Intramedullary spinal cord metastases from breast cancer: Detection with 18F-FDG PET/CT

A 35-year-old woman, already treated with surgery, chemotherapy, and radiotherapy for a ductal carcinoma of the left breast, underwent an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan for an increase of the serum markers carcinoembryonic antigen (CEA) and cancer antigen 15.3 (CA15.3). The scan showed multiple FDG-avid lesions in the liver and bone. The images also detected two areas of uptake in the dorsal and lumbar spinal cord, which were suspicious for metastases; magnetic resonance imaging (MRI) confirmed these lesions. © the authors; licensee ecancermedicalscience

Sentinel node detection and radioguided occult lesion localization in breast cancer

Sentinel lymph node biopsy might replace complete axillary dissection for staging of the axilla in clinically N0 breast cancer patients and represent a significant advantage as a minimally invasive procedure, considering that about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. In our Institute, Radioguided Occult Lesion Localization is the standard method to locate non-palpable breast lesions and the gamma probe is very effective in assisting intra-operative localization and removal, as in sentinel node biopsy. The rapid spread of sentinel lymph node biopsy has led to its use in clinical settings previously considered contraindications to sentinel lymph node biopsy. In this contest, we evaluated in a large group of patients possible factors affecting sentinel node detection and the reliability of sentinel lymph node biopsy carried out after large excisional breast biopsy. Our data confirm that a previous breast surgery does not prohibit efficient sentinel lymph node localization and sentinel lymph node biopsy can correctly stage the axilla in these patients

Extrapulmonary malignancies detected at lung cancer screening

PURPOSE: To retrospectively assess the detection rate, histologic characteristics, and clinical stage of screening-detected extrapulmonary malignancies in a population at high risk for lung cancer. MATERIALS AND METHODS: In this institutional review board-approved study, 5201 asymptomatic heavy smokers aged 50 years or older underwent annual low-dose computed tomography (CT) for 5 consecutive years. The 5-year cumulative effective dose was 5 mSv. Subjects with at least one "potentially significant extrapulmonary incidental finding" (PS-IF) were extracted from the study database. An extrapulmonary finding was classified as potentially significant if it required further diagnostic and/or clinical evaluation. In retrospect all clinically relevant information, including findings from diagnostic work-up and final diagnosis of the PS-IF, was collected. On the basis of the information collected, only histologically proved screening-detected extrapulmonary malignancies were eventually included in this study. The percentages of volunteers with extrapulmonary malignancies were calculated, along with 95% confidence intervals (CIs), on the basis of a binomial distribution. RESULTS: After 5 years of CT screening, 27 unsuspected extrapulmonary malignancies were diagnosed, representing 0.5% (27 of 5201 subjects; 95% CI: 0.34%, 0.75%) of volunteers enrolled and 6.2% (27 of 436 findings; 95% CI: 4.12%, 8.88%) of PS-IFs. Eight malignancies were diagnosed at the 1st year of screening, nine at the 2nd year, four at the 3rd year, two at the 4th year, and four at the 5th year. Twelve of the 27 extrapulmonary tumors (44%) were renal carcinomas (n = 7) or lymphomas (n = 5). Twenty-four of the 27 subjects with a malignancy were alive at the most recent follow-up. CONCLUSION: A considerable number of unsuspected extrapulmonary malignancies can be detected in lung cancer screening trials. A careful evaluation of extrapulmonary structures, with particular attention to the kidneys and lymph nodes, is recommended

First Live-Experience Session with PET/CT Specimen Imager: A Pilot Analysis in Prostate Cancer and Neuroendocrine Tumor

Objective: to evaluate the feasibility of the intra-operative application of a specimen PET/CT imager in a clinical setting. Materials and methods: this is a pilot analysis performed in three patients who received an intra-operative administration of 68Ga-PSMA-11 (n = 2) and 68Ga-DOTA-TOC (n = 1), respectively. Patients were administrated with PET radiopharmaceuticals to perform radio-guided surgery with a beta-probe detector during radical prostatectomy for prostate cancer (PCa) and salvage lymphadenectomy for recurrent neuroendocrine tumor (NET) of the ileum, respectively. All procedures have been performed within two ongoing clinical trials in our Institute (NCT05596851 and NCT05448157). Pathologic assessment with immunohistochemistry (PSMA-staining and SSA immunoreactivity) was considered as standard of truth. Specimen images were compared with baseline PET/CT images and histopathological analysis. Results: Patients received 1 MBq/Kg of 68Ga-PSMA-11 (PCa) or 1.2 MBq/Kg of 68Ga-DOTA-TOC (NET) prior to surgery. Specimens were collected, positioned in the dedicated specimen container, and scanned to obtain high-resolution PET/CT images. In all cases, a perfect match was observed between the findings detected by the specimen imager and histopathology. Overall, the PET spatial resolution was sensibly higher for the specimen images compared to the baseline whole-body PET/CT images. Furthermore, the use of the PET/CT specimen imager did not significantly interfere with any procedures, and the overall length of the surgery was not affected using the PET/CT specimen imager. Finally, the radiation exposure of the operating theater staff was lower than 40 µSv per procedure (range 26–40 μSv). Conclusions: the image acquisition of specimens obtained by patients who received intra-surgery injections of 68Ga-PSMA-11 and 68Ga-DOTA-TOC was feasible and reliable also in a live-experience session and has been easily adapted to surgery daily practice. The high sensitivity, together with the evaluation of intra-lesion tumor heterogeneity, were the most relevant results since the data derived from specimen PET/CT imaging matched perfectly with the histopathological analysis

[18F]FDG PET/CT: Lung Nodule Evaluation in Patients Affected by Renal Cell Carcinoma

Renal Cell Carcinoma (RCC) is generally characterized by low-FDG avidity, and [18F]FDG-PET/CT is not recommended to stage the primary tumor. However, its role to assess metastases is still unclear. The aim of this study was to evaluate the diagnostic accuracy of [18F]FDG-PET/CT in correctly identifying RCC lung metastases using histology as the standard of truth. The records of 350 patients affected by RCC were retrospectively analyzed. The inclusion criteria were: (a) biopsy- or histologically proven RCC; (b) Computed Tomography (CT) evidence of at least one lung nodule; (c) [18F]FDG-PET/CT performed prior to lung surgery; (d) lung surgery with histological analysis of surgical specimens; (e) complete follow-up available. A per-lesion analysis was performed, and diagnostic accuracy was reported as sensitivity and specificity, using histology as the standard of truth. [18F]FDG-PET/CT semiquantitative parameters (Standardized Uptake Value [SUVmax], Metabolic Tumor Volume [MTV] and Total Lesion Glycolysis [TLG]) were collected for each lesion. Sixty-seven patients with a total of 107 lesions were included: lung metastases from RCC were detected in 57 cases (53.3%), while 50 lesions (46.7%) were related to other lung malignancies. Applying a cut-off of SUVmax ≥ 2, the sensitivity and the specificity of [18F]FDG-PET/CT in detecting RCC lung metastases were 33.3% (95% CI: 21.4–47.1%) and 26% (95%CI: 14.6–40.3%), respectively. Although the analysis demonstrated a suboptimal diagnostic accuracy of [18F]FDG-PET/CT in discriminating between lung metastases from RCC and other malignancies, a semiquantitative analysis that also includes volumetric parameters (MTV and TLG) could support the correct interpretation of [18F]FDG-PET/CT images

The Impact of Segmentation Method and Target Lesion Selection on Radiomic Analysis of ¹⁸F-FDG PET Images in Diffuse Large B-Cell Lymphoma

Radiomic analysis of 18F[FDG] PET/CT images might identify predictive imaging biomarkers, however, the reproducibility of this quantitative approach might depend on the methodology adopted for image analysis. This retrospective study investigates the impact of PET segmentation method and the selection of different target lesions on the radiomic analysis of baseline 18F[FDG] PET/CT images in a population of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients. The whole tumor burden was segmented on PET images applying six methods: (1) 2.5 standardized uptake value (SUV) threshold; (2) 25% maximum SUV (SUVmax) threshold; (3) 42% SUVmax threshold; (4) 1.3∙liver uptake threshold; (5) intersection among 1, 2, 4; and (6) intersection among 1, 3, 4. For each method, total metabolic tumor volume (TMTV) and whole-body total lesion glycolysis (WTLG) were assessed, and their association with survival outcomes (progression-free survival PFS and overall survival OS) was investigated. Methods 1 and 2 provided stronger associations and were selected for the next steps. Radiomic analysis was then performed on two target lesions for each patient: the one with the highest SUV and the largest one. Fifty-three radiomic features were extracted, and radiomic scores to predict PFS and OS were obtained. Two proportional-hazard regression Cox models for PFS and OS were developed: (1) univariate radiomic models based on radiomic score; and (2) multivariable clinical–radiomic model including radiomic score and clinical/diagnostic parameters (IPI score, SUVmax, TMTV, WTLG, lesion volume). The models were created in the four scenarios obtained by varying the segmentation method and/or the target lesion; the models’ performances were compared (C-index). In all scenarios, the radiomic score was significantly associated with PFS and OS both at univariate and multivariable analysis (p < 0.001), in the latter case in association with the IPI score. When comparing the models’ performances in the four scenarios, the C-indexes agreed within the confidence interval. C-index ranges were 0.79–0.81 and 0.80–0.83 for PFS radiomic and clinical–radiomic models; 0.82–0.87 and 0.83–0.90 for OS radiomic and clinical–radiomic models. In conclusion, the selection of either between two PET segmentation methods and two target lesions for radiomic analysis did not significantly affect the performance of the prognostic models built on radiomic and clinical data of DLBCL patients. These results prompt further investigation of the proposed methodology on a validation dataset

A multiple points method for 4DCT image sorting

Purpose: Artifacts affect 4D CT images due to breathing irregularities or incorrect breathing phase identification. The purpose of this study is the reduction of artifacts in sorted 4D CT images. The assumption is that the use of multiple respiratory related signals may reduce uncertainties and increase robustness in breathing phase identification. Methods: Multiple respiratory related signals were provided by infrared 3D localization of a configuration of markers placed on the thoracoabdominal surface. Multidimensional K-means clustering was used for retrospective 4D CT image sorting, which was based on multiple marker variables, in order to identify clusters representing different breathing phases. The proposed technique was tested on computational simulations, phantom experimental acquisitions, and clinical data coming from two patients. Computational simulations provided a controlled and noise-free condition for testing the clustering technique on regular and irregular breathing signals, including baseline drift, time variant amplitude, time variant frequency, and end-expiration plateau. Specific attention was given to cluster initialization. Phantom experiments involved two moving phantoms fitted with multiple markers. Phantoms underwent 4D CT acquisition while performing controlled rigid motion patterns and featuring end-expiration plateau. Breathing cycle period and plateau duration were controlled by means of weights leaned upon the phantom during repeated 4D CT scans. The implemented sorting technique was applied to clinical 4D CT scans acquired on two patients and results were compared to conventional sorting methods. Results: For computational simulations and phantom studies, the performance of the multidimensional clustering technique was evaluated by measuring the repeatability in identifying the breathing phase among adjacent couch positions and the uniformity in sampling the breathing cycle. When breathing irregularities were present, the clustering technique consistently improved breathing phase identification with respect to conventional sorting methods based on monodimensional signals. In patient studies, a qualitative comparison was performed between corresponding breathing phases of 4D CT images obtained by conventional sorting methods and by the described clustering technique. Artifact reduction was clearly observable on both data set especially in the lower lung region. Conclusions: The implemented multiple point method demonstrated the ability to reduce artifacts in 4D CT imaging. Further optimization and development are needed to make the most of the availability of multiple respiratory related variables and to extend the method to 4D CT-PET hybrid scan

Neoadjuvant therapy in locally advanced breast cancer : 99mTc-MIBI mammoscintigraphy is not a reliable technique to predict therapy response

Mammoscintigraphy (MMS) has been indicated as a useful tool in predicting response to therapy in cancer. However, contrasting results have been reported in the literature for breast cancer patients. The aim of this study was to explore the role of MMS in locally advanced breast cancer (LABC) patients. Fifty-one patients affected by LABC and scheduled for neoadjuvant therapy were enrolled. Breast tumor status was evaluated at baseline, during therapy and at the completion of therapy by radiological techniques and by MMS. Pre-therapy (MMS1) and post-therapy MIBI (2-methoxyisobutilysonitrile) images (MMS2-3) were analyzed. MMS1 was performed in all pts, 41 carried out MMS2 and 27 had MMS3. Tumor uptake and washout in MMS1 did not show any correlation with the therapy response. The absence of any association between tumor uptake and washout with respect to therapy response suggests that MMS is not a reliable technique to predict therapy response in LABC