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Background: Management of neutropenic fever in high-risk haematology patients is challenging; there are often few localising clinical features, and diagnostic tests have poor sensitivity and specificity. We aimed to compare how [ 18 F]flurodeoxyglucose ([ 18 F]FDG)-PET-CT scans and conventional CT scans affected the guidance of antimicrobial management and the outcomes of patients with persistent or recurrent neutropenic fever., Methods: We did a multicentre, open-label, phase 3, randomised, controlled trial in two tertiary referral hospitals in Australia. We recruited adults aged 18 years or older who were receiving conditioning chemotherapy for haematopoietic stem-cell transplantation or chemotherapy for acute leukaemia and had persistent (>72 h) or recurrent (new fever beyond 72 h of initial onset interspersed with >48 h defervescence) neutropenic fever. Exclusion criteria were pregnancy, allergy to iodinated contrast, or estimated glomerular filtration rate of less than 30 mL/min. Patients were randomly assigned by computer-generated randomisation chart (1:1) to [ 18 F]FDG-PET-CT or conventional CT. Masking was not possible because of the nature of the investigation. Scans were done within 3 days of random assignment. The primary endpoint was a composite of starting, stopping, or changing the spectrum (broadening or narrowing) of antimicrobial therapy-referred to here as antimicrobial rationalisation-within 96 h of the assigned scan, analysed per protocol. This trial is registered with clinicaltrials.gov, NCT03429387, and is complete., Findings: Between Jan 8, 2018, and July 23, 2020, we assessed 316 patients for eligibility. 169 patients were excluded and 147 patients were randomly assigned to either [ 18 F]FDG-PET-CT (n=73) or CT (n=74). Nine patients did not receive a scan per protocol, and two participants in each group were excluded for repeat entry into the study. 65 patients received [ 18 F]FDG-PET-CT (38 [58%] male; 53 [82%] White) and 69 patients received CT (50 [72%] male; 58 [84%] White) per protocol. Median follow up was 6 months (IQR 6-6). Antimicrobial rationalisation occurred in 53 (82%) of 65 patients in the [ 18 F]FDG-PET-CT group and 45 (65%) of 69 patients in the CT group (OR 2·36, 95% CI 1·06-5·24; p=0·033). The most frequent component of antimicrobial rationalisation was narrowing spectrum of therapy, in 28 (43%) of 65 patients in the [ 18 F]FDG-PET-CT group compared with 17 (25%) of 69 patients in the CT group (OR 2·31, 95% CI 1·11-4·83; p=0·024)., Interpretation: [ 18 F]FDG-PET-CT was associated with more frequent antimicrobial rationalisation than conventional CT. [ 18 F]FDG-PET-CT can support decision making regarding antimicrobial cessation or de-escalation and should be considered in the management of patients with haematological diseases and persistent or recurrent high-risk neutropenic fever after chemotherapy or transplant conditioning., Funding: National Health and Medical Research Council Centre of Research Excellence (APP1116876), Melbourne Health foundation, Gilead Research Fellowship grants supported this study., Competing Interests: Declaration of interests SH has received a grant from Janssen, and honoraria from Celgene, Janseen, Novartis, and Kite/Gilead. OB has received honoraria from MSD and Abbvie. BT has received grants from Sanofi Pasteur, MSD, and Seqirus; received honoraria from Pfizer, MSD, and Gilead; and is on the data safety monitoring board (DSMB) of a study with CSL-Behring. SC has received educational grants from F2G and MSD Australia. JS has received honoraria from Alexian Australasia, Sobi Pharmaceuticals, Novartis, and Takeda; is on the DSMB and advisory board from Prevail Therapeutics; and has a leadership role in the Australian Bone Marrow Donor Registry. MY has received grants from the National Health and Medical Research Council (NHMRC) of Australia, MSD Australia, and the Medical Research Futures Fund and consulting fees, honoraria, and Advisory Board involvement for MSD Australia. TS has received speaker fees from Novartis and is on scientific committees for Biogen and Hartmann DE. SYT and AD have received a grant from Gilead. RH is the honorary director of Neuroendocrine Cancer Australia and PreMIT Pty and is the founder and equity holder of PreMIT Pty. MS has been awarded two NHMRC grants as well as grants from Gilead, Merck, and F2G and honoraria from Pfizer, Merck, and Gilead and is on the DSMB and advisory board of Pfizer, F2G, and Roche with all payments to an institution. All other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Purpose: Invasive fungal infections (IFIs) are common in immunocompromised patients. While early diagnosis can reduce otherwise high morbidity and mortality, conventional CT has suboptimal sensitivity and specificity. Small studies have suggested that the use of FDG PET/CT may improve the ability to detect IFI. The objective of this study was to describe the proven and probable IFIs detected on FDG PET/CT at our centre and compare the performance with that of CT for localization of infection, dissemination and response to therapy., Methods: FDG PET/CT reports for adults investigated at Peter MacCallum Cancer Centre were searched using keywords suggestive of fungal infection. Chart review was performed to describe the risk factors, type and location of IFIs, indication for FDG PET/CT, and comparison with CT for the detection of infection, and its dissemination and response to treatment., Results: Between 2007 and 2017, 45 patients had 48 proven/probable IFIs diagnosed prior to or following FDG PET/CT. Overall 96% had a known malignancy with 78% being haematological. FDG PET/CT located clinically occult infection or dissemination to another organ in 40% and 38% of IFI patients, respectively. Of 40 patients who had both FDG PET/CT and CT, sites of IFI dissemination were detected in 35% and 5%, respectively (p < 0.001). Of 18 patents who had both FDG PET/CT and CT follow-up imaging, there were discordant findings between the two imaging modalities in 11 (61%), in whom normalization of FDG avidity of a lesion suggested resolution of active infection despite a residual lesion on CT., Conclusion: FDG PET/CT was able to localize clinically occult infection and dissemination and was particularly helpful in demonstrating response to antifungal therapy.

Background: As early detection of recurrent melanoma maximizes treatment options, patients usually undergo post-operative imaging surveillance, increasingly with FDG-PET/CT (PET). To assess this, we evaluated stage 3 melanoma patients who underwent prospectively applied and sub-stage-specific schedules of PET surveillance., Patients and Methods: From 2009, patients with stage 3 melanoma routinely underwent PET +/- MRI brain scans via defined schedules based on sub-stage-specific relapse probabilities. Data were collected regarding patient characteristics and outcomes. Contingency analyses were carried out of imaging outcomes., Results: One hundred and seventy patients (stage 3A: 34; 3B: 93; 3C: 43) underwent radiological surveillance. Relapses were identified in 65 (38%) patients, of which 45 (69%) were asymptomatic. False-positive imaging findings occurred in 7%, and 6% had treatable second (non-melanoma) malignancies. Positive predictive values (PPV) of individual scans were 56%-83%. Negative scans had predictive values of 89%-96% for true non-recurrence [negative predictive values (NPV)] until the next scan. A negative PET at 18 months had NPVs of 80%-84% for true non-recurrence at any time in the 47-month (median) follow-up period. Sensitivity and specificity of the overall approach of sub-stage-specific PET surveillance were 70% and 87%, respectively. Of relapsed patients, 33 (52%) underwent potentially curative resection and 10 (16%) remained disease-free after 24 months (median)., Conclusions: Application of sub-stage-specific PET in stage 3 melanoma enables asymptomatic detection of most recurrences, has high NPVs that may provide patient reassurance, and is associated with a high rate of detection of resectable and potentially curable disease at relapse.

Background: Combination blockade of human epidermal growth factor receptor (HER) family signaling may confer enhanced antitumor activity than single-agent blockade. We performed a single-arm study of pertuzumab, a monoclonal antibody that inhibits HER2 dimerization, and erlotinib in relapsed non-small cell lung cancer (NSCLC)., Methods: Patients received pertuzumab (840-mg loading dose and 420-mg maintenance intravenously every 3 weeks) and erlotinib (150-mg or 100-mg dose orally, daily). The primary endpoint was response rate (RR) by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) at day 56 in all patients and those with EGFR wild-type tumors., Results: Of 41 patients, 28 (68.3%) experienced treatment-related grade ≥3 adverse events, including pneumatosis intestinalis (3 patients), resulting in early cessation of enrollment. Tissue samples from 32 patients showed mutated EGFR status in 9 of 41 (22%) and wild-type EGFR in 23 of 41 (56%). The FDG-PET RR for patients with assessments at day 56 was 19.5% in all patients (n = 41) and 8.7% in patients with wild-type EGFR NSCLC (n = 23). Investigator-assessed computed tomography RR at day 56 was 12.2%., Conclusion: FDG-PET suggests that pertuzumab plus erlotinib is an active combination, but combination therapy was poorly tolerated, which limits its clinical applicability. More research is warranted to identify drug combinations that disrupt HER receptor signaling but that exhibit improved tolerability profiles.

Background: FDG-PET/CT is widely used in the management of a variety of malignancies with excellent overall accuracy, despite the potential for false positive results related to infection and inflammation., Aim:   As cancer patients can develop clinically inapparent infections, we evaluated the prevalence and nature of incidental findings reported to be suggestive of infections that had been identified during clinical cancer staging with FDG-PET/CT., Methods: The study involved a retrospective analysis of 60 patients managed primarily at our facility from a total of 121 cases identified as having possible infection on clinical reporting of more than 4500 cancer staging investigations performed during the calendar year of 2008., Results: Occult infections were uncommon overall (≤1%), but most often because of pneumonia (31.6%), upper respiratory tract infections (21.1%) or wound infections (15.8%). Abnormal scans contributed to patients' management in 52.7% of cases. Two out of 13 patients whose scan abnormalities were not investigated further had worsening changes on repeated scan and one of these patients had clinical deterioration., Conclusions: In patients with FDG-PET/CT scans suggestive of infection and in whom a final diagnosis could be reached, the positive predictive value for FDG-PET/CT scans was 89% suggesting that abnormal scans indicative of infection should be investigated further in this population., (© 2011 The Authors. Internal Medicine Journal © 2011 Royal Australasian College of Physicians.)

Background: The aim was to investigate the correlation between (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic response to chemoradiotherapy and clinical outcomes in squamous cell carcinoma (SCC) of the anus., Methods: A total of 48 patients with biopsy-proven anal SCC underwent FDG-PET scans at baseline and post chemoradiotherapy (54 Gy, concurrent 5-FU/mitomycin). Kaplan-Meier analysis was used to determine survival outcomes according to FDG-PET metabolic response., Results: In all, 79% patients (n=38) had a complete metabolic response (CMR) at all sites of disease, 15% (n=7) had a CMR in regional nodes but only partial response in the primary tumour (overall partial metabolic response (PMR)) and 6% (n=3) had progressive distant disease despite CMR locoregionally (overall no response (NR)). The 2-year progression-free survival (PFS) was 95% for patients with a CMR, 71% for PMR and 0% for NR (P<0.0001). The 5-year overall survival (OS) was 88% in CMR, 69% in PMR and 0% in NR (P<0.0001). Cox proportional hazards regression analyses for PFS and OS found significant associations for incomplete (PMR+NR) vs complete FDG-PET response to treatment only, (HR 4.1 (95% CI: 1.5-11.5, P=0.013) and 6.7 (95% CI: 2.1-21.6, P=0.002), respectively)., Conclusion: FDG-PET metabolic response to chemoradiotherapy in anal cancer is significantly associated with PFS and OS, and in this cohort incomplete FDG-PET response was a stronger predictor than T or N stage.

Background: Complete pathological response has proven prognostic benefits in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy. Sequential 18-FDG PET may be an early surrogate for pathological response to chemoradiotherapy., Objectives: The aim of this study was to identify whether metabolic response measured by FDG PET following chemoradiotherapy is prognostic for tumor recurrence and survival following neoadjuvant therapy and surgical treatment for primary rectal cancer., Methods: Patients with primary rectal cancer treated by long-course neoadjuvant chemoradiotherapy followed by surgery had FDG PET performed before and 4 weeks after treatment, before surgical resection was performed. Retrospective chart review was undertaken for patient demographics, tumor staging, recurrence rates, and survival., Results: : Between 2000 and 2007, 78 patients were identified (53 male, 25 female; median age, 64 y). After chemoradiotherapy, 37 patients (47%) had a complete metabolic response, 26 (33%) had a partial metabolic response, and 14 (18%) had no metabolic response as assessed by FDG PET (1 patient had missing data). However, only 4 patients (5%) had a complete pathological response. The median postoperative follow-up period was 3.1 years during which 14 patients (19%) had a recurrence: 2 local, 9 distant, and 3 with both local and distant. The estimated percentage without recurrence was 77% at 5 years (95% CI 66%-89%). There was an inverse relationship between FDG PET metabolic response and the incidence of recurrence within 3 years (P = .04). Kaplan-Meier analysis of FDG PET metabolic response and overall survival demonstrated a significant difference in survival among patients in the 3 arms: complete, partial, and no metabolic response (P = .04); the patients with complete metabolic response had the best prognosis., Conclusion: Complete or partial metabolic response on PET following neoadjuvant chemoradiotherapy and surgery predicts a lower local recurrence rate and improved survival compared with patients with no metabolic response. Metabolic response may be used to stratify prognosis in patients with rectal cancer.

Introduction: Conventional imaging (CI) is known to have limitations with respect to staging of patients with primary or relapsed prostate cancer. Positron emission tomography/computed tomography (PET/CT) with (18)F-flurodeoxyglucose (FDG) is also often suboptimal because of low tracer avidity, but (18)F-fluorocholine (FCH) appears to be a promising alternative molecular imaging probe. We report a prospective pilot study of PET/CT comparing both tracers for staging and restaging of patients with prostate cancer., Methods: Sixteen prostate cancer patients were evaluated (7 for staging and 9 for restaging). All patients also underwent CI, comprising at least an abdominopelvic CT and a bone scan. All imaging results and other relevant data were extracted from the imaging reports and medical charts., Results: Based on all imaging-detected disease sites, both FCH-PET/CT and FDG-PET/CT (79%) were more sensitive than CI (14%), with the highest number of sites of nodal and distant disease on FCH PET/CT. FCH-PET/CT alone would have provided sufficient clinical information to form an appropriate management plan in 88% of cases, as compared with 56% for CI., Conclusion: FCH-PET/CT has the potential to impact on the management of patients with prostate cancer significantly more often than CI.

The aim of this study was to retrospectively evaluate the value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in extrapulmonary small-cell cancer (EPSCC). Patients with EPSCC who underwent PET for staging or response assessment between 1996 and 2007 were identified from a database. Patient records were reviewed. PET-based, and conventional staging and restaging results were compared. The binary staging classification of limited disease (LD) versus extensive disease (ED) was used. Patients with LD had tumours that could be encompassed within a tolerable radiation therapy (RT) volume. Of 33 eligible patients, 12 had staging PET scans, 11 had restaging scans and 10 had both. All known gross disease sites were FDG-avid. PET and conventional stage groupings were concordant in 21 of 22 cases. One patient was appropriately upstaged from LD to ED by PET. PET detected additional disease sites, without causing upstaging in three further patients. Restaging PET scans identified previously unrecognised persistent or progressive disease in 4 of 21 cases. In four further cases, persistent FDG uptake after treatment was either false positive (n = 2) or of uncertain (n = 2) aetiology. PPV was 100% for staging and 82% for restaging. In 8 of 43 imaging episodes (19%), PET appropriately influenced management in five cases by changing treatment intent from radical to palliative, and in three cases by altering the RT volume. PET has incremental value compared to conventional imaging for staging EPSCC, and may also be useful for restaging after therapy. PET influenced patient management in 19% of 43 imaging episodes.

Accurate inguinal and pelvic nodal staging in anal cancer is important for the prognosis and planning of radiation fields. There is evidence for the role of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging and management of cancer, with early reports of an increasing role in outcome prognostication in a number of tumours. We aimed to determine the effect of FDG-PET on the nodal staging, radiotherapy planning and prognostication of patients with primary anal cancer. Sixty-one consecutive patients with anal cancer who were referred to a tertiary centre between August 1997 and November 2005 were staged with conventional imaging (CIm) (including computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound and chest X-ray) and by FDG-PET. The stage determined by CIm and the proposed management plan were prospectively recorded and changes in stage and management as a result of FDG-PET assessed. Patients were treated with a uniform radiotherapy technique and dose. The accuracy of changes and prognostication of FDG-PET were validated by subsequent clinical follow-up. Kaplan-Meier survival analysis was used to estimate survival for the whole cohort and by FDG-PET and CIm stage. The tumour-stage group was changed in 23% (14 out of 61) as a result of FDG-PET (15% up-staged, 8% down-staged). Fourteen percent of T1 patients (3 out of 22), 42% of T2 patients (10 out of 24) and 40% of T3-4 patients (6 out of 15) assessed using CIm, had a change in their nodal or metastatic stage following FDG-PET. Sensitivity for nodal regional disease by FDG-PET and CIm was 89% and 62%, respectively. The staging FDG-PET scan altered management intent in 3% (2 out of 61) and radiotherapy fields in 13% (8 out of 61). The estimated 5-year overall survival (OS) and progression-free survival (PFS) for the cohort were 77.3% (95% confidence interval (CI): 55.3-90.4%) and 72.2% (95% CI: 51.5-86.4%), respectively. The estimated 5-year PFS for FDG-PET and CIm staged N2-3 disease was 70% (95% CI: 42.8-87.9%) and 55.3% (95% CI: 23.3-83.4%), respectively. FDG-PET shows increased sensitivity over CIm for staging nodal disease in anal cancer and changes treatment intent or radiotherapy prescription in a significant proportion of patients.

Objective: To assess the impact of FDG PET-CT on the management of patients with suspected recurrent ovarian cancer and to determine the incremental information provided by PET-CT., Methods: This was a prospective, multi-centre, cohort study. Ninety women (mean age 59.9 years; age range 35-85 years) with a previous history of treated epithelial ovarian carcinoma and suspected recurrence based on elevated CA-125, anatomical imaging or clinical symptoms were studied with FDG PET-CT across two States. Referring doctors were asked to specify a management plan pre-PET, if management was altered after PET-CT and, the impact (rated - none, low, medium, high) of PET-CT on patient management. The pre-PET management plan could include radiotherapy, chemotherapy, surgery, and 'other' including observation. Patients were followed at 6 and 12 months and clinical status, evidence of recurrence and progression were recorded., Results: Patients were referred by 34 individual specialists. At least 168 additional sites of disease in 61 patients (68%), not identified by conventional imaging were identified by PET-CT. In 77% the additional lesions were located below the diaphragm and most were nodal or peritoneal. PET-CT affected management in 60% (49% high, 11% medium impact). Patients where more disease was detected with PET-CT were more likely to progress in the following 12 months., Conclusions: For women with previously treated ovarian carcinoma with recurrent disease, PET-CT can: a) alter management in close to 60% of patients, b) detect more sites of disease than abdominal and pelvic CT, c) is superior in the detection of nodal, peritoneal and subcapsular liver disease and d) offers the opportunity for technology replacement in this setting.

Purpose: 18-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) has a role in recurrent colorectal cancer. This study was designed to assess the impact of PET-CT on management of primary rectal cancer., Methods: Eighty-three patients with rectal cancer underwent PET-CT scan between 2002 and 2005. Referring physicians prospectively recorded stage and management plan after conventional imaging before PET-CT scan, which were compared to subsequent stage and management after PET-CT., Results: Staging PET-CT caused a change in stage from conventional imaging in 26 patients (31 percent). Twelve (14 percent) were upstaged (7 change in N stage; 4 change in M stage; 1 change in N and M stage), and 14 (17 percent) were downstaged (10 change in N stage; 3 change in M stage; 1 change in N and M stage). PET-CT scan altered management intent in seven patients (8 percent) (curative to palliative 6 patients; palliative to curative 1 patient). Management was altered in ten patients (12 percent). There was no difference in impact with respect to tumor height., Conclusions: PET-CT scan impacts the management of patients with primary rectal cancer and influences staging/therapy in a third of patients and should be a component of rectal cancer workup.

The objective of the current study was to evaluate the effect of PET on the management of primary tumours of the thymus. Patients with a primary tumour of the thymus who underwent PET were identified from a prospective database. Forty-three PET scans were carried out on 26 patients with primary thymic tumours. Sensitivity, specificity and accuracy were 79, 100 and 85%, respectively. Conventional imaging and PET findings were discordant in 10 cases (23%). PET appropriately changed patient management in three (7.0%) cases based on accurate results that differed from pre-PET imaging. Most PET scans carried out (88%) did not influence clinical management. Patient comorbidities, limited treatment options and already planned surgery are factors that may hinder the effect of PET in the setting of thymic tumours. The potential for false-negative results, probably because of a combination of low-fluorodeoxyglucose avidity and small volume residual disease, needs to be considered in management planning. However, the positive predictive value of PET is high and enables appropriate modification of management in a small, but potentially important subset of patients.

Radio-labelling of blood cells is an established technique for evaluating in vivo migration of normal cells to sites of pathology such as infection and haemorrhage. A limitation of cellular immunotherapies to induce anti-tumour responses is in part due to the uncertain ability of cellular effectors to reach their intended target. We extended the approach of cell radiolabelling to accurately examine the in vivo distribution of cellular immunotherapy with ex-vivo macrophage activated killer (MAK) cells. We describe the use of two methods of cell labelling for tracking the destination of autologous-derived macrophage activated killer (MAK) cells linked to the bi-specific antibody MDX-H210 delivered either by intravenous (i.v.) or intraperitoneal (i.p.) injection in ten patients with peritoneal relapse of epithelial ovarian carcinoma. Our results demonstrate the feasibility of generating high numbers and purity of GMP quality MAK cells, which can be radiolabelled with (18)F-FDG or (111)In-oxime. MAK cell administration produced minimal infusional toxicity and demonstrated a reproducible pattern of in vivo distribution and active in vivo tracking to sites of known tumour following 8 of 16 i.v. infusions or 4 of 6 i.p. infusions. However, the leakage of (18)F-FDG limited the ability to confidently confirm the tracking of MAK cells to tumour in all cases and improved PET labels are required. The addition of MDX-H210 bispecific antibody did not alter the distribution of cells to tumour sites, but did accelerate the clearance of i.v. administered MAK cells from the pulmonary circulation. This data demonstrates that cellular cancer immunotherapies may be successfully delivered to the sites of active tumour following either i.v. or i.p. injection in a proportion of patients with metastatic cancer. Incorporation of tracking studies in early cycles of cellular immunotherapy may allow selection of patients who demonstrate successful targeting of the immunotherapy for ongoing treatment.

Objective: The extent of disease in patients with multiple myeloma or related conditions may be difficult to assess. In previous small studies, both FDG-PET (PET) and Tc-99m sestamibi scans (MIBI) have identified sites of occult disease in myeloma., Methods: We reviewed the results for patients at our institution who have undergone PET and/or MIBI scans to assess myeloma. Concordance between the scans, ability to identify otherwise occult disease and impact on patient management was assessed., Results: Thirty-six patients had > or =1 PET scan, 56 had > or =1 MIBI scan and 23 had concurrent PET and MIBI scans. MIBI detected additional sites to skeletal survey in 38 of 56 (68%) cases. PET detected additional sites to skeletal survey in 18 of 36 (50%) cases. MIBI generally detected more disease sites than PET. PET and MIBI were concordant in eight of 23 (35%) cases. The percentage plasma cell infiltrate within the marrow correlated with the number of sites detected by MIBI, but not by PET. In 23 of 69 cases (33%), scan results impacted on management, particularly by upstaging disease at diagnosis and by recognising subsequent disease progression. The results were also helpful for evaluating the presence of ongoing disease activity in previously irradiated sites remaining abnormal on skeletal survey following treatment., Conclusions: MIBI and PET are useful additional diagnostic tools for detecting otherwise occult sites of myeloma. The use of MIBI PET should particularly be considered in the evaluation of a patient with an early-stage plasma cell dyscrasia to exclude the presence of more extensive disease.

This study uses Australian data to confirm the accuracy of dedicated sodium iodide (NaI) fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in evaluating indeterminate solitary pulmonary nodules (SPNs) and to determine the conditions under which PET could play a cost-effective role in this evaluation. Ninety-two patients from two Australian hospitals in different states underwent FDG-PET for evaluation of an SPN. Observed values for prior probability of malignancy and diagnostic accuracy of PET were applied to previously published decision tree models using published Australian health care costs. The accuracy of FDG-PET was 93% with a sensitivity of 92% and a specificity of 95%. The prior probability of malignancy (0.54), PET sensitivity and PET specificity indicated cost savings per patient of up to EUR 455 (Adollars 774) based on a PET cost of EUR 706 (Adollars 1,200). PET would remain cost-effective for levels of prior probability up to 0.8-0.9 and a PET cost of EUR 736-1,161 (Adollars 1,252-Adollars 1,974). It is concluded that NaI PET is accurate, cost saving and cost-effective for the characterisation of indeterminate pulmonary nodules in Australia. Comparison with previous reports from the United States confirms that FDG-PET can remain cost-effective despite population differences in medical costs, disease prevalence and PET diagnostic performance.

The purpose of this study was to document the accuracy of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) with sodium iodide detectors in characterizing indeterminate lung nodules or masses and in identifying additional extra-lesional findings. 50 consecutive patients without a confident diagnosis of malignancy on CT underwent (18)FDG PET with and without attenuation correction. The diagnosis of malignancy was made using visual diagnostic criteria, and tumour-to-blood pool ratios were calculated. The final diagnosis was established by surgery, biopsy or long-term follow-up. Any additional findings made at PET were recorded and similarly verified. Using blinded visual diagnostic criteria for the differentiation of malignant from benign nodules, sodium iodide PET achieved a sensitivity of 91% (30 of 33 cases), a specificity of 88% (15 of 17 cases), a positive predictive value for malignancy of 94% (30 of 32 cases) and a negative predictive value of 83% (15 of 18 cases). False positives occurred with active tuberculosis and sarcoidosis. False negatives were a 3 cm bronchoalveolar carcinoma, a 1.3 cm sarcoma metastasis and a 1 cm carcinoma. Use of tumour-to-blood pool ratios did not improve performance. PET suggested the presence of nodal or distant metastases in 13 of 33 patients with a malignant pulmonary lesion. These PET findings were confirmed in 11 patients. These results indicate that sodium iodide PET is an accurate tool for the characterization of indeterminate pulmonary masses or nodules and simultaneously provides non-invasive staging information that can alter patient management in up to one-third of such patients. Performance of sodium iodide PET is comparable with reported results for PET scanners using other detector materials.

The aim of this study was to investigate FDG-PET (fluorodeoxyglucose positron emission tomography) imaging in the management of prostate cancer. Twenty-two patients were studied during different disease phases of prostate cancer, for staging or restaging to clarify specific clinical questions. FDG-PET was performed encompassing the thorax, abdomen and pelvis using the Penn PET 300H scanner. Scanning was begun 60 min after 18F fluorodeoxyglucose marker. Patients were catheterized and administered diuretics to minimize urinary activity. Information obtained with FDG-PET was concordant with findings from other investigations in 7/22 (32%) patients, discordant in 15/22 (68%) patients and equivalent in one patient (4%). PET indicated progressive disease in five patients with prostate-specific antigen (PSA) < 4 ng/L. The impact on management of the patients was high in 46% of cases, low in 41% and for 14% there was no impact on management. The accuracy of FDG-PET was 72% (95% CI 50-89) as confirmed by invasive diagnostics/follow-up. FDG-PET can provide useful information and improve the clinician's decision on further management procedures in selected patients with low PSA and bone or lymph node changes. A negative PET scan in prostate cancer should be interpreted with caution.

Unlabelled: After potentially curative therapy of non-small cell lung cancer (NSCLC), masses or symptoms suggestive of relapse are common but may be difficult to characterize. Early detection is important because salvage therapies are available for localized recurrence. This study evaluated whether (18)F-FDG PET is useful and predictive of outcome in this setting., Methods: For 63 consecutive patients with suspected relapse >6 mo after definitive treatment of NSCLC, the apparent extent of disease on conventional restaging was compared with that on FDG PET. Patients with already confirmed systemic metastases were excluded unless locally aggressive treatment of these was being considered. Serial imaging and pathologic results were obtained during a median follow-up of 19 mo to validate diagnostic findings. Prognostic significance was tested using the Cox proportional hazards regression model., Results: PET had positive findings in 41 of 42 patients with confirmed relapse (sensitivity, 98%). No disease was evident during a minimum follow-up of 12 mo in 14 of 15 patients with clinically suspected relapse but negative PET findings (negative predictive value, 93%). PET induced a major management change in 40 patients (63%), including 6 whose treatment was changed from curative to palliative, 3 whose treatment was changed from palliative to curative, and 9 for whom negative PET findings prevented active management. Both the presence (P = 0.012) and the extent (P < 0.0001) of relapse on PET were highly significant prognostic factors. There was also significant prognostic stratification based on the treatment delivered after the PET study (P = 0.011), but after adjustment for this treatment, PET status remained highly predictive of survival., Conclusion: PET better assesses the status of disease and stratifies prognosis than does conventional staging, affects patient management, and should be incorporated into paradigms for suspected recurrence of NSCLC.

Unlabelled: Survival of lung cancer patients remains poor despite increasingly aggressive treatment. Conventional staging has well-described limitations. (18)F-FDG PET has been shown to stage lung cancer more accurately than does CT scanning, but the impact on patient treatment and outcome is poorly defined. This study evaluated this impact in routine clinical practice within a tertiary oncology facility., Methods: For 153 consecutive patients with newly diagnosed non-small cell lung cancer, the treatment plan based on conventional staging methods was compared with the treatment plan based on incorporation of PET findings. Survival was analyzed using the Cox proportional hazards regression model., Results: For broad groupings of stage, 10% of cases were downstaged and 33% upstaged by PET. When assessable, the PET stage was confirmed in 89% of patients. PET had a high impact on 54 patients (35%), including 34 whose therapy was changed from curative to palliative, 6 whose therapy was changed from palliative to curative, and 14 whose treatment modality was changed but not the treatment intent. For 39 patients (25%), a previously selected therapy was altered because of the PET findings. The Cox model indicated that the pre-PET stage was significantly associated with survival (P = 0.013) but that the post-PET stage provided much stronger prognostic stratification (P < 0.0001) and remained significant after adjustment for treatment delivered., Conclusion: Staging that incorporated PET provided a more accurate prognostic stratification than did staging based on conventional investigations. Further, the additional information provided by PET significantly and appropriately changed management in the majority of patients.

Thallium-201 (Tl-201) single photon emission computed tomography (SPECT) is funded for evaluation of malignancy in Australia and may have utility for staging of non-small cell lung cancer (NSCLC) if CT results are equivocal. Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET) is superior to CT for staging NSCLC but is more expensive and less widely available than Tl-201 SPECT. Therefore, these techniques were prospectively compared in 27 radical radiation therapy candidates. Patients were allocated a conventional, PET and Tl-201 stage. Tumour to background ratios (TBR) were recorded for the primary on both techniques. Metastatic disease was confirmed by surgical pathology, serial imaging or clinical follow up. Tumour to background ratios were consistently higher for FDG PET than Tl-201 SPECT (P < 0.0001). Positron emission tomography detected all known primary tumours but Tl-201 failed to image four primary tumours (15%). In 10 of 18 cases of discordance between PET and Tl-201 SPECT regarding stage, corroboration was available from pathology or disease progression. Positron emission tomography was shown to have a 100% positive predictive value, including all three patients with PET-detected distant metastases (P=0.002). Results indicate that PET is superior to Tl-201 SPECT scanning in the staging of NSCLC for radical radiation therapy, and that the low sensitivity for detection of local and metastatic disease is likely to limit the clinical impact and cost-effectiveness of this technique despite its lower cost.

Unlabelled: Excretion of radiopharmaceuticals into breast milk poses a potential risk to infants and clear recommendations regarding interruption times are required. There are few data available regarding the impact of (18)F-FDG on this issue. With increasing use of PET for oncologic imaging and its potential advantages to nursing mothers because of its short physical half-life compared with other commonly used tumor imaging agents such as (67)Ga and (201)Tl, evaluation of the excretion pattern of this agent in breast milk is important., Methods: We have evaluated the uptake of FDG in the breasts in 7 women, 6 of whom were lactating and 1 of whom was in early postpartum but had not commenced breast-feeding. Milk samples were obtained from 4 of the lactating women, including serial samples from 1., Results: Significantly increased breast uptake was identified in all lactating breasts but not in 1 breast consistently refused by the nursing infant or in the woman who had not begun breast-feeding after delivery of her child. No qualitative change or semiquantitative estimate of radiotracer uptake in the breast was seen after expression of breast milk. Decay-corrected activity measurable in breast milk ranged from 5.54 to 19.3 Bq/mL/MBq injected. Using a standard model of breast-feeding, the calculated maximum cumulative dose to the infant, 0.085 mSv with no interruption of breast-feeding, is well below the recommended limit of 1 mSv., Conclusion: High uptake of FDG in the lactating breast appears to be related to suckling. There is, however, little secretion of activity into breast milk. Accordingly, a higher radiation dose is received by the infant from close contact with the breast than from ingestion of radioactive milk.

Purpose: To prospectively study the impact of (18)F fluorodeoxyglucose (FDG) positron emission tomography (PET) on clinical management of patients with non-small-cell lung cancer (NSCLC)., Patients and Methods: One hundred five consecutive patients with NSCLC undergoing (18)F FDG PET were analyzed. Before PET, referring physicians recorded scan indication, conventional clinical stage, and proposed treatment plan. PET scan results were reported in conjunction with available clinical and imaging data, including results of computed tomography (CT). Subsequent management and appropriateness of PET-induced changes were assessed by follow-up for at least 6 months or until the patient's death., Results: Indications for PET were primary staging (n = 59), restaging (n = 34), and suspected malignancy subsequently proven to be NSCLC (n = 12). In 27 (26%) of 105 of cases, PET results led to a change from curative to palliative therapy by upstaging disease extent. Validity of the PET result was established in all but one case. PET appropriately downstaged 10 of 16 patients initially planned for palliative therapy, allowing either potentially curative treatment (four patients) or no treatment (six patients). PET influenced the radiation delivery in 22 (65%) of 34 patients who subsequently received radical radiotherapy. Twelve patients considered probably inoperable on conventional imaging studies were downstaged by PET and underwent potentially curative surgery. PET missed only one primary tumor (5-mm scar carcinoma). CT and PET understaged three of 20 surgical patients (two with N1 lesions < 5 mm and one with unrecognized atrial involvement), and PET missed one small intrapulmonary metastasis apparent on CT. No pathological N2 disease was missed on PET., Conclusion: FDG PET scanning changed or influenced management decisions in 70 patients (67%) with NSCLC. Patients were frequently spared unnecessary treatment, and management was more appropriately targeted.