Performance evaluation of InfectID-BSI: A rapid quantitative PCR assay for detecting sepsis-associated organisms directly from whole blood

BACKGROUND

Bloodstream infections (BSIs) (presence of pathogenic organism in blood) that progress to sepsis (life-threatening organ dysfunction caused by the body's dysregulated response to an infection) is a major healthcare issue globally with close to 50 million cases annually and 11 million sepsis-related deaths, representing about 20% of all global deaths. A rapid diagnostic assay with accurate pathogen identification has the potential to improve antibiotic stewardship and clinical outcomes.

METHODS

The InfectID-Bloodstream Infection (InfectID-BSI) test is a real-time quantitative PCR assay, which detects 26 of the most prevalent BSI-causing pathogens (bacteria and yeast) directly from blood (without need for pre-culture). InfectID-BSI identifies pathogens using highly discriminatory single nucleotide polymorphisms located in conserved regions of bacterial and fungal genomes. This report details the findings of a patient study which compared InfectID-BSI with conventional blood culture at two public hospitals in Queensland, Australia, using 375 whole blood samples (from multiple anatomical sites, eg. left arm, right arm, etc.) from 203 patients that have been clinically assessed to have signs and symptoms of suspected BSI, sepsis and septic shock.

FINDINGS

InfectID-BSI was a more sensitive method for microorganism detection compared with blood culture (BacT/ALERT, bioMerieux) for positivity rate (102 vs 54 detections), detection of fastidious organisms (Streptococcus pneumoniae and Aerococcus viridans) (25 vs 0), detection of low bioburden infections (measured as genome copies/0.35 mL of blood), time to result (<3 h including DNA extraction for InfectID-BSI vs 16 h-48 h for blood culture), and volume of blood required for testing (0.5 mL vs 40-60 mL). InfectID-BSI is an excellent 'rule out' test for BSI, with a negative predictive value of 99.7%. InfectID-BSI's ability to detect 'difficult to culture' microorganisms re-defines the four most prevalent BSI-associated pathogens as E. coli (28.4%), S. pneumoniae (17.6%), S. aureus (13.7%), and S. epidermidis (13.7%).

INTERPRETATION

InfectID-BSI has the potential to alter the clinical treatment pathway for patients with BSIs that are at risk of progressing to sepsis.

Tilmanocept as a novel tracer for lymphatic mapping and sentinel lymph node biopsy in melanoma and oral cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) has been pivotal for pathological assessment of nodal status in cutaneous melanoma (CM) and oral cavity squamous cell carcinoma (OCSCC) thus crucial for staging. An ideal agent for lymphatic mapping should have a standardized preparation, appropriate accumulation in first-echelon nodes and no side effects. Tilmanocept, a CD206-receptor targeted novel radiotracer fulfils these properties. This study investigated Tilmanocept for lymphoscintigraphy and intraoperative identification of sentinel lymph nodes (SLN) in CM and OCSCC.

METHODS

This prospective cross sectional study examined patients who presented to Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney. Patients had biopsy proven tumours with clinically and radiologically negative regional lymph nodes. Tilmanocept guided lymphoscintigraphy was followed by intraoperative SLNs identification via handheld gamma probe. Primary endpoints were detection and retrieval rate of SLNs while secondary endpoints included pathological status of SLNs.

RESULTS

Thirty-five patients were included (26 with CM and 9 with OCSCC) with the most common primary tumour site for CM on the extremities (33.3%). Lymphoscintigraphy with Tilmanocept identified at least 1 SLN (sensitivity 100%) in all patients. SLNs were retrieved in all of patients intraoperatively (100% retrieval rate) with positive nodes found in 20% of patients. Tilmanocept also demonstrated 100% tissue specificity, with lymph nodal tissue confirmed histologically, with no false positives.

CONCLUSION

Tilmanocept is a reliable radiotracer for assessing the nodal status in patients with CM and OCSCC. Our group is the first to evaluate the use of Tilmanocept in the Australian setting, adding to the limited studies worldwide.

The diagnostic accuracy of temporal artery ultrasound and temporal artery biopsy in giant cell arteritis: A single center Australian experience over 10 years

Aim

Method

Results

Conclusion

Correlation Between Quantitative Uptake of 99mTC-DPD and Echocardiographic Parameters in Cardiac ATTR: A Novel Follow-Up Strategy

Aims: There has been a paradigm shift in diagnosis of cardiac transthyretin amyloidosis (ATTR) with non-invasive techniques including technetium-99m 3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) bone scintigraphy. We evaluated structural and functional biventricular alterations by transthoracic echocardiography (TTE) and determined the correlation with 99mTc-DPD tracer uptake in ATTR. Materials and Methods: ATTR patients (wild-type, hereditary or asymptomatic transthyretin [TTR] variant carriers) with 99mTc-DPD and TTE were selected; 99mTc-DPD uptake was analyzed quantitatively. TTE assessment of left ventricle (LV) and right ventricle (RV) parameters was performed. Results: Forty ATTR patients (wild-type n = 17; hereditary ATTR and TTR variant carriers n = 23; median age 68.8 ± 22 years) were included. TTE parameters displaying good correlation with 99mTc-DPD tracer uptake included LV average wall thickness (r = 0.837), LV indexed mass (LVMI; r = 0.802), RV wall thickness (r = 0.610), average e' (r = -0.830), E/e' ratio (r = 0.786), LV global longitudinal strain (GLS; r = 0.714) and RV GLS (r = 0.632; p < 0.001 for all). Hereditary ATTR and TTR variant carriers without cardiac tracer uptake had normal echocardiographic parameters. Receiver operating characteristic curves demonstrated strong diagnostic accuracies for structural (LV wall thickness, LVMI and RV wall thickness; area under the curve (AUC) of 0.96 for all) and functional (LV and RV GLS; AUC of 0.86 and 0.88, respectively) parameters. Conclusion: Good correlations between TTE biventricular structural and functional parameters were demonstrated with quantitative 99mTc-DPD uptake. Echocardiography may potentially assume a significant role in longitudinal follow-up for monitoring disease progression and for evaluating treatment response.

Personal innovative approach in radiation therapy of lung cancer- functional lung avoidance SPECT-guided (ASPECT) radiation therapy: a study protocol for phase II randomised double-blind clinical trial

BACKGROUND

Radiation therapy (RT) plays a key role in curative-intent treatment for locally advanced lung cancer. Radiation induced pulmonary toxicity can be significant for some patients and becomes a limiting factor for radiation dose, suitability for treatment, as well as post treatment quality of life and suitability for the newly introduced adjuvant immunotherapy. Modern RT techniques aim to minimise the radiation dose to the lungs, without accounting for regional distribution of lung function. Many lung cancer patients have significant regional differences in pulmonary function due to smoking and chronic lung co-morbidity. Even though reduction of dose to functional lung has shown to be feasible, the method of preferential functional lung avoidance has not been investigated in a randomised clinical trial.

METHODS

In this study, single photon emission computed tomography (SPECT/CT) imaging technique is used for functional lung definition, in conjunction with advanced radiation dose delivery method in randomised, double-blind trial. The study aims to assess the impact of functional lung avoidance technique on pulmonary toxicity and quality of life in patients receiving chemo-RT for lung cancer. Eligibility criteria are biopsy verified lung cancer, scheduled to receive (chemo)-RT with curative intent. Every patient will undergo a pre-treatment perfusion SPECT/CT to identify functional lung. At radiation dose planning, two plans will be produced for all patients on trial. Standard reference plan, without the use of SPECT imaging data, and functional avoidance plan, will be optimised to reduce the dose to functional lung within the predefined constraints. Both plans will be clinically approved. Patients will then be randomised in a 2:1 ratio to be treated according to either the functional avoidance or the standard plan. This study aims to accrue a total of 200 patients within 3 years. The primary endpoint is symptomatic radiation-induced lung toxicity, measured serially 1-12 months after RT. Secondary endpoints include: a quality of life and patient reported lung symptoms assessment, overall survival, progression-free survival, and loco-regional disease control.

DISCUSSION

ASPECT trial will investigate functional avoidance method of radiation delivery in clinical practice, and will establish toxicity outcomes for patients with lung cancer undergoing curative chemo-RT.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT04676828 . Registered 1 December 2020.

Rest tremor correlates with reduced contralateral striatal dopamine transporter binding in Parkinson's disease

INTRODUCTION

In vivo dopamine transporter imaging is a useful tool for distinguishing nigrostriatal pathologies (e.g. Parkinson's disease) from other causes of tremor. However, while many of the motoric features of Parkinson's disease (e.g. bradykinesia, rigidity, hypomimia) correlate well with reduced striatal dopamine transporter binding, the same relationship has not been demonstrated for tremor. We investigated the relationship between striatal dopamine transporter binding and quantitative measures of tremor.

METHODS

23 participants with Parkinson's disease underwent standardised clinical assessment including structured, videotaped clinical examination, tremor neurophysiology study of both upper limbs using accelerometry and surface EMG, and Technitium-99 m TRODAT-1 brain SPECT imaging. Normalised striatal uptake values were calculated. Tremor EMG and accelerometry time series were processed with Fourier transformation to identify peak tremor power within a window of 3-10Hz and to calculate the tremor stability index (TSI).

RESULTS

Spearman correlation analyses revealed an association between tremor power and contralaterally reduced striatal uptake in a number of recording conditions. This association was strongest for rest tremor, followed by postural tremor, with the weakest association observed for kinetic tremor. Lower TSI was also associated with lower contralateral striatal uptake in a number of rest and postural conditions.

CONCLUSION

These data suggest a relationship between Parkinsonian rest tremor and contralateral reduction in striatal dopamine binding. Use of quantitative neurophysiology techniques may allow the demonstration of clinico-pathophysiological relationships in tremor that have remained occult to previous studies.

SUN-621 Lessons from beyond the Graves'

Introduction: The coexistence of thyrotoxicosis and thyroid carcinoma is a well-recognised clinical phenomenon. Patients with Graves’ disease have an increased risk of developing thyroid carcinomas than in patients with toxic adenoma or toxic multinodular goiter. We report a patient with Graves’ disease who had a ‘silent’ thyroid cancer. Clinical Case: A 20 year-old female was diagnosed with Graves’ disease. She had clinical signs of Graves’ ophthalmopathy, a thyroid goiter, sinus tachycardia and unintentional weight loss. Her TSH level was <0.005 mIU/L [0.40 - 3.50 mIU/L], free T4 level was 40.9 pmol/L [9.0 - 19.0 pmol/L], free T3 level was >46.1 pmol/L [2.6 - 6.0 pmol/L] and TSH receptor antibody (TRAb) level was 27.5 IU/L [<1.0 IU/L]. She denied prior head/neck irradiation or a family history of thyroid disorders. She was commenced on carbimazole. &nbsp; Her initial thyroid ultrasound (January 2016) demonstrated a heterogenous, hypervascular goiter (right lobe measured 65 x 31 x 25 mm and left lobe measured 50 x 21 x 31 mm). On her repeat thyroid ultrasound (April 2017), the heterogeneous hypervascular goiter had increased in size (right lobe 81 x 37 x 36 mm and left lobe 64 x 31 x 36 mm). A thyroid technetium scan identified diffuse radiotracer uptake (82.51%), consistent with Graves’ disease. Due to refractory Graves’ disease and the presence of Graves’ ophthalmopathy, a total thyroidectomy was performed (February 2018). Surprisingly, post-operative histopathology identified a 60 mm papillary thyroid carcinoma in the right lobe and a 36 mm papillary thyroid carcinoma in the left lobe, with lymphovascular and adipose tissue invasion. The tumours&nbsp;were negative for BRAF V600E. The remaining thyroid tissue showed Graves’ thyroiditis. Six weeks post-thyroidectomy, she had a thyroglobulin&nbsp;level at 16.3 μg/L [0 - 28 μg/L], undetectable anti-thyroglobulin antibody and TRAb level at 4.4 IU/L.&nbsp;Radioactive iodine remnant ablation was performed (August 2018) with steroid cover for persisting Graves’ ophthalmopathy. Her whole body I-131 scan identified residual thyroidal type tissue in the thyroid bed and diffuse uptake throughout both lungs, likely secondary to inflammation from a flu-like illness prior to her scan. Her thyroglobulin levels had reduced to 1.1 μg/L, with TSH level of 12 mIU/L, free T4 level of 18 pmol/L and free T3 level of 3.3 pmol/L. Conclusions: Patients with Graves’ disease have an increased risk of thyroid carcinomas, possibly related to TSH receptor antibodies. It is usually either clinically apparent or occult micro-carcinomas. Large&nbsp;papillary thyroid carcinomas&nbsp;in Graves’ disease not detected by thyroid technetium scan or thyroid ultrasound is rare.

Location of arm draining lymph node in relation to breast cancer radiotherapy field and target volume

BACKGROUND

Lymphoedema of the arm following axillary surgery or radiotherapy remains a significant side effect affecting some women after breast cancer treatment. Axillary reverse mapping (ARM) is a technique used to identify the lymph node draining the arm (ARM node). Our study aim was to examine the location of the ARM nodes in relation to target volumes and treatment fields for breast cancer radiotherapy.

MATERIALS AND METHODS

Eighteen breast cancer patients underwent lymphoscintigraphy of contralateral arm (left 10, right 8) and SPECT CT scan on a research study. Patient position for the SPECT CT scan approximated the position used for radiotherapy. Using MIM software™, the ARM node for each subject was contoured on the SPECT CT and verified by a nuclear medicine physician. The CT component of the SPECT CT was then transferred to ECLIPSE™ radiotherapy planning software, and the contralateral breast and axilla were contoured on this CT scan according to the ESTRO contouring guideline. Two radiotherapy plans were generated for each subject using standard tangential IMRT technique at a dose of 50 Gy in 25 fractions, one treating contralateral breast alone, the other treating contralateral breast and contralateral axilla level 1-4. The ARM node was considered "within the radiotherapy field" if the mean dose received by the ARM node was more than 50% of the prescribed dose: i.e., 25 Gy.

RESULTS

One right-sided subject had 2 ARM nodes, all others had 1 ARM node. All ARM nodes (left 10, right 9) were located within level 1 of the axilla. For the subject with 2 ARM nodes, the node that received a higher dose was used for the analysis. The mean dose received by the ARM node in the whole breast radiotherapy plans ranged from 0.8 to 45.5 Gy, with a median of 10.9 Gy. The mean dose received by the ARM node in the whole breast and axilla plans ranged from 43.4 to 52.5 Gy, with a median of 49.3 Gy. In the whole breast radiotherapy plans, only 5 out of 18 ARM nodes were found to be "within radiotherapy field", and only 2 ARM nodes received more than 40 Gy. In the breast and axilla plans, all 18 ARM nodes were "within radiotherapy field" and all received more than 40 Gy. To better visualise the locations of ARM nodes, all left sided ARM nodes were then mapped onto a CT set from one of the left-sided subjects, and all the right sided ARM nodes mapped onto one of the right-sided subjects, and digitally reconstructed radiograph (DRR) for radiotherapy fields were produced.

CONCLUSIONS

Our study demonstrates that the vast majority of ARM nodes (72%) are outside the tangential whole breast radiotherapy fields. In our study, all the ARM nodes were within the axillary radiotherapy fields covering level 1-4 axillary volumes according to the ESTRO contouring guideline, and complete shielding of the humeral head according to the EORTC consensus did not lead to sparing of the ARM nodes. A prospective study is needed to examine the oncological safety of ARM node-sparing axillary radiotherapy and its potential to reduce the risk of arm lymphoedema.

Multicentre, randomised, blinded, control trial of drug-eluting balloon vs Sham in recurrent native dialysis fistula stenoses

Background:

Endovascular treatment of autogenous arteriovenous haemodialysis fistula stenosis has high reintervention rates. We investigate the effect of drug-eluting balloons in the treatment of recurrent haemodialysis fistula stenosis.

Methods:

This is a randomised, controlled, investigator-initiated and run, prospective, blinded, multicentre trial. Patients with recurrent autogenous arteriovenous haemodialysis fistula stenosis received standard endovascular treatment plus drug-eluting balloon or standard endovascular treatment plus uncoated balloon (Sham). Primary endpoint was late lumen loss in trial area on ultrasound at 6 weeks, 3, 6 and 12 months. Secondary endpoints were freedom from reintervention to the Index Trial Area and decline in fistula flow (Qa). Interim analysis was performed at 6 months (unblinded due to timeliness).

Results:

Patients with 132 recurrent stenoses (48% in bare Nitinol stents) were randomised with 70 receiving drug-eluting balloon and 62 Sham. At 6 months, decline in late lumen loss was 0.23 ± 0.03 mm/month for Sham and 0.045 ± 0.03 mm/month for drug-eluting balloon arm, a significant difference (0.18 mm, p = 0.0002). At 12 months, this difference persisted at 0.12 mm (p = 0.0003). At 6 months, significant difference in late lumen loss for instent restenoses (p = 0.0004) was observed, with non-significant difference for unstented restenoses (p = 0.065). Mean time for freedom from reintervention was 10.14 months for Sham versus 42.39 months for drug-eluting balloon (p = 0.001). The same was shown for instent (p = 0.014) and unstented (p = 0.029) restenoses. Qa decline rate at 6 months was 36.89 mL/min/month (Sham) and 0.41 mL/min (drug-eluting balloon). The difference was significant (36.48 mL/min; p = 0.02) and persisted to 12 months (p = 0.44).

Conclusion:

Paclitaxel drug-eluting balloon significantly delays restenosis after angioplasty for recurrent autogenous arteriovenous haemodialysis fistula stenosis, persisting to 12 months. Drug-eluting balloon significantly increases freedom from reintervention at 12 months with these effects true in stented and unstented fistulas.

Sentinel lymph node biopsy for early oral cancers: Westmead Hospital experience

BACKGROUND

Sentinel lymph node biopsy (SLNB) has become an alternative option to elective neck dissection (END) for early oral cavity squamous cell carcinoma (OCSCC) outside of Australia. We sought to assess the technical feasibility of SLNB and validate its accuracy against that of END in an Australian setting.

METHODS

We performed a prospective cohort study consisting of 30 consecutive patients with cT_1-2 N₀ OCSCC referred to the Head and Neck Cancer Service, Westmead Hospital, Sydney, between 2011 and 2014. All patients underwent SLNB followed by immediate selective neck dissection (levels I-III).

RESULTS

A total of 30 patients were diagnosed with an early clinically node-negative OCSCC (seven cT1 and 23 cT2), with the majority located on the oral tongue. A median of three (range: 1-14) sentinel nodes were identified on lymphoscintigraphy, and all sentinel nodes were successfully retrieved, with 50% having a pathologically positive sentinel node. No false-negative sentinel nodes were identified using selective neck dissection as the gold standard. The negative predictive value (NPV) of SLNB was 100%, with 40% having a sentinel node identified outside the field of planned neck dissection on lymphoscintigraphy. Of these, one patient had a positive sentinel node outside of the ipsilateral supraomohyoid neck dissection template.

CONCLUSION

SLNB for early OCSCC is technically feasible in an Australian setting. It has a high NPV and can potentially identify at-risk lymphatic basins outside the traditional selective neck dissection levels even in well-lateralized lesions.

Utility of hybrid SPECT/CT in primary melanoma lymphoscintigraphy: A retrospective case series

INTRODUCTION

Sentinel lymph node (SLN) biopsy is widely accepted as an important part of staging cutaneous malignant melanoma. Hybrid single photon emission computed tomography and computed tomography (SPECT/CT) may identify additional SLN and provide important information to the surgeon performing SLN biopsy. We report our experience at a major referral centre for melanoma surgery.

METHODS

Retrospective case series of pre-operative sentinel node lymphoscintigraphy for primary melanoma over a consecutive 12-month period. All patients had planar imaging and hybrid SPECT/CT.

RESULTS

At least 1 SLN was successfully identified in 82 of 86 eligible patients (95.3%). These 82 patients had 144 SLNs (mean 1.8). There were no patients where the SLN was seen only with SPECT/CT. Additional information was provided by SPECT/CT in 32 patients (39.0%). Histology reports were available for 52 patients, 9 (17.3%) had at least 1 SLN positive for metastatic disease.

CONCLUSIONS

We achieved a high rate of SLN identification. SPECT/CT was most frequently helpful when the primary melanoma was located in the head, neck and trunk. Routine use of SPECT/CT during lymphoscintigraphy provides important anatomical information and may reduce the false-negative rate.

Right ventricular dysfunction predisposes to inducible ventricular tachycardia at electrophysiology studies in patients with acute ST-segment-elevation myocardial infarction and reduced left ventricular ejection fraction

BACKGROUND

Inducible ventricular tachycardia (VT) is a strong predictor of spontaneous ventricular tachyarrhythmia following ST-segment-elevation myocardial infarction. Reduced left ventricular ejection fraction (EF) predisposes patients to inducible VT after ST-segment-elevation myocardial infarction. However, the role of right ventricular (RV) dysfunction in predisposing to inducible VT has not been described previously.

METHODS AND RESULTS

Consecutive patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention underwent predischarge radionuclide gated heart pool scan to assess ventricular EF. The study cohort included patients with reduced left ventricular EF (left ventricular EF ≤40%) who underwent electrophysiology study (n=220) in an attempt to induce VT. We defined RV dysfunction as RVEF ≤35%. The end point was sustained monomorphic VT (cycle length ≥200 ms). This was considered a positive study. No inducible arrhythmia, ventricular fibrillation, or flutter (cycle length <200 ms) was considered a negative study. Infarct region, infarct-related artery, male sex, and RVEF ≤35% were univariable predictors of positive test. After multivariable analysis, RVEF ≤35% had the strongest association as an independent predictor of inducible VT at electrophysiology study (P<0.001; odds ratio, 5.8; 95% confidence interval, 3.005-11.262).

CONCLUSIONS

RV dysfunction (RVEF ≤35%) predisposed to inducible VT at electrophysiology study in patients with impaired left ventricular EF (≤40%) after acute ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention.

Impact of F18-fluorodeoxyglycose positron emission tomography/computed tomography on the management of resectable pancreatic tumours

BACKGROUND

Positron emission tomography/computed tomography (PET/CT) using F18-fluorodeoxyglucose has been shown to be valuable in the management of malignant disease. The aim of this study is to investigate the impact of this technique on the management of patients with resectable pancreatic tumours.

METHODS

Thirty-six patients with 37 potentially resectable pancreatic tumours on diagnostic CT imaging underwent PET/CT scans. Operative findings, histological reports and/or clinical follow-up served as standard of reference. The impact of PET/CT on patient management was estimated by calculating the percentage of patients whose treatment plan was altered due to PET/CT.

RESULTS

Pancreatic adenocarcinoma was diagnosed in 30 patients, neuroendocrine tumours in 3, mass-forming pancreatitis in 3 and serous cystadenoma in 1. The median standard uptake (max) value was 5.0 (range 2.2-12.0). Sensitivity and specificity of detecting extrapancreatic metastatic disease were 73% and 100%, respectively. Three occult liver metastases were detected at laparotomy following negative PET/CT. PET/CT findings influenced the management of 8 (22%) patients - 3 with liver metastases, 3 with bone metastases, 1 with lymph node metastases and 1 by identifying the benign appearance of the pancreatic tumour.

CONCLUSION

PET/CT achieves a significant diagnostic impact in detecting extrapancreatic metastatic disease. F18-fluorodeoxyglucose PET/CT appears to be useful in assessing suspicious pancreatic masses.

Predictors of Vinorelbine Pharmacokinetics and Pharmacodynamics in Patients With Cancer

Purpose

Marked interindividual variation in drug disposition and toxicity pose an ongoing challenge to chemotherapy dosage individualization. The aim of this study was to evaluate pretreatment clinical features, genotype and functional indicators of drug clearance as predictors of vinorelbine clearance, and myelotoxicity that could inform dosage optimization.

Patients and Methods

Forty-one patients with cancer received a 60 mg intravenous dose of vinorelbine. Pretreatment routine body size measurements and blood tests were performed. Midazolam clearance and hepatic technetium labeled sestamibi (99mTc-MIBI) clearance were used to investigate CYP3A and ABCB1 (MDR1, P-glycoprotein) phenotype respectively and selected single nucleotide polymorphisms in CYP3A and ABCB1 were documented. A limited blood sampling strategy was employed and vinorelbine concentrations were determined by high-performance liquid chromatography. Posterior Bayesian estimates of vinorelbine clearance were obtained for each patient using population pharmacokinetic modeling. Myelotoxicity was estimated from the fractional survival of neutrophils post-treatment.

Results

There was 4.3-fold variation in vinorelbine clearance across the cohort. In a multivariable analysis, pretreatment estimated creatinine clearance (P < .01) and hepatic 99mTc-MIBI clearance (P = .01) were independent predictors of vinorelbine clearance. Fractional survival of neutrophils ranged from 1.3% to 100% and was significantly correlated with vinorelbine clearance (P < .01). Body-surface area was the only pretreatment predictor of fractional survival of neutrophils independent of vinorelbine clearance (P = .02).

Conclusion

Specific indicators of drug clearance provide predictive information about vinorelbine pharmacokinetics, and body-surface area, probably reflecting normal bone marrow reserve, provides an additional pharmacodynamic indicator. Use of a fixed dose of vinorelbine with modifications guided by pretreatment measures is worthy of prospective evaluation.

Hepatic technetium Tc 99m?labeled sestamibi elimination rate and () genotype as indicators of ABCB1 (P-glycoprotein) activity in patients with cancer

BACKGROUND AND OBJECTIVE

The adenosine triphosphate-binding cassette transporter ABCB1 (P-glycoprotein) mediates terminal excretion of many chemotherapeutic agents, and variable ABCB1 activity may be an important contributor to interpatient variability in the clearance of chemotherapeutic agents. Our objective was to determine the elimination constant (kH) for hepatic elimination of technetium Tc 99m-labeled sestamibi (99mTc-MIBI) in patients with cancer and to compare this putative indicator of ABCB1 phenotype with clinical features and common ABCB1 genetic variants.

METHODS

99mTc-MIBI kH was determined from the time-dependent elimination profile of 99mTc-MIBI over a 90-minute hepatic scanning period in 66 patients with cancer. Single nucleotide polymorphisms (SNPs) in ABCB1 exons 12 (C1236T), 21 (G2677T/A), and 26 (C3435T) were documented by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

There was a 12-fold variation in 99mTc-MIBI kH across the cohort, which was not correlated with sex, age, conventional liver function test results, previous chemotherapy treatment, or history of liver metastasis. Mean 99mTc-MIBI kH was significantly reduced in patients with SNPs in exons 21 and 26 such that mean 99mTc-MIBI kH was 1.90 times (95% confidence interval, 1.14-2.66; P = .02) and 2.21 times (95% confidence interval, 1.47-2.97; P < .01) higher in subjects homozygous for the wild-type alleles than in those homozygous for these SNPs, respectively.

CONCLUSION

Hepatic elimination of 99mTc-MIBI is a potential in vivo probe of hepatic ABCB1 activity that is significantly associated with the presence of common SNPs in ABCB1. 99mTc-MIBI hepatic scanning may provide a useful pretreatment indicator of ABCB1-mediated drug clearance in cancer patients.

Assessment of pediatric hydronephrosis using output efficiency

Diagnosing obstruction in pediatric patients with hydronephrosis, and renal impairment is often difficult. Renal output efficiency (OE) is a parameter that may improve diagnostic accuracy by allowing normalization of washout according to renal function. The aims of this study were to define a normal range for OE in infants and children and to evaluate its diagnostic accuracy in cases with hydronephrosis.

METHODS

Seventy-four children (91 hydronephrotic kidneys; median age, 4 mo; 22 girls and 52 boys) underwent 99mTc-labeled mercaptoacetyl-triglycine scintigraphy using intravenous volume expansion (15 ml/kg normal saline), furosemide diuresis and urethral catheterization, if vesicoureteric reflux was present. Images were interpreted by consensus of two or more experienced observers using visual assessment of the images, differential function and clearance half-time after furosemide (T(1/2)), as well as OE. The final diagnosis was based on surgical findings (n = 23 kidneys) or follow-up for >12 mo (n = 68).

RESULTS

Final diagnosis in 22 of the 91 hydronephrotic kidneys was obstruction at the pelviureteric (n = 21) or vesicoureteric (n = 1) junction and no obstruction in the remaining 69. The overall diagnostic accuracy of OE was 89%. Using exhaustive search multivariate logistic regression analysis, only reduced OE (p < 0.001) and decreased renal uptake by visual assessment (p = 0.058) were independently predictive of obstruction (R2 = 0.726). In dilated but unobstructed kidneys, mean OE was 93% +/- 7.1%. In the normal kidneys, mean OE was 96% +/- 3.1%.

CONCLUSION

OE improves the diagnostic accuracy of diuretic renography in children and neonates with hydronephrosis and suspected obstruction. Output efficiency should exceed 89% in normal kidneys and 79% in unobstructed, hydronephrotic kidneys.

Twice-daily dosing of loracarbef 200 mg versus 400 mg in the treatment of patients with acute maxillary sinusitis

Loracarbef is an oral synthetic beta-lactam antibiotic in the new carbacephem class. We conducted a multicenter, randomized, double-blind, parallel-group study to compare the efficacy and safety of loracarbef 200 mg twice daily (BID) and 400 mg BID when given orally for 10 days to patients 12 years of age and older with acute maxillary sinusitis. Because sinus aspirates for culture are not routinely obtained in the management of acute maxillary sinusitis, antimicrobial therapy usually is selected empirically. This study was designed to provide data simulating the usual clinical practice of treatment without sinus aspiration. Two hundred nine patients who met the entry criteria, which included abnormal pretherapy sinus radiographs compatible with acute maxillary sinusitis and symptoms of fewer than 4 weeks' duration, qualified for the clinical analyses. Of the 106 clinically qualified patients assigned to the 200-mg BID group, favorable clinical responses (cure and improvement) were noted in 86 (81.1%) patients. Of the 103 clinically qualified patients assigned to the 400-mg BID group, 84 (81.6%) patients had favorable clinical responses. These results compare favorably with accepted clinical response rates of 70% to 80% for beta-lactams selected on an empiric basis. At the end of the treatment period, favorable radiologic responses (resolved and improved) and favorable clinical responses occurred in 55 (51.9%) of the 106 clinically qualified patients in the 200-mg BID group and in 57 (55.3%) of the 103 clinically qualified patients in the 400-mg BID group. Mean roentgenogram scores for the clinically qualified patients were 2.3 for both groups before therapy and 1.3 and 1.5 after therapy for the 200-mg BID and 400-mg BID groups, respectively. The mean change from pretherapy to posttherapy by patient was 1.0 for the 200-mg BID group and 0.8 for the 400-mg BID group. There were no statistically significant differences between treatment groups in the incidence of specific adverse events reported during therapy. These data suggest that loracarbef 200 mg BID is comparable in efficacy and safety to loracarbef 400 mg BID in the treatment of patients with acute maxillary sinusitis.

Loracarbef (LY163892) versus amoxicillin/clavulanate in the treatment of acute purulent bacterial bronchitis

In this single-blind study, 488 patients with acute bronchitis were randomly assigned to receive 400 mg of loracarbef twice daily or 500/125 mg of amoxicillin/clavulanate three times daily for seven days. Treatment efficacy was evaluated in 98 patients treated with loracarbef and in 99 treated with amoxicillin-clavulanate in whom pretreatment positive cultures of pathogens susceptible to both study drugs were found. Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis, and Klebsiella pneumoniae were isolated in pure or mixed cultures in 64% of the evaluable patients; S pneumoniae was found in 26%. Among the evaluable patients, the rate of favorable clinical responses (cure and improvement) in the loracarbef group (96 of 98 patients; 98.0%) was similar to that in the amoxicillin/clavulanate group (96 of 99 patients; 97.0%); the favorable bacteriologic response rates were also similar (93.7% vs 92.9%, respectively). Eight patients in the loracarbef group and nine in the amoxicillin/clavulanate group discontinued treatment because of adverse events. The events were presumed to be drug related in five of the loracarbef group and in seven of the amoxicillin/clavulanate group. During therapy, diarrhea was the most frequently reported event in both groups. However, it occurred in only 8.2% of the loracarbef-treated patients compared with 22.5% of the amoxicillin/clavulanate patients (P less than 0.001). It is concluded that both loracarbef and amoxicillin/clavulanate are safe and effective in the treatment of acute purulent bacterial bronchitis.

Loracarbef (LY163892) versus amoxicillin/clavulanate in the treatment of acute bacterial exacerbations of chronic bronchitis

In this single-blind study, 579 patients with chronic bronchitis were randomly assigned to receive 400 mg of loracarbef twice daily or 500/125 mg of amoxicillin/clavulanate thrice daily for seven days. Treatment efficacy was evaluated in 129 of the loracarbef-treated patients and 120 amoxicillin/clavulanate-treated patients in whom pretreatment positive cultures of pathogens susceptible to both antibiotics were isolated. Three organisms predominated in either pure or mixed cultures in 57.0% of the evaluable patients: Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella (Branhamella) catarrhalis; H influenzae was isolated in 25.0% of the patients with single pathogens. Among the evaluable patients, favorable clinical responses (cure or improvement) were noted in 93.8% of the loracarbef-treated patients and in 95.0% of the amoxicillin/clavulanate-treated patients. A favorable bacteriologic response (pathogen eliminated or presumed eliminated) was found in 82.2% of loracarbef-treated patients and 90.0% of amoxicillin/clavulanate-treated patients. Six patients in the loracarbef group and 14 in the amoxicillin/clavulanate group discontinued treatment because of adverse events. The events were judged to be drug related in four loracarbef-treated patients and in 11 amoxicillin/clavulanate-treated patients. The incidence of diarrhea and other gastrointestinal symptoms was significantly more frequent in the amoxicillin/clavulanate group (13.5% and 5.6%) than in the loracarbef group (4.5% and 1.7%), while the incidence of severe headaches was significantly more frequent in the loracarbef than the amoxicillin/clavulanate group (7.2% vs 3.1%). It is concluded that loracarbef and amoxicillin/clavulanate are safe and effective in the treatment of acute bacterial exacerbations of chronic bronchitis.

Loracarbef (LY163892) versus cefaclor in the treatment of acute bacterial bronchitis

In this double-blind study, 319 patients (133 men, 186 women) with acute bronchitis were randomly assigned to receive 200 mg of loracarbef twice daily (n = 160; mean age, 42 years) or 250 mg of cefaclor thrice daily (n = 159; mean age, 43 years) for seven days. Clinical and bacteriologic responses were assessed in 63 loracarbef-treated and 56 cefaclor-treated patients in whom pretreatment positive cultures of pathogens susceptible to loracarbef and cefaclor were found. Among these evaluable patients, a clinical cure was found in 68.3% of the loracarbef-treated patients and in 66.1% of the cefaclor-treated patients and improvement in 27.0% and 28.6%, respectively; the pathogen was eliminated in 7.9% and 10.7% and presumed eliminated in 82.5% and 82.1%, respectively. Three in the loracarbef group discontinued treatment because of adverse events, two of which (nausea, nausea/diarrhea/vomiting) were presumably related to the drug. Headache was reported by 9.4% of the 160 patients in the loracarbef group and 6.9% of the 159 patients in the cefaclor group; diarrhea by 5.6% and 6.9%, respectively; and dyspepsia/abdominal pain/gastrointestinal disorders by 5.6% and 4.4%, respectively. It is concluded that both loracarbef and cefaclor are safe and effective in the treatment of acute bacterial bronchitis.