Novel Ga-68-FAPI PET/CT offers oncologic staging without COVID-19 vaccine-related pitfalls

Ziel/Aim The global SARS-CoV-2 vaccination campaign brought attention to a recent pitfall in tumor staging by PET/CT. Several publications reported a non-specific F-18-FDG tracer uptake in axillary lymph nodes after COVID-19 vaccination. Ga-68-FAPI PET/CT is a new oncologic imaging tool that may overcome this limitation. Methodik/Methods For this purpose, we compared the tracer uptake in a head-to-head and same-day F-18-FDG and Ga-68-FAPI PET/CT study. 11 patients from our prospective database (NCT04571086) were included showing vaccine-related tracer uptake in axillary lymph nodes up to 6 weeks after COVID- 19 vaccination. Ergebnisse/Results Among the total of 11 patients, all (n = 11) showed visual positive uptake in the lymph nodes ipsilateral to the injection side on F-18-FDG PET. None (n = 0) of the included patients showed significant tracer uptake on Ga-68-FAPI PET. Follow-up imaging confirmed reactive nodal uptake in all patients. The tumor detection efficacy for these patients was 73 % for F-18-FDG and 94 % for Ga-68-FAPI. Schlussfolgerungen/Conclusions In our case series, Ga-68-FAPI demonstrated resistance to vaccine-related pitfalls while presenting superior tumor detection.

COVID-19 vaccination-related [18F]FDG-avid lymph node in a patient with marginal zone B-cell lymphoma

The [18F]FDG PET/CT is a crucial tool in the diagnostic process and monitoring of neoplastic diseases. Currently, during the global program of vaccination against COVID-19 and the possibility of axillary lymphadenopathy after this injection, the correct interpretation of PET/CT images is vitally significant and may create some difficulties. We present a case of increased uptake of [18F]FDG in an axillary lymph node in a PET/CT scan performed 2 days after the Pfizer BioNTech COVID-19 vaccine in a 48-year-old patient newly diagnosed with marginal zone B-cell lymphoma.Copyright © 2023 Via Medica.

The Effects of CoronaVac (Sinovac) and BNT162b2 (BioNTech/Pfizer) Vaccination on Oncologic 18F-FDG PET/CT Studies.

Objectives: BioNTech (Pfizer) and CoronaVac (Sinovac) vaccines are two of the most administered coronavirus disease-2019 (COVID-19) vaccines worldwide. Vaccination against severe acute respiratory syndrome-coronavirus-2 has caused a diagnostic challenge in oncological 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) studies. The aim of our study was to evaluate the 18F-FDG PET/CT findings of the two most commonly administered vaccines worldwide. Methods: Patients over 18 years old who underwent 18F-FDG PET/CT for oncological purposes in our institution between January 13, 2021 and January 31, 2022, who received a single or second dose of the BioNTech or CoronaVac vaccines in the last two months, were included in the study. Descriptive analyses were presented as mean, standard deviation, frequency and ratio. Additionally, chi-square test was used to analyze categorical variables. Results: Ipsilateral deltoid muscle hypermetabolism was observed in 6.9% (n=15) and 14.3% (n=22) patients who received CoronaVac and BioNTech vaccines, respectively. Ipsilateral axillary lymph node hypermetabolism was observed in 11% (n=24) and 41.6% (n=64) patients who received CoronaVac and BioNTech vaccines, respectively. Synchronous deltoid muscle and axillary lymph node hypermetabolism was observed in 4.14% (n=9) and 12.33% (n=19) patients who received CoronaVac and BioNTech vaccines, respectively. Significant differences were detected between CoronaVac and BioNTech vaccines in terms of ipsilateral deltoid muscle hypermetabolism, ipsilateral axillary lymph node hypermetabolism and synchronous deltoid muscle and axillary lymph node hypermetabolism (p<0.05). Conclusion: COVID-19 vaccination may result in ipsilateral axillary lymph node hypermetabolism, ipsilateral deltoid muscle hypermetabolism, or synchronous deltoid muscle and axillary lymph node hypermetabolism with different frequencies depending on the type of vaccination. Although synchronous deltoid muscle and axillary lymph node hypermetabolism can reduce misinterpretation of 18F-FDG PET/CT, to avoid misinterpretation, it is important to question the vaccination history during ongoing COVID-19 vaccination process.

Breast Cancer-Related Lymphedema and its Relationship to Major Landmark Trials in Surgical Oncology and Radiation Oncology

INTRODUCTION: Many landmark trials have challenged the need for extensive axillary surgery and radiation in breast cancer patients. De-escalation of axillary treatment could potentially result in less breast cancer-related lymphedema (BCRL). Our study aims to define the incidence and trends of BRCL over the last 15 years. METHOD(S): Since 2005, our institution has prospectively screened breast cancer patients for lymphedema during and after treatment with a Perometer. 2,334 women diagnosed with breast cancer with baseline arm volume measurements and at least 2 follow-up measurements were divided into 3 cohorts based on date of surgery (Cohort 1: 2005-2010, Cohort 2:2011-2016, Cohort 3: 2016-2022). The cohorts were selected to coincide with publications of the landmark trials NSABP B-32, ASCOG Z0011, ASCOG Z1071, and EORTC 10981-22023 AMAROS which demonstrated safety in reducing the number of axillary lymph node dissections (ALND). Lymphedema was defined as a relative volume change of 10% or greater from preoperative baseline at least 3 months post-operatively. In cases of bilateral surgery, the weight-adjusted arm volume change equation was utilized. Cohort, age, BMI, axillary surgery type, chemotherapy timing, radiation type, and surgery type were all included in the multivariate analysis. RESULT(S): The overall incidence of BCRL was 12.8%, with a 29.6% incidence for those undergoing ALND and a 6.4% incidence for those undergoing sentinel lymph node biopsy. While the number of ALND performed decreased between cohorts (Figure 1), there was no significant difference in BCRL between assigned cohorts (HR 1.02 (95% CI [0.69, 1.51], p=0.930 for cohort 3 vs cohort 1). On multivariate analysis, significant associations with development of BCRL were identified with older age (HR 1.02;95% CI [1.01, 1.03], p=0.002), higher BMI (HR 1.05;95% CI [1.04, 1.07], p< 0.0001) and ALND (HR increased the risk of (HR 3.67;95% CI [2.62, 5.13], p< .0001). Regional lymph node radiation was not significantly associated with BCRL. CONCLUSION(S): Despite a reduction in the number of ALND performed over time, we did not see a dramatic reduction in the incidence of BCRL. Interestingly, between cohort 2 and cohort 3 there was a stable incidence of ALND which could be related to the COVID pandemic with an increase in more advanced cancers and a decrease in the ability to screen patients for BCRL during that time period.

Physician-led ultrasound interventions: Rapid diagnosis of lung cancer during the COVID-19 pandemic

Introduction: Lung cancer management depends upon a timely histological diagnosis. Unprecedented pressure on various diagnostic facilities were observed during the COVID-19 pandemic. In our hospital, physician-led thoracic ultrasound guided biopsies and Rapid-On-Site-Evaluation (ROSE) ensured the prompt enrollment in the lung cancer diagnostic pathway. Aim and objectives: The COVID-19 pandemic has affected the lung cancer pathway adversely due to aerosol generating procedures, infection control, limited bronchoscopy, endobronchial ultrasound and computed tomography (CT) sessions. During this challenging time, we aimed to maintain a swift and consistent lung cancer pathway, aided by physician-led ultrasound guided interventions. Method(s): A twelve-month prospective analysis was performed on a cohort of all patients with a histological diagnosis of lung cancer, examining methods used for tissue sampling. Result(s): Between April 2020 to March 2021, our lung multi-disciplinary meeting decided the clinical management of 91 patients with confirmed histology. 41% (37/91) of those had biopsies via physician-led ultrasound-interventions. Sites sampled yielding tissue diagnosis were;59% (22/37) supraclavicular fossa nodes, 30% (11/37) lung lesions, 5% (2/37) pleural lesions, 3% (1/37) bone and 3% (1/37) axillary lymph node. Conclusion(s): Our study shows that physician led ultrasound guided biopsies and ROSE are safe and robust for prompt and speedy lung cancer management. It has future research potentials. We welcome comments and experience of other teams in this regard.

Recruitment, clinical equipoise, patient acceptance and compliance in the UK-ANZ POSNOC trial

Background: POSNOC is a UK-ANZ multicentre, non-inferiority, randomised trial comparing systemic therapy alone with systemic therapy plus Axillary Treatment (Axillary radiotherapy or ALND) for women with <=2 macrometastases at SNB. The primary outcome is axillary recurrence within 5 years. This paper describes screening, recruitment and compliance data. Method(s): Sites were requested on a monthly basis to upload screening data and provide reasons for nonrecruitment of eligible patients into the trial. Sites entered in the online database whether the patients were compliant with their randomisation allocation. Result(s): The study opened in July 2014 and completed target recruitment of 1900 women (24% of those screened) in July 2021, at 95 sites in the UK and 20 sites in Australia and New Zealand. The reason for non-enrolment was unknown in 1300 women. Of the remaining 4774 women with known reasons, who were screened but not randomised, the most common reasons for non-recruitment were due to either patients (n=2219, 46.5%) or their clinicians (n=782, 16.4%) favouring axillary treatment, or patients (n=490, 10.3%) or their clinicians (n=170, 3.6%) not wishing to have axillary treatment. Over the course of the study, there was an increase in the proportion of patients wanting axillary treatment and declining the trial (Mean % patients declined 2015 - 17.9%, 2021 - 39.1%). Mean number of participants recruited per site per month was 0.24 (SD 0.18) overall, 0.25 (SD 0.19) in the UK, and 0.19(SD 0.15) in ANZ. The mean was < 0.3 in 79 sites and >0.9 in only one site. Recruitment rate remained consistent throughout the study (mean 25.3 per month) except for during the first 6 months of recruitment (5.7) and during the COVID pandemic Apr-Sep 2020 (7.5). Of 89 (4.8%) participants non-compliant with allocation, n=45 (50.6%) received systemic therapy alone and n=44 (49.4%) received systemic therapy plus axillary treatment. There was no fluctuation in the direction of non-compliance during the study duration. There was increasing uptake of axillary radiotherapy to treat the axilla instead of ALND over the course of the study in patients receiving axillary treatment (Number who had ART of all who had axilla treatment2014-2017 - 248/454 (54.6 %);2018-2021 - 315/449 (70.2%)). Conclusion(s): Recruitment and compliance with randomised allocation remained consistent over a seven-year period. POSNOC with in-built radiotherapy QA will provide definitive data on axillary management in patients undergoing mastectomy or BCS with <=2 macrometastases on SNB.

OPTIMA, a prospective randomized trial to validate the clinical utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in high clinical risk early breast cancer

Background: Multi-parameter tumor gene expression assays (MPAs) are used to estimate individual patient risk and guide chemotherapy use in hormone-sensitive, HER2-negative early breast cancer. The TAILORx trial supports MPA use in a node-negative population. Evidence for MPA use in postmenopausal node-positive breast cancer has been provided by the RxPONDER trial interim analysis but this relies on the absence of superiority in an analysis where >50% of events were unrelated to breast cancer. There is much uncertainty about MPA use for premenopausal patients. OPTIMA (Optimal Personalised Treatment of early breast cancer usIng Multi-parameter Analysis) (ISRCTN42400492) is a prospective international randomized controlled trial designed to validate MPAs as predictors of chemotherapy sensitivity in a largely node-positive breast cancer population. Method(s): OPTIMA is a partially blinded study with an adaptive two-stage design. The trial recruits women and men age 40 or older with resected ER-positive, HER2-negative invasive breast cancer and up to 9 involved axillary lymph nodes. Randomization is to standard management (chemotherapy and endocrine therapy) or to MPA-directed treatment using the Prosigna (PAM50) test. Those with a Prosigna tumor Score (ROR-PT) >60 receive standard management whilst those with a low score (<=60) tumor are treated with endocrine therapy alone. Endocrine therapy for premenopausal women includes ovarian suppression for all participants unless they experience a chemotherapy-induced menopause. Adjuvant abemaciclib is permitted. The trial will be analyzed for (1) non-inferiority of recurrence according to randomization and (2) cost-effectiveness. The key secondary outcome is non-inferiority of recurrence for patients with low ROR-PT score tumors. The efficacy analyses will be performed Per Protocol using Invasive Breast Cancer Free Survival (IBCFS) as the primary outcome measure to limit the risk of a false non-inferiority conclusion. Recruitment of 4500 patients over 8 years will permit demonstration of up to 3% non-inferiority of test-directed treatment with at least 83% power, assuming 5-year IBCFS is 87% with standard management. An integrated qualitative recruitment study addresses challenges to consent and recruitment, building on experience from the feasibility study which found that a multidisciplinary approach is important for recruitment success. OPTIMA is strongly supported by a patient group which has helped design all patient documents and which is represented on the TMG. Result(s): The OPTIMA main trial opened in January 2017 and has continued to recruit throughout the COVID-19 pandemic. Overall recruitment as of 1 July 2022 was 2814 (2593 from UK, 221 from Norway). Patient characteristics are well balanced between the trial arms. Currently 95% of randomized participants are eligible for inclusion in the PP analysis. 66% of the MPA-directed arm participants have been allocated to endocrine therapy only. The test failure rate is < 1%. Conclusion(s): OPTIMA will provide robust unbiased evidence on test-directed chemotherapy safety for both postmenopausal and premenopausal women with 1-3 involved nodes as well as for patients with 4-9 involved nodes and for patients treated with abemaciclib.

Axillary Lymph Node Uptake on 18F-FDG PET/CT after COVID-19 Vaccination: A Direct Comparison Study with Influenza Vaccination.

Objectives: To compare vaccinated-side axillary lymph node uptake on 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after coronavirus disease-2019 (COVID-19) and influenza vaccination. Methods: We retrospectively analyzed 177 patients who underwent 18F-FDG PET/CT after COVID-19 or influenza vaccination. We compared the uptake of the vaccinated-side axillary lymph nodes of 109 COVID-19 vaccinated patients with those of a lot of influenza-vaccinated patients. We also compared the uptake between 66 patients who received the first COVID-19 vaccination with 43 who received the second COVID-19 vaccination. Results: 18F-FDG-avid axillary lymph nodes on the vaccinated side were significantly more frequently observed in the COVID-19 group (45%) than in the influenza group (19%) (p<0.001). When the interval between vaccination to PET/CT was within 7 days, there was no significant difference in the frequency of 18F-FDG-avid vaccinated-side axillary lymph nodes between the groups (COVID-19 group: 41% vs. influenza group: 45%, p=0.724). When the interval was over 7 days, 18F-FDG-avid lymph nodes were much more frequent in the COVID-19 group (47%) than in the influenza group (7%) (p<0.001). Comparing the first and second COVID-19 groups, 18F-FDG-avid lymph nodes were more frequent in the second vaccination group than in the first vaccination group, but the difference was not significant. Conclusion: 18F-FDG-avid vaccinated-side axillary lymph nodes were more frequently observed in the COVID-19 group than in the influenza group. In the case of the COVID-19 vaccine, a delay of 18F-FDG PET/CT examination is recommended by a longer interval from vaccination than in the influenza vaccine.

The Impact of different COVID-19 vaccines in 18F-FDG PET/CT

Aim/Introduction: Austria started its COVID-19-vaccination program in December 2020 with three different vaccines. As the vaccination program continues, we encountered increased F-18- FDG-activity not only in axillary lymph nodes ipsilateral to the injection site but also in other organs. The aim of this retrospective study is to present results of the metabolic activity of ipsilateral axillary lymph nodes, liver, blood pool, spleen, and bone marrow after three different vaccines. Material(s) and Method(s): The data of 220 eligible vaccinated patients (127 with BioNTech/Pfizer, 61 with Moderna, and 32 with AstraZeneca) examined with F18-FDG-PET/ CT were enrolled. The PET/CT examinations were evaluated from day 1 to day 120 (SD: 23.2, Median: 26) after different vaccinations. Seventy out of these 220 patients were at least once examined with F18-FDG-PET/CT before vacciantion. SUVmax of axillary node(s), and blood pool, liver, spleen, and bone marrow as reference organs were calculated. Relation of SUVmax activity of axillary lymph node to reference organs was also compared in all patients. Result(s): Ten days after BioNTech/Pfizer and AstraZeneca vaccination the axillary FDG uptake was at its highest activity. This was with Moderna vaccination after 30 days. There was no significant statistical difference of SUVmax of lymph nodes or its ratios to other reference organs between three groups of vaccines. SUVmax in lymph nodes in relation to SUVmax in the liver, spleen, and bone marrow was statistically significant with p-values of <.001, 0.044, and 0.001, respectively. In the group of 70 patients with a pre-vaccination PET/CT examination, the SUVmax of lymph nodes (median: 0.820, standard deviation 1.233) changed significantly after vaccination (p <.001). A significant change of tracer activity in the liver was also observed (p = 0.032). There was no significant change of tracer activity after vaccination in other reference regions or between different types of vaccines. Conclusion(s): Local site and ipsilateral axillary lymph node activity in F18-FDG PET/CT after COVID19-vaccination is suggested in many studies. The main challenge is recognizing the changes in lymph nodes after vaccination to minimize false interpretation, foremost in patients with oncological diagnoses. Moreover, different vaccines cause different system metabolic changes. The knowledge of vaccine type, the time interval between vaccination and PET/CT scan is essential, especially in therapy evaluation.

FDG-avid lymph nodes (LN) in response to vaccines for SARS-CoV-2

Aim/Introduction: Vaccines against SARS-CoV-2 virus were developed due to the impetuous coronavirus pandemic. Vaccines hold a possibility to provoke side effects. The aim of our study was to examine the impact of COVID-19 vaccination on the incidence and duration of false-positive FDG-avid lymphadenopathy after vaccination with different types of vaccines and to determine its relationship with age, gender, and vaccine type. Material(s) and Method(s): The retrospective study included 103 patients who met the following criteria:18F-FDG PET/CT scan performed (in the period from August 2021 to December 2021) for staging or restaging of diagnosed oncological diseases at different time periods after vaccination Pfizer-BioNTech, Moderna-BioNTech and Oxford-AstraZeneca. Exclusion criteria were incomplete information about vaccination, patients with a diagnosed malignant lymphoproliferative disease, concomitant benign pathology of the lymphatic system, history of acute viral infection up to 3 months from the date of PET/CT. Result(s): False-positive reactive lymphadenopathy was identified in 35 (34%) of 103 patients included in our study cohort, which occurred during the first 2 weeks to 12 weeks after vaccination and manifested as increased metabolic activity in regional non-enlarged lymph nodes: ipsilateral axillary lymph nodes of levels I-III, as well as cervical LN of levels IV and VB). A significant moderate decline in metabolic activity in the LN over time was reported, as well as a decrease in the detection rate of PET-positive reactive findings with time. The results showed a trend of a positive relationship - the occurrence of reactive lymphadenopathy more often in women than in men. The detection rate, as well as the intensity of the activity of glucose metabolism, were higher in patients under the age of 50 compared to those >= 50 years. However, we did not find significant differences between the studied types of vaccines (p >0.05). Conclusion(s): Multidisciplinary physician awareness is essential regarding the possibility of false-positive FDG lymphadenopathy in relation to local inflammation and as a manifestation of the immune response due to COVID-19 RNA vaccination and adenoviral vector-based vaccine up to 12 weeks after injection, in order to optimize the clinical interpretation of hybrid scan results that determine the subsequent therapeutic approach of cancer patients. The results of the present study demonstrate the importance of vaccination on the contralateral side of the tumor drainage, as well as taking a thorough anamnesis. Keywords: FDG PET/CT, false positive lymphadenopathy, vaccination.

Evaluation of Side Effects After Heterologous Vaccination with BNT162b2 Vaccine in Healthcare Workers Vaccinated with Two Doses of Inactive COVID-19 Vaccine.

Objective: Vaccination is the most effective way to control the COVID-19 pandemic all over the world. We aimed to evaluate the relationship between antibody titers and vaccine side effects after the BNT162b2 vaccine was administered as a reminder dose in healthcare workers (HCW) who received two doses of inactivated SARS-CoV-2 vaccine name CoronaVac (Sinovac Life Sciences, Beijing, China). Method(s): A total of 428 HCWs participated in the study. Participants who received the mRNA vaccine as a reminder dose were evaluated with a questionnaire regarding antibody values and vaccine side effects. Three weeks after the first BNT162b2 vaccine, the same questionnaire was applied face-to-face to HCW, and the same questionnaire was applied to those who received a second reminder dose via telephone. Result(s): Out of 428, 373 (87.1%) HCWs preferred one and 55 (12.9%) two doses of the BNT162b2 vaccine as reminder doses after being vaccinated with an inactivated vaccine. It was observed that side effects were more frequent in women aged 18-40 after a single dose of the BNT162b2 vaccine (p<0.001). The most common side effects are redness, swelling, and pain at the injection site, with a rate of 59.6%. Fatigue-weakness was the most common systemic reaction, with a rate of 58.6%. Axillary lymphadenopathy was observed seen in 3 (1.1%) HCWs. The median value of IgG titers in the third week after the reminder dose was found to be higher in HCW with side effects than those without side effects (p<0.001). When the cumulative incidence rate of vaccinated people was evaluated over 389 people, no cases were observed on the 14th and 30th days after the first reminder dose of BNT162b2. However, the first case was observed on the 60th day, and after the second reminder dose, cases were seen on the 14th, 30th, and 60th days. Conclusion(s): Since the side effects detected after the BNT162b2 reminder dose were mild to moderate and progressed with local symptoms, it was concluded that highly protective mRNA vaccines could be safely preferred for protection from COVID-19. Copyright © 2022, DOC Design and Informatics Co. Ltd.. All rights reserved.

Comparing operative techniques for non-palpable breast tumours: Wire-guided localisation vs LOCaliser

Introduction: Wire-guided localisation (WGL) has been the standard operative technique for non-palpable breast tumours. LOCaliser is an alternative method, with a clinical effectiveness that may be equal to the standard while providing additional benefits regarding the patient experience. Method(s): A single-centre, retrospective study of WGL vs LOCaliser from January 2020 to December 2021. We collected demographic and outcome data from electronic records. The primary outcome was rates of complications, this included seromas, haematomas, pain and re-excisions. Secondary outcomes included operative time. Result(s): 21 WGL and 16 LOCaliser patients were identified. The average age was similar between the two groups (62 vs 61;P=0.291). There were fewer complications in the LOCaliser group, however without statistical significance (1 vs 5;P=0.206). The LOCaliser group had less re-excisions (1 vs 5;P=0.206), with 3 of 5 patients requiring 2 margins to be re-excised in the WGL group. There was no difference in the operative time between the two groups (107 minutes vs 104 minutes;P=0.070), sub-group analysis was not done to compare axillary node clearances and sentinel lymph node biopsies. Conclusion(s): LOCaliser is as effective if not superior to WGL when measuring clinical outcomes. The data did not demonstrate statistical significance, however demonstrated differences which could become significant with larger patient cohorts. LOCaliser prevented the need for pre-operative procedures, which was particularly important during the COVID-19 pandemic as it reduced patient exposure and hospital attendances prior to surgery. A larger scale audit and assessing patients' experiences by collection patient reported outcomes measures (PROM) would be beneficial. Copyright © 2022

Morphological and metabolic criteria of COVID-19 vaccine associated axillary nodes on 18FDG PET/CT in patients with breast cancer

Aim/Introduction: In the current era vaccine-associated lymphadenopathy (VAL) is not an uncommon presentation on 18F-FDG PET/CT examinations in patients inoculated with Coronavirus disease 2019 (COVID-19) vaccination. In this study, we are presenting data of VAL on 18F-FDG PET/CT regarding its prevalence, temporal response to vaccination and imaging characteristics of VAL. Material(s) and Method(s): Seventy-eight (78) consecutive vaccinated patients with biopsy proven breast cancer who had 18FDG PET/CT for staging or response evaluation were retrospectively analyzed. All patients had COVID-19 vaccine shots in contralateral arms and none in breast cancer site axilla (BSA). In 35 patients 18FDG avid nodes were found in vaccine site axilla (VSA). Morphological criteria on CT images like size, presence of fatty hila and fat stranding of axillary nodes were analyzed. Metabolic criteria on PET images like maximum standardized uptake value (SUVmax) of positive axillary nodes and liver as reference were also measured. Result(s): Out of 78 patients, 35 patients had positive nodes in vaccinated axilla (45% prevalence) and 25/78 had breast cancer axilla (33% prevalence). Mean duration of COVID-19 vaccination in each group was 8 +/-04 week (non-significant p-value). On CT images, 18FDG avid nodes in VSA were significantly smaller (10 +/- 03 mm) and with intact fatty hila without fat stranding than nodes in BSA with loss of fatty hila (25 +/-10 mm;p <0.0001). Mean SUVmax of nodes in VSA was significantly lower (2.4 +/-1.1) than nodes in BSA (10.2 +/-5.5 - p-value <0.0001). Nodes in VSA showed a significant positive linear correlation between size and SUVmax (p-value 0.00001). Similarly, nodes in VSA showed a significant negative linear correlation between duration and SUVmax (p-value 0.00003). In VSA group, 03 patients having SUVmax >2 SD of Hepatic SUVmax were subjected to ultrasound guided fine needle aspiration (FNA) and turned out to be metastatic in nature. Conclusion(s): In COVID-19 vaccinated patients with BC, enhanced 18FDG uptake on PET/CT by axillary nodes in VSA is quite common and may pose diagnostic dilemma. However, morphological (size < 10 mm, intact fatty hila without fat stranding) and metabolic criteria (SUVmax <2.4 with negative correlation with time of inoculation) have higher diagnostic accuracy in resolving the dilemma. Nodes in VSA having SUVmax > 2 SD of hepatic SUVmax should be considered for FNA to rule out possible metastasis.

PSMA PET/CT Detected Prostate Cancer Metastasis in a Patient with Negative mpMRI and Prostate Gland Biopsy

Aim/Introduction: This is a case of [68 Ga]Ga-Prostate-specific membrane antigen(PSMA)-11 PET/CT in a 73-years old patient with significantly high iPSA level despite both multiparametric magnetic resonance imaging (mpMRI) and 12-core saturation biopsy negative for prostate cancer (Pca). Material(s) and Method(s): In November 2021 the patient underwent a routinary abdomen ultrasound with the detection of several pelvic and retro-peritoneal adenomegalies, confirmed by diagnostic CT. Initially the suspect of Pca origin was raised, due to high PSA levels (55 ng/dl versus 2.1ng/dl the previous year). A 12-samples saturation biopsy was then performed, with inconclusive result. Nevertheless, due to further increase in PSA level up to 77ng/dl in December (PSA doubling time approximately 4 months), a mpMRI was performed in January showing absence of clinically significant PCa (PIRADS 2) and persistence of enlarged pelvic lymph nodes. The patient was subsequently referred for a [68Ga]Ga-PSMA-PET/CT, which was performed and reported following standard EANM guidelines. A delayed 90 min scan on the pelvis was also acquired. Result(s): In accordance with previous mpMRI, PSMA-PET/CT detected no significant nor focal uptake within the prostate gland even at delayed acquisition (diffuse pattern, SUVmax 3.6). Interestingly, multiple PSMA-avid pelvic and retroperitoneal lymphadenopathies were detected (SUVmax 34) as well as a single, intense focal bone lesion at L3 vertebral body (SUVmax 14, corresponding with initial focal osteoblastic lesion at low-dose CT images-LDCT), and a single focal uptake in a left axillary lymph-node (SUVmax 19). Of note, the latter lymph-node was homolateral to the injection site of recent anti-SARS-Cov2 vaccination and without clearly pathological pattern on LDCT. However, due to its high PSMA expression, it was chosen for ultrasound-guided biopsy and finally diagnosed as Pca metastasis. Conclusion(s): Several malignancies can present with subdiaphragmatic nodal findings, but this is a highly interesting case as, despite the advanced metastatic spread at initial presentation, the primary Pca was detected by none of the diagnostic techniques. The importance of [68Ga]Ga-PSMA-PET/ CT was to rapidly pave the way to reach the final diagnosis by selecting the unusual axillary lesion with elevated PSMA expression as the target biopsy for a mini-invasive approach optimizing patient management;in addition, it was able to detect a single PSMA avid sclerotic lesion typical for initial bone spread of PCa.

The Impact of different COVID-19 vaccines in 18F-FDG PET/CT

Aim/Introduction: Austria started its COVID-19-vaccination program in December 2020 with three different vaccines. As the vaccination program continues, we encountered increased F-18- FDG-activity not only in axillary lymph nodes ipsilateral to the injection site but also in other organs. The aim of this retrospective study is to present results of the metabolic activity of ipsilateral axillary lymph nodes, liver, blood pool, spleen, and bone marrow after three different vaccines. Material(s) and Method(s): The data of 220 eligible vaccinated patients (127 with BioNTech/Pfizer, 61 with Moderna, and 32 with AstraZeneca) examined with F18-FDG-PET/ CT were enrolled. The PET/CT examinations were evaluated from day 1 to day 120 (SD: 23.2, Median: 26) after different vaccinations. Seventy out of these 220 patients were at least once examined with F18-FDG-PET/CT before vacciantion. SUVmax of axillary node(s), and blood pool, liver, spleen, and bone marrow as reference organs were calculated. Relation of SUVmax activity of axillary lymph node to reference organs was also compared in all patients. Result(s): Ten days after BioNTech/Pfizer and AstraZeneca vaccination the axillary FDG uptake was at its highest activity. This was with Moderna vaccination after 30 days. There was no significant statistical difference of SUVmax of lymph nodes or its ratios to other reference organs between three groups of vaccines. SUVmax in lymph nodes in relation to SUVmax in the liver, spleen, and bone marrow was statistically significant with p-values of <.001, 0.044, and 0.001, respectively. In the group of 70 patients with a pre-vaccination PET/CT examination, the SUVmax of lymph nodes (median: 0.820, standard deviation 1.233) changed significantly after vaccination (p <.001). A significant change of tracer activity in the liver was also observed (p = 0.032). There was no significant change of tracer activity after vaccination in other reference regions or between different types of vaccines. Conclusion(s): Local site and ipsilateral axillary lymph node activity in F18-FDG PET/CT after COVID19-vaccination is suggested in many studies. The main challenge is recognizing the changes in lymph nodes after vaccination to minimize false interpretation, foremost in patients with oncological diagnoses. Moreover, different vaccines cause different system metabolic changes. The knowledge of vaccine type, the time interval between vaccination and PET/CT scan is essential, especially in therapy evaluation.

New perspectives obtained during the COVID 19 pandemic: the importance of an adequate directed structured clinical interview prior to [18]FDG-PET/CT in cancer patients

Aim/Introduction: During the COVID 19 pandemic, mass vaccination campaign has played an important role, with a special importance in oncological and immunosuppressed patients, who form a large part of our [18F]FDG-PET/CT studies. Unexpected findings in the form of reactive lymphadenopathy were commonly detected in [18F]FDG-PET/CT studies. It is essential to recognize them and adapt their interpretation to the current epidemiological context. Material(s) and Method(s): Retrospective study of consecutive [18F] FDG-PET/CT studies performed at our center in 219 patients with oncological pathology from June 15 to September 20, 2021. A structured interview was conducted on all the patients who came to undergo [18F]FDG-PET/CT, in which they were asked about the type, date and arm of administration of the vaccine. The frequency of appearance of reactive lymphadenopathy, its relationship with the type of vaccine, sex, age and the importance of a detailed clinical interview prior to the isotope injection and/ or study interpretation were analyzed. Patients that presented ipsilateral axillary lymphadenopathies following vaccination and presented increased metabolic activity regardless of node size were considered positive, size and SUVmax were assessed. Result(s): From De 219 patients reviewed, 32% presented positive [18F]FDG-PET/CT axillary lymph nodes ipsilateral to the arm where the vaccine was inoculated. There was a relationship (p=0.01) between the mean size of the lymph nodes (11+/-9mm) and its mean metabolic activity (3.7+/-2.6 SUVmax). The appearance of lymphadenopathy was more frequent in women (40.5% vs 21% p<0.001), in younger patients (mean age 53+/-14 years vs 68.5+/-13 years p<0.001), in patients who had received the Moderna vaccine (58.5% p<0.001) and in which the time elapsed between vaccination and the performance of [18F]FDG-PET/CT was shorter. Conclusion(s): The appearance of post SARS-CoV2-vaccination reactive lymphadenopathies has been a frequent finding in [18F]FDG-PET/CT despite the main oncological indication of the study. Knowing the circumstances of these findings in oncological patients is important when interpreting them, so the use of a structured directed clinical interview has been very useful to help the physician understand and differentiate these findings.

FDG-avid lymph nodes (LN) in response to vaccines for SARS-CoV-2

Aim/Introduction: Vaccines against SARS-CoV-2 virus were developed due to the impetuous coronavirus pandemic. Vaccines hold a possibility to provoke side effects. The aim of our study was to examine the impact of COVID-19 vaccination on the incidence and duration of false-positive FDG-avid lymphadenopathy after vaccination with different types of vaccines and to determine its relationship with age, gender, and vaccine type. Material(s) and Method(s): The retrospective study included 103 patients who met the following criteria:18F-FDG PET/CT scan performed (in the period from August 2021 to December 2021) for staging or restaging of diagnosed oncological diseases at different time periods after vaccination Pfizer-BioNTech, Moderna-BioNTech and Oxford-AstraZeneca. Exclusion criteria were incomplete information about vaccination, patients with a diagnosed malignant lymphoproliferative disease, concomitant benign pathology of the lymphatic system, history of acute viral infection up to 3 months from the date of PET/CT. Result(s): False-positive reactive lymphadenopathy was identified in 35 (34%) of 103 patients included in our study cohort, which occurred during the first 2 weeks to 12 weeks after vaccination and manifested as increased metabolic activity in regional non-enlarged lymph nodes: ipsilateral axillary lymph nodes of levels I-III, as well as cervical LN of levels IV and VB). A significant moderate decline in metabolic activity in the LN over time was reported, as well as a decrease in the detection rate of PET-positive reactive findings with time. The results showed a trend of a positive relationship - the occurrence of reactive lymphadenopathy more often in women than in men. The detection rate, as well as the intensity of the activity of glucose metabolism, were higher in patients under the age of 50 compared to those >= 50 years. However, we did not find significant differences between the studied types of vaccines (p >0.05). Conclusion(s): Multidisciplinary physician awareness is essential regarding the possibility of false-positive FDG lymphadenopathy in relation to local inflammation and as a manifestation of the immune response due to COVID-19 RNA vaccination and adenoviral vector-based vaccine up to 12 weeks after injection, in order to optimize the clinical interpretation of hybrid scan results that determine the subsequent therapeutic approach of cancer patients. The results of the present study demonstrate the importance of vaccination on the contralateral side of the tumor drainage, as well as taking a thorough anamnesis. Keywords: FDG PET/CT, false positive lymphadenopathy, vaccination.

PET after COVID19 vaccination: influence of patient characteristics, vaccine types and radiotracers in the lymph node uptake

Aim/Introduction: The aim of the study was to assess the presence of lymph node uptake (LNU) in patients who had received a COVID-19 vaccine and to evaluate its association with patient characteristics, type of vaccines, and PET/CT radiotracers. Material(s) and Method(s): 361 patients who underwent a PET/CT scan with 18F-FDG (FDG), 68Ga-PSMA (PSMA), or 11C-Choline (CHOL) performed in two EARL PET/CT accredited centers, from May to July 2021, and who had received single or double dose of COVID-19 vaccine (mRNA-based and viral-vector) were selected. Data from age, tumor histology, type of vaccine, location of LNU and time from vaccination (time- Vacc) were prospectively collected. A retrospective analysis of scans was conducted evaluating the presence/absence of LNU (chisquare test). Additionally we performed a semiquantitative analysis (SUVmax of LNU), to explore possible differences according to type and number of vaccination doses, time-Vacc, patient age and tumor hystologies (independent t-tests). Result(s): From the 361 eligible subjects (median age: 67 years), 319 (88%) underwent PET/CT with FDG, 23 (6.3%) with PSMA, 19 (5,2%) with CHOL. 296 (82%) subjects received mRNA-based vaccine, 62 (17%) viral-vector (V-V) and 3 (1%) received mixed vaccines. Positive LNU was seen in 203 subjects (56.2%) independently of vaccine types (mRNA=59.68, V-V=55.7, p=0.74) and number of doses (1 dose: V-V=56.76%, mRNA=58.62 p=0.83;2 doses: mRNA=55%). Similar frequency of LNU positivity was observed using FDG and CHOL (57.6% and 57.8%, respectively), while with PSMA only 34.8% showed LNU positivity. LNU limited to ipsilateral axillar region was the most frequent location (global: 70.44%;FDG:69.6%;CHOL:63.6%;PSMA:100%), followed by both ipsilateral axillar and retropectoral region (global: 18.72%;CHOL: 36.4%). Positive LNU was less frequent in older patients (p=0.007), and ranged between 40 to 68% among the neoplastic pathologies, with the exception of multiple myeloma (15.8%;p=0.001). Positive LNU appeared in most cases in the first week post-vaccination (82%), persisted in second and third week (68.49%, 62.64%), and decreased after the fourth week (38.8%). Moreover, an inverse correlation between the time-Vacc and the SUVmax value calculated in the LNU using FDG (2.82 +/- 1.44;p=0.008) was observed. Conclusion(s): Patients referred to a FDG or CHOL PET scan due to diverse neoplastic diseases displayed high percentage of axillar LNU one week after COVID-19 vaccination, independently of vaccine type and number of doses. Our results also suggest a lower percentage of positive LNU in older subjects, patients with multiple myeloma, and when using PSMA-PET.

Axillary Treatment Management in Breast Cancer during COVID-19 Pandemic (Association between ACOSOG Z0011 Criteria and OSNA Test).

The outbreak of the SARS-COVID-2 pandemic (COVID-19) had a significant effect on the organisation of healthcare systems. Surgical units saw a significant reduction in the volume of surgical procedures performed, with lengthening waiting lists as a consequence. We assessed the surgical activity in relation to breast cancer that took place at the University Hospital of Cagliari, Italy, from February 2018 to March 2022. Two phases were identified based on the epidemiological circumstances: Phase 1-February 2018 to February 2020; Phase 2-March 2020 to March 2022. The surgery performed in the two phases was then compared. All the patients in our sample underwent a breast surgical procedure involving a lymph node biopsy using OSNA associated with the ACOSOG Z0011 criteria. In the study period overall at our facility, there were 4214 procedures, 417 of which involved breast surgery. In Phase 2, 91 procedures were performed using the OSNA method and ACOSOG Z0011 criteria, enabling the intraoperative staging of axillary nodes. Axillary treatment in breast cancer using this approach resulted in a significant reduction in the number of reoperations for the radicalisation of metastatic sentinel lymph nodes.