David Wong

Background: Sarcoidosis is a multisystem granulomatous disease that commonly affects the lungs and intrathoracic lymph nodes. On imaging, characteristic patterns of lymphadenopathy, such as the lambda sign on fluorodeoxyglucose positron emission tomography (FDG PET), are considered suggestive of the disease and can assist in differentiating sarcoidosis from differential diagnoses. FDG PET/CT is increasingly used to assess disease extent, identify extrapulmonary involvement, guide biopsy and monitor inflammatory activity. The prevalence and imaging characteristics of the lambda sign and periportal/portocaval lymphadenopathy, termed the 1–2–3‐4 sign on FDG PET/CT in sarcoidosis, remain poorly defined. Methods: A retrospective cohort study was performed of patients with sarcoidosis who underwent FDG PET/CT imaging at a tertiary centre in 2019. PET studies were assessed for the presence of the lambda sign and for FDG‐avid periportal and/or portocaval lymph nodes. The frequency of the lambda and 1–2–3‐4 sign, nodal distribution, and metabolic activity were analysed, including maximum standardised uptake values (SUVmax). Results: The lambda sign was identified in a substantial proportion of patients. FDG‐avid periportal and/or portocaval lymph nodes were observed in a subset of cases, although only one patient demonstrated the complete 1–2–3‐4 sign. Periportal and portocaval nodes showed FDG uptake comparable to intrathoracic nodal disease. Conclusion: FDG‐avid periportal and portocaval lymphadenopathy may occur alongside classic intrathoracic nodal patterns in sarcoidosis, although the complete 1–2–3‐4 sign appears uncommon. Recognition of this imaging pattern on FDG PET/CT may support diagnostic confidence in appropriate clinical contexts and help differentiate sarcoidosis from alternative causes of mediastinal and abdominal lymphadenopathy.

Purpose: To evaluate the feasibility of ⁶⁸ Ga‐FAPI PET/CT in pancreatic cancer by comparing radiotracer uptake, lesion detection, and diagnostic value with ¹⁸ F‐FDG PET/CT. Methods: Ten participants (seven male, three female; mean age 68 years) with suspected or confirmed pancreatic cancer underwent both ⁶⁸ Ga‐FAPI and ¹⁸ F‐FDG PET/CT. Imaging was assessed for uptake, lesion detection, and diagnostic usefulness as determined by clinicians. Results: Ten participants (seven male, three female; mean age 68 years) underwent imaging. Mean SUVmax of the primary lesion was higher for ⁶⁸ Ga‐FAPI compared with ¹⁸ F‐FDG in participants with an identifiable primary lesion ( n = 9) (13.8 [range 6.2–19.6] vs. 7.0 [range 0.0–12.5]). ⁶⁸ Ga‐FAPI identified additional lesions in three participants, resulting in imaging‐based upstaging in three cases. Clinicians considered FAPI more diagnostically useful in five participants and equivalent in the remainder, based on comparison of lesion detection, delineation, and staging impact. Increased uptake was also seen in areas of presumed inflammation. No adverse events were reported. Conclusions: This feasibility study shows that ⁶⁸ Ga‐FAPI PET/CT is safe, demonstrates higher uptake than FDG, and can reveal additional lesions that influence staging. Imaging‐based upstaging was observed in three participants, supporting further investigation of FAPI as a complementary tool in pancreatic cancer imaging. Larger prospective studies are needed to determine the clinical impact of ⁶⁸ Ga‐FAPI PET/CT in pancreatic cancer.

Intracranial synovial sarcoma is exceedingly rare, with only 24 cases reported in the literature. Given prostate specific membrane antigen (PSMA) expression is found in the neovascular endothelium of solid tumours, including sarcomas, Lutetium‐177‐PSMA (LuPSMA) presents a potential therapeutic option. The case presented here describes the first application of LuPSMA in a patient with synovial sarcoma. Our patient, a 27‐year‐old female underwent seven LuPSMA treatment cycles over the last 8 months of her life. Disease stability and prolongation in time to progression was observed across the treatment course with subjective tumour regression also seen after two cycles. Overall, our initial experience with this novel approach demonstrates proof‐of‐principle of LuPSMA treatment beyond prostate cancer, for patients with other PSMA‐expressing cancer diseases.

Background: In the area of oncology, molecular imaging techniques are becoming increasingly utilised. In neuro‐oncology imaging, ¹⁸Fluoro‐O‐(2) fluoroethyl‐L‐tyrosine (¹⁸F‐FET) is one of the molecular tracers used in positron‐emission tomography (PET). Here, we investigated the correlation between maximum standard uptake value (SUV) of ¹⁸F‐FET PET and histologically determined World Health Organization (WHO) grade in glioma.Patients and Methods: This was a retrospective review of all ¹⁸F‐FET PET studies conducted between August 2014 and August 2019. Review was conducted to identify imaging studies performed on patients who had a glioma with histopathology results from surgical resection or biopsy available.Results: A total of 31 ¹⁸F‐FET PET studies of histologically confirmed glioma were included. WHO grades ranged from II‐IV. A positive correlation between maximum SUV uptake on ¹⁸F‐FET PET and WHO grade was observed.Conclusions: There was a correlation identified between WHO glioma grade and maximum SUV on ¹⁸F‐FET PET. Further studies are recommended to explore this relationship.

Introduction: Radioligand therapies, or ‘theranostics’, have an emerging role in patients with metastatic castration‐resistant prostate cancer (mCRPC). Lutetium‐177 (Lu), targeting prostate‐specific membrane antigen (PSMA), has demonstrated promising outcomes including reduced disease progression and improved overall survival. We aim to determine overall survival demonstrated by our LuPSMA patient cohort to date.Methods: Kaplan–Meier survival analysis and log‐rank test were performed on all LuPSMA therapy patients with at least 12 months of follow‐up data available (n = 68). Comparison across patients was made based on several variables including the baseline characteristics of prostate‐specific antigen (PSA) level, maximum standard uptake value (SUV_max) and metastasis site and by biochemical response.Results: The 18‐month overall survival estimate for the patient cohort was 63.8%. Patients with baseline serum PSA P < 0.05). Patients with an SUV_max >15 had an 18‐month survival estimate of 56.0%, compared to 38.0% in patients with SUV_max ≤15 (P < 0.05). No significant difference in overall survival was observed by metastasis site. Both a decrease in PSA after two LuPSMA therapy cycles and the maximum response over the treatment course being a decline in PSA were indicative of greater overall survival (P < 0.01 and P < 0.001 respectively).Conclusion: Our study reported an 18‐month overall survival of 64% in patients with mCRPC who have undergone LuPSMA therapy. Our study identified that baseline serum PSA, SUV_max and biochemical response to treatment are prognostic markers for increased overall survival.

Background: Prostate cancer commonly metastasises to bone and regional lymphatics and more rarely to locations such as the brain, skin and penis. Gallium‐68 prostate‐specific membrane antigen (⁶⁸Ga‐PSMA) positron emission tomography/computed tomography (PET/CT) has widely become the routine imaging modality for prostate cancer staging and re‐staging in Australia. The aim of this study was to retrospectively review all ⁶⁸Ga‐PSMA PET/CT examinations performed to date at our institution to determine the frequency of penile metastases.Methods: A total of 4860 ⁶⁸Ga‐PSMA PET/CT examinations were performed between 16/07/2014 and 31/10/2019. Radiology reports for each examination were filtered to identify those with the words ‘penis’ or ‘penile’. Once identified, relevant reports and images were individually reviewed to confirm the presence of a PSMA‐avid penile lesion.Results: The incidence of penile metastasis of prostate cancer observed in this study was 0.1% with six examinations identified as having PSMA‐avid penile lesions in five prostate cancer patients (age range: 71–88 years). The patients had a 1–8 year history of prostate cancer with varying severity of disease. Appearance of PSMA‐avidity varied between single focal lesion, multiple focal lesions and diffuse lesion.Conclusions: An incidence of 0.1% in our study confirms the rarity of penile metastases of prostate cancer. Although rare, identification of prostate cancer penile metastases is important for appropriate treatment management and symptom‐relief.

Background: Acute pulmonary embolism (PE) is characterized hemodynamically by abrupt obstruction in trans-pulmonary blood flow. The echocardiographic Pulmonary to Left Atrial ratio (ePLAR, tricuspid regurgitation V_max/mitral E/e’) has been validated as a non-invasive surrogate for trans-pulmonary gradient (TPG) that accurately differentiates pre-capillary from post-capillary chronic pulmonary hypertension. This study assessed ePLAR as an incremental echocardiographic assessment tool compared with traditional measures of right ventricular pressure and function. Methods: In total, 110 (57.4 ± 17.6 years) patients with confirmed sub-massive pulmonary emboli with contemporaneous echocardiograms (0.3 ± 0.9 days) were compared with 110 age-matched controls (AMC). Results: Tricuspid velocities were higher than AMC (2.6 ± 0.6 m/s vs. 2.4 ± 0.3 m/s, p < 0.05), although still consistent with “normal” right ventricular systolic pressures (34.2 ± 13.5 mmHg vs. 25 ± 5.3 mmHg, p < 0.05) with lower mitral E/e’ values (8.2 ± 3.8 vs. 10.8 ± 5.1, p < 0.05). ePLAR values were higher than AMC (0.36 ± 0.14 m/s vs. 0.26 ± 0.10, p < 0.05) suggesting significantly elevated TPG. Detection of abnormal echocardiographic findings increased from 29% (TRV_max ≥ 2.9 m/s) and 32% (reduced tricuspid annular plane systolic excursion) to 70% with ePLAR ≥ 0.3 m/s. Conclusions: Raised ePLAR values in acute sub-massive pulmonary embolism suggest elevated trans-pulmonary gradients even in the absence of acutely increased pulmonary artery pressures. ePLAR dramatically increases the sensitivity of echocardiography for detection of hemodynamic perturbations in sub-massive pulmonary embolism patients, which may offer clinical utility in diagnosis and management.

Introduction: Lutetium‐177‐PSMA (LuPSMA) is a targeted systemic radioligand treatment for metastatic castration‐resistant prostate cancer (mCRPC). LuPSMA is considered as an experimental treatment not yet used in routine practice. Here, we report our experience following the introduction of LuPSMA therapy at our institution.Methods: Referred mCRPC patients were assessed for treatment suitability including Gallium‐68‐PSMA PET/CT and blood tests. Suitable patients underwent up to four cycles of LuPSMA treatment. Response to treatment was assessed by changes in serum prostate‐specific antigen (PSA) levels. Toxicity was assessed by recording of adverse events.Results: In an 18 month period, 50 patients underwent 132 cycles of LuPSMA therapy. Patients underwent a median of three cycles each (range: 1–4) and the mean administered amount of activity per cycle was 5.9 GBq (range: 3.5–8.2 GBq). PSA decline could be calculated for 49 patients, with a best PSA decline of ≥ 50% observed in 22 patients (44.9%). Adverse events were reported across 45 of 132 LuPSMA cycles. Most adverse events were grade I (42/45) and the remaining three events were grade II.Conclusion: Initial experience at our site supports the use of LuPSMA as an emerging safe and effective treatment for mCRPC. Since introducing LuPSMA therapy at our institution, 44.9% of patients have experienced a decline in PSA level ≥ 50% with low or minimal toxicity. This is an important finding as these patients had previously exhausted all available treatment options. Overall, we have found patients and their primary care doctors have eagerly accepted LuPSMA as another line of defence against mCRPC.