Nuclear Medicine and Molecular Imaging最新文献

We describe the case of 74-year-old-male, previously treated with fronto-parietal craniotomy due to primary glioblastoma multiforme (GBM), followed by concurrent radiation therapy (RT) and temozolomide (TMZ) chemotherapy. Magnetic resonance imaging (MRI) of the brain, at 1 month after completing RT + TMZ, depicted partial response. Three months later, the patient was submitted to a further brain MRI, that resulted doubtful for therapy induced changes (i.e., pseudoprogression). The patient, who had been previously treated with prostatectomy for prostate cancer (PC), underwent a positron emission tomography/computed tomography (PET/CT) scan with ¹⁸F-choline for PC biochemical recurrence. ¹⁸F-choline whole body PET/CT resulted negative for PC relapse, while segmental brain PET, co-registered with MRI, demonstrated increased tracer uptake corresponding to tumor boundaries. In order to solve differential diagnosis between pseudoprogression and GBM recurrence, brain PET/CT with ¹⁸F-L-dihydroxy-phenil-alanine (¹⁸F-DOPA) was subsequently performed: fused axial PET/MRI images showed increased ¹⁸F-DOPA incorporation in the peri-tumoral edema, but not in tumor boundaries, consistent with the suspicion of GBM pseudoprogression, as then confirmed by clinical and radiological follow-up.

The 18F-FDG PET/CT imaging is a non-invasive modality for diagnosis and staging of metastatic melanoma. Venous thromboembolism (VTE) is a common complication of cancers, which needs anticoagulant therapy. Tumor thrombosis (TT), on the other hand, is an infrequent complication of solid malignancies that may need aggressive management. Accurate diagnosis of TT and its differentiation from VTE may change patient management and avoid unnecessary anticoagulation treatment. The objective of this case is to introduce a patient with malignant melanoma presenting with extensive venous tumor thrombi with intense FDG uptake.

Purpose: Neuroblastoma (NB) is childhood's most common extracranial solid malignancy. We have compared two imaging modalities, ¹³¹I-MIBG and ¹⁸F-DOPA PET/CT, to evaluate NB. Also, feasibility of the application of standardised scoring systems, SIOPEN and Curie scoring systems, in ¹⁸F-DOPA PET/CT was explored.

Methods: Patients with histopathology-proven NB underwent ¹³¹I-MIBG (planar and SPECT/CT) and ¹⁸F-DOPA PET/CT scans, as per standard imaging protocols. Duration between scans ranged from 1 to 30 days (median = 8 days). Number of lesions in Curie and SIOPEN scoring systems applied on both modalities was compared.

Results: Forty-six patients were included (M:F = 29:17) with a median age of 36 months. Both ¹³¹I-MIBG and ¹⁸F-DOPA scans were positive in 39 patients and negative in four patients. ¹⁸F-DOPA PET/CT was positive in additional three patients, in which ¹³¹I-MIBG was negative (p = 0.25). Overall, ¹⁸F-DOPA identified significantly greater number of lesions than ¹³¹I-MIBG, especially metastatic skeletal lesions (p < 0.05). Significant difference was observed between Curie scores in the two modalities, unlike SIOPEN scores. However, when the cut-off age of 18 months was taken, no significant difference was seen in either of the scoring systems in both the scans (p > 0.05). CS and SIOPEN scores were significantly higher in bone marrow-positive patients.

Conclusion: ¹⁸F-DOPA PET/CT detected more lesions than ¹³¹I-MIBG but had little impact on staging of the disease. For evaluation of NB, both scans can be used interchangeably as per the availability. Furthermore, both SIOPEN and Curie scoring systems, standardised for MIBG, can also be used to semi-quantify disease extent in ¹⁸F-DOPA PET/CT.

Supplementary information: The online version contains supplementary material available at 10.1007/s13139-022-00762-6.

Purpose: This study evaluated the clinical utility of the highest bone scan index (BSI), among other BSIs, for each bone metastatic site in patients with bone metastatic castration-resistant prostate cancer (bmCRPC).

Methods: Thirty patients, diagnosed with bmCRPC by bone scintigraphy, were included. Total BSI, the number of hot spots, and regional BSI on each hot spot from bone scintigraphy at diagnosis with bmCRPC were evaluated by VSBONE BSI®. Highest regional BSI was defined as the highest value among regional BSIs on each hot spot in each patient. Related factors to overall survival and skeletal-related events (SREs) were evaluated using the Cox proportional-hazards model.

Results: The median follow-up time from diagnosis with bmCRPC was 29.0 months. During this time, 24 patients died, of which 22 patients died from prostate cancer. On univariate analysis, alkaline phosphatase (ALP) [Hazard ratio (HR): 5.96, 95% confidence interval (CI): 2.05-17.3] and highest regional BSI (HR: 2.01, 95% CI: 1.17-7.05) had significant correlation with overall survival. On multivariate analysis, ALP (HR: 4.79, 95% CI: 1.61-14.2) had significant correlation with overall survival. SREs were found in eight patients. Only the highest regional BSI (HR: 9.99, 95% CI: 2.46-40.6) significantly correlated with SREs on univariate analysis.

Conclusion: Highest regional BSI may provide important information regarding prognosis and SREs in patients with bmCRPC.

A 56-year-old man presented with vague upper abdominal pain for more than 4 months. His abdominal ultrasound and MRI showed thickening of the neck and base of the gallbladder and nodule formation at the base of the gallbladder. ¹⁸F-FDG PET/CT revealed intense FDG uptake in the base of the gallbladder and multiple lymph nodes. ⁶⁸ Ga-FAPI-04 PET/CT not only showed intense FAPI uptake in the above mentioned FDG-avid lesions but also showed intense FAPI uptake in the neck lesion of the gallbladder and some other additional lymph nodes. Finally, histopathological examination confirmed poorly differentiated tubular adenocarcinoma of the neck and base of the gallbladder. Our case illustrated that ⁶⁸ Ga-FAPI-04 PET/CT may outperform ¹⁸F-FDG PET/CT in the detection of gallbladder cancer primary and metastatic lesions.

Purpose: Radium-223 has been demonstrated in clinical trials to improve survival in castration-resistant prostate cancer (CRPC) patients with bone metastases. However, its performance in routine use remains to be fully characterized. This study aims to describe patient outcomes in the real world as well as identify factors associated with completion of the 6-dose regimen and alkaline phosphatase (ALP) response.

Methods: Thirty-six patients who received at least one dose of radium-223 at the Jewish General Hospital in Montréal, Canada, were analysed in a retrospective manner. Using logistic regression, the primary analysis aimed to identify factors associated with treatment completion, and the secondary analysis aimed to identify factors associated with ALP response.

Results: Twenty-one out of 36 patients received all 6 doses of radium-223. Fifteen patients had an ALP response, defined as a 30% decrease in ALP from baseline values. On primary analysis, baseline ALP > 120 U/L and prostate-specific antigen (PSA) > 50 μg/L were significantly associated with lower therapy completion rates (OR = 0.10, p = 0.004; OR = 0.18, p = 0.022 respectively). On adjustment for confounders, only ALP remained significant (OR = 0.14, p = 0.021). Clinical disease progression was the most common reason for treatment non-completion, and it was also associated with elevated baseline ALP (OR = 6.00, p = 0.044). On secondary analysis, previous chemotherapy for CRPC was a negative predictor of ALP response (OR = 0.15, p = 0.034).

Conclusion: Elevated baseline ALP and PSA were associated with a lower rate of radium-223 regimen completion; receiving chemotherapy for CRPC prior to radium-223 was associated with a lower rate of ALP response.

Supplementary information: The online version contains supplementary material available at 10.1007/s13139-022-00760-8.

Purpose: The goal of partial gland ablation (PGA) is to eradicate focal lesions of clinically significant prostate cancer (csPCa) with minimal adverse impact on functional outcomes. The primary objective of this study is to characterize the performance of 18F-Fluciclovine PET imaging for detection of prostate cancer following PGA.

Materials and methods: Subjects 2 years following primary partial gland cryoablation (PPGCA) were invited to participate in an IRB-approved study providing they met the following inclusion criteria: a single reported mpMRI region of interest (ROI) concordant with biopsy Gleason Grade Group (GGG) < 4, no gross extra-prostatic extension on mpMRI, and no GGG > 1 or GGG 1 with a core length > 6 mm on contralateral systematic biopsy. 18F-Fluciclovine PET MRI imaging of the prostate was performed followed by in and out-of-field biopsies.

Results: Twenty-seven men who met eligibility criteria participated in the prospective study. In-field and out-of-field csPCa recurrence rate was 7.4% and 22.2%, respectively. The sensitivity and positive predictive value of mpMRI and PET imaging did not reach performance to reliably inform who should undergo prostate biopsy.

Conclusion: At 2 years following PPGCA, the rate of in-field csPCa was exceedingly low indicating a limited role for imaging to inform in-field biopsy decisions. The csPCa detection rate of out-of-field recurrence was 22% which provides an opportunity for imaging to inform out-of-field biopsy decisions. Based on our findings, 18F-Fluciclovine PET MRI cannot be used to inform who should undergo out-of-field prostate biopsy at 2 years following PPGCA.

Imaging of metastatic castrate-resistant prostate cancer to select patients suitable for peptide receptor radioligand therapy can be performed with both SPECT and PET PSMA radiotracers. Although PET radiotracers generally have higher sensitivity and spatial resolution, SPECT tracers can be an effective alternative when PET/CT systems are unavailable in the clinical setting. We present a case of a 43-year-old male, who was referred to our facility for workup for radioligand PSMA therapy. His Tc-99m PSMA images revealed diffuse bone infiltration in a pattern mimicking a bone scan.

Background: Radium-223, an alpha-emitting therapeutic radiopharmaceutical, prolongs overall survival (OS) in patients with symptomatic bone-predominant metastatic castration-resistant prostate cancer (mCRPC). PSMA PET/CT is a molecular imaging tool for whole-body imaging of prostate cancer and may inform on the mechanisms of radium-223 activity and treatment resistance in mCRPC patients.

Methods: In an open-label, single-arm, prospective trial, we enrolled patients with bone-predominant mCRPC to undergo baseline PSMA PET/CT, 6 cycles of radium-223, and post-therapy PSMA PET/CT. We assessed the relationship between multiple parameters of interval change on PSMA PET/CT on aPROMISE PSMA automated analysis and a human reader, and laboratory measurements.

Results: Fourteen patients were enrolled and 9 patients completed both protocol-defined PSMA PET/CT. Of the 9 evaluable patients, 1 (11%) had a complete response and 8 (89%) had PSMA PET progressive disease. All patients showed decreases in PSMA uptake in some disease sites evident on the baseline scan. The change in overall burden of disease on PSMA PET was more strongly correlated with changes in PSA (ρ = 0.95) than ALP (ρ = 0.62). Progression in bone was a common finding on post-treatment PSMA PET/CT.

Conclusion: PSMA PET was able to assess response in individual lesions during radium-223 therapy in mCRPC patients. PSMA PET responses in previously established disease sites were universal, but most patients also showed overall PSMA PET progression during 6 cycles of radium-223. Given high correlation with changes in PSA, PSMA PET may be of limited value in follow-up during or after radium-223 in bone-predominant mCRPC.

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