Tumor physiological changes during hypofractionated stereotactic body radiation therapy assessed using multi-parametric magnetic resonance imaging.
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ABSTRACT:
SUBMITTER: Zhou H
PROVIDER: S-EPMC5514922 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Stereotactic body radiation (SBRT) is an emerging tool in radiation oncology in which the targeting accuracy is improved via the detection and processing of a three-dimensional coordinate system that is aligned to the target. With improved targeting accuracy, SBRT allows for the minimization of normal tissue volume exposed to high radiation dose as well as the escalation of fractional dose delivery. The goal of SBRT is to minimize toxicity while maximizing tumor control. This review will discuss the basic principles of SBRT, the radiobiology of hypofractionated radiation and the outcome from published clinical trials of SBRT, with a focus on late toxicity after SBRT. While clinical data has shown SBRT to be safe in most circumstances, more data is needed to refine the ideal dose-volume metrics.
| S-EPMC2596155 | biostudies-literature
Project description:PurposeStereotactic body radiotherapy is increasingly used for the treatment of oligometastatic disease. Magnetic resonance-guided stereotactic radiotherapy (MRgSBRT) offers the opportunity to perform dose escalation protocols while reducing the unnecessary irradiation of the surrounding organs at risk. The aim of this retrospective, monoinstitutional study is to evaluate the feasibility and clinical benefit (CB) of MRgSBRT in the setting of oligometastatic patients.Materials and methodsData from oligometastatic patients treated with MRgSBRT were collected. The primary objectives were to define the 12-month progression-free survival (PFS) and local progression-free survival (LPFS) and 24-month overall survival (OS) rate. The objective response rate (ORR) included complete response (CR) and partial response (PR). CB was defined as the achievement of ORR and stable disease (SD). Toxicities were also assessed according to the CTCAE version 5.0 scale.ResultsFrom February 2017 to March 2021, 59 consecutive patients with a total of 80 lesions were treated by MRgSBRT on a 0.35 T hybrid unit. CR and PR as well as SD were observed in 30 (37.5%), 7 (8.75%), and 17 (21.25%) lesions, respectively. Furthermore, CB was evaluated at a rate of 67.5% with an ORR of 46.25%. Median follow-up time was 14 months (range: 3-46 months). The 12-month LPFS and PFS rates were 70% and 23%, while 24-month OS rate was 93%. No acute toxicity was reported, whereas late pulmonary fibrosis G1 was observed in 9 patients (15.25%).ConclusionMRgSBRT was well tolerated by patients with reported low toxicity levels and a satisfying CB.
| S-EPMC10116467 | biostudies-literature
Project description:Reirradiation is a feasible option for patients who do not otherwise have treatment options available. Depending on the location and extent of the tumor, reirradiation may be accomplished with external beam radiotherapy, brachytherapy, radiosurgery, or intensity modulated radiation therapy (IMRT). Although there has been limited experience with hypofractionated stereotactic radiotherapy (hSRT), it may have the potential for curative or palliative treatment due to its advanced precision technology, particularly for limited small lesion. On the other hand, severe late adverse reactions are anticipated with reirradiation than with initial radiation therapy. The risk of severe late complications has been reported to be 20- 40% and is related to prior radiotherapy dose, primary site, retreatment radiotherapy dose, treatment volume, and technique. Early researchers have observed lethal bleeding in such patients up to a rate of 14%. Recently, similar rate of 10-15% was observed for fatal bleeding with use of modern hSRT like in case of carotid blowout syndrome. To determine the feasibility and efficacy of reirradiation using modern technology, we reviewed the pertinent literature. The potentially lethal side effects should be kept in mind when reirradiation by hSRT is considered for treatment, and efforts should be made to minimize the risk in any future investigations.
| S-EPMC3179722 | biostudies-literature
Project description:This study reports dose corresponding to visible radiation induced liver damage following Stereotactic Body Radiation Therapy (SBRT) for liver metastasis, and the optimal time for follow up scans using post radiation imaging. Diagnostic magnetic resonance scans of nine patients treated with liver SBRT using a 0.35 T MRI-guided radiotherapy system were analyzed. The dice coefficients between the region of visible liver damage and the delivered dose were calculated. A median dose of 35 Gy correlated most closely with the visible radiation induced liver damage. We compared scans over two to nine months and observed maximal dice coefficients at two to five months post radiation. We have presented a new method for developing treatment planning guidelines for liver SBRT.
| S-EPMC8058022 | biostudies-literature
Project description:Background Little is known about the effectiveness of hypofractionated radiation therapy (HFRT) or stereotactic body radiation therapy (SBRT) for the treatment of patients with oligometastatic (OM) or oligoprogressive (OP) thymic malignancies. Methods We retrospectively reviewed Stage IV patients with OM or OP thymic malignancies treated with HFRT or SBRT between 2009–2021. We defined OM as 5 or fewer sites of metastatic disease and OP as 5 or fewer sites of metastatic disease increasing in radiological size at the time of radiation. Analysis of local failure (LF, defined as failure within a treated lesion) and distant failure (DF, defined as failure outside the treated lesion) was done at the treatment course level using univariate analysis Fine-Gray regression adjusted for clustering. Analysis of overall survival (OS) and progression-free survival (PFS) was done at the patient level utilizing only the first course of treatment for each patient. Results Our analysis included 50 patients with 92 treatment courses. Patients had thymoma (50%), thymic carcinoma (TC, 40%), or atypical thymic carcinoid (ATC, 10%). The median biologic effective dose (BED) was 51 Gy (range, 38–106 Gy). With a median follow-up of 36 months, the median OS and PFS were 50 and 6.5 months, respectively. Patients with TC or ATC had significantly worse PFS than those with thymoma [hazard ratio (HR) 2.37; 95% confidence interval (CI): 1.18–4.76, P=0.013], but similar OS (P=0.55) and LF (P=0.729). Treated thymoma lesions had a lower hazard of DF than TC/ATC lesions, but this was not statistically significant (HR 0.59; 95% CI: 0.34–1.03, P=0.065). Lesions treated to a BED higher than 60 Gy had lower hazards of LF and DF, although this was not statistically significant (HR 0.29; 95% CI: 0.05–1.68, P=0.166 and HR 0.58; 95% CI: 0.3–1.1, P=0.096, respectively). Conclusions In our analysis, patients with TC or ATC had worse PFS than those with thymoma. Treated thymoma and TC/ATC lesions had similar hazards of LF, indicating similar radiation sensitivity in thymic lesions regardless of histology. There was a trend towards increased local control with higher BED regimens, but this did not reach statistical significance. Overall, our analysis points to the need for clinical trials on HFRT/SBRT for the treatment of these rare malignancies.
| S-EPMC9792842 | biostudies-literature
Project description:PURPOSE:To determine the natural history of imaging findings seen on magnetic resonance imaging (MRI) of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT). Although arterial hyperenhancement is a key feature of untreated HCC, our clinical experience suggested that tumors that never progressed could still show hyperenhancement. Therefore, we undertook a systematic study to test the hypothesis that persistent arterial phase hyperenhancement (APHE) after SBRT is an expected finding that does not suggest failure of treatment. METHODS AND MATERIALS:One hundred forty-six patients undergoing SBRT for HCC between January 1, 2007, and December 31, 2015, were screened retrospectively using an institutional review board-approved prospectively maintained registry. Inclusion criteria were (1) HCC treated with SBRT, (2) multiphasic MRI ?3 months before SBRT, (3) up to 1 year of follow-up MRI post-SBRT, and (4) cirrhosis. The exclusion criterion was ?3 months of locoregional therapy to the liver segment containing the SBRT-treated HCC. Pre- and post-SBRT MRI from up to 3 years were analyzed in consensus by independent pairs of subspecialty-trained radiologists to determine the temporal evolution of major features for HCC and imaging findings in off-target parenchyma. RESULTS:Sixty-two patients with 67 HCCs (Organ Procurement and Transplantation Network imaging criteria [OPTN] 5a [n = 26], OPTN 5b [n = 28], OPTN 5x [n = 7]; Liver Imaging Reporting Data System [LI-RAD]-M [n = 4] and LiRADs-4 [n = 2]) were studied. Tumor size either decreased (66% [44 of 67]) or remained unchanged (34% [23 of 67]) within the first 12 months. Post-SBRT APHE was common (58% [39 of 67]). When graded using modified Response Evaluation Criteria in Solid Tumors at 3 to 6 months, 25% (17 of 67) met criteria for complete response and 75% (50 of 67) met criteria for stable disease. CONCLUSIONS:SBRT is an effective locoregional treatment option for HCC. Persistent APHE is common and does not necessarily indicate viable neoplasm; thus, standard response assessment such as modified Response Evaluation Criteria should be used with caution, particularly in the early phases after SBRT therapy.
| S-EPMC6301102 | biostudies-literature
Project description:ObjectiveThe aim of this study was to characterize response to photodynamic therapy (PDT) in a mouse cancer model using a multi-parametric quantitative MRI protocol and to identify MR parameters as potential biomarkers for early assessment of treatment outcome.MethodsCT26.WT colon carcinoma tumors were grown subcutaneously in the hind limb of BALB/c mice. Therapy consisted of intravenous injection of the photosensitizer Bremachlorin, followed by 10 min laser illumination (200 mW/cm2) of the tumor 6 h post injection. MRI at 7 T was performed at baseline, directly after PDT, as well as at 24 h, and 72 h. Tumor relaxation time constants (T1 and T2) and apparent diffusion coefficient (ADC) were quantified at each time point. Additionally, Gd-DOTA dynamic contrast-enhanced (DCE) MRI was performed to estimate transfer constants (Ktrans) and volume fractions of the extravascular extracellular space (ve) using standard Tofts-Kermode tracer kinetic modeling. At the end of the experiment, tumor viability was characterized by histology using NADH-diaphorase staining.ResultsThe therapy induced extensive cell death in the tumor and resulted in significant reduction in tumor growth, as compared to untreated controls. Tumor T1 and T2 relaxation times remained unchanged up to 24 h, but decreased at 72 h after treatment. Tumor ADC values significantly increased at 24 h and 72 h. DCE-MRI derived tracer kinetic parameters displayed an early response to the treatment. Directly after PDT complete vascular shutdown was observed in large parts of the tumors and reduced uptake (decreased Ktrans) in remaining tumor tissue. At 24 h, contrast uptake in most tumors was essentially absent. Out of 5 animals that were monitored for 2 weeks after treatment, 3 had tumor recurrence, in locations that showed strong contrast uptake at 72 h.ConclusionDCE-MRI is an effective tool for visualization of vascular effects directly after PDT. Endogenous contrast parameters T1, T2, and ADC, measured at 24 to 72 h after PDT, are also potential biomarkers for evaluation of therapy outcome.
| S-EPMC5098733 | biostudies-literature
Project description:BackgroundTo evaluate acute and late genitourinary and gastrointestinal toxicities and patient reported urinary and sexual function following accelerated, hypofractionated external beam radiotherapy to the prostate, seminal vesicles and pelvic lymph nodes and high dose rate (HDR) brachytherapy or stereotactic body radiation therapy (SBRT) prostate boost.MethodsPatients at a single institution with NCCN intermediate- and high-risk localized prostate cancer with logistical barriers to completing five weeks of whole pelvic radiotherapy (WPRT) were retrospectively reviewed for toxicity following accelerated, hypofractionated WPRT (41.25 Gy in 15 fractions of 2.75 Gy). Patients also received prostate boost radiotherapy with either HDR brachytherapy (1 fraction of 15 Gy) or SBRT (19 Gy in 2 fractions of 9.5 Gy). The duration of androgen deprivation therapy was at the discretion of the treating radiation oncologist. Toxicity was evaluated by NCI CTCAE v 5.0.ResultsBetween 2015 and 2017, 22 patients with a median age of 71 years completed accelerated, hypofractionated WPRT. Median follow-up from the end of radiotherapy was 32 months (range 2-57). 5%, 73%, and 23% of patients had clinical T1, T2, and T3 disease, respectively. 86% of tumors were Gleason grade 7 and 14% were Gleason grade 9. 68% and 32% of patients had NCCN intermediate- and high-risk disease, respectively. 91% and 9% of patients received HDR brachytherapy and SBRT prostate boost following WPRT, respectively. Crude rates of grade 2 or higher GI and GU toxicities were 23% and 23%, respectively. 3 patients (14%) had late or persistent grade 2 toxicities of urinary frequency and 1 patient (5%) had late or persistent GI toxicity of diarrhea. No patient experienced grade 3 or higher toxicity at any time. No difference in patient-reported urinary or sexual function was noted at 12 months.ConclusionsAccelerated, hypofractionated whole pelvis radiotherapy was associated with acceptable GU and GI toxicities and should be further validated for those at risk for harboring occult nodal disease.
| S-EPMC8772149 | biostudies-literature
Project description:Purpose:Daily magnetic resonance (MR)-guided radiation has the potential to improve stereotactic body radiation therapy (SBRT) for tumors of the liver. Magnetic resonance imaging (MRI) introduces unique variables that are untested clinically: electron return effect, MRI geometric distortion, MRI to radiation therapy isocenter uncertainty, multileaf collimator position error, and uncertainties with voxel size and tracking. All could lead to increased toxicity and/or local recurrences with SBRT. In this multi-institutional study, we hypothesized that direct visualization provided by MR guidance could allow the use of small treatment volumes to spare normal tissues while maintaining clinical outcomes despite the aforementioned uncertainties in MR-guided treatment. Methods and materials:Patients with primary liver tumors or metastatic lesions treated with MR-guided liver SBRT were reviewed at 3 institutions. Toxicity was assessed using National Cancer Institute Common Terminology Criteria for Adverse Events Version 4. Freedom from local progression (FFLP) and overall survival were analyzed with the Kaplan-Meier method and ?2 test. Results:The study population consisted of 26 patients: 6 hepatocellular carcinomas, 2 cholangiocarcinomas, and 18 metastatic liver lesions (44% colorectal metastasis). The median follow-up was 21.2 months. The median dose delivered was 50 Gy at 10 Gy/fraction. No grade 4 or greater gastrointestinal toxicities were observed after treatment. The 1-year and 2-year overall survival in this cohort is 69% and 60%, respectively. At the median follow-up, FFLP for this cohort was 80.4%. FFLP for patients with hepatocellular carcinomas, colorectal metastasis, and all other lesions were 100%, 75%, and 83%, respectively. Conclusions:This study describes the first clinical outcomes of MR-guided liver SBRT. Treatment was well tolerated by patients with excellent local control. This study lays the foundation for future dose escalation and adaptive treatment for liver-based primary malignancies and/or metastatic disease.
| S-EPMC6349638 | biostudies-literature
Project description:PurposeAblative radiation therapy (A-RT) appears to improve outcomes in locally advanced pancreatic cancer (LAPC) yet requires solutions for respiratory and digestive motion. We report outcomes of A-RT for pancreatic cancer using 1.5 T MR-adaptive treatment delivery.MethodsBetween March 2020 and July 2021, we treated 30 patients with pancreatic cancer with 50 Gy in 5 fractions (biologically effective dose [BED10] = 100 Gy10) using a novel compression belt workflow and remote planning on the Unity 1.5 T MR linac system. Cumulative incidence of progression was computed from A-RT initiation with death as a competing risk. Overall (OS) and progression-free survival (PFS) were calculated using Kaplan Meier methods.ResultsOf 30 patients, most (73 %) were locally advanced, 4 (13 %) were metastatic, 2 (7 %) were medically inoperable, and 2 (7 %) were locally recurrent. Most (73 %) received FOLFIRINOX prior to A-RT. Median follow-up times from diagnosis and A-RT were 17.6 (IQR 15.8-23.1) and 11.5 months (IQR 9.7-16.1), respectively. Cumulative incidences at 1-year of local and distant progression were 19.3 % (95 %CI 6.7-36.8 %) and 47.4 % (95 %CI 26.7-65.6 %), respectively. Median OS from diagnosis and A-RT were not reached. One-year OS from diagnosis and A-RT were 96.4 % (95 %CI 77.2-99.5 %) and 80.0 % (95 %CI 57.3-91.4 %), respectively. Median and 1-year PFS were 10.1 months (95 %CI 4.4-14.4) and 39.7 % (95 %CI 20.3-58.5 %), respectively. No grade 3 + toxicities were observed.ConclusionsA-RT using the 1.5 T Unity MR Linac resulted in promising LC and OS with no severe toxicity in patients with LAPC despite radiosensitive organs adjacent to the target volumes. Longer follow-up is needed to assess long-term outcomes.
| S-EPMC9640311 | biostudies-literature