223Ra-Dichloride in castration-resistant metastatic prostate cancer: improving outcomes and identifying predictors of survival in clinical practice.

PURPOSE: We first assessed whether the pattern of referrals to a nuclear medicine clinic improved as experience with 223Ra-dichloride increased, and whether referral patterns affected patient outcomes, and second assessed the value of bone scintigraphy, total alkaline phosphatase (tALP) and lymphadenopathy as prognostic factors in patients receiving 223Ra-dichloride. METHODS: A total of 57 patients eligible to receive 223Ra-dichloride over a 2-year period (March 2014 to March 2016) were retrospectively assessed and prospectively followed (median follow up 298 days). 223Ra-Dichloride was administered at 4-week intervals for a maximum of six injections. The numbers of patients in years 1 and 2 referred in relation to extent of bone disease (EOBD) category and overall survival (OS) were determined. The prognostic factors EOBD category, baseline tALP (tALPBL), tALP response, greatest percentage reduction in tALP from baseline in any treatment cycle (ALPmax; among patients with elevated ALPBL), and the presence of lymphadenopathy were assessed as predictors of OS. RESULTS: The proportion of patients with EOBD1 was higher in year 2 than in year 1 (29% and 4%, respectively), and in year 2 there was a lower rate of symptomatic skeleton-related events, a higher proportion of patients completing six cycles, and longer (albeit nonsignificant) OS (p = 0.55). There were significant differences in OS between EOBD4 patients and those in all other groups and between EOBD1 and EOBD3 patients (p < 0.05). OS was longer in patients with normal tALPBL than in those with elevated tALPBL (p = 0.01), in ALP responders than in nonresponders (p < 0.05), and in patients without lymphadenopathy than in those with lymphadenopathy (p = 0.29). OS was correlated with ALPmax (r2 = 0.24). CONCLUSION: A collaborative multidisciplinary referrals pathway, together with increased experience with 223Ra-dichloride, led to improved outcomes. In patients with elevated tALPBL, tALP dynamics may be useful for monitoring response and predicting OS. Imaging and prognostic markers may therefore be of value for individualizing 223Ra-dichloride treatment and planning retreatment; however, further studies are required.

The British nuclear medicine research strategy - the framework.

The British Nuclear Medicine Society (BNMS) has developed a Research Strategy framework led by the Research Champions of the BNMS and overseen by the BNMS Research and Innovation Committee. The objectives of the Research Strategy are to improve translation of cutting-edge nuclear medicine research from bench to bedside, the implementation of state-of-the-art multimodality technologies and to enhance multicentre radionuclide research in the UK. It strives to involve patients and the public in radionuclide research and to contribute to and work with the multi-professional national and international organisations involved in research with an ultimate aim to improve nuclear medicine services, and patients' outcomes and care.

Quantitative [123]I-Ioflupane DaTSCAN single-photon computed tomography-computed tomography in Parkinsonism.

AIM: [123]I-Ioflupane (DaTSCAN) binds to the presynaptic dopamine transporter (DAT) and with a lower affinity to the serotonin transporter (SERT). We aimed to develop a novel method to quantify absolute uptake in the striatal (predominantly DAT binding) and extra-striatal regions (mainly SERT binding) using single-photon computed tomography-computed tomography (SPECT-CT) DaTSCAN and to improve DaTSCAN image quality. METHOD: Twenty-six patients with Parkinsonism underwent DaTSCAN SPECT-CT prospectively. The scans were visually analyzed independently by two experienced reporters. Specific binding ratios (SBRs) from Chang attenuation corrected SPECT were obtained using GE DaTQuant. Normalized concentrations and specific uptakes (NSU) from measured attenuation and modelled scatter-corrected SPECT-CT were obtained using HERMES Hybrid Recon and Affinity and modified EARL volumes of interest. RESULTS: Striatal NSU and SBR positively correlate ( R  = 0.65-0.88, P  = 0.00). SBR, normalized concentrations, and NSU box plots differentiated between scans without evidence of dopaminergic deficit and abnormal scans. Interestingly, body weight inversely correlated with normalized concentrations values in extra-striatal regions [frontal ( R  = 0.81, P  = 0.00); thalamus ( R  = 0.58, P  = 0.00); occipital ( R  = 0.69, P  = 0.00)] and both caudate nuclei [ R  = 0.42, P  = 0.03 (Right), R  = 0.52, P  = 0.01 (Left)]. Both reporters noted improved visual quality of SPECT-CT versus SPECT images for all scans. CONCLUSION: DaTSCAN SPECT-CT resulted in more accurate quantification, improved image quality, and enabled absolute quantification of extra-striatal regions. More extensive studies are required to establish the full value of absolute quantification for diagnosis and monitoring the progression of neurodegenerative disease, to assess an interplay between DAT and SERT, and to verify whether serotonin and DATs are potentially dysfunctional in obesity.

Association between body mass index (BMI) and [123I]Ioflupane (DaTSCAN) availabilities in patients with parkinsonism using single-photon emission computed tomography-computed tomography (SPECT-CT).

AIM: [123I]Ioflupane (DaTSCAN) has a high binding affinity to the dopamine (DA) transporter (DaT) and tenfold less affinity to serotonin (5-HT) transporter (SERT). Both neurotransmitters are considered to contribute to body weight regulation. This study assesses the association between body mass index (BMI) and DaTSCAN availability in brain. METHOD: Scans from 74 consecutive patients who had undergone DaTSCAN single-photon emission computed tomography-computed tomography (SPECT-CT) were used to obtain semi- and absolute quantitative data in several volumes of interest (VOIs). Relative semi-quantitative specific binding ratios (SBRs) from Chang attenuated SPECT were obtained from GE DaTQUANT. Absolute normalised concentration (NC) was calculated from attenuation/scatter corrected SPECT-CT images, using an adapted version of the EARL Ltd (European Association of Nuclear Medicine (EANM) Research 4 Life) template. Scans were subdivided into either degenerative parkinsonism (abnormal = 49), borderline (n = 14) or scan without evidence of dopaminergic deficit (SWEDD = 11) using visual assessment and SBR values by two nuclear medicine consultants. RESULTS: SBRs did not correlate with BMI. However, NC values correlated negatively in the entire cohort, with the strongest correlation in the frontal (r = - 0.649. p = 0.000), occipital (r = - 0.555, p = 0.000) regions and pons (r = - 0.555, p = 0.000). In the abnormal (n = 49) and SWEDD group (n = 11), NC of the frontal region was the most correlated with BMI (r = - 0.570, p = 0.000; r = - 0.813, p = 0.002, respectively). In the borderline group (n = 14), the left posterior putamen displayed the strongest correlation (r = - 0.765, p = 0.001). CONCLUSION: Absolute NC values demonstrate a strong inverse correlation with BMI, strongest in the extrastriatal regions. Due to the predominately non-overlapping distribution of DaT and SERT, this study suggests greater involvement of SERT in obesity with possible interplay with DA transmission.

Lacrimal scintigraphy BNMS Guidelines.

PURPOSE: The purpose of this guideline is to assist specialists in Nuclear Medicine and Radionuclide Radiology in recommending, performing, interpreting and reporting the results of lacrimal scintigraphy (also known as Dacroscintigraphy). This guideline will assist individual departments to formulate their own local protocols. This does not aim to be prescriptive regarding technical aspects of individual camera acquisitions, which need to be developed in conjunction with the local experts in medical physics. There are numerous radiological techniques to assess the physiology of the lacrimal system. This guideline will describe the application of a drop of radiotracer into each eye and consecutive imaging to demonstrate the level of impaired drainage, with the possibility of quantifying such impairment. This guideline is a recent and updated version of a previously published guideline on the British Nuclear Medicine Society website in 2018 [1].

Establishing a Local Diagnostic Reference Level for Bone Scintigraphy in a Nigerian Tertiary Hospital.

It is of vital importance to optimize the radiation dose to patients undergoing radionuclide bone scanning. This is one of the most common nuclear medicine procedures in many parts of the world, including Nigeria, and the current study was performed as part of a national survey to establish diagnostic reference levels (DRLs) for common nuclear medicine procedures in Nigeria in order to optimize their use. Nuclear medicine was only recently introduced to the health-care system in Nigeria, with only 2 centers presently conducting these procedures. Methods: A retrospective, cross-sectional study was performed in the nuclear medicine department of a tertiary hospital in southwest Nigeria to determine the preliminary local DRL for radionuclide bone scanning. One hundred and nine patients who met the study criteria were included. Data were obtained from June 2017 to March 2019 and were analyzed to obtain the third quartile of the distributed administered activity and achievable dose (anthropometric variables and radiation dose to bone surface). Results: The mean administered activity, achievable dose, and DRL were 833.98 ± 106.93, 832.5, and 895.4 MBq, respectively. The calculated preliminary local DRL was larger than values reported in studies done in Sudan, the United Kingdom, and Australia or by the International Commission on Radiological Protection. Conclusion: The preliminary DRL from this first-of-its-kind study in Nigeria was high because of practitioners' lack of experience. However, the values were still within the international best-practice range, which when optimized will go a long way toward reducing medical exposure without compromising image quality.

123I-Ioflupane dopamine transporter imaging (DaTSCAN) appearances in relation to emotional responsiveness, impulsivity and olfaction in suspected Parkinsonian syndrome.

OBJECTIVE: The aim of our study was to ascertain relationships between DaTSCAN, olfactory loss, behavioural and subjective measurements of impulsivity and emotional responsiveness in patients with clinically suspected Parkinsonian syndrome (PS). METHODS: A prospective study of 20 drug-naive patients with parkinsonism, underwent the University of Pennsylvania Smell Identification Test, impulsivity measurements and mood-state-questionnaires before visual and semi-quantitative DaTQUANT analyses. There were two subgroups: nine patients with scans without evidence of dopaminergic deficit (SWEDD - controls) and 11 patients with PS. RESULTS: The PS group reported lower non-planning impulsivity than the SWEDD group (P = 0.039). A positive correlation was found between the non-planning impulsivity ratings and right anterior putamen/background (bck) ratio in PS group (r = 0.598, P = 0.068). Higher ratings of anger (r = 0.575, P = 0.016), fatigue (r = 0.746, P = 0.001), confusion (r = 0.561, P = 0.019) and depression were positively correlated with putamen/caudate ratios (R > L) on DaTSCAN. Higher self-reported arousal was associated with lower right putamen/caudate ratio (P = -0.581, P = 0.014). Only fatigue was positively correlated with putamen/bck (r = 0.564, P = 0.018). The degree of smell deficit correlated negatively with performance on reflection impulsivity tasks (r = -0.470, P = 0.049). CONCLUSION: DaTSCAN appearances correlated with emotional dysfunction and self-reported impulsivity in patients with PS. Olfactory impairment was associated with increased reflection impulsivity and the age of patients. Higher DaTSCAN putamen/caudate ratios were associated with higher emotional responsiveness and higher non-planning impulsivity in PS patients. These preliminary findings may be relevant in clinical practice in differentiating PS from SWEDD and identifying susceptibility to impulse control disorder although larger studies are warranted.

Bone scan index as metastatic bone disease quantifier and predictor of radium-223-dichloride biochemical response.

OBJECTIVES: This work aims to assess whether the biochemical response of radium-223-dichloride treatment can be predicted based on the pretherapy bone scan, and consequently if bone scan index (BSI) and maximum lesion intensity have a place as alternatives or as complements to extent of bone disease (EOBD) scoring in predicting biochemical response to treatment. Many cases of advanced prostate cancer have evidence of bone metastasis. Accurate EOBD quantification could help predict the response to radium-223-dichloride therapy. Current EOBD score is simple to use but does not consider size, intensity or localisation of lesion BSI might be more suitable for stratification of bone metastases. PATIENTS AND METHODS: Bone scans (n=20) preceding radium-223-dichloride treatment for prostate cancer were assessed retrospectively using automated BSI software (EXINI) and by assessing maximum counts per lesion. Results were then compared to total alkaline phosphatase (ALP) as a measure of biochemical response to therapy using linear regressions and to their EOBD scores using box plot analysis. RESULTS: Moderate correlation was found between ALP response and maximum lesion intensity (R=0.41) and BSI (R=0.46). Strong correlation (R=0.71) was found between baseline ALP and BSI and between lesion number and BSI (R=0.60). Visual assessment of EOBD score was found to correlate well with baseline ALP and maximum ALP response. CONCLUSION: BSI is a useful asset in stratification of patients with metastatic bone disease. It may also have a place in prediction of biochemical response.

Lesion detection performance: comparative analysis of low-dose CT data of the chest on two hybrid imaging systems.

UNLABELLED: Incidental findings on low-dose CT images obtained during hybrid imaging are an increasing phenomenon as CT technology advances. Understanding the diagnostic value of incidental findings along with the technical limitations is important when reporting image results and recommending follow-up, which may result in an additional radiation dose from further diagnostic imaging and an increase in patient anxiety. This study assessed lesions incidentally detected on CT images acquired for attenuation correction on two SPECT/CT systems. METHODS: An anthropomorphic chest phantom containing simulated lesions of varying size and density was imaged on an Infinia Hawkeye 4 and a Symbia T6 using the low-dose CT settings applied for attenuation correction acquisitions in myocardial perfusion imaging. Twenty-two interpreters assessed 46 images from each SPECT/CT system (15 normal images and 31 abnormal images; 41 lesions). Data were evaluated using a jackknife alternative free-response receiver-operating-characteristic analysis (JAFROC). RESULTS: JAFROC analysis showed a significant difference (P < 0.0001) in lesion detection, with the figures of merit being 0.599 (95% confidence interval, 0.568, 0.631) and 0.810 (95% confidence interval, 0.781, 0.839) for the Infinia Hawkeye 4 and Symbia T6, respectively. Lesion detection on the Infinia Hawkeye 4 was generally limited to larger, higher-density lesions. The Symbia T6 allowed improved detection rates for midsized lesions and some lower-density lesions. However, interpreters struggled to detect small (5 mm) lesions on both image sets, irrespective of density. CONCLUSION: Lesion detection is more reliable on low-dose CT images from the Symbia T6 than from the Infinia Hawkeye 4. This phantom-based study gives an indication of potential lesion detection in the clinical context as shown by two commonly used SPECT/CT systems, which may assist the clinician in determining whether further diagnostic imaging is justified.