A bicentric retrospective study of the correlation of EAU BCR risk groups with 18F-PSMA-1007 PET/CT detection in prostate cancer biochemical recurrence.

The European Association of Urology (EAU) has proposed a risk stratification for patients harboring biochemical recurrence (BCR) after radical prostatectomy: ISUP < 4 and PSA doubling time (PSAdt) > 12 months for low risk, and ISUP ≥ 4 or PSAdt ≤ 12 months for high risk. This dual-center retrospective study aims to investigate the correlation between the EAU risk stratification for BCR following radical prostatectomy and the detection rate of lesions using 18F-PSMA-1007 PET/CT. Among the 71 included patients (58 high-risk, 13 low-risk), with a median PSA level of 1.43 ng/ml, PET/CT demonstrated a significantly higher positivity in the high-risk group compared to the low-risk group (72.4% vs. 38.0%, p = 0.026). Analysis of recurrence sites revealed a similar proportion of pelvic-confined disease in both groups (24.1% vs. 23.1%, p = 0.935), but a significantly higher incidence of metastatic disease in the high-risk group (51.7% vs. 15.4%, p = 0.017), with detailed findings indicating an increased prevalence of bone metastases in the high-risk BCR group (37.8% vs. 7.7%, p = 0.048). Therefore, PSMA PET/CT offers valuable insights for treatment decisions, aligning with the evolving landscape of prostate cancer management.

A Hangover Under 177 Lu-PSMA-617 Therapy : A Red Flag for Brain 68 Ga-PSMA-11 PET/MRI?

ABSTRACT: Leptomeningeal carcinomatosis in prostate cancer is extremely rare. Because of the low overall penetration of drugs into the brain and the prolonged survival of castration-resistant prostate cancer (CRPC) patients, a special attention should be paid to the appearance of neurological symptoms in long-term CRPC survivors. A patient suffering from a CRPC with bone metastases underwent 4 cycles of 177 Lu-PSMA (prostate-specific membrane antigen)-617. Starting from the third cycle, he reported an increasing feeling of a permanent hangover. A 68 Ga-PSMA-11 brain PET/MRI was carried out after the fourth cycle. It revealed intraparenchymatous brain metastases with intense uptake and evidences of leptomeningeal carcinomatosis.

Nuclear medicine imaging for bone metastases assessment: what else besides bone scintigraphy in the era of personalized medicine?

Accurate detection and reliable assessment of therapeutic responses in bone metastases are imperative for guiding treatment decisions, preserving quality of life, and ultimately enhancing overall survival. Nuclear imaging has historically played a pivotal role in this realm, offering a diverse range of radiotracers and imaging modalities. While the conventional bone scan using 99mTc marked bisphosphonates has remained widely utilized, its diagnostic performance is hindered by certain limitations. Positron emission tomography, particularly when coupled with computed tomography, provides improved spatial resolution and diagnostic performance with various pathology-specific radiotracers. This review aims to evaluate the performance of different nuclear imaging modalities in clinical practice for detecting and monitoring the therapeutic responses in bone metastases of diverse origins, addressing their limitations and implications for image interpretation.

Impact of pelvic dynamic acquisition on final reading of 18 F-Fluorocholine positron emission tomography in patients with prostate adenocarcinoma: True need or unnecessary burden?

INTRODUCTION: Despite the increasing use of 18 F-fluorocholine (18 F-FCH) positron emission tomography (PET) in patients with prostate cancer, the acquisition protocol remains debated. We have evaluated the influence of the pelvic dynamic phase on the final reading of whole-body 18 F-FCH PET, to assess the need for a two-stage protocol. Reading the physician's experience and patient's previous treatment profile was also considered as potential influencing factors on final PET interpretation. METHODS: All 18 F-FCH PET/CT performed from January 2018 to September 2019 in patients with prostate cancer and including a pelvic dynamic phase followed by a delayed whole-body acquisition were retrospectively retrieved. PET/CT were analysed by one expert nuclear medicine physician and one resident. The whole-body scan was analysed blinded (first reading) and nonblinded from the results of the dynamic phase. RESULTS: 221 consecutive PET/CT were selected from 201 patients previously treated by radical prostatectomy (n = 31), pelvic radiation therapy (n = 60), or both (n = 94). 24 patients had no previous treatments, and 12 benefited from other focal treatments. In the whole population, dynamic acquisition modified final interpretation of 32/221 scans (14.5%) for residents, 26 (11.8%) for experts and 19 (8.6%) for consensual reading. No influence of previous treatments was found. The availability of a dynamic phase would have been responsible for treatment modification in 5/221 scans (2.3%). Considering only the prostate bed, dynamic acquisition modified the final interpretation in 7/125 (5.6%) studies (consensual reading) from patients with previous prostatic surgery and 4/84 (4.8%) scans from patients without a history of prostatic surgical intervention. No significant influence of dynamic acquisition was found on the final PET interpretation on prostate lodge accordingly to previous prostatic surgery. CONCLUSION: The dynamic phase changes the interpretation of 18 F-FCH PET in about 9% of cases and the therapeutic strategy in <3% of patients. The influence of the early phase reduces with physician experience. Patient's treatment profile does not appear to have a significant influence on the variability of interpretation, also including the prostate bed.

High risk of recurrence for grade II meningioma: a 10-year multicenter analysis of prognosis factors.

BACKGROUND: Atypical meningioma is a variant of meningioma with a high risk of recurrence. Gross total resection is the standard of treatment, while no consensus on optimal adjuvant management has been found. METHODS: Between 2008 and 2018, a retrospective search identified 216 grade II meningiomas treated in six centers. Clinical, histological, and therapeutic data were analyzed to determine the prognostic factors of recurrence and survival. RESULTS: In total, 216 patients underwent surgical resection. Among these, 122 patients (56%) underwent gross total resection, and 21% of the patients received adjuvant radiotherapy. Univariate analysis reported subtotal resection, high Ki-67, negative progesterone receptor (PR) and histological grade evolution as unfavorable prognosis factors. According to multivariate analysis, the Ki-67 proliferative index (cut-off value of 17.5%) was the only prognostic factor of recurrence (HR 1.1; 95% CI, 1.0-1.2, P=0.048). Gross total resection improved progression-free survival (PFS) (P=0.03) but without impact on overall survival (OS) (P=0.2). Median PFS and OS times were longer for patients receiving adjuvant radiotherapy than those who did not receive adjuvant radiotherapy. PFS (P=0.3) and OS (P=0.7) were associated with adjuvant RT by trend only. After a median follow-up time of 6.7 years, 99 (46%) patients relapsed. Median progression-free and OS rates were 4.5 (95% CI, 3.5-5.5) and 14.7 years (11.4-NA), respectively. CONCLUSIONS: In this study, Ki-67 proliferative index was significantly associated with recurrence. Gross total resection significantly improved PFS without impacting OS. Adjuvant radiotherapy delayed recurrence and improved OS, but a longer follow-up time is needed to distinguish a statistically significant difference. Large prospective studies are needed to determine postoperative treatment guidelines.

18F-FDG PET/CT Monitoring of Tumor Response to Tyrosine Kinase Inhibitors and Alkylating Drugs in an SDH-Deficient GIST.

ABSTRACT: Succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumors (GISTs) are associated with loss of function of SDH complex and represent 5% to 7.5% of GISTs. SDH-deficient GISTs usually develop in the stomach of children and young adults, and could be part of Carney triad or Carney-Stratakis syndromes including paraganglioma. SDH-deficient GISTs are often indolent despite the high rate of distant metastasis, and overall unresponsive to tyrosine kinase inhibitors. However, epigenetic inactivation of MGMT leads to potential effectiveness of alkylating agents. We report the 18F-FDG PET/CT results for monitoring response to TKI and alkylating drugs in a patient with refractory SDHB-deficient GIST.

Usefulness of 18F-FDOPA PET for the management of primary brain tumors: a systematic review of the literature.

Contrast-enhanced magnetic resonance imaging is currently the standard of care in the management of primary brain tumors, although certain limitations remain. Metabolic imaging has proven useful for an increasing number of indications in oncology over the past few years, most particularly 18F-FDG PET/CT. In neuro-oncology, 18F-FDG was insufficient to clearly evaluate brain tumors. Amino-acid radiotracers such as 18F-FDOPA were then evaluated in the management of brain diseases, notably tumoral diseases. Even though European guidelines on the use of amino-acid PET in gliomas have been published, it is crucial that future studies standardize acquisition and interpretation parameters. The aim of this article was to systematically review the potential effect of this metabolic imaging technique in numerous steps of the disease: primary and recurrence diagnosis, grading, local and systemic treatment assessment, and prognosis. A total of 41 articles were included and analyzed in this review. It appears that 18F-FDOPA PET holds promise as an effective additional tool in the management of gliomas. More consistent prospective studies are still needed.

Solid pseudopapillary tumour should be part of differential diagnosis of focal pancreatic lesions with increased 18 F-FDOPA uptake.

OBJECTIVE: To assess the specificity of increased 18 F-dihydroxyphenylalanine (18 F-FDOPA) uptake in patients who underwent PET/CT for suspicion of isolated pancreatic neuroendocrine tumour (pNET). False-positive results mimicking a pNET have been investigated. MATERIAL AND METHODS: Carbidopa-assisted 18 F-FDOPA PET/CT scans performed in patients with suspicion of localized pNET were retrieved. Only patients with a definitive diagnosis were retrospectively included. When available, the histopathological result after pancreatic surgery was the gold standard. In other cases, the diagnosis was based on endoscopic ultrasonography (EUS)/cytology and/or on concordant imaging results of at least two of the following: contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI) and somatostatin receptor scintigraphy (SRS). RESULTS: Forty-four among 731 patients were selected. Among these, 36 patients (82%) were surgically treated, revealing pNET (n = 28), solid pseudopapillary tumour (SPT) (n = 4), adenocarcinoma (n = 2), serous cystadenomas (n = 1) and solitary fibrous tumour (n = 1) cases. An additional three cases of pNET were diagnosed by EUS/cytology. In the remaining five patients, a consensus was reached on follow-up imaging results: pNET (n = 1), serous cystadenoma (n = 2) and undetermined/no pNET (n = 2). Both specificity and negative predictive value of 18 F-FDOPA PET/CT for localized pNET were 67%. Surprisingly, all four false-positive results were SPTs showing intense 18 F-FDOPA uptake and negative SRS. There was no significant difference in 18 F-FDOPA uptake intensity between PET-positive pNETs and SPTs. CONCLUSION: 18 F-FDOPA PET/CT is not specific for pNET in patients with localized pancreatic lesions. SPT could mimic pNET and should be part of differential diagnosis in such a clinical situation. If these results are confirmed in a broader population, the imaging pattern 18 F-FDOPA PET-positive/SRS-negative lesions might be considered as the imaging phenotype of SPT.

Metabolomic Profile of Aggressive Meningiomas by Using High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

Meningiomas are in most cases benign brain tumors. The WHO 2016 classification defines three grades of meningiomas. This classification had a prognosis value because grade III meningiomas have a worse prognosis value compared to grades I and II meningiomas. However, some benign or atypical meningiomas can have a clinical aggressive behavior. There are currently no reliable markers which allow distinguishing between the meningiomas with a good prognosis and those which may recur. High-resolution magic angle spinning (HRMAS) spectrometry is a noninvasive method able to determine the metabolite profile of a tissue sample. We retrospectively analyzed 62 meningioma samples by using HRMAS spectrometry (43 metabolites). We described a metabolic profile defined by a high concentration for acetate, threonine, N-acetyl-lysine, hydroxybutyrate, myoinositol, ascorbate, scylloinositol, and total choline and a low concentration for aspartate, glucose, isoleucine, valine, adenosine, arginine, and alanine. This metabolomic signature was associated with poor prognosis histological markers [Ki-67 ≥ 40%, high histological grade and negative progesterone receptor (PR) expression]. We also described a similar metabolomic spectrum between grade III and grade I meningiomas. Moreover, all grade I meningiomas with a low Ki-67 expression and a positive PR expression did not have the same metabolomic profile. Metabolomic analysis could be used to determine an aggressive meningioma in order to discuss a personalized treatment. Further studies are needed to confirm these results and to correlate this metabolic profile with survival data.

Evaluation of Oxalate Osteopathy Secondary to Hyperoxaluria With 18F-FDG PET/CT and 99mTc-HMDP Bone Scan.

We report a case of a 69-year-old woman with primary hyperoxaluria type I, who developed a severe hypercalcemia despite controlled secondary hyperparathyroidism. Bone scintigraphy showed diffuse increased uptake in axial and peripheral skeleton. F-FDG PET/CT showed countless striking hypermetabolic foci, interesting 2 types of lesions (joint calcifications and periosteal resorptions). Bone biopsy demonstrated inflammatory changes around many calcium oxalate crystals; hypercalcemia was then related to oxalate osteopathy. Immunotherapy with denosumab was thus initiated. Eighteen months later, a second PET/CT showed decreased F-FDG uptake, reflecting treatment efficacy on inflammatory reaction secondary to calcium oxalosis skeletal deposits.