scholarly journals Longitudinal Changes in Brain Diffusion MRI Indices during and after Proton Beam Therapy in a Child with Pilocytic Astrocytoma: A Case Report

Diagnostics ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Lisa Novello ◽  
Nivedita Agarwal ◽  
Sabina Vennarini ◽  
Stefano Lorentini ◽  
Domenico Zacà ◽  
...  
Keyword(s):  
Proton Beam ◽  
Pilocytic Astrocytoma ◽  
Tumor Volume ◽  
Diffusion Tensor ◽  
Free Water ◽  
Pediatric Brain Tumor ◽  
Proton Beam Therapy ◽  
Microstructural Changes ◽  
Fluid Content

Proton beam therapy (PBT) is an effective pediatric brain tumor treatment. However, the resulting microstructural changes within and around irradiated tumors are unknown. We retrospectively applied diffusion tensor imaging (DTI) and free-water imaging (FWI) on diffusion-weighted magnetic resonance imaging (dMRI) data to monitor microstructural changes during the PBT and after 8 months in a pilocytic astrocytoma (PA) and normal-appearing white matter (NAWM). We evaluated the conventional MRI- and dMRI-derived indices from six MRI sessions (t0–t5) in a Caucasian child with a hypothalamic PA: at baseline (t0), during the PBT (t1–t4) and after 8 months (t5). The tumor voxels were classified as “solid” or “fluid” based on the FWI. While the tumor volume remained stable during the PBT, the dMRI analyses identified two different response patterns: (i) an increase in fluid content and diffusivity with anisotropy reductions in the solid voxels at t1, followed by (ii) smaller variations in fluid content but higher anisotropy in the solid voxels at t2–t4. At follow-up (t5), the tumor volume, fluid content, and diffusivity in the solid voxels increased. The NAWM showed dose-dependent microstructural changes. The use of the dMRI and FWI showed complex dynamic microstructural changes in the irradiated mass during the PBT and at follow-up, opening new avenues in our understanding of radiation-induced pathophysiologic mechanisms in tumors and the surrounding tissues.

scholarly journals Longitudinal changes in brain diffusion MRI indices during and after proton beam therapy in a child with pilocytic astrocytoma: a case report

2021 ◽  
Author(s):  
Lisa Novello ◽  
Nivedita Agarwal ◽  
Stefano Lorentini ◽  
Sabina Vennarini ◽  
Domenico Zacà ◽  
...  
Keyword(s):  
Proton Beam ◽  
Pilocytic Astrocytoma ◽  
Tumor Volume ◽  
Diffusion Tensor ◽  
Free Water ◽  
Pediatric Brain Tumor ◽  
Proton Beam Therapy ◽  
Microstructural Changes ◽  
Fluid Content

ABSTRACTBackgroundProton beam therapy (PBT) is an effective pediatric brain tumor treatment. However, resulting microstructural changes within and around irradiated tumors are unknown. We retrospectively applied Diffusion-Tensor-Imaging (DTI) and Free-Water-Imaging (FWI) on diffusion-weighted Magnetic Resonance Imaging (dMRI) data to monitor microstructural changes during-PBT and after 8 months, in a pilocytic astrocytoma (PA) and normal-appearing white matter (NAWM).MethodsWe evaluated conventional MRI and dMRI-derived indices from six MRI sessions in a child with a hypothalamic PA: at baseline (t0), during-PBT (t1-t4), and after 8 months (t5). Tumor voxels were classified as “solid” or “fluid” based on FWI.ResultsWhile during PBT tumor volume remained stable, dMRI analyses identified two different response patterns: i) an increase in fluid content and diffusivity with anisotropy reductions in solid voxels at t1, followed by ii) smaller variations in fluid content but higher anisotropy in solid voxels at t2-t4. At follow-up (t5), tumor volume, its fluid content, and diffusivity in solid voxels increased. NAWM showed dose-dependent microstructural changes.ConclusionsThe use of dMRI and FWI showed complex dynamic microstructural changes in the irradiated mass during PBT and at follow-up, opening new avenues in our understanding of radiation-induced pathophysiologic mechanisms in tumor and surrounding tissues.

scholarly journals Feasibility of Proton Beam Therapy as a Rescue Therapy in Heavily Pre-Treated Retinoblastoma Eyes

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1862
Author(s):  
Eva Biewald ◽  
Tobias Kiefer ◽  
Dirk Geismar ◽  
Sabrina Schlüter ◽  
Anke Manthey ◽  
...  
Keyword(s):  
Proton Beam ◽  
Rescue Therapy ◽  
Therapeutic Option ◽  
Proton Beam Therapy ◽  
External Beam Radiation ◽  
Time Interval ◽  
Beam Radiation ◽  
Primary Tumors ◽  
Increased Risk

Despite the increased risk of subsequent primary tumors (SPTs) external beam radiation (EBRT) may be the only therapeutic option to preserve a retinoblastoma eye. Due to their physical properties, proton beam therapy (PBT) offers the possibility to use the effectiveness of EBRT in tumor treatment and to decisively reduce the treatment-related morbidity. We report our experiences of PBT as rescue therapy in a retrospectively studied cohort of 15 advanced retinoblastoma eyes as final option for eye-preserving therapy. The average age at the initiation of PBT was 35 (14–97) months, mean follow-up was 22 (2–46) months. Prior to PBT, all eyes were treated with systemic chemotherapy and a mean number of 7.1 additional treatments. Indication for PBT was non-feasibility of intra-arterial chemotherapy (IAC) in 10 eyes, tumor recurrence after IAC in another 3 eyes and diffuse infiltrating retinoblastoma in 2 eyes. Six eyes (40%) were enucleated after a mean time interval of 4.8 (1–8) months. Cataract formation was the most common complication affecting 44.4% of the preserved eyes, yet 77.8% achieved a visual acuity of >20/200. Two of the 15 children treated developed metastatic disease during follow-up, resulting in a 13.3% metastasis rate. PBT is a useful treatment modality as a rescue therapy in retinoblastoma eyes with an eye-preserving rate of 60%. As patients are at lifetime risk of SPTs consistent monitoring is mandatory.

Enhanced Fiber Tractography Using Edema Correction: Application and Evaluation in High-Grade Gliomas

Neurosurgery ◽  
2021 ◽  
Author(s):  
Fraser Henderson Jr ◽  
Drew Parker ◽  
Anupa A Vijayakumari ◽  
Mark Elliott ◽  
Timothy Lucas ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Free Water ◽  
High Grade Glioma ◽  
Fiber Tracking ◽  
High Grade ◽  
Peritumoral Edema ◽  
Fiber Tractography ◽  
Motor Pathways

Abstract BACKGROUND A limitation of diffusion tensor imaging (DTI)-based tractography is peritumoral edema that confounds traditional diffusion-based magnetic resonance metrics. OBJECTIVE To augment fiber-tracking through peritumoral regions by performing novel edema correction on clinically feasible DTI acquisitions and assess the accuracy of the fiber-tracks using intraoperative stimulation mapping (ISM), task-based functional magnetic resonance imaging (fMRI) activation maps, and postoperative follow-up as reference standards. METHODS Edema correction, using our bi-compartment free water modeling algorithm (FERNET), was performed on clinically acquired DTI data from a cohort of 10 patients presenting with suspected high-grade glioma and peritumoral edema in proximity to and/or infiltrating language or motor pathways. Deterministic fiber-tracking was then performed on the corrected and uncorrected DTI to identify tracts pertaining to the eloquent region involved (language or motor). Tracking results were compared visually and quantitatively using mean fiber count, voxel count, and mean fiber length. The tracts through the edematous region were verified based on overlay with the corresponding motor or language task-based fMRI activation maps and intraoperative ISM points, as well as at time points after surgery when peritumoral edema had subsided. RESULTS Volume and number of fibers increased with application of edema correction; concordantly, mean fractional anisotropy decreased. Overlay with functional activation maps and ISM-verified eloquence of the increased fibers. Comparison with postsurgical follow-up scans with lower edema further confirmed the accuracy of the tracts. CONCLUSION This method of edema correction can be applied to standard clinical DTI to improve visualization of motor and language tracts in patients with glioma-associated peritumoral edema.

The Effectiveness of Diffusion Tensor Imaging in Determining Radiological Response after Radiosurgery in Patients with Vestibular Schwannoma

2021 ◽  
Vol 17 ◽  
Author(s):  
Dilek Hacer Cesme ◽  
Alpay Alkan ◽  
Lutfullah Sari ◽  
Ahmet Kaya ◽  
Ismail Yurtsever ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Vestibular Schwannoma ◽  
Tumor Volume ◽  
Diffusion Tensor ◽  
Response To Treatment ◽  
Adc Values ◽  
Radiological Response ◽  
Group 2 ◽  
Group 1

Background: The effectiveness of Diffusion Tensor Imaging (DTI) in demonstrating functional changes in the tumor in determining the response to treatment after radiosurgery in patients with vestibular schwannoma (VS) is not clear yet. Objective: The study aimed to determine the change total in tumor volume (TTV) in terms of radiological response in patients who had VS and were treated with radiosurgery and investigate the relationship between the TTV, follow-up times and DTI parameters. Methods: Thirty-one patients were assessed using DTI and MRI. TTV, apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated. Patients were divided into tree groups: those who responded to the treatment (group 1) (n=11), who did not (group 0) (n=9) and who remained stable (group 2) (n=11). Background: The effectiveness of Diffusion Tensor Imaging (DTI) in demonstrating functional changes in the tumor in determining the response to treatment after radiosurgery in patients with vestibular schwannoma (VS) is not clear yet. Objective: The study aimed to determine the change total in tumor volume (TTV) in terms of radiological response in patients who had VS and were treated with radiosurgery and investigate the relationship between the TTV, follow-up times and DTI parameters. Methods: Thirty-one patients were assessed using DTI and MRI. TTV, apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated. Patients were divided into tree groups: those who responded to the treatment (group 1) (n=11), who did not (group 0) (n=9) and who remained stable (group 2) (n=11). Results: The mean duration of follow-up was 28.81±14 months. ADC values increased in patients with VS after radiosurgery (p=0.004). There was no statistical difference in the FA values. A significant reduction in TTV after radiosurgery was detected in group 1 (p=0.003). ADC values increased significantly after radiosurgery in group 2 (p=0.04). Although there were no significant differences, ADC values after radiosurgery increased in group 1 and group 0. Conclusions: ADC values continuously increase due to radiation damage in the period before the tumor volume shrinks after radiosurgery. We think that it is not appropriate to diagnose inadequate treatment or progression only when TTV is evaluated in terms of response to treatment in the early period after radiosurgery.

scholarly journals Proton beam therapy for malignant transformation of intracranial epidermoid cyst

2019 ◽  
Vol 12 (7) ◽  
pp. e229388
Author(s):  
Zhe Chen ◽  
Masayuki Araya ◽  
Hiroshi Onishi
Keyword(s):  
Proton Beam ◽  
Malignant Transformation ◽  
Epidermoid Cyst ◽  
Clinical Case ◽  
Proton Beam Therapy ◽  
Facial Paresis ◽  
Surgical Interventions ◽  
Radiation Induced ◽  
Intracranial Epidermoid

We report the first clinical case on the successful use of proton beam therapy in the management of malignant transformation of intracranial epidermoid cyst. A 43-year-old man was initially diagnosed as this disease with left facial paresis, hypesthesia and hypoalgesia in the territories of the trigeminal nerve. After failure of surgical interventions, he was referred to our radiation centre. We performed a postoperative proton beam therapy for treatment. We delivered a total dose of 57 GyE in 31 fractions. He tolerated the treatment well with mild acute toxicities and remained healthy and functional by 2-year follow-up postradiotherapy. No evidence of delayed radiation-induced neurotoxicity was observed.

Intravitreal Dexamethasone Implant (Ozurdex®) for Exudative Retinal Detachment after Proton Beam Therapy for Choroidal Melanoma

2017 ◽  
Vol 27 (5) ◽  
pp. 596-600 ◽  
Author(s):  
Ariane Malclès ◽  
Anh-Minh Nguyen ◽  
Thibaud Mathis ◽  
Jean-Daniel Grange ◽  
Laurent Kodjikian
Keyword(s):  
Visual Acuity ◽  
Retinal Detachment ◽  
Proton Beam ◽  
Safety Profile ◽  
Choroidal Melanoma ◽  
Case Series ◽  
Proton Beam Therapy ◽  
Exudative Retinal Detachment ◽  
Dexamethasone Implant

Purpose To evaluate the efficacy and safety of intravitreal 0.7-mg dexamethasone implant (DEX-I) (Ozurdex®) in the treatment of extensive exudative retinal detachment (RD) associated with uveal melanoma treated using proton beam therapy (PBT). Methods Data from 10 patients with exudative RD after PBT treated with intravitreal injection of 0.7-mg DEX-I were reviewed retrospectively. The main outcome measures were resolution of exudative RD, visual acuity, and safety profile. Results Mean age was 55.6 years (range 34-85). Mean time between PBT and DEX-I was 12.4 months (range 3-25). Mean follow-up was 9.9 months (range 4-15). Intravitreal Ozurdex® reduced exudative RD in 7 cases (70%) on average 3.1 months after injection with complete resolution of RD in 6 of these (60%). For half of the patients, their level of vision remained stable; the other half experienced a deterioration in visual acuity at the end of follow-up. No adverse effects were observed. Conclusions In this small case series, treatment with intravitreal DEX-I reduced exudative RD in the majority of cases and had an acceptable safety profile.

Radiation Therapy for Arteriovenous Malformations: A Review

Neurosurgery ◽  
1990 ◽  
Vol 26 (5) ◽  
pp. 725-735 ◽  
Author(s):  
Christopher S. Ogilvy
Keyword(s):  
Proton Beam ◽  
Gamma Knife ◽  
Linear Accelerator ◽  
Arteriovenous Malformations ◽  
Proton Beam Therapy ◽  
Recurrent Hemorrhage ◽  
Brain Irradiation ◽  
History Of ◽  
Gamma Knife Therapy

Abstract There have been numerous case reports and series of patients treated with partial brain irradiation, linear accelerator-based radiosurgery, gamma knife radiosurgery, and Bragg peak therapy for inoperable arteriovenous malformations (AVMs). These cases are summarized and compared. There is convincing evidence that radiation therapy does have a role in obliterating carefully chosen inoperable lesions. The changes that occur in vessel walls after radiation are reviewed. Data about x-ray and gamma radiation are mostly historical and difficult to evaluate because of the techniques of partial brain irradiation. There is a lack of data about the volume of AVM treated and the minimum dose delivered to the AVM nidus. For gamma knife, heavy particle, and linear accelerator therapy, more complete data are available. The incidence of hemorrhage during the first 2 years after treatment, when radiation-induced vascular changes are proposed to occur, is approximately 2.6% per year for gamma knife therapy, 2% per year for proton beam therapy, 2.3% per year for helium beam therapy, and 2.3% per year for linear accelerator therapy. These rates are similar to the recurrence rate for hemorrhage of 2.2 to 3% per year expected based on the natural history of untreated AVMs. If AVM obliteration after therapy is not achieved, the incidence of recurrent hemorrhage remains between 2% per year after treatment with gamma knife therapy. The incidence of hemorrhage for all patients treated was reported as 0.15% per year in one study and 20% over 8 years in a follow-up study using proton beam therapy. Mortality from hemorrhage after treatment was 0.6% after gamma knife therapy, 2.3% after helium beam therapy, and 2 to 5% after proton beam therapy. These figures for mortality are all lower than the 11% observed for the natural history of untreated AVMs. Permanent neurological deficits experienced as a complication of radiation occurred in 2 to 3% of patients treated with gamma knife therapy, 4% of patients treated with helium beam therapy, 1.7% of patients treated with proton beam therapy, and 3% of patients treated with stereotactic linear accelerator therapy. Proton beam therapy has been used for both small and large lesions. The majority of lesions in patients treated with gamma knife, helium beam, and linear accelerator therapy have been small (usually less than 3.0 cm average diameter) lesions. In these patients with small inoperable lesions treated with accurately directed fields of isocentric radiation, the greatest incidence of AVM obliteration has been observed on follow-up angiograms. Larger lesions may undergo vascular wall thickening with subsequent protection from recurrent hemorrhage, but more data are needed to support this hypothesis.

scholarly journals Proton Therapy for Juvenile Pilocytic Astrocytoma: Quantifying Treatment Responses by Magnetic Resonance Diffusion Tensor Imaging

2016 ◽  
Vol 3 (3) ◽  
pp. 414-420
Author(s):  
Ping Hou ◽  
Katherine H. Zhu ◽  
Peter C. Park ◽  
Heng Li ◽  
Anita Mahajan ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Brain Tissue ◽  
Proton Therapy ◽  
Pilocytic Astrocytoma ◽  
Diffusion Tensor ◽  
Resonance Imaging ◽  
Mr Images ◽  
Juvenile Pilocytic Astrocytoma ◽  
Tissue Responses

Purpose: Proton therapy is increasingly used to treat pediatric brain tumors. However, the response of both tumors and healthy tissues to proton therapy is currently under investigation. One way of assessing this response is magnetic resonance (MR) diffusion tensor imaging (DTI), which can measure molecular mobility at the cellular level, quantified by the apparent diffusion coefficient (ADC). In addition, DTI may reveal axonal fiber directional information in white matter, quantified by fractional anisotropy (FA). Here we report use of DTI to assess tumor and unexposed healthy brain tissue responses in a child who received proton therapy for juvenile pilocytic astrocytoma. Materials and Methods: A 10-year-old boy with recurrent juvenile pilocytic astrocytoma of the left thalamus received proton therapy to a dose of 50.4Gy (RBE) in 28 fractions. Functional magnetic resonance imaging was used to select beam angles for treatment planning. Over the course of the 7-year follow-up period, magnetic resonance imaging including DTI was done to assess response. The MR images were registered to the treatment-planning computed tomography scan, and the gross tumor volume (GTV) was mapped onto the MR images at each follow-up. The GTV contour was then mirrored to the right side of brain through the midline to represent unexposed healthy brain tissue. Results: Proton therapy delivered the full prescribed dose to the target while completely sparing the contralateral brain. The MR ADC images obtained before and after proton therapy showed that enhancement corresponding to the GTV had nearly disappeared by 25 months. The ADC and FA measurements confirmed that contralateral healthy brain tissue was not affected, and the GTV reverted to clinically normal ADC and FA values. Conclusion: Use of DTI allowed quantitative evaluation of tumor and healthy brain tissue responses to proton therapy.

scholarly journals Radiotherapeutic Management of Synchronous Prostate and Rectal Cancers Using Proton Beam Therapy

2021 ◽  
Author(s):  
Jennifer S. Chiang ◽  
Nathan Y. Yu ◽  
Janina T. Sheedy ◽  
Robin E. Hayden ◽  
Pamela R. Lemish ◽  
...  
Keyword(s):  
Proton Beam ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Proton Beam Therapy ◽  
Definitive Treatment ◽  
Mild Anemia ◽  
Surveillance Imaging ◽  
Rectal Cancers ◽  
American Urological Association

Abstract Treatment of synchronous prostate and rectal cancers is a rare yet challenging problem with compounded toxicities. We report a case of a 65-year-old man who underwent proton beam therapy (PBT) with concurrent capecitabine and hormonal therapy for his synchronously found prostate (intermediate-risk) and rectal (cT2, N2b, stage IIIB) cancers; he also received low anterior resection. Before PBT, the patient experienced hematochezia. His baseline American Urological Association symptom score was a total of 0, and he was not sexually active. He completed PBT with grade 1 acute toxicities including fatigue, nausea, and increased urinary and bowel frequencies. He also developed mild anemia (10.7), which was resolved. Subsequent surgical pathology showed a pathologic complete response in his rectum. At follow-up of 2.5 years, he remained disease-free on surveillance imaging for both malignancies and reported increased bowel urgency and frequency, minimal urinary leakage when having urgency, and peripheral neuropathy. This case, along with a succinct literature review, demonstrates that PBT can be successful in the definitive treatment of synchronous prostate and rectal cancers with minimal toxicities. Further research is required to evaluate the efficacy and side effect profiles of PBT.

scholarly journals Follow-up, surgery and proton beam therapy for a pituitary sella chondrosarcoma

2014 ◽  
Author(s):  
Yasir Mohamed Elhassan ◽  
Bernie Foran ◽  
Tim Hodgson ◽  
Paul Ince ◽  
Saurabh Sinha ◽  
...  
Keyword(s):  
Proton Beam ◽  
Proton Beam Therapy
Sign in / Sign up

Export Citation Format

Share Document