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Radiology. Cardiothoracic Imaging Jun 2024Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium... (Comparative Study)
Comparative Study
Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium score (CACS) and radiation dose reductions compared with the standard 120-kV CT protocol. Materials and Methods This prospective, blinded reader study included 201 participants (mean age, 60 years ± 9.8 [SD]; 119 female, 82 male) who underwent standard 120-kV CT and additional kV-independent and tin filter research CT scans from October 2020 to July 2021. Scans were reconstructed using a Qr36f kernel for standard scans and an Sa36f kernel for research scans simulating artificial 120-kV images. CACS, risk categorization, and radiation doses were compared by analyzing data with analysis of variance, Kruskal-Wallis test, Mann-Whitney test, Bland-Altman analysis, Pearson correlations, and κ analysis for agreement. Results There was no evidence of differences in CACS across standard 120-kV, kV-independent, and tin filter scans, with median CACS values of 1 (IQR, 0-48), 0.6 (IQR, 0-58), and 0 (IQR, 0-51), respectively ( = .85). Compared with standard 120-kV scans, kV-independent and tin filter scans showed excellent correlation in CACS values ( = 0.993 and = 0.999, respectively), with high agreement in CACS risk categorization (κ = 0.95 and κ = 0.93, respectively). Standard 120-kV scans had a mean radiation dose of 2.09 mSv ± 0.84, while kV-independent and tin filter scans reduced it to 1.21 mSv ± 0.85 and 0.26 mSv ± 0.11, cutting doses by 42% and 87%, respectively ( < .001). Conclusion The kV-independent and tin filter research CT acquisition techniques showed excellent agreement and high accuracy in CACS estimation compared with standard 120-kV scans, with large reductions in radiation dose. CT, Cardiac, Coronary Arteries, Radiation Safety, Coronary Artery Calcium Score, Radiation Dose Reduction, Low-Dose CT Scan, Tin Filter, kV-Independent © RSNA, 2024.
Topics: Humans; Middle Aged; Female; Male; Radiation Dosage; Prospective Studies; Coronary Artery Disease; Coronary Vessels; Tomography, X-Ray Computed; Vascular Calcification; Tin; Aged; Coronary Angiography; Reproducibility of Results
PubMed: 38934769
DOI: 10.1148/ryct.230246 -
Medicina (Kaunas, Lithuania) Jun 2024: Cervical radiculopathy (CR) manifests as pain and sensorimotor disturbances in the upper extremities, often resulting from nerve root compression due to intervertebral...
: Cervical radiculopathy (CR) manifests as pain and sensorimotor disturbances in the upper extremities, often resulting from nerve root compression due to intervertebral disc herniation, degenerative changes, or trauma. While conservative treatments are initially preferred, persistent or severe cases may require surgical intervention. Ultrasound-guided selective nerve root block (SNRB) has emerged as a promising intervention for alleviating symptoms and potentially obviating the need for surgery. This study evaluates the therapeutic efficacy of ultrasound-guided SNRB in managing chronic CR, aiming to determine its potential in symptom relief and delaying or avoiding surgical procedures. : A retrospective analysis was conducted on 720 outpatients treated for CR between October 2019 and March 2022. After excluding patients with traumatic CR, previous surgeries, malignancies, progressive neurological symptoms requiring immediate surgery, or inadequate conservative treatment, 92 patients who had experienced cervical radicular pain for more than three months and had failed to improve after more than six weeks of conservative treatment with VAS scores ≥ 5 were included. The patients underwent single or multiple ultrasound-guided SNRB procedures, involving the injection of dexamethasone and lidocaine under real-time ultrasound guidance. Symptom severity was assessed at the baseline, and at 4, 8, and 12 weeks post-procedure using the Visual Analog Scale (VAS). The data collected included age, sex, presence of neck and/or radicular pain, physical examination findings, recurrence of symptoms, improvement in symptoms, and whether surgical intervention was ultimately required. Statistical analyses were performed to identify the factors associated with symptom improvement or recurrence. : Significant symptom improvement was observed in 69 (75.0%) participants post-SNRB, with 55 (79.7%) showing improvement at 4 weeks, 11 (15.9%) at 8 weeks, and 3 (4.4%) at 12 weeks. Symptom recurrence, defined by an increase in VAS score accompanied by a pain flare lasting at least 24 h after a pain-free interval of at least one month, was noted in 48 (52.2%) patients. The presence of combined neck and radicular pain was a significant predictor of recurrence ( = 0.008). No significant associations were found between symptom relief and factors such as age, gender, initial pain severity, or MRI findings. : Ultrasound-guided SNRB effectively manages chronic CR, providing substantial symptom relief and potentially reducing the need for surgical intervention. This technique offers a promising conservative treatment option, especially given its real-time visualization advantages and minimal radiation exposure.
Topics: Humans; Female; Male; Middle Aged; Radiculopathy; Retrospective Studies; Nerve Block; Ultrasonography, Interventional; Adult; Treatment Outcome; Pain Measurement; Aged; Lidocaine; Chronic Disease; Dexamethasone
PubMed: 38929619
DOI: 10.3390/medicina60061002 -
International Journal of Molecular... Jun 2024Application of laser-generated electron beams in radiotherapy is a recent development. Accordingly, mechanisms of biological response to radiation damage need to be...
Application of laser-generated electron beams in radiotherapy is a recent development. Accordingly, mechanisms of biological response to radiation damage need to be investigated. In this study, telomere length (TL) as endpoint of genetic damage was analyzed in human blood cells (leukocytes) and K562 leukemic cells irradiated with laser-generated ultrashort electron beam. Metaphases and interphases were analyzed in quantitative fluorescence in situ hybridization (Q-FISH) to assess TL. TLs were shortened compared to non-irradiated controls in both settings (metaphase and interphase) after irradiation with 0.5, 1.5, and 3.0 Gy in blood leukocytes. Radiation also caused a significant TL shortening detectable in the interphase of K562 cells. Overall, a negative correlation between TL and radiation doses was observed in normal and leukemic cells in a dose-dependent manner. K562 cells were more sensitive than normal blood cells to increasing doses of ultrashort electron beam radiation. As telomere shortening leads to genome instability and cell death, the results obtained confirm the suitability of this biomarker for assessing genotoxic effects of accelerated electrons for their further use in radiation therapy. Observed differences in TL shortening between normal and K562 cells provide an opportunity for further development of optimal radiation parameters to reduce side effects in normal cells during radiotherapy.
Topics: Humans; K562 Cells; Leukocytes; Electrons; Telomere; Leukemia; Telomere Homeostasis; In Situ Hybridization, Fluorescence; Telomere Shortening; DNA Damage; Dose-Response Relationship, Radiation
PubMed: 38928414
DOI: 10.3390/ijms25126709 -
Scientific Reports Jun 2024Ultra-high dose rate (UHDR) irradiation has been shown to have a sparing effect on healthy tissue, an effect known as 'FLASH'. This effect has been studied across...
Ultra-high dose rate (UHDR) irradiation has been shown to have a sparing effect on healthy tissue, an effect known as 'FLASH'. This effect has been studied across several radiation modalities, including photons, protons and clinical energy electrons, however, very little data is available for the effect of FLASH with Very High Energy Electrons (VHEE). pBR322 plasmid DNA was used as a biological model to measure DNA damage in response to Very High Energy Electron (VHEE) irradiation at conventional (0.08 Gy/s), intermediate (96 Gy/s) and ultra-high dose rates (UHDR, (2 × 10 Gy/s) at the CERN Linear Electron Accelerator (CLEAR) user facility. UHDRs were used to determine if the biological FLASH effect could be measured in the plasmid model, within a hydroxyl scavenging environment. Two different concentrations of the hydroxyl radical scavenger Tris were used in the plasmid environment to alter the proportions of indirect damage, and to replicate a cellular scavenging capacity. Indirect damage refers to the interaction of ionising radiation with molecules and species to generate reactive species which can then attack DNA. UHDR irradiated plasmid was shown to have significantly reduced amounts of damage in comparison to conventionally irradiated, where single strand breaks (SSBs) was used as the biological endpoint. This was the case for both hydroxyl scavenging capacities. A reduced electron energy within the VHEE range was also determined to increase the DNA damage to pBR322 plasmid. Results indicate that the pBR322 plasmid model can be successfully used to explore and test the effect of UHDR regimes on DNA damage. This is the first study to report FLASH sparing with VHEE, with induced damage to pBR322 plasmid DNA as the biological endpoint. UHDR irradiated plasmid had reduced amounts of DNA single-strand breaks (SSBs) in comparison with conventional dose rates. The magnitude of the FLASH sparing was a 27% reduction in SSB frequency in a 10 mM Tris environment and a 16% reduction in a 100 mM Tris environment.
Topics: Plasmids; DNA Damage; Electrons; Dose-Response Relationship, Radiation; Humans; Particle Accelerators; DNA Breaks, Single-Stranded
PubMed: 38926450
DOI: 10.1038/s41598-024-65055-8 -
Anticancer Research Jul 2024Pre-clinical studies have shown that irradiation with electrons at an ultra-high dose-rate (FLASH) spares normal tissue while maintaining tumor control. However, most in...
BACKGROUND/AIM
Pre-clinical studies have shown that irradiation with electrons at an ultra-high dose-rate (FLASH) spares normal tissue while maintaining tumor control. However, most in vitro experiments with protons have been conducted using a non-clinical irradiation system in normoxia alone. This study evaluated the biological response of non-tumor and tumor cells at different oxygen concentrations irradiated with ultra-high dose-rate protons using a clinical system and compared it with the conventional dose rate (CONV).
MATERIALS AND METHODS
Non-tumor cells (V79) and tumor cells (U-251 and A549) were irradiated with 230 MeV protons at a dose rate of >50 Gy/s or 0.1 Gy/s under normoxic or hypoxic (<2%) conditions. The surviving fraction was analyzed using a clonogenic cell survival assay.
RESULTS
No significant difference in the survival of non-tumor or tumor cells irradiated with FLASH was observed under normoxia or hypoxia compared to the CONV.
CONCLUSION
Proton irradiation at a dose rate above 40 Gy/s, the FLASH dose rate, did not induce a sparing effect on either non-tumor or tumor cells under the conditions examined. Further studies are required on the influence of various factors on cell survival after FLASH irradiation.
Topics: Humans; Cell Survival; Protons; Proton Therapy; Dose-Response Relationship, Radiation; Cell Hypoxia; Animals; Cell Line, Tumor; Cricetulus; A549 Cells; Oxygen
PubMed: 38925851
DOI: 10.21873/anticanres.17109 -
Anticancer Research Jul 2024The aim of this study was to develop an enhanced intestinal toxicity assay with three outputs assessing proliferation, villi morphology and DNA damage after irradiation.
BACKGROUND/AIM
The aim of this study was to develop an enhanced intestinal toxicity assay with three outputs assessing proliferation, villi morphology and DNA damage after irradiation.
MATERIALS AND METHODS
Whole 5 cm jejunal lengths were collected from mice following total body x-ray irradiation (0-15 Gy) at 0-84 h. Tissues were wrapped into swirls for cryopreservation and immunohistochemically stained for EdU, CD31, and γH2AX. A semi-automated image analysis was developed for the proliferation, villi morphology, and DNA damage models.
RESULTS
Proliferation assessed via EdU staining varied with cycles of damage repair, hyperproliferation, and homeostasis after radiation, with the time to onset of each cycle variable based on radiation dose. An analysis model evaluating the amount of proliferation per unit length of jejunum analyzed was developed, with a dose-response curve identified at 48 h post treatment. The villi length model measured the length of intact and healthy CD31-stained capillary beds between the crypts and villi tips at 3.5 days post treatment within a 0-10 Gy dose range. The DNA damage model evaluated the intensity of γH2AX staining within cellular nuclei, with a useful dose-response identified at 1 h post-radiation treatment.
CONCLUSION
This assay demonstrates flexibility for assessing radiation-induced damage, with analysis of proliferation, villi length, or direct DNA damage achievable at defined time points and within useful radiation dose curves. The software-assisted image analysis allows for rapid, comprehensive, and objective data generation with an assay turnover time of days instead of weeks on samples that are representative of most of the treated jejunum.
Topics: Animals; Mice; Cell Proliferation; DNA Damage; Jejunum; Radiation Tolerance; Intestinal Mucosa; Intestines; Whole-Body Irradiation; Dose-Response Relationship, Radiation; Histones; Male; Mice, Inbred C57BL
PubMed: 38925821
DOI: 10.21873/anticanres.17091 -
Anticancer Research Jul 2024Endoscopic submucosal dissection (ESD) followed by chemoradiotherapy (CRT) has become a promising treatment modality in the management of early-stage superficial...
BACKGROUND/AIM
Endoscopic submucosal dissection (ESD) followed by chemoradiotherapy (CRT) has become a promising treatment modality in the management of early-stage superficial esophageal squamous cell carcinoma (SESCC). However, radiotherapy often leads to significant adverse events (AEs), including cardiopulmonary toxicity, limiting the delivery of this treatment modality. This study aimed to evaluate the efficacy of reduced-volume radiotherapy and dose-dense chemotherapy in mitigating AEs for high-risk SESCC following ESD.
PATIENTS AND METHODS
We retrospectively analyzed patients treated with customized CRT after ESD between 2014 and 2023.
RESULTS
Thirty-nine consecutive patients were identified. The median follow-up period was 63.4 months (range=8.3-99.8 months). All patients completed CRT, with a low incidence (3%) of grade ≥3 nonhematologic AEs. Thirteen patients (33%) had a recurrence: 10 local, one regional, and two distant. The 5-year overall and disease-free survival rates were 77% and 64%, respectively. A positive vertical resection margin was identified as a prognostic factor associated with survival.
CONCLUSION
Our novel approach of combining ESD with customized reduced-volume radiotherapy and dose-dense chemotherapy shows promise in providing favorable oncologic outcomes and a safer nonsurgical strategy for high-risk SESCC. Specifically, this regimen minimized cardiopulmonary toxicity without compromising therapeutic efficacy. More aggressive adjuvant therapy may be required for patients with positive vertical resection margins after ESD.
Topics: Humans; Male; Esophageal Neoplasms; Female; Aged; Middle Aged; Retrospective Studies; Esophageal Squamous Cell Carcinoma; Chemoradiotherapy; Radiotherapy Dosage; Endoscopic Mucosal Resection; Aged, 80 and over; Neoplasm Recurrence, Local; Treatment Outcome; Adult
PubMed: 38925806
DOI: 10.21873/anticanres.17127 -
International Journal of Radiation... Jul 2024
Topics: Humans; Mediastinal Neoplasms; Quality of Life; Sarcoma; Radiotherapy Dosage; Male
PubMed: 38925761
DOI: 10.1016/j.ijrobp.2024.01.230 -
The Urologic Clinics of North America Aug 2024Testicular cancer is a rare but curable male malignancy. Seminoma represents the majority of germ cell tumors and is considered radiation sensitive. Radiation treatment... (Review)
Review
Testicular cancer is a rare but curable male malignancy. Seminoma represents the majority of germ cell tumors and is considered radiation sensitive. Radiation treatment plays a role in adjuvant therapy after orchiectomy of stage I, IIA, and IIB seminomas. Radiation dose de-escalation has been effective in preventing tumor recurrences while also limiting acute and long-term toxicities. However, long-term risks, including the prevailing concern of secondary malignancy risk, between adjuvant radiation and chemotherapy play a role in recommendations. Ongoing work continues to be performed to reduce radiation field and dose in combination with chemotherapy while still maintaining excellent outcomes.
Topics: Humans; Male; Testicular Neoplasms; Seminoma; Radiotherapy, Adjuvant; Orchiectomy; Neoplasm Staging; Neoplasms, Germ Cell and Embryonal; Radiotherapy Dosage; Neoplasm Recurrence, Local
PubMed: 38925742
DOI: 10.1016/j.ucl.2024.03.008 -
Cancer Reports (Hoboken, N.J.) Jun 2024Reduced ovarian reserve is among the crucial long-term side effects of using chemotherapy agents in breast cancer, yielding early ovarian failure. On the other hand,... (Randomized Controlled Trial)
Randomized Controlled Trial
The protective effect of vitamin D on ovarian reserve and anti-mullerian hormone in patients undergoing chemotherapy for breast cancer, a randomized phase ΙΙ clinical trial.
BACKGROUND
Reduced ovarian reserve is among the crucial long-term side effects of using chemotherapy agents in breast cancer, yielding early ovarian failure. On the other hand, vitamin D is an essential factor in protecting the follicles and an important predictive factor for successful IVF therapy.
AIM
The aim of this study is evaluation of vitamin D as a agent that can reduce fertility complications of chemotherapy specially in young women.
METHODS
Breast cancer patients undergoing chemotherapy at two cancer institutes were enrolled in this study. The case group received 1000 IU of calcitriol, and the AMH level was measured at the baseline, after chemotherapy, and six months after chemotherapy. The primary end point was improvement in the AMH level after six months of chemotherapy. the secondary endpoint was to evaluate the predictive factors of AMH level decline during chemotherapy.
RESULTS
Between 2018 and 2019, 18 and 15 patients were enrolled in the case and control groups, respectively. The mean AMH level (ngr/ml) of the patients in the case and control group were 3.16 and 2.37 ng/mL, respectively (p-value = .16). These levels were 0.387 and 0.19 after six months (p-value = .38). The AMH rise immediately after chemotherapy cycles to six months after chemotherapy, in the case and control groups were 0.86 and 0.44 ng/mL, respectively, which was slightly higher in the case group but not statistically significant between two groups (p-value = .054).
CONCLUSION
Despite a minimal rise in the AMH level after six months of chemotherapy, the study could not demonstrate any protective effect of vitamin D on patients' ovarian reserve undergoing chemotherapy for breast cancer. Further larger studies are needed to evaluate the effect of vitamin D supplements on ovarian reserve beside optimal dose and duration.
Topics: Humans; Female; Anti-Mullerian Hormone; Ovarian Reserve; Breast Neoplasms; Adult; Vitamin D; Antineoplastic Combined Chemotherapy Protocols
PubMed: 38925607
DOI: 10.1002/cnr2.2104