The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of...最新文献

Background: To investigate the clinical, hematological and biochemical toxicity differences between glass and resin yttrium-90 (⁹⁰Y)-microspheres radioembolization treatment of primary and metastatic liver disease.

Methods: Between May 2014 and November 2016 all consecutive glass and resin ⁹⁰Y microspheres radioembolization treatments were retrospectively analyzed. Biochemical, hematological and clinical data were collected at treatment day, two weeks, one month and three months follow-up. Post-treatment ⁹⁰Y PET/CTs were assessed for the absorbed doses in non-tumorous liver volume (DNTLV) and tumor volume (DTV). Biochemical, hematological and clinical toxicity were compared between glass and resin using chi square tests and repeated ANOVA measures. Biochemical and clinical toxicity was correlated with DNTLV,total by means of Pearson correlation and independent t-tests.

Results: A total of 85 patients were included (N.=44 glass, N.=41 resin). Clinical toxicity the day after treatment (i.e. abdominal pain [P=0.000], nausea [P=0.000] and vomiting [P=0.003]) was more prevalent for resin. Biochemical and hematological toxicities were similar for both microspheres. The DNTLV,total was significantly higher in patients with REILD grade ≥3 in the resin group (43.5 versus 33.3 Gy [P=0.050]). A similar non-significant trend was seen in the glass group: 95.0 versus 69.0 Gy [P=0.144].

Conclusions: The clinical, hematological and biochemical toxicity of radioembolization treatment with glass and resin is comparable, however, post-embolization syndrome related complaints are more common for resin.

Background: ⁹⁹Tc^m-MDP SPECT/CT is widely used to diagnose early bone metastasis. Ribs are high-risk bone metastasis sites, while few study is related to ribs. The study is to investigate the risk factors of rib metastases in lung cancer patients.

Methods: We retrospectively analyzed the patients' clinical characteristics and SPECT/CT imaging features. The patients were divided into a rib metastasis group (108 cases) and a non-rib metastasis group (103 cases).

Results: In 211 patients, rib metastases were closely related to tumor markers, T stage, N stage, clinical staging, lymph node (LN) involvement, number of rib foci, localization on rib and foci type (P<0.05). In 93 patients with pure rib foci, rib metastases were affected by clinical staging, LN involvement, localization on the rib and primary lung cancer localization (P<0.001, 0.038,<0.001, 0.034, respectively). In 100 patients with a solitary rib focus, rib metastases were associated with clinical staging, localization on the rib, and LN involvement (P<0.001, 0.001, and 0.014, respectively). In all 633 rib foci, localization on the rib was an effective risk factor for rib metastases (P<0.001).

Conclusions: Patients with increased tumor markers, stage IV lung adenocarcinoma and multiple rib foci located ipsilaterally with the primary lung tumor, or rib foci accompanied other bone foci are more likely to develop rib metastasis. Patients with pure rib foci or a solitary rib focus, especially in the anterior rib with negative LN involvement, have a low probability of rib metastasis.

Background: The objective was to carry out a prospective study to compare the current extended pelvic lymph node dissection (ePLND) to the sentinel node (SN) technique with ^99mTcnanocolloid.

Methods: We conducted a prospective study between January 2013 and May 2020. In the first 74 patients, ^99mTc-nanocolloid was used. Then from June 2017 onwards, in 38 patients we used a combined radiotracer prepared by adding indocyanine green (ICG). A preoperative SPECT/CT was also performed to check on the SNs. We extracted the SNs guided by a laparoscopic gamma-ray detection probe and/or a fluorescence camera.

Results: We included 112 patients with a Briganti nomogram-assessed risk of 5% or more. In 4 out of the total, the radiotracer did not migrate. The mean number of extracted nodes was 21.56 (13.46-29.71) and the mean of extracted SNs was 5.17 (1.83-8.51) (P<0.001). The technique that registered the most nodes with high activity was SPECT/CT, with an average of 4.33 nodes (2.42-6.23) (P<0.001). We found SNs outside the template in 78% of the patients. A total of 46% of the complications were related to ePLND. The SN biopsy showed a sensitivity of 100%, specificity of 97.5%, PVV of 92.86%, and NPV of 100%.

Conclusions: Our results prove that ePLND is a technique with significant morbidity; up to 46% of the complications were related to the ePLND. The SN surgery showed great accuracy in detecting metastases due to the SPECT/CT and a lower rate of complications than ePLND.

Background: The effect of second ¹³¹I treatment (RT) in totally thyroidectomized differentiated thyroid cancer (TT-DTC) patients with true-positive thyroid beds and false-negative metastasis (TB+/M-) on initial post-therapeutic whole-body scan (Rx-WBS) remains unknown.

Methods: TT-DTC patients with TB+/M- on initial Rx-WBS receiving and not receiving second RT were categorized into group A and group B, respectively, while patients with ¹³¹I-avid metastasis receiving second RT were referred to as group C. Biochemical remission (BR) was defined as a decrease of ≥25.0% in thyrotropin-suppressed thyroglobulin (Tgon) level, while the structural response (SR) was determined by the change in the size of the largest lesion.

Results: In total, 145 patients were eligible. In group A, the median Tgon measured 3.3 ng/mL before and 3.0 ng/mL at 4 months after second RT (P=0.307), yielding a decrease in the median Tgon (∆Tgon%) of 13.3%, a BR rate of 36%, and an insignificant SR, which were comparable to those in group B. In group C, however, a median ∆Tgon% of 37.8% and a BR rate of 64% were obtained, which were significantly higher than those in group A (P=0.038 and 0.022, respectively), with SR distributions similar to those in group A. In addition, ¹³¹I uptake in the neck was not statistically associated with the detection of metastasis on initial Rx-WBS.

Conclusions: This controlled study demonstrated a subtle response to second RT in TT-DTC patients with TB+/M- on initial Rx-WBS, representing a meaningful advancement in avoiding ineffective repeated RT.

Background: This study aimed to investigate improvements in ⁶⁸Ga-FAPI PET/CT image quality due to using total variation regularized expectation maximization (TVR-EM) and ordered subset expectation maximization (OS-EM) reconstruction.

Methods: Data from a total of 24 patients were retrospectively analyzed in this study. Positron emission tomography (PET) images were reconstructed using OS-EM and TVR-EM for 2 and 3 minutes-per-bed (min/bed) acquisition. The SUVmean of a region-of-interest on the liver, image noise, signal-to-noise ratios (SNR), the SUVmax of the lesions and the tumour-to-background ratios (TBR) were measured and compared between the 2 methods. Subjective image qualities were evaluated by two experienced radiologists using a 5-point score scale (5-excellent, 1-poor).

Results: In total, 132 lesions were analyzed. The image noise in TVR-EM reconstruction groups was lower than in the OS-EM groups (all P<0.05). The SNR, SUVmax of lesions and the TBR were higher for the TVR-EM reconstruction groups compared to OS-EM groups (all P<0.05). Also, the SUVmax of the lesions in the TVR-EM groups increased by at least 12% compared to OS-EM 3 min/bed group. The SUVmax for small (<10 mm) and large lesions (>10 mm) in the TVR-EM 2 min/bed group were significantly larger compared to the OS-EM 3 min/bed groups (all P<0.05). The highest image quality score resulted from the TVR-EM 3 min/bed group with a penalization factor of 0.25 (3.92±0.19).

Conclusions: TVR-EM reduces image noise and improved the SNR, SUVmax and TBR of the lesions. It also enables fast acquisition without compromising image quality compared to standard OS-EM.

Background: Attenuation correction (AC) is an important topic in PET/MRI and particularly challenging after brain tumor surgery, near metal implants, adjacent bone and burr holes. In this study, we evaluated the performance of two MR-driven AC methods, zero-echo-time AC (ZTE-AC) and atlas-AC, in comparison to reference standard CT-AC in patients with surgically treated brain tumors at ¹¹C-methionine PET/MRI.

Methods: This retrospective study investigated seven postoperative patients with neuropathologically confirmed brain tumor at ¹¹C-methionine PET/MRI. Three AC maps - ZTE-AC, atlas-AC and reference standard CT-AC - were generated for each patient. Standardized uptake values (SUV) were obtained at the metal implant, adjacent bone and burr hole. Standard uptake ratio (SUR) SURmetal/mirror, SURbone/mirror and SURburrhole/mirror were then calculated and analyzed with Bland-Altman, Pearson correlation and intraclass correlation reliability.

Results: Smaller mean percent bias range (Bland-Altman) was found for ZTE-AC than atlas-AC in all analyses (metal ZTE -0.46 to -0.02, metal atlas -3.57 to -3.26; bone ZTE -4.60 to -2.16, bone atlas -5.25 to -3.81; burr hole ZTE -0.95 to -0.52, burr hole atlas 7.86 to 8.87). Percent SD range (Bland-Altman) was large for both methods in all analyses, with lower absolute values for ZTE-AC (ZTE 7.02-8.49; atlas 11.47-14.83). A very strong correlation (Pearson correlation) was demonstrated for both methods compared to CT-AC (ZTE ρ 0.97-0.99, P<0.001; atlas ρ 0.88-0.91, P≤0.009) with higher absolute values for ZTE. An excellent intraclass correlation coefficient was found across all analyses for ZTE, atlas and CT maps (ICC ≥0.88).

Conclusions: ZTE for MR-driven PET attenuation correction presented a more comparable performance to reference standard CT-AC at the postoperative site. ZTE-AC may serve as a useful diagnostic tool for MR-driven AC in patients with surgically treated brain tumors.

Guidelines for bone scintigraphy are well established and recommend the use of planar early phase images to investigate a number of clinical indications. With recent advances in gamma camera technology the use of SPECT/CT imaging in the early phases is now possible, offering the potential of improved diagnostic confidence and prognostic value. To date little work has been carried out to optimize the acquisition of early phase bone images using SPECT/CT with most of the available studies acquiring SPECT images after the traditional planar images to allow comparison of the two techniques. Imaging durations of 7 to 10 minutes have been commonly used. However, the use of iterative reconstruction algorithms has been investigated with rapid SPECT imaging to allow imaging durations as low as 4 minutes. The use of CZT based systems with increased sensitivity and improved energy and spatial resolution also offers the potential to reduce imaging times. The optimization of projection measurement order has been investigated as a method of reducing image artefacts as a result of changing tracer distribution during the SPECT acquisition. In this article we consider the current state of early phase SPECT imaging and possible areas for future investigation as well as recommendations for departments looking to adopt blood pool SPECT imaging as part of their routine clinical practice.

Background: The aim of the present study is to evaluate the reliability of a ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET adaptive threshold segmentation (ATS) algorithm, previously validated in a preclinical setting on several scanners, for the biological target volume (BTV) delineation of head and neck radiotherapy planning.

Methods: [18F]FDG PET ATS algorithm was studied in treatment plans of head and neck squamous cell carcinoma on a dedicated workstation (iTaRT, Tecnologie Avanzate, Turin, Italy). BTVs segmented by the present ATS algorithm (BTVATS) were compared with those manually segmented for the original radiotherapy treatment planning (BTVVIS). We performed a qualitative and quantitative volumetric analysis with a comparison tool within the ImSimQA ^TM software package (Oncology Systems Limited, Shrewsbury, UK). We reported figures of merit (FOMs) to convey complementary information: Dice Similarity Coefficient, Sensitivity Index, and Inclusiveness Index.

Results: The study was conducted on 32 treatment plans. Median BTVATS was 11 cm³ while median BTVVIS was 14 cm³. The median Dice Similarity Coefficient, Sensitivity Index, Inclusiveness Index were 0.72, 63%, 88%, respectively. Interestingly, the median volume and the median distance of the voxels that are over contoured by ATS were respectively 1 cm³ and 1 mm.

Conclusions: ATS algorithm could be a smart and an independent operator tool when implemented for ¹⁸F-FDG-PET-based tumor volume delineation. Furthermore, it might be relevant in case of BTV-based dose painting.

Background: The role of positron emission tomography/computed tomography (PET/CT) in hepatocellular carcinoma (HCC) management is not clearly defined. Our objective was to analyze the utility of dual-PET/CT (¹⁸F-FDG + ¹⁸F-Choline) imaging findings on the BCLC staging and treatment decision for HCC patients.

Methods: Between January 2011 and April 2019, 168 consecutive HCC patients with available baseline dual-PET/CT imaging data were retrospectively analyzed. To identify potential refinement criteria for surgically-treated patients, survival Kaplan-Meier curves of various standard-of-care and dual-PET/CT baseline parameters were estimated. Finally, multivariate cox proportional hazard ratios of the most relevant clinico-biological and/or PET parameters were estimated.

Results: Dual-PET/CT findings increased the score of BCLC staging in 21 (12.5%) cases. In 24.4% (N.=41) of patients, the treatment strategy was modified by the PET findings. Combining AFP levels at a threshold of 10 ng/mL with ¹⁸F-FDG or ¹⁸F-Choline N status significantly impacted DFS (P<0.05). In particular, the combined criteria of the N⁺ status assessed by ¹⁸F-Choline with AFP threshold of 10 ng/mL provided a highly predictive composite parameter for estimation of DFS according to multivariate analysis (HR=10.6, P<0.05).

Conclusions: The ¹⁸F-Choline / AFP composite parameter appears promising, and further prospective studies are mandatory to validate its oncological impact.