Difference In Number Of Lesions Research Articles

Comparison of [18F]DOPA and [68Ga]DOTA-TOC as a PET imaging tracer before peptide receptor radionuclide therapy

BackgroundIn treatment of neuroendocrine neoplasms (NENs), confirmation of somatostatin receptor expression with 68Ga-DOTA somatostatin analogues is mandatory to determine eligibility for peptide receptor radionuclide therapy (PRRT). [18F]DOPA can detect additional lesions compared to [68Ga]DOTA-TOC. The aim of this study was to explore differences in tumour detection of both tracers and their relevance for selecting patients for PRRT. We retrospectively studied eight patients with NENs who underwent both [68Ga]DOTA-TOC and carbidopa-enhanced [18F]DOPA PET/CT, before first-time PRRT with [177Lu]DOTA-TATE. Tracer order was influenced due to stock availability or to detect suspected metastases with a second tracer. On CT, disease control was defined as a lesion showing complete response, partial response, or stable disease, according to RECIST 1.1. criteria.ResultsSeven patients with in total 89 lesions completed four infusions of 7.4 GBq [177Lu]DOTA-TATE, one patient received only two cycles. Before treatment, [18F]DOPA PET/CT detected significantly more lesions than [68Ga]DOTA-TOC PET/CT (79 vs. 62, p < .001). After treatment, no difference in number of lesions with disease control was found for [18F]DOPA-only (5/27) and [68Ga]DOTA-TOC-only lesions (4/10, p = .25). [18F]DOPA detected more liver metastases (24/27) compared to [68Ga]DOTA-TOC (7/10, p = .006). Six patients showed inpatient heterogeneity in treatment response between [18F]DOPA-only and [68Ga]DOTA-TOC-only lesions.ConclusionsResponse to PRRT with [177Lu]DOTA-TATE was comparable for both [68Ga]DOTA-TOC- and [18F]DOPA-only NEN lesions. [18F]DOPA may be capable of predicting response to PRRT while finding more lesions compared to [68Ga]DOTA-TOC, although these additional lesions are often small of size and undetected by diagnostic CT.

Utility of Short Initial MRI Brain in Brain Metastases Patients Treated With Stereotactic Radiosurgery

The optimal timing of interval MRI surveillance following stereotactic radiosurgery (SRS) to detect most new lesions while asymptomatic and treatable by additional radiosurgery is unknown. As frequent MRI follow-up is an important patient burden and contributor to cost of care for brain metastases, we aimed to characterize the utility of early initial post-treatment MRI brain surveillance and to identify patient characteristics that might be used to risk-stratify patients who may benefit from early surveillance scans.An IRB-approved retrospective single-institution cohort of patients with brain metastases treated with frameless SRS was analyzed. Baseline demographics, treatment characteristics, and timing of follow-up MRI findings were reviewed in the electronic medical record. Fisher's exact test and Pearson's Chi-square test were used to compare proportions. Mann-Whitney-U test was used to compare continuous variables.One hundred consecutive patients treated from January 2018 - March 2020 were included, with plan for 6-week follow-up MRI post-treatment. Thirteen lacked follow-up MRI brain, leaving 87 for analysis. Median time to MRI was 6.7 weeks, with 78% of scans obtained less than 8 weeks post-SRS. Twenty-four (28%) patients had findings concerning for new or progressive disease on follow-up MRI. Nine were symptomatic. Of the 24, ten (42%) received SRS, 1 (8%) received whole brain radiotherapy (WBRT), 1 (4%) received surgery, 1 (4%) started systemic therapy, 7 received a short interval MRI scan, and 3 (12%) went to hospice. Of the 10 who received SRS, 3 were symptomatic, 6 had lesions ≥ 5 mm, and all 10 had lesions ≥ 5 mm. Of the 7 recommended for short interval MRI, 1 received SRS, 1 received WBRT, and 5 had no further evidence of disease progression, resuming routine surveillance. Comparing patients with suspicious findings to those with stable disease on follow-up MRI, there was a statistically significant difference (Table) in the distribution of histology (P = 0.02) and performance status (P = 0.047), but no difference in number of lesions, extra-cranial disease control, prior receipt of SRS, or use of targeted therapy or immune checkpoint inhibitors.A small but significant number of brain metastases patients treated with SRS may have additional therapy based on initial short interval surveillance MRI scans. Further investigation in larger cohorts may help identify patient characteristics that predispose to benefit from short interval MRI scans, and determine the value of earlier detection of new lesions compared with a longer interval to first scan.

Low-Dose Radiation Spillage During Stereotactic Radiosurgery for Brain Metastases is Associated with a Decreased Incidence of New Supratentorial Brain Metastases.

Stereotactic radiosurgery (SRS) for brain metastases is increasingly used in lieu of whole brain radiation (WBRT), with reduced risk of cognitive side effects but at the expense of an increased risk of developing new lesions in non-treated parts of the brain. Here we investigated whether the low dose fall-off during SRS is associated with a lower incidence of brain metastases. We reviewed 130 patients treated with single or fractionated SRS for definitive or post-op brain metastases at our institution during 2016-2017. Patients with MRI findings of local recurrence or new brain metastases within 18 months of the first SRS were selected. WBRT before SRS was an exclusion. MRI or CT simulation for repeat treatment was fused with the initial SRS treatment plan. The new lesions and the corresponding contralateral anatomical site were outlined on the initial planning scan. The mean doses delivered to the site of these new lesions from the initial SRS treatment were tabulated. Comparison of mean doses to the new lesions and contralateral site were performed using t-test, and the difference in number of lesions at varying low dose levels was examined using Z-test for proportion. Thirty-six patients met the inclusion criteria. 24 patients (67%) had lung primary (2 squamous cell carcinoma and 19 adenocarcinoma), 6 breast (17%), 2 renal cell carcinoma (RCC), one each of esophagus, melanoma, cervix and unknown primary. 21 patients (58%) received chemotherapy during the time interval of 18 months, and 20 (56%) received immunotherapy. One hundred sixty-six new brain lesions were evaluated. Three of the 7 cerebellar lesions (43%) showed local recurrence. In patients with initial supratentorial metastasis, only 5 of total 159 lesions (3%) appeared when exposed to >6 Gy from prior SRS. 11 (6.9%), 30 (19%) and 49 (31%) lesions occurred in the >4 Gy, >2 Gy and >1 Gy dose levels, respectively. 14 lesions (9%) had no recurrences in their contralateral comparable site which received >6 Gy (p= 0.033) and 21 lesions had no recurrences in their contralateral comparable site if >4 Gy was received (13%) (p=0.063). Among the lesions that appeared after exposure to >6 Gy and >4 Gy dose, 2/5 (40%) and 5/11 (55%) lesions, respectively, were from RCC primaries. New metastases developed in sites that received less mean dose from prior treatments as compared to mean dose received in the corresponding contralateral hemisphere, where the patients did not experience recurrence. This was true for all dose levels, >1Gy through >6 Gy (all p values ≤0.02). New lesions appeared more often on the side that received lower dose of radiation compared to their contralateral site. Dose levels of >6 Gy or >4 Gy were associated with decreased incidence of new supratentorial brain metastases, less so for RCC primaries. Low dose bath to the non-target brain may be protective. Validation in larger dataset is warranted.

Assessing bone response to cabozantinib in patients (pts) with metastatic urothelial carcinoma (mUC) using 18F-Sodium Fluoride (NaF) PET/CT.

328 Background: NaF PET/CT is a radiotracer used for the assessment of bone metastases (mets). The goal of our study was to assess bone mets using NaF PET/CT imaging in mUC pts treated with cabozantinib. Methods: We conducted a single-arm phase II trial of cabozantinib in pts with mUC. Pts with known bone mets underwent a NaF PET/CT scan at baseline and every 8 weeks until progression. At each scan, we captured, the number of lesions per pt and per anatomical site, the maximum standardized uptake values (SUV), and serum alkaline phosphatase (AP). Bone responses (bone response (BR), stable disease (SD), progressive disease (PD)) were assigned to each pt based on the NaF report. Change from baseline to the time of best response for SUV, the number of lesions, and AP were compared between BR + SD vs PD were analyzed using an exact Wilcoxon rank sum test. The Kaplan-Meier method was used to determine the association of progression free survival (PFS) or overall survival (OS) with baseline SUV and number of lesions. Results: 68 pts enrolled on study, 22 pts had bone mets at baseline (6 bone only and 16 with bone and soft-tissue mets) (median OS 4.6 mo (95% CI: 3.4-7.7 mo), and median PFS 2.0 mo (95% CI: 1.8-3.9 mo)) of which 15 pts had follow up NaF scans. At baseline, 147 total lesions were analyzed, and the lesion distribution was: spine 29%, ribs 21%, pelvis 18%, skull 11%, femur 6%, scapula 3%, humerus 3%, sternum 3%, sacrum 3%, fibula 1%, and clavicle 0.7%. 5/15 pts had BR (and remained on study 238, 252, 182, 161, and 56 days), 4/15 SD, and 6/15 PD at best response. Sites of PD occurred in bone 10/22, bone and soft-tissue 5/22, and soft-tissue 7/22. The percent difference in number of lesions among responders and non-responders was 43% (p = 0.0039). At baseline, there was no association with PFS or OS and number of lesions (p = 0.84, p = 0.97), SUV (p = 0.83, p = 0.97), or AP (p = 0.97, p = 0.33). Conclusions: Pts with mUC and bone disease have poor overall outcome. Most bone lesions were found in the spine, ribs, and pelvis. Larger studies are needed to assess the correlation of NaF response with clinical outcome in mUC. We have an ongoing study using NaF PET to assess bone mets in mUC treated with cabozantinib/nivolumab/ipilimumab. Clinical trial information: NCT01688999.

Relationship between white matter hyperintensities volume and the circle of Willis configurations in patients with carotid artery pathology

PurposeWe aimed to assess if there is a difference of distribution and volume of white matter hyperintensities (WMH) in the brain according to the Circle of Willis (CoW) configuration in patients with carotid artery pathology. Material and methodsOne-hundred consecutive patients (79 males, 21 females; mean age 70 years; age range 46–84 years) that underwent brain MRI before carotid endarterectomy (CEA) were included. FLAIR-WMH lesion volume was performed using a semi-automated segmentation technique and the status of the circle of Willis was assessed by two neuroradiologists in consensus. ResultsWe found a prevalence of 55% of variants in the CoW configuration; 22 cases had one variants (40%); 25 cases had two variants (45.45%) and 8 cases showed 3 variants (14.55%). The configuration that was associated with the biggest WMH volume and number of lesions was the A1+PcoA+PcoA. The PcoA variants were the most prevalent and there was no statistically significant difference in number of lesions and WMH for each vascular territory assessed and the same results were found for AcoA and A1 variants. ConclusionResults of our study suggest that the more common CoW variants are not associated with the presence of an increased WMH or number of lesions whereas uncommon configurations, in particular when 2 or more segment are missing increase the WMH volume and number of lesions. The WHM volume of the MCA territory seems to be more affected by the CoW configuration.

JOURNAL CLUB: Shoulder MRI Utilization: Relationship of Physician MRI Equipment Ownership to Negative Study Frequency

The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians influences the frequency of negative shoulder MRI scans. A retrospective review was performed of 1140 consecutive shoulder MRI scans ordered by two separate referring physician groups serving the same geographic community. The first group (financially incentivized) owned the scanners used and received technical fees for their use. The second group (non-financially incentivized) did not own the scanners used and had no direct financial interest. All examinations were performed with identical protocols and were interpreted by a single radiologist group without financial interest in the imaging equipment used. The frequency of negative examinations and the number of abnormalities in each positive study was tabulated for each group. A total of 1140 shoulder MRI scans met inclusion criteria; 255 were negative (142 for the financially incentivized group and 113 for the non-financially incentivized group). There were 25.6% more negative scans in the financially incentivized group (p=0.047). There was no statistically significant difference in the average number of lesions per positive scan (1.67 for the financially incentivized group and 1.71 for the non-financially incentivized group; p=0.34). No statistically significant difference was found in the frequency of 19 of 20 examined lesions. Shoulder MRI examinations referred by physicians with a financial interest in the imaging equipment used were significantly more likely to be negative. Positive examinations exhibited no statistically significant difference in the number of lesions per scan or in the frequency of 19 of 20 lesion subtypes. This finding suggests a highly similar distribution and severity of disease among the two patient groups.

Abstract 2754: Pulmonary Vein Isolation Using Irrigated vs. Conventional 4-mm Tip Catheters- Do Short and Long-Term Outcomes Differ?

Open saline-irrigated tip ablation catheters have largely supplanted standard 4 mm tip ablation catheters for pulmonary vein isolation (PVI) of atrial fibrillation (AF), based on the assumption that the procedure is safer and more efficacious. However, outcomes after procedures that use identical techniques but different radiofrequency ablation catheters have not been compared. We studied 432 consecutive patients (age 57 ± 11 yrs) with AF (duration 7.9 ± 6.1 yrs) who underwent PVI; 320 (74 %) using a conventional 4 mm catheter and 112 (26 %) using an open irrigated tip catheter. Segmental PVI targeting the earliest LA-PV activation for all PVs in each patient was used for all patients regardless of catheter for the entire study cohort. Radiofrequency energy was delivered for ≥60 secs at each target site. The pts in the 2 groups were similar with respect to age, gender and duration of AF. All 432 pts had successful complete PVI. There was no significant difference in the total number of lesions delivered per PV in the conventional 4 mm group and the irrigated tip group (Table ) at the initial procedure. Following a single procedure, 227/ 320 (71%) patients in the conventional 4 mm and 75/112 (67%) in the irrigated group were AF-free on no antiarrhythmic drug at 12 mos (p=0.43). The number of patients who required repeat procedures was similar in the conventional group (57/320, 18%) and the irrigated tip group (22/112, 20%) (p=0.66). Serious complications were also similar (2.2% vs. 1.0 %, p=0.21) Contrary to conventional wisdom, the safety and 12 month efficacy of PVI for management of AF was similar for the two types of ablation catheters. These data suggest that PVI cohorts derived from differing ablation techniques can be combined for purposes of clinical investigation. Longer term outcomes may differ and should be studied as well.

벼깨씨무늬병균의 월동과 발병조건에 관한 연구

This study was carried out to investigate factors affecting disease development of rice brown spot caused by Cochliobolus miyabeanus in the field and under the greenhouse conditions. In normal paddy fields, the pathogen was more frequently isolated from dried rice straws than wet straws after overwintering. The pathogen was also readily isolated from wet rice straws of salty paddy fields although infection rate of the fields was low. The disease symptom was first observed at 2 to 3days after inoculation when the seedlings were kept for 6 hours in dew chamber. The number of lesions peaked at 14 hr incubation in cultivars Chucheongbyeo and 24 hr incubation in cultivar Daesanbyeo and Tetep. Sixty three-d-old seedlings were more susceptible than 21 to 49-d-old seedlings regardless of cultivar. There was some difference in number of lesions observed, but the lesions were evenly spread regardless of leaf position. Light on the rice seedlings at 3,000 lux or 6,000 lux showed more severe symptoms than those in the dark.

Comparison of Single-Echo T2-weighted Fast Spin-Echo and Conventional Spin-Echo MR Sequences

We compared single-echo T2-weighted fast spin-echo (FSE) magnetic resonance imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 16 patients with clinically definite MS underwent brain imaging at 0.5 T with T2-weighted single-echo fast spin-echo (FSE) and conventional spin-echo (CSE) sequences. Image analysis was performed by three of the investigators who worked together to reduce interobserver variability. Statistical analysis was performed using Student's t test to assess the difference in the contrast-to-noise (C/N) ratio of MS lesions between CSE and FSE sequences. The Wilcoxon signed rank test was used to evaluate the difference in the number of lesions between the two sequences. There was no significant difference in the overall total number of lesions detected on FSE vs CSE (964 vs 1009, P &gt;.05). However significantly (P = .02) more posterior fossa lesions were detected using FSE than CSE, whereas significantly (P = .002) more periventricular lesions were detected using CSE than FSE. The difference in the number of lesions in the other sites was not significant (P &gt; .05). There was no significant difference in the overall total C/N ratio of MS lesions between FSE and CSE sequences (11.7 ± 3.9 vs 12.6 ± 4). Considerable time savings can be made when substituting FSE for CSE sequences in T2-weighted imaging, and this is a compelling reason to employ such sequences in clinical practice. Our results suggest that for single-echo T2-weighted imaging, FSE can replace CSE in long term monitoring especially when patient movement prevents a useful investigation and when optional scanning planes are required.

Valutazione comparativa delle sequenze fast Spin-echo e Spin-echo T2-dipendenti nella dimostrazione delle lesioni demielinizzanti encefaliche in corso di sclerosi multipla

We compared T2-weighted fast spin-echo (FSE) magnetic resonance (MR) imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 20 patients with clinically definite MS underwent brain imaging with both FSE and CSE T2-weighted imaging. There was no significant difference in total number of lesions detected on FSE vs CSE (1354 vs 1378). Slightly more periventricular and subcortical lesions were detected using CSE than FSE, whereas more posterior cranial fossa lesions were detected by FSE. There was no statistically significant difference in the signal intensity (SI) ratio of MS lesions to that of surrounding normal white matter on FSE vs CSE, however the SI ratio of MS lesions was lower on FSE T2-weighted images (FSE ? 1.87 ± 0.39 vs CSE = 2.09 ± 0.36). Considerable time savings can accrue when substituting FSE for CSE sequences in T2-weighted imaging, and this is a compelling reason to employ such sequence in clinical practice. Our results suggest that although CSE sequences are required to confirm the diagnosis of brain involvement of MS lesions, T2-weighted FSE sequences can replace CSE sequences in long term monitoring especially when patient's movements preclude useful investigation and when optional scanning planes are required.

Microinfarction in classic migraine? A study with magnetic resonance imaging findings.

By means of magnetic resonance imaging we investigated a total of 45 patients suffering from classic migraine; 25 patients had been treated in our department for classic migraine over the past 2 years (group A), and 20 other patients investigated between 1976 and 1984 were reexamined for this study (group B). Thirty-two age- and roughly sex-matched healthy volunteers underwent magnetic resonance imaging and served as controls (group C). There was a trend for patients with classic migraine to have more subcortical patchy lesions on T2-weighted magnetic resonance imaging. In a comparison of our control subjects and patients with a history of greater than 20 attacks of classic migraine taken from groups A and B, this difference in number of lesions was significant (p = 0.02). The results suggest that patchy lesions in patients with classic migraine should be interpreted with particular caution before diagnosing a demyelinating disease since the lesions could be ischemic in origin.

POWDERY MILDEW INOCULATION TECHNIQUES FOR A Cucurbita moschata BREEDING PROGRAM

In order to effectively use recurrent selection for developing polygenic resistance to powdery mildew (Erysiphe cichoracearum), methods to quantify resistance need to be developed. Our objective was to compare several inoculation methods for their effectiveness in a half-sib selection breeding program. Seven inoculation methods and 3 controls were applied to each of two susceptible C. moschata varieties planted in pots and arranged in a randomized complete block design with five replications. The experiment was repeated two times. Single degree of freedom comparisons found no difference in number of lesions resulting from inoculation by rubbing host with infected tissue vs. attaching infected tissue. Using no adherent resulted in as many lesions as using triton. Egg white as an adherent resulted in fewer lesions than using triton or no adherent. Spraying with a triton spore suspension was not an effective method. While rubbing leaves is fast and easy, attaching pieces of infected tissue may afford more control of spore concentration.