Reflections on the Teaching Symposium at the Microbiology Society Annual Conference 2023

The Microbiology Society Education and Outreach Network (EON) recently hosted the Teaching Symposium at the Microbiology Society Annual Conference, sponsored by Access Microbiology. The presence of the Symposium as an established parallel session within the wider Annual Conference reflects the importance of high-quality, contemporary microbiology education and outreach delivered in an enthusiastic and inclusive manner. At the 2023 Symposium, a variety of pedagogical research projects in higher education learning, teaching and assessment, as well as public engagement projects, were showcased through invited talks, offered talks, flash talks and posters. The event was attended by up to 70 delegates. Several themes were noted throughout the day: engaging with Gen Z (Generation Z, those born between 1996 and 2010), active learning, art in science and engaging with non-higher education (HE) audiences. Inclusivity was a key driver in the organization of the Symposium; the room was set up to encourage discussion and participants could ask questions using an online platform as well as speaking in the room. We now encourage all speakers to consider publishing their work as a peer-reviewed article for further dissemination and impact.

Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent or metastatic breast cancer (PERUSE)

BACKGROUND

Pertuzumab combined with trastuzumab and docetaxel is the standard first-line therapy for HER2-positive metastatic breast cancer, based on results from the phase III CLEOPATRA trial. PERUSE was designed to assess the safety and efficacy of investigator-selected taxane with pertuzumab and trastuzumab in this setting.

PATIENTS AND METHODS

In the ongoing multicentre single-arm phase IIIb PERUSE study, patients with inoperable HER2-positive advanced breast cancer (locally recurrent/metastatic) (LR/MBC) and no prior systemic therapy for LR/MBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab [8 mg/kg loading dose, then 6 mg/kg every 3 weeks (q3w)] and pertuzumab (840 mg loading dose, then 420 mg q3w) until disease progression or unacceptable toxicity. The primary end point was safety. Secondary end points included overall response rate (ORR) and progression-free survival (PFS).

RESULTS

Overall, 1436 patients received at least one treatment dose (initially docetaxel in 775 patients, paclitaxel in 589, nab-paclitaxel in 65; 7 discontinued before starting taxane). Median age was 54 years; 29% had received prior trastuzumab. Median treatment duration was 16 months for pertuzumab and trastuzumab and 4 months for taxane. Compared with docetaxel-containing therapy, paclitaxel-containing therapy was associated with more neuropathy (all-grade peripheral neuropathy 31% versus 16%) but less febrile neutropenia (1% versus 11%) and mucositis (14% versus 25%). At this preliminary analysis (52 months' median follow-up), median PFS was 20.6 [95% confidence interval (CI) 18.9-22.7] months overall (19.6, 23.0 and 18.1 months with docetaxel, paclitaxel and nab-paclitaxel, respectively). ORR was 80% (95% CI 78%-82%) overall (docetaxel 79%, paclitaxel 83%, nab-paclitaxel 77%).

CONCLUSIONS

Preliminary findings from PERUSE suggest that the safety and efficacy of first-line pertuzumab, trastuzumab and taxane for HER2-positive LR/MBC are consistent with results from CLEOPATRA. Paclitaxel appears to be a valid alternative taxane backbone to docetaxel, offering similar PFS and ORR with a predictable safety profile.

CLINICALTRIALS.GOV

NCT01572038.

Abstract OT1-01-01: IMpassion131: A phase III study comparing 1L atezolizumab with paclitaxel vs placebo with paclitaxel in treatment-naive patients with inoperable locally advanced or metastatic triple negative breast cancer (TNBC)

Background: Chemotherapy (including paclitaxel) remains the predominant treatment for metastatic TNBC but clinical outcomes remain poor. Therefore, new therapeutic approaches are needed. Atezolizumab blocks the binding of PD-L1 to its receptors PD-1 and B7.1, thus restoring tumor-specific T cell immunity. TNBC is a rational target for atezolizumab therapy due to high PD-L1 expression on tumor-infiltrating immune cells (IC) and elevated T cell tumor infiltration. Furthermore, combining chemotherapy with atezolizumab is hypothesized to enhance anti-tumor immune response via neoantigen release. Atezolizumab alone and in combination with nab-paclitaxel has demonstrated promising clinical benefit in metastatic TNBC and was well tolerated, with no exacerbation of chemotherapy-associated adverse events. Atezolizumab in combination with nab-paclitaxel is being further investigated as 1L TNBC treatment in IMpassion130. IMpassion131 is a global, multi-center, randomized, double-blind, placebo-controlled study comparing the efficacy and safety of 1L atezolizumab + paclitaxel vs placebo + paclitaxel in patients with untreated, inoperable, locally advanced or metastatic TNBC. (NCT03125902)

Methods: Eligibility criteria include patients with inoperable, locally advanced or metastatic TNBC, histologically confirmed; de novo or recurrent disease after early breast cancer treated with chemotherapy ≥ 12 months prior; eligible for taxane monotherapy; no prior chemotherapy or targeted systemic therapy for inoperable locally advanced or metastatic disease; ECOG PS 0-1 and measurable disease by RECIST v1.1. Exclusion criteria include known symptomatic CNS disease, prior immunotherapy and a history of autoimmune disease. Approximately 495 patients will be randomized 2:1 to receive atezolizumab (840 mg) or placebo (q2w; days 1 and 15 of 28-day cycle) plus paclitaxel (90 mg/m2; days 1, 8, 15 of 28-day cycle) until disease progression. Stratification factors are PD-L1 expression on tumor-infiltrating IC (IC0 < 1% vs IC1/2/3 ≥ 1% with VENTANA SP142 IHC assay), prior taxane therapy, presence of liver metastases and geographical region. The primary endpoint is progression-free survival (PFS) measured by RECIST v1.1. Key secondary endpoints include overall survival (OS), 12- and 18-month OS rates, 12-month PFS rate, objective response rate, duration of response, and safety. Tumor biopsies will be collected at baseline, on treatment and at disease progression to assess for biomarkers of treatment response and immune escape.

Citation Format: Miles D, André F, Gligorov J, Verma S, Xu B, Cameron D, Barrios CH, Schneeweiss A, Easton V, Ghazi Y, O'Shaughnessy J. IMpassion131: A phase III study comparing 1L atezolizumab with paclitaxel vs placebo with paclitaxel in treatment-naive patients with inoperable locally advanced or metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-01-01.

Abstract P4-21-04: Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent/metastatic breast cancer (PERUSE)

Background: First-line (1L) docetaxel+trastuzumab+pertuzumab (THP) for HER2-positive metastatic breast cancer (MBC) significantly improved progression-free survival (PFS) and overall survival in the phase III CLEOPATRA trial, and led to the approval of this regimen. PERUSE (NCT01572038) was designed to assess the safety and efficacy of investigator's choice of taxane+HP for 1L locally recurrent (LR)/MBC, and allows exploration of safety and efficacy in a larger population.

Methods:

PERUSE is a multicenter, single-arm phase IIIb study. Patients (pts) with Eastern Cooperative Oncology Group performance status ≤2 and no prior systemic therapy for LR/MBC (except endocrine therapy) receive T, paclitaxel (PAC), or nab-PAC plus H (8 mg/kg→6 mg/kg every 3 weeks [q3w]) and P (840 mg→420 mg q3w) until disease progression (PD) or unacceptable toxicity. The primary endpoint is safety. Secondary endpoints include best overall response (BOR) and PFS.

Results:

The safety/ITT population includes 1436 pts at data cutoff (1 Apr 2016). Median follow-up was 17.2 mo (range, <1–41.4). The median pt age was 54 years (range 23–87), 64% had hormone receptor-positive disease, 27% received adjuvant H, and 75% had visceral disease. Pts received T, PAC, nab-PAC, H, and P for a median of 3.8 mo (range <1–24.2; n=791), 4.2 mo (<1–36.6; n=618), 3.9 mo (<1–17.3; n=73), 16.0 mo (<1–45.9; n=1435), and 16.1 mo (<1–45.9; n=1436), respectively.

Most pts discontinued taxanes for 'other' reasons (25%), adverse events (AEs; 16%), PD, or investigator decision (15% each); H, for PD or AEs (46% and 7%); and P, for PD or AEs (46% and 8%).

Grade ≥3 treatment-emergent AEs (TEAEs) of interest are shown in table 1. Serious TEAEs were reported in 282 (36%) pts on T, 185 (31%) on PAC, and 21 (32%) on nab-PAC. Preliminary efficacy by taxane is shown in table 2.

Table 1Pts, n (%)TPACNab-PAC n=775n=589n=65Neutropenia110 (14)31 (5)1 (2)Diarrhea62 (8)50 (8)4 (6)Febrile neutropenia81 (10)7 (1)0Fatigue21 (3)10 (2)1 (2)Asthenia16 (2)10 (2)0Peripheral neuropathy10 (1)15 (3)0Anemia11 (1)12 (2)2 (3)Left ventricular dysfunction1 (<1)9 (2)1 (2)

Table 2 TPACNab-PACBOR, based on pts with measureable disease at baseline, n (%)n=659n=482n=53Complete72 (11)80 (17)4 (8)Partial442 (67)319 (66)38 (72)Stable disease112 (17)62 (13)8 (15)PD18 (3)12 (2)2 (4)Missing15 (2)9 (2)1 (2)PFS, ITT populationn=775n=589n=65Pts with events, n (%)439 (57)324 (55)40 (62)Median, mo (95% confidence interval)19.6 (17.4–22.6)24.8 (20.7–27.0)18.1 (11.9–34.2)25th–75th percentile, mo9.4–not reached (NR)10.2–NR7.9–NR

Conclusion:

The preliminary findings of this large, single-arm study suggest that safety and efficacy of 1L taxane+HP for HER2-positive LR/MBC are in keeping with the results of the phase III CLEOPATRA study. There was less febrile neutropenia with PAC/nab-PAC+HP compared with THP, and preliminary PFS was similar to that seen in the CLEOPATRA study for all taxane+HP combinations.

Citation Format: Bachelot T, Puglisi F, Ciruelos E, Peretz-Yablonski T, Schneeweiss A, Easton V, Lindegger N, Restuccia E, Miles D. Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent/metastatic breast cancer (PERUSE) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-04.

Final results of the TANIA randomised phase III trial of bevacizumab after progression on first-line bevacizumab therapy for HER2-negative locally recurrent/metastatic breast cancer

BACKGROUND

The randomised phase III TANIA trial demonstrated that continuing bevacizumab with second-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC) after progression on first-line bevacizumab-containing therapy significantly improved progression-free survival (PFS) compared with chemotherapy alone [hazard ratio (HR) = 0.75, 95% confidence interval (CI) 0.61-0.93]. We report final results from the TANIA trial, including overall survival (OS) and health-related quality of life (HRQoL).

PATIENTS AND METHODS

Patients with HER2-negative LR/mBC that had progressed on or after first-line bevacizumab plus chemotherapy were randomised to receive standard second-line chemotherapy either alone or with bevacizumab. At second progression, patients initially randomised to bevacizumab continued bevacizumab with their third-line chemotherapy, but those randomised to chemotherapy alone were not allowed to cross over to receive third-line bevacizumab. The primary end point was second-line PFS; secondary end points included third-line PFS, combined second- and third-line PFS, OS, HRQoL and safety.

RESULTS

Of the 494 patients randomised, 483 received second-line therapy; 234 patients (47% of the randomised population) continued to third-line study treatment. The median duration of follow-up at the final analysis was 32.1 months in the chemotherapy-alone arm and 30.9 months in the bevacizumab plus chemotherapy arm. There was no statistically significant difference between treatment arms in third-line PFS (HR = 0.79, 95% CI 0.59-1.06), combined second- and third-line PFS (HR = 0.85, 95% CI 0.68-1.05) or OS (HR = 0.96, 95% CI 0.76-1.21). Third-line safety results showed increased incidences of proteinuria and hypertension with bevacizumab, consistent with safety results for the second-line treatment phase. No differences in HRQoL were detected.

CONCLUSIONS

In this trial, continuing bevacizumab beyond first and second progression of LR/mBC improved second-line PFS, but no improvement in longer term efficacy was observed. The second-line PFS benefit appears to be achieved without detrimentally affecting quality of life.

CLINICALTRIALSGOV

NCT01250379.

Abstract P6-14-01: Final results of the TANIA randomized phase III trial of bevacizumab (BEV) after progression on 1st-line BEV therapy for HER2-negative locally recurrent/metastatic breast cancer (LR/mBC)

BACKGROUND: The open-label randomized phase III TANIA trial (NCT01250379) evaluated 2nd-line BEV-containing therapy in BEV-pretreated LR/mBC. The primary objective was met: 2nd-line PFS was statistically significantly improved in patients (pts) receiving further BEV (hazard ratio [HR] 0.75, 95% CI 0.61–0.93; p=0.0068) [von Minckwitz, Lancet Oncol 2014]. We report final efficacy, safety, and health-related quality of life (HRQoL) results.

METHODS: Eligible pts had HER2-negative LR/mBC that had progressed on/after 1st-line BEV plus chemotherapy (CT). Pts were randomized to receive 2nd-line CT (investigator's choice) either alone or combined with BEV (15 mg/kg q3w or 10 mg/kg q2w) until disease progression (PD), unacceptable toxicity, or consent withdrawal. At 2nd PD, pts in the CT arm received 3rd-line CT without BEV (no crossover); pts initially randomized to BEV–CT received 3rd-line BEV–CT. Secondary endpoints included 3rd-line PFS, 2nd- and 3rd-line PFS (from randomization to 3rd PD/death), overall survival (OS), HRQoL, and safety. HRQoL was assessed using FACT-B at baseline, every 8/9 weeks (depending on treatment schedule) during 2nd-line therapy, and at the time of 2nd PD. Prespecified HRQoL analyses included differences between treatment arms in mean change from baseline for each FACT-B subscale.

RESULTS: At the time of data cut-off for the prespecified final analysis (April 30, 2015, 24 months after the last pt was randomized), median follow-up was 32.1 vs 30.9 months in the CT vs BEV–CT arms, respectively. All pts had stopped study treatment. Of the 494 pts randomized to 2nd-line therapy, 234 began 3rd-line therapy (105 initially randomized to CT; 129 from the BEV–CT arm, of whom 17 received CT without BEV). The most commonly selected 3rd-line CT was vinorelbine (33% of CT pts vs 31% of BEV–CT pts).

EndpointNo. of events/pts (%)Median, months (95% CI)Stratified HR (95% CI)p-value CTBEV–CTCTBEV–CT  3rd-line PFS99/105 (94)124/129 (96)2.9 (2.2-3.9)3.8 (2.4-5.1)0.79 (0.59-1.06)0.10802nd- and 3rd-line PFS177/247 (72)206/247 (83)10.7 (9.2-12.5)12.8 (10.7-14.5)0.85 (0.68-1.05)0.1349OS156/247 (63)163/247 (66)18.7 (15.4-21.2)19.7 (17.6-21.0)0.96 (0.76-1.21)0.7253

Subgroup analyses of 3rd-line PFS and OS according to stratification factors were consistent with the overall ITT result. Before study closure, 68% and 61% of pts in the 3rd-line ITT population CT and BEV–CT arms, respectively, received further CT. 3rd-line safety results showed no new safety signals. At week 8/9, mean change from baseline for all FACT-B subscales was <1.5 points in either direction in both treatment arms, representing no significant difference. Similarly, exploratory HRQoL analyses of the physical and functional wellbeing subscales using mixed-model repeated measures and responder analyses revealed no meaningful significant differences between treatment arms.

CONCLUSIONS: Although BEV given after PD on 1st-line BEV-containing therapy showed improvement in 2nd-line PFS, no OS benefit was demonstrated. No new safety signals were observed. There were no differences in HRQoL between treatment arms, suggesting that the PFS benefit with BEV is achieved with maintained HRQoL.

Citation Format: Vrdoljak E, Marschner N, Zielinski C, Gligorov J, Cortes J, Puglisi F, Aapro M, Fallowfield L, Fontana A, Inbar M, Kahan Z, Welt A, Lévy C, Brain E, Pivot X, Putzu C, Gonzalez-Martin A, Ebel K, Easton V, von Minckwitz G. Final results of the TANIA randomized phase III trial of bevacizumab (BEV) after progression on 1st-line BEV therapy for HER2-negative locally recurrent/metastatic breast cancer (LR/mBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-14-01.

An evaluation of prenatal ultrasound screening for CTEV: accuracy data from a single NHS University Teaching Hospital

Congenital Talipes Equinovarus (CTEV) is one of the most common congenital limb deformities. We reviewed the records of infants who had received treatment for structural CTEV between 1 January 2007 and 30 November 2012. This was cross-referenced with the prenatal scans of mothers over a corresponding period of time. We investigated the sensitivity, specificity, and positive and negative predictive values of the fetal anomaly scan for the detection of CTEV and explored whether the publication of Fetal Anomaly Screening Programme guidelines in 2010 affected the rate of detection. During the study period there were 95 532 prenatal scans and 34 373 live births at our hospital. A total of 37 fetuses with findings suggestive of CTEV were included in the study, of whom 30 were found to have structural CTEV at birth. The sensitivity of screening for CTEV was 71.4% and the positive predictive value was 81.1%. The negative predictive value and specificity were more than 99.5%. There was no significant difference between the rates of detection before and after publication of the guidelines (p = 0.5). We conclude that a prenatal fetal anomaly ultrasound screening diagnosis of CTEV has a good positive predictive value enabling prenatal counselling. The change in screening guidance has not affected the proportion of missed cases. This information will aid counselling parents about the effectiveness and accuracy of prenatal ultrasound in diagnosing CTEV.

Do people with benign joint hypermobility syndrome (BJHS) have reduced joint proprioception? A systematic review and meta-analysis

Joint proprioceptive deficit is documented in a variety of musculoskeletal conditions including osteoarthritis, ligament and meniscal injuries, and individuals with increased joint hypermobility, such as those with Ehlers-Danlos. No systematic reviews have assessed joint proprioception in people with benign joint hypermobility syndrome (BJHS). This study addresses this to determine whether people with BJHS exhibit reduced joint proprioception, and, if so, whether this is evident in all age groups. The search strategy was conducted on 31st January 2013. The published literature was assessed using the databases: AMED, CINAHL, MEDLINE, EMBASE, PubMed and the Cochrane Library. Unpublished literature and trial registries were assessed including: OpenGrey, the WHO International Clinical Trials Registry Platform, Current Controlled Trials, the UK National Research Register Archive. All studies comparing the proprioceptive capability of people with and without BJHS were included. Study methodological quality was assessed using the CASP appraisal tool. Meta-analysis techniques were used when study homogeneity permitted. Five studies including 254 people were identified. People with BJHS demonstrated statistically significantly poorer lower limb joint position sense (JPS) (p < 0.001) and threshold detection to movement (p < 0.001) than those without BJHS. The evidence for upper limb proprioceptive difference was less clear, with no statistically significant difference between the cohorts for shoulder JPS (p = 0.10), but a statistically significant difference in finger JPS (p < 0.001). One study which assessed childhood BJHS reported reduced knee proprioceptive capability in those with BJHS (p < 0.001). To conclude, lower limb joint proprioception is reduced in those with BJHS compared to non-BJHS cohorts, whilst unclear in the upper limb.

The bovine chemokine receptors and their mRNA abundance in mononuclear phagocytes

BACKGROUND

The chemokine and chemokine receptor families play critical roles in both the healthy and diseased organism mediating the migration of cells. The chemokine system is complex in that multiple chemokines can bind to one chemokine receptor and vice versa. Although chemokine receptors have been well characterised in humans, the chemokine receptor repertoire of cattle is not well characterised and many sequences are yet to be experimentally validated.

RESULTS

We have identified and sequenced bovine homologs to all identified functional human chemokine receptors. The bovine chemokine receptors show high levels of similarity to their human counterparts and similar genome arrangements. We have also characterised an additional bovine chemokine receptor, not present in the available genome sequence of humans or the more closely related pigs or horses. This receptor shows the highest level of similarity to CCR1 but shows significant differences in regions of the protein that are likely to be involved in ligand binding and signalling. We have also examined the mRNA abundance levels of all identified bovine chemokine receptors in mononuclear phagocytic cells. Considerable differences were observed in the mRNA abundance levels of the receptors, and interestingly the identified novel chemokine receptor showed differing levels of mRNA abundance to its closest homolog CCR1. The chemokine receptor repertoire was shown to differ between monocytes, macrophages and dendritic cells. This may reflect the differing roles of these cells in the immune response and may have functional consequences for the trafficking of these cells in vivo.

CONCLUSIONS

In summary, we have provided the first characterisation of the complete bovine chemokine receptor gene repertoire including a gene that is potentially unique to cattle. Further study of this receptor and its ligands may reveal a specific role of this receptor in cattle. The availability of the bovine chemokine receptor sequences will allow further characterisation of the function of these genes and will confer wide-reaching benefits to the study of this important aspect of the bovine immune response.

Achieving full-dose, on-schedule administration of ACE chemotherapy every 14 days for the treatment of patients with extensive small-cell lung cancer

Extensive small-cell lung cancer (SCLC) is commonly treated with multiple cycles of chemotherapy. Reducing the time interval between cycles of chemotherapy (dose-dense chemotherapy) may improve outcomes in the treatment of extensive SCLC, as it has in other chemosensitive malignancies. To evaluate the feasibility of dose-dense chemotherapy in patients with extensive SCLC, this study evaluates a dose-dense doxorubicin/cyclophosphamide/etoposide (ACE) regimen, supported by the once-per-cycle administration of the hematopoietic growth factor pegfilgrastim. Patients received up to six 14-day cycles of ACE chemotherapy (doxorubicin 40 mg/m,(2) cyclophosphamide 1000 mg/m(2), etoposide 120 mg/m(2) on day 1 IV, plus oral etoposide 240 mg/m(2) daily on days 2-3). On day 4 of each cycle, patients received pegfilgrastim 6 mg by subcutaneous injection. Of 30 patients enrolled, 27 started chemotherapy and received pegfilgrastim. Full-dose, on-schedule chemotherapy was given to all 22 patients starting cycle 2, and in 107 (88%) of 121 cycles. Eighteen of the 27 patients (67%) received full-dose, on-schedule chemotherapy for all 6 cycles. The overall response rate was 17/27 (63%). Nine patients (33%) experienced hematologic toxicities that investigators considered severe or life-threatening. Four patients (15%) had febrile neutropenia. Full-dose, on-schedule dose-dense ACE chemotherapy is feasible with once-per-cycle pegfilgrastim support in extensive SCLC.

Pegfilgrastim supports delivery of FEC-100 chemotherapy in elderly patients with high risk breast cancer: a randomized phase 2 trial

This randomized phase 2 study explored the feasibility of delivering four to six cycles of the dose-intensified regimen FEC-100 (5-fluorouracil, epirubicin, and cyclophosphamide) to elderly patients with stage II-III breast cancer, using pegfilgrastim for neutrophil support. Sixty patients aged 65-77 years received single 6mg doses of pegfilgrastim on day 2 of FEC-100, either as primary prophylaxis (all cycles: PP), or as secondary prophylaxis (all cycles following a neutropenic event: SP). Neutropenic events (a composite endpoint that included grade 3 neutropenia+fever, grade 4 neutropenia, infectious complication requiring systemic anti-infectives and chemotherapy dose delay/reduction) occurred in 24/30 (80%) of the PP and 21/29 (72%) of the SP group in the first cycle. Most patients received all chemotherapy cycles at full dose on schedule (26/30 [87%] PP; 20/29 [69%] SP). These data indicate that delivery of FEC-100 is feasible with pegfilgrastim support in elderly breast cancer patients.

What is the most sensitive non-invasive imaging strategy for the diagnosis of intracranial aneurysms?

OBJECTIVES

To determine whether combining non-invasive tests for intracranial aneurysms together would significantly improve aneurysm detection over individual tests.

METHODS

114 patients undergoing intra-arterial digital subtraction angiography to confirm or exclude an intracranial aneurysm were also examined by CT angiography, MR angiography, and transcranial power Doppler ultrasound. The reviewers and ultrasonographers were blinded to the angiogram result, other imaging results and all clinical information.

RESULTS

The combination of non-invasive tests did improve diagnostic performance on a per patient basis. The combination of power Doppler and CT angiography had the greatest sensitivity for aneurysm detection (0.83; 05% confidence interval (95% CI) 0.66-0.93) and the level of agreement for this strategy with the reference angiographic standard was excellent (kappa 0.84; 95% CI 0.72-0.95). The improvement in sensitivity of adding power Doppler to CT angiography was not significant (p=0.55) but the improvement in the level of agreement with the reference standard was substantial. However, even the most sensitive combination strategy performed poorly in the detection of small (3-5 mm) and very small (<3 mm) aneurysms with a sensitivity of 0.43 (95% CI 0.23-0.66) and 0.00 (95% CI 0.00-0.31) respectively.

CONCLUSIONS

The addition of transcranial power Doppler ultrasound to either CT angiography or MR angiography does improve diagnostic performance on a per patient basis but aneurysms of 5 mm or smaller can still not be reliably identified by current standard clinical non-invasive imaging modalities.

Power transcranial Doppler ultrasound in the detection of intracranial aneurysms

BACKGROUND AND PURPOSE

We sought to perform a large, prospective, multicenter, blinded study comparing power transcranial color duplex sonography (power TCDS) with intra-arterial digital subtraction angiography (IADSA) in the detection of intracranial aneurysms.

METHODS

Contemporaneous TCDS and IADSA examinations were performed in 171 subjects with suspected intracranial aneurysm. Via the temporal bone window, a 2-dimensional hand-held noncontrast transcranial duplex ultrasound imaging system was used operating in power and spectral modes. Sonographers were blinded to clinical history and results of brain CT and IADSA.

RESULTS

We found that 157 subjects (92%) had an adequate bone window. Sensitivity per patient was 0.78 (95% CI, 0.66 to 0.87) and 0.46 (95% CI, 0.36 to 0.56) for any anterior circulation aneurysms. Sensitivity was 0.35 (95% CI, 0.24 to 0.46) for aneurysms </=5 mm and 0.81 (95% CI, 0.62 to 0.94) for aneurysms >5 mm. Accuracy was lower for aneurysms on the cavernous and terminal internal carotid arteries, including posterior communicating artery origin (0.71; 95% CI, 0.63 to 0.79), than for those on the anterior (0.82; 95% CI, 0.74 to 0.89) or the middle cerebral arteries (0.79; 95% CI, 0.71 to 0.86).

CONCLUSIONS

Power TCDS is a promising, inexpensive, noninvasive test for anterior circulation intracranial aneurysms but is less sensitive per aneurysm than alternatives such as CT angiography or MR angiography. Sensitivity is poor for aneurysms </=5 mm in diameter. The internal carotid artery is the most difficult segment to interpret.

Intracranial aneurysms: CT angiography and MR angiography for detection prospective blinded comparison in a large patient cohort

PURPOSE

To compare computed tomographic (CT) angiography and magnetic resonance (MR) angiography with intraarterial digital subtraction angiography (DSA) in the detection of intracranial aneurysms.

MATERIALS AND METHODS

One hundred forty-two patients underwent intraarterial DSA to detect aneurysms. CT angiography, three-dimensional time-of-flight MR angiography, and intraarterial DSA were performed contemporaneously. Film hard-copy images and maximum intensity projection reconstructions of the CT angiograms and MR angiograms were reviewed at different times.

RESULTS

The accuracy per patient for the best observer was 0.87 at CT angiography and 0.85 at MR angiography. The accuracy per aneurysm for the best observer was 0.73 at CT angiography and 0.67 at MR angiography. Differences between readers and modalities were not significant. Interobserver agreement was good: kappa value of 0.73 for CT angiography and of 0.74 for MR angiography. The sensitivity for detection of aneurysms smaller than 5 mm was 0.57 for CT angiography and 0.35 for MR angiography compared with 0.94 and 0.86, respectively, for detection of aneurysms 5 mm or larger. The accuracy of both CT angiography and MR angiography was lower for detection of internal carotid artery aneurysms compared with that at other sites. With low observer confidence, the likelihood of correct interpretation was significantly poorer.

CONCLUSION

CT angiography and MR angiography have limited sensitivity in the detection of small aneurysms but good interobserver agreement. There is no significant difference in diagnostic performance between the noninvasive modalities.

Can noninvasive imaging accurately depict intracranial aneurysms? A systematic review

PURPOSE

To perform a systematic review to determine the accuracy of computed tomographic (CT) angiography, magnetic resonance (MR) angiography, and transcranial Doppler ultrasonography (US) in depicting intracranial aneurysms.

MATERIALS AND METHODS

A 1988-1998 literature search for studies with 10 or more subjects in which noninvasive imaging was compared with angiography was undertaken. Studies meeting initial criteria were evaluated by using intrinsically weighted standardized assessment to determine suitability for inclusion. Studies scoring greater than 50% were included.

RESULTS

Of 103 studies that met initial criteria, 38 scored greater than 50%. CT angiography and MR angiography had accuracies per aneurysm of 89% (95% CI: 87%, 91%) and 90% (95% CI: 87%, 92%), respectively. For US, data were scanty and accuracy was lower, although the CIs overlapped those of CT angiography and MR angiography. Sensitivity was greater for detection of aneurysms larger than 3 mm than for detection of aneurysms 3 mm or smaller-for CT angiography, 96% (95% CI: 94%, 98%) versus 61% (95% CI: 51%, 70%), and for MR angiography, 94% (95% CI: 90%, 97%) versus 38% (95% CI: 25%, 53%). Diagnostic accuracy was similar for anterior and posterior circulation aneurysms.

CONCLUSION

CT angiography and MR angiography depicted aneurysms with an accuracy of about 90%. Most studies were performed in populations with high aneurysm prevalence, which may have introduced bias toward noninvasive examinations.