Search

Background Prompt and accurate diagnosis of lymphadenopathy is important, yet there is wide variability in clinical approach and referral patterns, leading to unnecessary investigations and delays in diagnosis. To address this, a lymph node diagnostic clinic (LNDC) was established at our tertiary referral center. Patients and Methods We retrospectively analyzed data from 320 consecutive patients referred to the LNDC from March 2008 to March 2020, to describe their management and outcomes. Results The most common diagnoses were reactive (57%) and malignant lymphadenopathy (28%). In those with reactive lymphadenopathy, 33% did not undergo further investigations, 37% underwent imaging only, and 29% underwent biopsy. For malignant lymphadenopathy, diagnosis was made at a median (interquartile range) of 9 (6-16) days from first LNDC review, with the decision to biopsy made at the first LNDC review in 95% of cases. Clinical features significantly associated with malignancy included age > 45, B symptoms, history of malignancy, and lymphadenopathy that was ≥ 2 cm, in multiple regions, bilateral, multiple nodes, or supraclavicular. At least 3 of these features were present in 88% of patients with malignant lymphadenopathy. Ultrasound had a sensitivity of 98% and negative predictive value of 97% for detecting malignant lymphadenopathy. Conclusion A dedicated LNDC in a tertiary referral center facilitates rapid assessment and diagnosis of lymphadenopathy through a risk-stratified model of management. Ultrasonography, as well as the presence of defined clinical risk factors, were most useful to differentiate benign from malignant lymphadenopathy.

PURPOSE: Patients with indolent non-Hodgkin lymphoma (iNHL) undergo regular active surveillance in between treatment periods to detect disease relapse or progression. As part of surveillance, international guidelines recommend regular routine blood testing, which is based on consensus rather than evidence of utility. METHODS: We conducted a retrospective analysis of all patients older than age 16 years diagnosed with grade 1-3A follicular or marginal zone lymphoma between 2008 and 2017 from 2 Australian cancer centers to assess the utility of full blood examination, lactate dehydrogenase, and β2-microglobulin in detecting progression events, defined as either disease relapse or progression of disease. RESULTS: One hundred eighty patients attended 1,757 outpatient appointments (median follow-up, 36 months). Routine blood tests (RBTs) were performed before 83% of appointments. Seventy-four progression events occurred in 62 patients. Only 2 events (3%) were detected by RBTs alone, both of which occurred in treatment-naïve patients who subsequently developed symptoms within 3 weeks. The remainder of progression events were suspected clinically (88%) or detected by imaging (9%). RBT results were frequently abnormal in asymptomatic patients (19%), with abnormal results leading to either additional investigations or an increased surveillance frequency in 8% of cases. The overall sensitivity and positive predictive value of abnormal RBT results in detecting progression events were 39% and 9%, respectively. CONCLUSION: RBTs have poor performance characteristics and rarely detect clinically significant disease progression or relapse in asymptomatic patients with iNHL.

Metastatic spread of testicular cancer has been well documented, with 95% of cases involving para-aortic retroperitoneal lymph nodes. Mesenteric lymphatic basins do not lie within the canonical drainage pathway of the testes and represent a rare site of metastasis. Various mechanisms of spread to the mesentery have been described, including direct extension and haematogenous dissemination. We present a case of a previously-well 43-year-old man who presented with right scrotal discomfort and intermittent lower back pain, who was found to have mesenteric metastases from a non-seminomatous germ cell tumour of the testis. Managing lymphadenopathy that lies outside of standard resection templates remains a complex surgical challenge. Here we present the first case in the English medical literature with co-existing supradiaphragmatic axillary and mediastinal nodal disease.

First-line tyrosine kinase inhibitors are standard of care for non-small-cell lung cancers (NSCLC) harbouring an epidermal growth factor receptor mutation, anaplastic lymphoma kinase fusion or c-ros oncogene 1 rearrangement. Other targetable oncogenic drivers have been identified but testing for these is neither funded nor commonly performed in Australia. Using a case example, we discuss the importance of considering several other genomic aberrations in our population, such as rearrangements in the RET proto-oncogene, which occur in 1-2% of lung adenocarcinoma. New oncogenic drivers and corresponding targeted agents are constantly being discovered; these will continue to refine the treatment of non-small-cell lung cancer in the era of precision medicine.

BACKGROUND Current guidelines recommend a step-wise screening algorithm for all colorectal carcinomas (CRC) to identify patients with Lynch syndrome (LS). AIM To describe the frequencies of mismatch repair deficiency (dMMR), BRAFV600E mutations and MLH1 methylation in resected CRC, and evaluate the impact of universal screening on LS detection. METHODS Retrospectively, 1171 consecutive cases of resected CRC were identified between 2010 and 2017 from a large multi-centre pathology service. Testing for dMMR by immunohistochemistry (IHC) was initiated by the reporting pathologist from 2010, until universal testing was introduced in 2015. Patients with dMMR were referred to the Family Cancer Clinic (FCC) for consideration of germline mutation analysis. RESULTS IHC was performed on 680 tumours, with abnormal expression in 124 (18%). Referral to FCC was made for 44 of the 88 patients with abnormal IHC (excluding those with BRAFV600E mutations). Of the 29 who attended, 16 underwent germline genetic testing, and LS was diagnosed in 7 with a germline mutation. After implementation of universal testing, there was a greater incidence of dMMR (17% vs 10%, P = 0.02), rate of BRAFV600E testing (79% vs 25%, P

Elderly patients may be heterogeneous in their abilities to tolerate immunochemotherapy-associated toxicities. We describe the morbidity of rituximab-chemotherapy combinations among 205 newly-diagnosed diffuse large B-cell lymphoma (DLBCL) patients aged ≥60 years from 3 tertiary hospitals between 2009 and 2016, and explore the utility of retrospectively-assigned baseline Comprehensive Geriatric Assessment (CGA) in predicting these toxicities. Seventy-three percent (146/201) experienced grade ≥3 toxicities, 81% (163/201) needed admission, 52% (107/205) had ≥2 unplanned admissions, 82/201 (41%) required dose reductions (DR) subsequent to Cycle 1, 39/166 (23%) had chemotherapy delays and 26/198 (13%) ceased therapy early. CGA was associated with pre-emptive baseline DR and perhaps because of this, did not predict grade ≥3 toxicities, ≥2 unplanned admissions or subsequent DR. Three-year overall survival (OS) of CGA-fit, CGA-unfit and CGA-frail patients was 82%, 60% and 53%, respectively. Three-year progression-free survival (PFS) of CGA-fit, CGA-unfit and CGA-frail patients was 66%, 58% and 46%, respectively. OS of CGA-fit patients was not statistically different from CGA-unfit patients, but was superior to CGA-frail patients (hazard ratio 2·892, 95% confidence interval 1·275-6·559, P = 0·011). PFS differences were not statistically significant. Baseline DR and early therapy cessation were associated with inferior OS and PFS independent of CGA. Prospective studies are needed to confirm if CGA-adapted treatment strategies minimize morbidity and improves survival.

Background: Leptomeningeal spread in non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor ( EGFR ) mutations who experience disease progression on TKIs portends a poor prognosis. Mutation profiling of tumour DNA in cerebrospinal fluid (CSF) samples can be used to determine the presence of the EGFR T790M resistance mutation, indicating that osimertinib, a CNS-penetrating 3 rd generation TKI may be efficacious. Methods: Eight patients on EGFR TKIs who progressed with cytology-proven leptomeningeal disease at our institution were studied. EGFR mutations were profiled in CSF using droplet digital PCR (ddPCR) and compared to matched plasma samples. Clinical characteristics and survival outcomes on subsequent therapies tailored to ddPCR analysis were reported. Results: None of the four patients who developed leptomeningeal disease while receiving 1st generation EGFR TKIs developed the EGFR T790M mutation in CSF. One patient who did not have extra-cranial disease and was EGFR T790M-negative in both plasma and CSF was nevertheless treated with standard-dose osimertinib, and achieved a rapid and durable response lasting 9 months to date. Three patients developed leptomeningeal disease on osimertinib, with one patient developing the EGFR C797S mutation in a cis-allelic conformation with the EGFR T790M mutation in plasma. Conclusions: Standard-dose osimertinib resulted in a clinically meaningful response in a patient with EGFR T790M-negative 1st generation EGFR TKI refractory leptomeningeal disease. Next generation sequencing and ddPCR has a role at identifying the C797S mutation and its allelic conformation with the T790M mutation with clinical implications.

There is a paucity of data regarding the utility of routine urine cultures in adults with febrile neutropenia (FN) without urinary symptoms receiving protocolised antibiotics. This is reflected by inconsistent recommendations in international and regional FN guidelines. We addressed this issue by retrospectively reviewing the impact of routine urine cultures on antibiotic management in haematology cancer inpatients at a tertiary hospital. All haematology inpatients over a 5-year period (2011–2015) were retrospectively reviewed for episodes of FN (neutrophil count 37.5 °C). For each episode, demographic data, urinary tract symptoms and signs (absence of which was termed ‘asymptomatic’), urinalysis and urine culture results, antibiotic therapy and duration, and patient outcomes were collected. A urine culture was considered positive if > 105 colony forming units (CFU)/L were detected. Empiric antibiotic therapy for FN consisted of intravenous piperacillin/tazobactam in stable patients, with the addition of vancomycin and a single dose of gentamicin if systemically compromised. Four hundred and thirty-three episodes of FN were identified in 317 patients. Urine cultures were performed in 362 (84%) episodes. Cultures were positive in 9 of 48 (19%) symptomatic episodes versus 8 of 314 (2.5%) asymptomatic episodes (RR = 7.4, p

BACKGROUND: Anti-HER2 therapy-related cardiotoxicity is well described in the context of clinical trials, particularly in the setting of early stage disease, but there is more limited data in advanced breast cancer and in the real world setting. MATERIAL AND METHODS: A prospectively-maintained registry database with 312 consecutive patients diagnosed with HER2 positive advanced breast cancer in Australia was analysed. RESULTS: 287 patients (92%) received anti-HER2 therapy, 17 (6%) experienced anti-HER2 therapy-related cardiotoxicity. Patients who experienced cardiotoxicity were more likely to have ≥2 risk factors for cardiotoxicity (OR 3.9 95% CI 1.4-11.3 p = 0.01). A prior diagnosis of cardiovascular disease was significantly associated with cardiotoxicity (OR 7.1 95% CI 1.3-39.5). Cardiotoxicity resolved on imaging in 65% of patients; there was no association between severity and resolution. 11 patients (65%) received cardiologist input. Of the patients who developed cardiotoxicity, 12 patients (71%) received further anti-HER2 therapy in the first- or second-line setting without recurrent cardiotoxicity. DISCUSSION AND CONCLUSION: Therapy-related cardiotoxicity is an uncommon complication of anti-HER2 therapy in the real world setting. Cardiac toxicity resolved in the majority of affected patients, and further anti-HER2 therapy was administered without recurrence of cardiac issues. Our data suggests anti-HER2 therapy can be safely given in routine care, even in patients with risk factors for toxicity.

Background Patients with aggressive lymphoma achieving complete remission (CR) after first-line combination chemotherapy undergo regular surveillance to detect relapse. Current international guidelines recommend routine follow-up blood tests in this context, but evidence supporting this practice is limited. Methods We conducted a multi-centre retrospective analysis of all patients diagnosed with aggressive lymphoma treated with curative-intent chemotherapy who achieved CR for at least 3 months between 2000 and 2015. An abnormal blood test was defined as any new and unexplained abnormality for full blood examination, lactate dehydrogenase or erythrocyte sedimentation rate. Results Three hundred and forty-six patients attended a total of 3084 outpatient visits; blood tests were performed at 90% of these appointments. Fifty-six (16%) patients relapsed. Routine laboratory testing detected relapse in only three patients (5% of relapses); in the remaining patients, relapse was suspected clinically (80%) or detected by imaging (15%). The sensitivity of all blood tests was 42% and the positive predictive value was 9%. No significant difference in survival was shown in patients who underwent a routine blood test within 3 months prior to relapse versus those who did not (p = 0.88). Conclusions Routine blood tests demonstrate unacceptably poor performance characteristics, have no impact on survival and thus have limited value in the detection of relapse in routine surveillance.

BACKGROUND: Routine chest X-ray (CXR) is recommended for neutropenic fever (NF) management however its role is relatively understudied in haematology patients. AIM: To investigate the utility of CXR in the diagnosis and management of patients with haematological conditions complicated by NF. METHODS: Retrospective, single-centre analysis of haematology patients admitted with NF between January 2011 and December 2015. Baseline demographics, treatment details and outcomes were collected from electronic patient records. CXR underwent independent radiology review. Primary endpoints were a proportion of NF episodes in which CXR detected a probable chest infection in the absence of respiratory symptoms/signs and/or resulted in a change in antibiotic management. RESULTS: Four hundred and thirty-five episodes were identified; CXR was performed in 75% of patients (65% within 2 days of NF). In 4 of 164 (2.4%) asymptomatic patients, CXR was consistent with infection, in contrast to 19 of 119 (16%) patients with clinical signs of respiratory infection. Only 3 of 283 (1.1%) CXR resulted in a change to antibiotics. CXR consistent with infection was not associated with increased mortality or increased admission length, although there was an association with intensive care unit admission (odds ratios: 7.61, 95% confidence interval: 2.04-28.31). CONCLUSION: In haematology patients with NF, CXR rarely detected chest infection or changed management in patients with no respiratory symptoms or signs. CXR in our institution is no longer part of routine assessment of NF in the absence of these features.

To describe the incidence of infective endocarditis (IE) detected on echocardiography in cancer patients with confirmed Staphylococcus aureus bacteraemia (SAB). We retrospectively identified 95 cases of SAB in cancer patients from January 2007–March 2016. Echocardiography was ordered at the discretion of the treating team, and positive findings defined according to the Modified Duke Criteria. Complicated bacteraemia was defined by prolonged bacteraemia, presence of intracardiac device/prosthetic valve, or signs of metastatic infection. Major predisposing risk factors for IE (intracardiac device, prosthetic valve, valvular disease, diabetes mellitus, renal dialysis) were present in 27% of cases. Fifty-one of 95 (54%) had a central venous catheter and 17 (18%) patients had complicated bacteraemia. Echocardiography was performed in 75/95 (79%) episodes, with transthoracic echocardiography (TTE) alone in 56, transoesophageal echocardiography (TOE) alone in 4 and both in 15. Echocardiography was diagnostic for IE in 2 patients (1 TTE, 1 TOE), including one result that led to the diagnosis of IE in a clinically unsuspected case. Four further cases of IE were diagnosed on clinical findings, resulting in an overall rate of IE of 6% (6/95). Five of these cases occurred in patients with complicated bacteraemia or ≥ 1 risk factor for IE. No patient was readmitted due to IE. IE is infrequent in cancer patients with uncomplicated SAB and no risk factors for IE. Performing echocardiography routinely in all cancer patients with SAB rarely alters diagnosis or affects antibiotic management and therefore should be reserved for patients with specific risk factors.

Introduction: The cancer research community increasingly question the rigidity of eligibility criteria in clinical trials. Common reasons for “screen failure” (RFSF) are well documented; however, their effect on subsequent standard therapy (SST) and outcomes is unclear. Methods: This retrospective study evaluated patients aged ≥18 years with solid malignancy who were listed as ineligible on a screening log between February 2011 and March 2018. Patients screen-failed for biomarker results or incorrect cancer stage/prior treatment profile were excluded. Data were collected from electronic hospital records, including demographics, cancer history, RFSF, subsequent therapy, and outcomes. Results: Overall, 217 patients were eligible. The most common histologies were lung (28%), melanoma, colon, and pancreatic (all 11%); 90% were metastatic. The most common RFSF were rapid disease progression (PD; 16%), performance status (PS) ≥2 (12%), and abnormal liver function tests (aLFT; 12%). After screen failure, 129/217 (59%) had SST; 9 were dose-reduced. Treatment-naïve or phase III trial-ineligible patients were more likely to receive SST than those pre-treated or phase I trial-ineligible (72/104 vs. 52/113, p = 0.0006; 71/109 vs. 15/42, p = 0.00013), respectively. RFSF stabilised/improved in 104/217 (48%); the main RFSF was co-morbidity (19/104). The most common RFSF to deteriorate were rapid PD (27/72), PS ≥2 (20/72), and aLFT with liver metastases (LM; 13/72). Conclusions: RFSF related to organ function rarely deteriorate unless directly involved with underlying malignancy. Most RFSF do not prevent patients from having SST, nor increase dose reductions, especially in treatment-naïve/phase III trial-ineligible patients. Those with RFSF of poor PS, rapid PD, and aLFT from LM are less suitable for SST. Careful broadening of trial eligibility is warranted.

Aedes aegypti and Anopheles gambiae harbor the causative agents of diseases such as dengue fever and malaria, afflicting human morbidity and mortality worldwide. Given the worldwide emergence of resistance to insecticides, the current mainstay for vector control, identification of alternative modes of action for future insecticides is paramount. The serotonergic (5-HT) system has been documented to impact physiological mechanisms involved in disease transmission, suggesting its potential as a new mode of action target for future insecticide development. Target 5-HT receptors were cloned and expressed in the HEK293 cell line for functional and pharmacological characterization. Manipulation of the 5-HT system through microinjection of compounds suggests its involvement in the modulation of flight performance and blood-feeding behavior. By attenuating these two determinants of vectorial capacity, transmission and burden of disease could effectively be reduced. Considering these positive global health implications, the 5-HT system is a compelling target for the novel insecticide pipeline.

We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community’s ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d’Urville, Jang Bogo and Dome Concordia) using 1–4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67°S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or “Polar Front”). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100–200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d’Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m-3 in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated.

e19027 Background: Pts with iNHL undergo active surveillance to detect disease relapse or progression. International guidelines recommend regular RBTs for surveillance but evidence for this practice is lacking. Methods: We conducted a retrospective analysis of pts aged ≥16 yrs from 2008-17 undergoing routine surveillance at 2 Australian centres for grade 1-3a follicular lymphoma (FL) or marginal zone lymphoma (MZL), to assess the utility of full blood count, lactate dehydrogenase & beta-2-microglobulin to detect progression events; (i.e relapse or progression) or to change management. Abnormal results were defined as acute deviations from local laboratory normal ranges not explained by a concurrent medical condition. Eligible pts were either treatment-naive or had achieved a response to lymphoma-directed therapy, had ≥6 mths follow up and an absence of progression events within 3 mths of prior therapy. Demographic data were collected as well as treatment, follow up appointment (appt) details including presence of signs/symptoms, RBT results, survival status & further therapy. The study was ethically approved. Results: 180 eligible pts (FL:142, MZL:38) underwent 1757 follow up appts (median follow up 38 months). RBTs were done at 83% of appts. 74 progression events occurred in a total of 62 pts; 48/74 (65%) had immediate therapy. 2/74 (3%) were detected by RBTs alone, (both treatment naïve pts); 88% by signs/symptoms & 9% by routine imaging. 20/243 (8%) of abnormal RBTs in asymptomatic pts led to a change in subsequent management (10 had imaging; 8 earlier appts; 2 repeat RBTs alone). The sensitivity & positive predictive value of abnormal RBTs to detect progression events were 39% & 9% respectively. In asymptomatic patients, the number of RBTs required to change management and to detect a progression event were 64 and 644 respectively. Conclusions: RBTs rarely detect clinically significant disease progression or relapse and seldom solely lead to a change in management in asymptomatic pts with iNHL. Clinical signs/symptoms are far more likely to detect progression or relapse. Guidelines should reflect the benefit & risk of RBTs in the clinical setting.

Background Patients with HGL achieving complete remission (CR) after first-line combination chemotherapy undergo regular surveillance to detect early signs of relapse. As follow-up imaging is associated with increased radiation-related risk and minimal benefit in asymptomatic (aSx) patients, imaging as surveillance is no longer routine. (Eichenauer Ann Oncol 2014, Tilly Ann Oncol 2015) Regular laboratory testing (Labs) still feature in internationally-recognised surveillance guidelines (eg NCCN), despite limited evidence in the modern era for their use in relapse detection. Studies conducted prior to modern imaging (PET/CT) and use of rituximab suggested LDH and ESR may be useful, and more recently the absolute lymphocyte count (ALC) and lymphocyte-monocyte ratio (LMR) have shown promise in small series (Weeks JCO 1991, Henry-Amar Ann Int Med 1991,Wei Leuk Lymph 2015, Porrata Leukemia 2010). However large scale data are lacking hence there is no consensus on the value and optimum frequency of specific laboratory parameters for use in routine surveillance of HGL. Methods We conducted a retrospective analysis of patients with histologically-proven cHL, DLBCL, T-cell lymphoma or Burkitt lymphoma receiving curative-intent treatment over a 15-year period. Eligible patients were aged≥16years, in CR for ≥3 months & had >12months follow-up. Primary CNS lymphoma, HIV-associated lymphomas and transformation from indolent subtypes were excluded. Data were collated from patient records. Laboratory results were considered abnormal if a) FBE, ALC, neutrophil count, absolute monocyte count (AMC), ESR or LDH fell outside local laboratory normal limits b) the derangement was not present previously and c) could not be explained by a concurrent medical condition. Abnormal Lab results were investigated at clinician discretion. Labs were evaluated based on their independent ability to detect relapse within 3 months of confirmation. Kaplan-Meier method was used for survival analysis and compared by the log-rank test between groups. Results Between 2000-2015, 346 eligible patients underwent 3048 outpatient visits. Median follow-up was 30 months (range 3-184). Labs were performed at 90% of appointments: FBE in 99.7%, LDH in 78% (of NHL), ESR in 38% (of HL) with abnormalities in 26%, 12% and 16% respectively. Fifty-five patients relapsed (16%). Routine Labs detected aSx relapse in 3/55 (5%); routine imaging detected 9/55 relapses (16%) and clinical symptoms/signs lead to diagnosis of relapse in 43/55 (78%; 19/43 were unscheduled visits). Unscheduled appointments due to patient-reported symptoms (3% of all visits) showed a significantly stronger association with relapse than scheduled visits (OR 50.4, p Table 1 presents sensitivity, specificity, PPV and NPV of Labs, demonstrating in particular a low PPV and high NPV. ALC, AMC and LMR were very poor markers for relapse, with area under the curve of 0.517, 0.529 and 0.576 respectively. In addition, an abnormal Lab result prompted a change in management for only 16% of aSx patients, (37 imaging, 38 repeat Labs, 22 earlier scheduling of next review), compared to 59% with symptoms/signs. In 43 episodes, abnormal Labs lead to further investigations which were subsequently negative (25 imaging, 6 biopsies, 11 repeat Labs). There was no significant difference in OS between patients who had Labs performed ≥3 months prior to documented relapse versus patients who did not (p=0.88, figure 1). Conclusion Although normal Lab results have a high NPV for relapse, most HGL relapses are detected by patient-reported symptoms, often at unscheduled visits. Abnormal Labs in aSx patients infrequently trigger a change in management. Routine Labs rarely detect relapse in aSx patients with HGL in CR after primary curative-intent chemotherapy, demonstrate unacceptably poor performance characteristics, have no impact on survival and have limited value in routine surveillance. Disclosures Hawkes: BMS: Other: travel expenses, Research Funding; Takeda: Other: travel expenses; Merck Serono: Research Funding.

Background Initial investigations for patients presenting to health services with febrile neutropenia (FN) aim to identify the infective source. Routine CXR is recommended by several international guidelines as a component of this assessment. However, in the era of rapid delivery of empirical broad-spectrum antibiotics, the evidence supporting use of CXR in detecting chest infection in asymptomatic patients and its role in directing management are lacking. While CXRs are considered relatively inexpensive, accessible and low-risk, they still contribute to the overall healthcare bill, expose patients to ionising radiation and may involve moving immunocompromised patients from a filtered 'clean air' environment. The aim of this study was to evaluate the use of CXR in haematology patients undergoing immunosuppressive therapy who presented for management of FN. Methods: A retrospective single-centre analysis of patients with haematological diseases undergoing chemotherapy admitted to a large cancer centre with FN over a 5 year period. FN was defined as fever and a neutrophil count below the lower limit of normal ( Results: Between January 2011 & December 2015, 427 FN episodes were identified in321patients with a median age 58 years (range 17-90); 56% were male; 98% had an underlying diagnosis of leukemia, lymphoma or myeloma. CXR was performed in 322 episodes (75%); 137 standard PA, 182 AP, 3 unknown (of these, 163 were portable). Twenty-seven CXRs (8%) demonstrated evidence of infection, 285 (89%) were normal and 10 (3%) were indeterminate. Only 4/182 (2%) of CXRs in patients with no reported respiratory symptoms or signs had evidence of infection; in those with reported respiratory symptoms/signs, 23/130 (18%) CXRs were consistent with chest infection. The presence of ≥1 respiratory symptom/sign was associated with an increased chance of an abnormal CXR (odds ratio 17.19; p=0.007, 95%CI:2.16-136.41). Only 5/322 (1.6%) of CXR results caused a change in antibiotic management, all 5 in patients with respiratory symptoms or signs. Conclusion: In FN patients undergoing chemotherapy for haematological conditions, CXR rarely detected chest infection or changed management in asymptomatic patients. CXR in our institution is no longer part of routine assessment of FN in the absence of clinical respiratory features in patients with haematological conditions. Disclosures Hawkes: Merck Serono: Research Funding; BMS: Other: travel expenses, Research Funding; Takeda: Other: travel expenses.

In an effort to elucidate their structures, mass-selected Cl--(CH4)n (n = 1-10) clusters are probed using infrared spectroscopy in the CH stretch region (2800-3100 cm(-1)). Accompanying ab initio calculations at the MP2/6-311++G(2df,2p) level for the n = 1-3 clusters suggest that methane molecules prefer to attach to the chloride anion by single linear H-bonds and sit adjacent to one another. These conclusions are supported by the agreement between experimental and calculated vibrational band frequencies and intensities. Infrared spectra in the CH stretch region for Cl--(CH4)n clusters containing up to ten CH4 ligands are remarkably simple, each being dominated by a single narrow peak associated with stretching motion of hydrogen-bonded CH groups. The observations are consistent with cluster structures in which at least ten equivalent methane molecules can be accommodated in the first solvation shell about a chloride anion.