PRRT: identikit of the perfect patient

Peptide receptor radionuclide therapy (PRRT) has been strengthened since the publication of NETTER-1. Nevertheless, the correct positioning in the therapeutic algorithm is debated, and no optimal sequence has yet been standardized. Possible criteria to predict the response to PRRT in neuroendocrine tumors (NET) have been proposed. The aim of this review is to define the perfect identity of the eligible patient who can mostly benefit from this therapy. Possible predictive criteria which have been analysed were: primary tumor site, grading, tumor burden, FDG PET and ⁶⁸Ga-PET uptake. Primary tumor site and ⁶⁸Ga-PET uptake do not play a pivotal role in predicting the response, while tumor burden, FDG PET uptake and grading seem to represent predictive/prognostic factors for response to PRRT. The heterogeneity in trial designs, patient populations, type of radionuclides, previous therapies and measurement of outcomes, inevitably limits the strength of our conclusions, therefore care must be taken in applying these results to clinical practice. In conclusion, the perfect patient, selected by ⁶⁸Ga-PET uptake, will likely have a relatively limited liver tumor burden, a ki67 index <20% and will respond to PRRT irrespective to primary tumor. Nevertheless, we have mostly prognostic than predictive factors to predict the efficacy of PRRT in individual patients, while a promising tool could be the NETest. However, to date, the identikit of the perfect patient for PRRT is a puzzle without some pieces and still we cannot disregard a multidisciplinary discussion of the individual case to select the patients who will mostly benefit from PRRT.

Effect of Kaolin/Defoliation Combined with Dry Ice on Lambrusco Red Wine Production to Constrain the Effects of Climate Change

Since viticulture is affected considerably by climate change, it is imperative to encourage research on newstrategies in order to constrain these critical effects on the composition of berries and the quality of wines.A multi-strategy approach composed of (i) kaolin application on foliage, (ii) late tree defoliation and (iii)cryomaceration of grapes with dry ice was evaluated in the production of Lambrusco Salamino wines.Physical, chemical and sensory analyses were carried out on the sample set, including the control wines.In general, cryomaceration with dry ice proved to be a winning choice to lower alcoholic strength (roughly5%). In addition, the wines showed an increase in anthocyanin content by approximately 17%, while thecontent of catechins, flavanols and hydroxycinnamic acids decreased. Consistent with the increase in theanthocyanin content, an increase in colour indices and sensory colour intensity scores was observed. As forthe aromatic profile, 2-phenylethanol showed an increase of approximately 18% in the treated wines while,in parallel, a lower content of C6 alcohols and volatile fatty acids was observed. The multiple adaptationstrategies put in place in the present study show an alternative way to mitigate the severe effects of climatechange on wine production, and to face changing consumer demands.

OP0069 THE ROLE OF POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY (PET/CT) IN DISEASE ACTIVITY ASSESSMENT IN PATIENTS WITH LARGE VESSEL VASCULITIS

Background:

Assessment of disease activity in large vessel vasculitis (LVV) is still an unmet need. PET Vascular Activity Score (PETVAS) is a new composite score aimed at quantifying the overall inflammatory burden by adding together PET qualitative visual scores (0-3, according to Meller) in nine selected arterial regions (1). In two independent cohorts, PETVAS showed to be effective in discriminating between patients with clinically active and inactive vasculitis.

Objectives:

To assess the role of PET/CT and the performance of PETVAS in differentiating between clinically active and inactive vasculitis in a single center cohort of patients with LVV.

Methods:

One-hundred patients with radiographic evidence of LVV were enrolled by the Rheumatology Unit of Reggio Emilia Hospital (Italy) between June 2007 and September 2020. All subjects underwent full clinical, laboratory and imaging evaluation (including PET/CT) at baseline, annually and when a relapse was suspected. Medical records of recruited patients were retrospectively reviewed from baseline visit until 30 September 2020, last follow-up or death.

For each PET/CT test, the nuclear medicine physician’s interpretation of scans (active/inactive vasculitis) was compared with disease activity clinical judgement (active disease/remission). The latter was based on comprehensive signs/symptoms assessment, laboratory and imaging (excluding PET/CT) data and was considered the reference standard.

For each PET/CT scan, PETVAS score was calculated and its performance in discriminating between patients with active and inactive disease was compared to clinical judgement.

Results:

In the study period 100 LVV patients [51 giant cell arteritis (GCA), 49 Takayasu arteritis (TAK)] underwent a total of 474 PET scans. Nuclear medicine physician’s interpretation of PET/CT was able to discriminate between patients in clinically active LVV (n 167) and those in clinical remission (n 307) with a sensitivity of 60% (95% CI, 51 to 69%) and a specificity of 80% (95% CI, 75 to 84%). The following sensitivity and specificity values were found in LVV subgroups: 73% (95% CI, 59 to 84%) and 77% (95% CI, 70 to 83%) for TAK, and 51% (95% CI, 38 to 63%) and 82% (95% CI, 76 to 88%) for GCA, respectively.

LVV patients with higher PETVAS scores were more frequently classified as having active disease: age and sex adjusted OR 1.15 (95% CI, 1.11 to 1.19), p<0.0001. Similar results were found in LVV subgroups, [age and sex adjusted OR 1.12 (95% CI, 1.08 to 1.17) for GCA and 1.22 (95% CI, 1.14 to 1.31) for TAK, all p<0.0001].

The area under receiver operating characteristics (ROC) curve (AUC) of PETVAS in differentiating between clinically active and inactive LVV was 0.73 (95% CI, 0.68 to 0.79). Similar results were found in LVV subgroups, [0.70 (95% CI, 0.62 to 0.78) for GCA, and 0.79 (95% CI, 0.71 to 0.87) for TAK]. A PETVAS ≥10 provided 61% sensitivity and 80% specificity in differentiating between clinically active and inactive LVV (52% sensitivity and 82% specificity in GCA subgroup and 73% sensitivity and 78% specificity in TAK subgroup).

Conclusion:

In our cohort PET/CT has shown to be useful in monitoring LVV disease activity.

PETVAS seems to be a reliable tool in helping clinicians to discriminate between LVV patients with active disease and those in remission.

References:

[1]Grayson PC, Alehashemi S, Bagheri AA, Civelek AC, Cupps TR, Kaplan MJ, Malayeri AA, Merkel PA, Novakovich E, Bluemke DA, Ahlman MA. 18 F-Fluorodeoxyglucose-Positron Emission Tomography as an Imaging Biomarker in a Prospective, Longitudinal Cohort of Patients with Large Vessel Vasculitis. Arthritis Rheumatol. 2018 Mar;70(3):439-449. doi: 10.1002/art.40379. Epub 2018 Feb 6. PMID: 29145713; PMCID: PMC5882488.

Disclosure of Interests:

None declared

Impact of the SARS-CoV2 pandemic dissemination on the management of neuroendocrine neoplasia in Italy: a report from the Italian Association for Neuroendocrine Tumors (Itanet)

INTRODUCTION

The organization of the healthcare system has significantly changed after the recent COVID-19 outbreak, with a negative impact on the management of oncological patients. The present survey reports data collected by the Italian Association for Neuroendocrine Tumors on the management of patients with neuroendocrine neoplasia (NEN) during the pandemic dissemination.

METHODS

A survey with 57 questions was sent to NEN-dedicated Italian centers regarding the management of patients in the period March 9, 2020, to May 9, 2020 RESULTS: The main modification in the centers' activity consisted of decreases in newly diagnosed NEN patients (- 76.8%), decreases in performed surgical procedures (- 58%), delays to starting peptide receptor radionuclide therapy (45.5%), postponed/canceled follow-up examinations (26%), and canceled multidisciplinary teams' activity (20.8%). A low proportion of centers (< 10%) reported having to withdraw systemic anti-tumor medical treatment due to concerns about the pandemic situation, whereas PRRT was withdrawn from no patients.

CONCLUSION

Although the COVID-19 outbreak induced the centers to reduce some important activities in the management of NEN patients, the Italian network was able to provide continuity in care without withdrawing anti-tumor treatment for the majority of patients.

Adaptive behavioural coping strategies as reaction to COVID-19 social distancing in Italy

OBJECTIVE

Social distancing, as experienced by the Italian population during the COVID-19 outbreak, generated the long-term activation of stress-response in individuals. This has been a crucial opportunity to study the coping strategies that people put in place to adapt their lives and habits to such a unique condition. For this reason, we have investigated both emotion-focused and problem-oriented coping strategies among the Italian population by relating them to other structural factors, such as social, economic and cultural conditions.

MATERIALS AND METHODS

More than 140,000 online interviews were collected in Italy from March 22 to April 2, 2020. This large dataset was used to carry out multivariate statistical data analysis with the aim of creating behavioral profiles, starting from coping parameters and other information. This technique has produced an association, showing a good level of statistical significance, between coping strategies and reactions to social distancing, due to the health emergency, during the data collection phase.

RESULTS

Two coping indicators - problem-oriented and focused on positive emotions coping strategies - were selected as objective variables in a "decision tree" modelling. The results have shown a link between individual factors (i.e., atmosphere at home) and educational and social factors (i.e., compliance with restrictions during the health emergency).

CONCLUSIONS

The reduction of social interaction had quite a significant impact on people's behavior; furthermore, coping strategies have played a crucial role in facing this stressor. For both the selected coping indicators, the best predictor was the atmosphere perceived at home. Moreover, the respondents' previous experiences have played a relevant role in the acceptance of new rules imposed by the government. This information can be useful in planning future social policies, both at national and international level, during such peculiar times.

CT protocol optimisation in PET/CT: a systematic review

Purpose

Currently, no consistent guidelines for CT scans used within PET/CT examinations are available. This systematic review provides an up-to-date overview of studies to answer the following questions: What are the specific CT protocols used in PET/CT? What are the possible purposes of requiring a CT study within a PET/CT scan? Is the CT protocol obtained from a dosimetric optimisation study?

Materials and method

PubMed/MEDLINE, Cochrane Library, Embase and Scopus were systematically searched for relevant studies in accordance with the PRISMA statement. The literature search was conducted from January 2007 until June 2019. Data derived from studies were standardized in order to reduce possible biases, and they were divided into clinically homogeneous subgroups (adult, child or phantom). Subsequently, we divided the CT protocol intents into 3 types (anatomic localization only, attenuation correction only and diagnostic purpose). A narrative approach was used to summarise datasets and to investigate their heterogeneity (due to medical prescription methodology) and their combination in multiseries CT protocols. When weighted computed tomography dose index (CTDI_w) was available, we calculated the volumetric computed tomography dose index (CTDI_vol) using the pitch value to make the results uniform. Eventually, the correlation between protocol intents and CTDI_vol values was obtained using a Kruskal–Wallis one-way ANOVA statistical test.

Result

Starting from a total of 1440 retrieved records, twenty-four studies were eligible for inclusion in addition to two large multicentric works that we used to compare the results. We analyzed 87 CT protocols. There was a considerable range of variation in the acquisition parameters: tube current–time product revealed to have the most variable range, which was 10–300 mAs for adults and 10–80 mAs for paediatric patients. Seventy percent of datasets presented scans acquired with tube current modulation, 9% used fixed tube current and in 21% of them, this information was not available. Dependence between mean CTDI_vol values and protocol intent was statistically significant (p = 0.002). As expected, in diagnostic protocols, there was a statistically significant difference between CTDI_vol values of with and without contrast acquisitions (11.68 mGy vs 7.99 mGy, p = 0.009). In 13 out of 87 studies, the optimisation aim was not reported; in 2 papers, a clinical protocol was used; and in 11 works, a dose optimisation protocol was applied.

Conclusions

According to this review, the dose optimisation in PET/CT exams depends heavily on the correct implementation of the CT protocol. In addition to this, considering the latest technology advances (i.e. iterative algorithms development), we suggest a periodic quality control audit to stay updated on new clinical utility modalities and to achieve a shared standardisation of clinical protocols. In conclusion, this study pointed out the necessity to better identify the specific CT protocol use within PET/CT scans, taking into account the continuous development of new technologies.

Real-life management and outcome of thyroid carcinoma-related bone metastases: results from a nationwide multicenter experience

PURPOSE AND PATIENTS

The M.O.S.CA.TI. (Metastases of the Skeleton from CArcinoma of the ThyroId) is a multicenter, retrospective study investigating the real-life outcome and management of bone metastases (BM) in 143 patients (63 M, 80 F; median age 64 years, range 11-87) with differentiated thyroid carcinoma (DTC).

RESULTS

Radio-active iodine (RAI) treatment was performed in 131 patients (91.6%), surgical approach and/or external radiotherapy in 68 patients (47.6%), and anti-resorptive bone-active drugs in 32 patients (22.4%; in 31 zoledronate and in one denosumab). At the start of treatment, 24 patients (75.0%) receiving anti-resorptive bone-active drugs had at least one clinical skeletal-related event (SRE) (p < 0.001). One or more clinical SREs (pathological fractures and/or malignant hypercalcemia and/or spinal cord compression) developed in 53 patients (37.1%). Development of SREs was significantly associated with metachronous BM (hazard ratio (HR) 2.04; p = 0.04), localization of BM to cervical spine (HR 3.89; p = 0.01), and lack of avid RAI uptake (HR 2.66; p = 0.02). Thirty-nine patients (27.3%) died in correlation with development of SREs (HR 6.97; p = 0.006) and localization of BM to the hip (HR 3.86; p = 0.02). Moreover, overall mortality was significantly decreased by RAI therapy (HR 0.10; p = 0.02), whereas no significant effects were induced by bone-active drugs (p = 0.36), external radiotherapy (p = 0.54), and surgery (p = 0.43) of BM.

CONCLUSIONS

SREs are very frequent in BM from DTC and they impact patient survival. In the real life, the use of bone-active drugs is currently limited to zoledronate in patients with pre-existing SREs. In this clinical setting, RAI therapy, but not zoledronate, decreased mortality.

Sharing distress increases helping and contact intentions via social identification and inclusion of the other in the self: Children’s prosocial behaviour after an earthquake

We surveyed young children ( N = 517) affected by two major earthquakes to shed light on the role of identity processes in relation to the common observation that disasters can bring survivors closer together and enhance helping amongst them. As expected, posttraumatic stress symptoms caused by the earthquake were positively associated with intentions to have contact with and help other survivors of the earthquake, these effects being sequentially mediated by inclusion of the other in the self and by one-group representation. These findings extend previous research on both the antecedents and the behavioural effects of identity-fusion. The results are also the first quantitative test of a social identity account of collective resilience in children. We argue that these findings have practical as well as theoretical significance, as they demonstrate the adaptive function of group processes in informal responses to disasters.

Applications of PET imaging with radiolabelled choline (11C/18F-choline)

The use of radiopharmaceuticals is the distinguishing characteristics of nuclear medicine. Among the panel of available radiopharmaceuticals in many PET centers around the world, choline is well represented, being widely used to image prostate cancer. Carbon-11 labelled choline can only be produced in centres with a cyclotron available, but the 18F-labelled radiopharmaceutical is distributed and licensed in several countries in Europe. Besides prostate cancer, other possible uses of choline are related to its ability to indirectly evaluate the cell proliferation as a measure of the synthesis of lipids required for cell membrane. In particular, the radiopharmaceutical can be successfully used in those districts where 18F-FDG has a high uptake, like the brain. Moreover, slow growing tumors, not always taking up 18F-FDG, like hepatocellular carcinoma, can also be imaged. We will evaluate possibly uses of this molecule in patients affected by prostate cancer, brain tumors and hepatocellular carcinoma.

Quantitative comparison between the commercial software STRATOS(®) by Philips and a homemade software for voxel-dosimetry in radiopeptide therapy

BACKGROUND

Targeted radionuclide therapy is a rapidly growing modality. A few commercial treatment planning systems are entering the market. However, some in-house systems are currently developed for a more flexible and customized dosimetry calculation at voxel-level. For this purpose, we developed a novel software, VoxelMed, and performed a comparison with the software STRATOS.

METHODS

The validation of both of them was undertaken using radioactive phantoms with different volume inserts. A cohort of 10 patients was also studied after a therapeutic administration of (177)Lu-labelled radiopeptides. The activity, number of disintegrations, absorbed dose and dose-volume histogram (DVH) were calculated for the phantoms and the kidneys in patients, which were the main critical organs at risk in this study.

RESULTS

In phantoms the absorbed doses computed with VoxelMed and STRATOS agree within 5%. In patients at the voxel-level the absorbed dose to kidneys (VoxelMed: mean 0.66 Gy/GBq) showed a limited difference of 5%, but with a remarkable range (-40%, +60%) between the two software packages. Voxel-dosimetry allows to estimate the dose non-homogeneities in volumes, which may be evaluated through DVHs.

CONCLUSION

This study demonstrates that a fully 3D voxel-dosimetry with multiple SPECT images is feasible by using home-made or commercial software package and absorbed dose results obtained are similar. The main difference between the studied tools was observed in the activity integration method (effective vs physical half-time to time activity curve tail). We believe that an effective half-time integration method produces a more accurate approximation of clinical uptake and resultant dosimetry.

Feeling like a group after a natural disaster: Common ingroup identity and relations with outgroup victims among majority and minority young children

We conducted a field study to test whether the common ingroup identity model (Gaertner & Dovidio, 2000, reducing intergroup bias: The common ingroup identity model. Philadelphia, PA: Psychology Press) could be a useful tool to improve intergroup relations in the aftermath of a natural disaster. Participants were majority (Italian) and minority (immigrant) elementary school children (N = 517) living in the area struck by powerful earthquakes in May 2012. Results revealed that, among majority children, the perceived external threat represented by the earthquake was associated with greater perceptions of belonging to a common ingroup including both ingroup and outgroup. In turn, heightened one-group perceptions were associated with greater willingness to meet and help outgroup victims, both directly and indirectly via more positive outgroup attitudes. Among immigrant children, perceived disaster threat was not associated with any of the dependent variables; one-group perceptions were positively associated with outgroup attitudes, helping and contact intentions towards outgroup victims. Thus, one-group perceptions after a natural disaster may promote more positive and supporting relations between the majority and the minority group. We discuss the theoretical and practical implications of the findings.

Tocilizumab in glucocorticoid-naïve large-vessel vasculitis

Glucocorticoids (GC) are the mainstay of treatment of large-vessel vasculitis (LVV), but a sizeable number of patients relapse upon tapering the GC dose or after discontinuation of GC therapy. In addition, GC cause numerous adverse events. Therefore, in patients with longstanding disease and in those at risk for GC-related adverse events, the use of alternative therapeutic agents should be considered. Interleukin-6 (IL-6) is a key player in the pathogenesis of LVV. Preliminary data suggest the efficacy of the IL-6 receptor inhibitor tocilizumab (TCZ) in patients with LVV. We report 2 treatment-naïve patients with a recent diagnosis of LVV who received monthly TCZ infusions (8 mg/kg body weight) for 6 consecutive months as monotherapy because of relative contraindications and patients' reluctance to take GC. In both cases we observed a complete clinical response and normalisation of inflammatory markers as well as a decrease in vascular FDG uptake and SUV ratio on fluorodeoxyglucose positron emission/computerised tomography. Serum IL-6 and soluble IL-6 receptor (sIL-6R) levels rose in both patients after TCZ therapy. TCZ may be an effective alternative to GC treatment for LVV patients at risk for GC-related adverse events. Larger studies are required to confirm our findings.

Pulmonary artery involvement in Takayasu arteritis. PET/CT versus CT angiography

OBJECTIVES

To report a patient with Takayasu arteritis in whom 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computerised tomography (CT) failed to demonstrate pulmonary artery involvement.

METHODS

A patient with Takayasu arteritis underwent PET/CT and CT angiography before and one year after immunosuppressive treatment.

RESULTS

Before treatment, PET/CT showed increased FDG uptake in the aortic arch and epiaortic arteries; pulmonary arteries were not visualised. Follow-up PET/CT one year later demonstrated resolution of abnormal vascular FDG uptake. CT angiography of the chest/abdomen prior to treatment revealed circumferential thickening of the ascending aorta, aortic arch, supra-aortic branches, and left inferior intralobar pulmonary artery with normal lumen diameter (27 mm). After therapy, CT angiography revealed decreased aortic wall thickening with complete resolution of intralobar wall thickening. However, the lumen of the central pulmonary artery was increased (32 mm).

CONCLUSIONS

PET/CT is very sensitive in depicting active vasculitis, but cannot visualise the pulmonary arteries, presumably because their diameter is below the power of detection of PET/CT. CT angiography or magnetic resonance angiography is required to evaluate pulmonary artery abnormalities.

[Disease activity assessment in large vessel vasculitis]

Disease activity assessment in large vessel vasculitis (LVV) is often challenging for physicians. In this study, we compared the assessment of disease activity based on inflammatory markers, clinical indices (Indian Takayasu Activity Score [ITAS] and the Kerr/National Institute of Health indices [Kerr/NIH]), and 18F-Fluorodesossiglucose (FGD) vascular uptake at positron emission tomography (Pet). We found that Pet results did not statistically correlate with the clinical indices ITAS and Kerr/NIH, because FDG uptake was increased (grade>2 on a 0-3 scale in at least one evaluated vascular segment) in many patients with inactive disease according to clinical and laboratory parameters (i.e., negative ITAS and Kerr/NIH indices as well as normal erythrocyte sedimentation rate (ESR) and C-reactive protein (PCR)). Similarly, interleukin- 6 and its soluble receptor did not statistically correlate with disease activity. In contrast, clinical indices showed a significant correlation between each other and with inflammatory markers (VES and PCR). These data suggest that while clinical indices and inflammatory markers may be useful to assess disease activity, Pet may be more sensitive.

PET/CT and radiotherapy : data transfer, radiotherapy workflow and quality assurance

The development of new technologies in radiation therapy has made it possible to introduce more sophisticated techniques that can deliver the prescribed dose with more conformation and accuracy and to apply dose escalation protocols without increasing the risk of healthy tissue damage. This has consented the simultaneous delivery of different dose levels to different parts of the target, making it possible to boost those tumour sub-volumes that are considered more radio resistant. The use of PET for radiotherapy planning purposes has become increasingly important in the last few years, because of its ability to provide valuable biologic and functional data. PET imaging can affect the treatment strategy definition and improve the target delineation and the assessment of therapy response. The most attractive aspect is the perspective to deliver differential doses inside target volumes for areas of different biologic behaviour based on functional imaging, moving closer to the goals of biologically conformal radiation therapy. Each single step of PET/CT-guided radiotherapy workflow, needs to be performed following high standard procedures, within a rigorous and appropriate quality assurance protocol to minimize the sources of errors and to maximize the efficacy of PET imaging in radiation therapy, ensuring safe and effective use of the technology. The present paper focuses on aspects concerning the use of PET/CT in radiation treatment process, with the aim to delineate different possible approaches to its clinical application and to highlight the critical aspects of the various subprocesses.