctioning adenoma status, younger age, higher margin dose, and higher doses to the pituitary stalk and normal pituitary gland were independent predictors of new or worsening hypopituitarism. Neither the dose to the hypothalamus nor the ratio between doses to the pituitary stalk and gland were significant predictors. The threshold of the median dose to the pituitary stalk for new endocrinopathy was 10.7 Gy in a single fraction (OR 1.77, 95% CI 1.17–2.68, p = 0.006). CONCLUSIONS SRS for the treatment of pituitary adenomas affords a high tumor control rate with an acceptable risk of new or worsening endocrinopathy. This evaluation of point dosimetry to adjacent neuroanatomical structures revealed that doses to the pituitary stalk, with a threshold of 10.7 Gy, and doses to the normal gland significantly increased the risk of post-SRS hypopituitarism. In patients with preserved pre-SRS neuroendocrine function, limiting the dose to the pituitary stalk and gland while still delivering an optimal dose to the tumor appears prudent.


2008 ◽  
Vol 101 (4) ◽  
pp. 376-382 ◽  
Author(s):  
William T. Brown ◽  
Xiaodong Wu ◽  
John F. Fowler ◽  
Silvio García ◽  
Fahed Fayad ◽  
...  

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