Early regression index (ERI) on MR images as response predictor in esophageal cancer treated with neoadjuvant chemo-radiotherapy: Interim analysis of the prospective ESCAPE trial.

PURPOSE: The early regression index (ERI) predicts treatment response in rectal cancer patients. Aim of current study was to prospectively assess tumor response to neoadjuvant chemo-radiotherapy (nCRT) of locally advanced esophageal cancer using ERI, based on MRI. MATERIAL AND METHODS: From January 2020 to May 2023, 30 patients with esophageal cancer were enrolled in a prospective study (ESCAPE). PET-MRI was performed: i) before nCRT (tpre); ii) at mid-radiotherapy, tmid; iii) after nCRT, 2-6 weeks before surgery (tpost); nCRT delivered 41.4 Gy/23fr with concurrent carboplatin and paclitaxel. For patients that skipped surgery, complete clinical response (cCR) was assessed if patients showed no local relapse after 18 months; patients with pathological complete response (pCR) or with cCR were considered as complete responders (pCR + cCR). GTV volumes were delineated by two observers (Vpre, Vmid, Vpost) on T2w MRI: ERI and other volume regression parameters at tmid and tpost were tested as predictors of pCR + cCR. RESULTS: Complete data of 25 patients were available at the time of the analysis: 3/25 with complete response at imaging refused surgery and 2/3 were cCR; in total, 10/25 patients showed pCR + cCR (pCR = 8/22). Both ERImid and ERIpost classified pCR + cCR patients, with ERImid showing better performance (AUC:0.78, p = 0.014): A two-variable logistic model combining ERImid and Vpre improved performances (AUC:0.93, p < 0.0001). Inter-observer variability in contouring GTV did not affect the results. CONCLUSIONS: Despite the limited numbers, interim analysis of ESCAPE study suggests ERI as a potential predictor of complete response after nCRT for esophageal cancer. Further validation on larger populations is warranted.

68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine well-differentiated tumours.

PURPOSE: To explore the role of fully hybrid 68Ga-DOTATOC PET/MR imaging and radiomic parameters in predicting histopathological prognostic factors in patients with pancreatic neuroendocrine tumours (PanNETs) undergoing surgery. METHODS: One hundred eighty-seven consecutive 68Ga-DOTATOC PET/MRI scans (March 2018-June 2020) performed for gastroenteropancreatic neuroendocrine tumour were retrospectively evaluated; 16/187 patients met the eligibility criteria (68Ga-DOTATOC PET/MRI for preoperative staging of PanNET and availability of histological data). PET/MR scans were qualitatively and quantitatively interpreted, and the following imaging parameters were derived: PET-derived SUVmax, SUVmean, somatostatin receptor density (SRD), total lesion somatostatin receptor density (TLSRD), and MRI-derived apparent diffusion coefficient (ADC), arterial and late enhancement, necrosis, cystic degeneration, and maximum diameter. Additionally, first-, second-, and higher-order radiomic parameters were extracted from both PET and MRI scans. Correlations with several PanNETs' histopathological prognostic factors were evaluated using Spearman's coefficient, while the area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to evaluate parameters' predictive performance. RESULTS: Primary tumour was detected in all 16 patients (15/16 by 68Ga-DOTATOC PET and 16/16 by MRI). SUVmax and SUVmean resulted good predictors of lymphnodal (LN) involvement (AUC of 0.850 and 0.783, respectively). Second-order radiomic parameters GrayLevelVariance and HighGrayLevelZoneEmphasis extracted from T2 MRI demonstrated significant correlations with LN involvement (adjusted p = 0.009), also showing good predictive performance (AUC = 0.992). CONCLUSION: This study demonstrates the role of the fully hybrid PET/MRI tool for the synergic function of imaging parameters extracted by the two modalities and highlights the potentiality of imaging and radiomic parameters in assessing histopathological features of PanNET aggressiveness.

Prognostic Value of 18F-Fluorocholine PET Parameters in Metastatic Castrate-Resistant Prostate Cancer Patients Treated with Docetaxel.

Background and Aim: The availability of new treatments for metastatic castrate-resistant prostate cancer (mCRPC) patients increases the need for reliable biomarkers to help clinicians to choose the better sequence strategy. The aim of the present retrospective and observational work is to investigate the prognostic value of 18F-fluorocholine (18F-FCH) positron emission tomography (PET) parameters in mCRPC. Materials and Methods: Between March 2013 and August 2016, 29 patients with mCRPC were included. They all received three-weekly docetaxel after androgen deprivation therapy, and they underwent 18F-FCH PET/computed tomography (CT) before and after the therapy. Semi-quantitative indices such as maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean) with partial volume effect (PVC-SUV) correction, metabolically active tumour volume (MATV), and total lesion activity (TLA) with partial volume effect (PVC-TLA) correction were measured both in pre-treatment and post-treatment 18F-FCH PET/CT scans for each lesion. Whole-body indices were calculated as sum of values measured for each lesion (SSUVmax, SPVC-SUV, SMATV, and STLA). Progression-free survival (PFS) and overall survival (OS) were considered as clinical endpoints. Univariate and multivariate hazard ratios for whole-body 18F-FCH PET indices were performed, and p < 0.05 was considered as significant. Results: Cox regression analysis showed a statistically significant correlation between PFS, SMATV, and STLA. No correlations between OS and 18F-FCH PET parameters were defined probably due to the small sample size. Conclusions: Semi-quantitative indices such as SMATV and STLA at baseline have a prognostic role in patients treated with docetaxel for mCRPC, suggesting a potential role of 18F-FCH PET/CT imaging in clinical decision-making.

Prognostic value of fluorodeoxyglucose positron emission tomography/computed tomography and inguinal sentinel lymph node biopsy in patients with anal cancer.

AIM: The aim of this study was to assess the value of positron emission tomography (PET)/CT and sentinel lymph node (SLN) biopsy in staging inguinal lymph nodes in anal cancer patients and to determine if the results of the two methods could be of prognostic value. METHOD: Sixty-three patients with anal cancer and clinically negative inguinal lymph nodes underwent lymphoscintigraphy and inguinal SLN biopsy and/or fluorodeoxyglucose (FDG) PET/CT scan. All patients were treated with radiotherapy combined with 5-fluorouracil and mitomycin-C. RESULTS: Overall (OS) and disease-free survival (DFS) were 43 months (range 5-211) and 43 months (range 4-142) respectively. PET/CT examination showed high FDG uptake in the inguinal lymph nodes in 25% of patients. Thirty-five patients with inguinal uptake at lymphoscintigraphy underwent inguinal SLN biopsy and metastatic nodes were found in 31.4%. There was no statistical difference in OS (55 vs 41 months; P = 0.652) and DFS (48 vs 38 months; P = 0.992) between the group which showed inguinal uptake on PET/CT and the group which did not, while a positive inguinal SLN was associated with a worse OS (28 vs 59 months; P = 0.028) and DFS (56 vs 21 months; P = 0.046). When the two examinations were compared PET/CT showed a sensitivity, specificity, positive predictive value and negative predictive value of 22%, 82%, 33% and 73% respectively. CONCLUSION: The technique of SLN biopsy had a better diagnostic accuracy than total body FDG-PET/CT for the staging of inguinal lymph nodes in anal cancer patients; moreover it was a stronger predictor of OS and DFS than PET/CT.

Partial volume corrected 18F-FDG PET mean standardized uptake value correlates with prognostic factors in breast cancer.

AIM: The aim of this paper was to assess the prognostic role of pretherapy partial volume corrected (PVC) 18F-fluorodeoxyglucose mean standardized uptake value (SUV) in breast cancer (BC). METHODS: Forty oncological patients, BC diagnosed by biopsy, with breast tumor mass diameter >1 cm measured to the mammography, designed for surgical intervention, underwent a pretherapy semi-quantitative 18F-FDG positron emission tomography/computed tomography (18F-FDG PET/CT) whole-body study for tumor staging. Mean Body-Weight Standardized Uptake Value with Correction for Partial Volume effect (PVC- SUVBW-mean) was calculated in all mammary detected lesions. Excised tissues from primitive BC were sectioned and classified according to the WHO guidelines, evaluating biological features. Univariate (Mann-Withney/Kruskal-Wallis) and multivariate (linear regression, hierarchical clustering) statistical tests were performed between PVC-SUVBW-mean and biological indexes. ROC analysis was performed. PVC-SUVBW-mean thresholds were derived allowing to distinguish groups of BC patients with different biological characteristics. Specificity and Sensitivity were also calculated. RESULTS: Statistical and multiple correlations between pretherapy 18F-FDG PET PVC-SUVBW-mean and histological type, grade, ER/PgR hormone receptors and Mib-1 cellular proliferation index were found. In our samples, PVC-SUVBW-mean <≈4 g/cc was found correlated to BC patients with Invasive Lobular Carcinoma (ILC) or well differentiated Invasive Ductal Carcinoma (IDC), a positive expression of ER and PgR and a negative expression of MiB-1, while PVC-SUVBW-mean >≈7.00 is associated to BC patients with moderately and poorly differentiated IDC, negative expression of ER and PgR and a positive expression of MiB-1. CONCLUSION: Pretherapy PVC 18F-FDG PET PVC-SUVBW-mean measurement correlates with prognostic factors in BC and could be used to stratify patients before intervention.

A partial volume effect correction tailored for 18F-FDG-PET oncological studies.

We have developed, optimized, and validated a method for partial volume effect (PVE) correction of oncological lesions in positron emission tomography (PET) clinical studies, based on recovery coefficients (RC) and on PET measurements of lesion-to-background ratio (L/B m) and of lesion metabolic volume. An operator-independent technique, based on an optimised threshold of the maximum lesion uptake, allows to define an isocontour around the lesion on PET images in order to measure both lesion radioactivity uptake and lesion metabolic volume. RC are experimentally derived from PET measurements of hot spheres in hot background, miming oncological lesions. RC were obtained as a function of PET measured sphere-to-background ratio and PET measured sphere metabolic volume, both resulting from the threshold-isocontour technique. PVE correction of lesions of a diameter ranging from 10 mm to 40 mm and for measured L/B m from 2 to 30 was performed using measured RC curves tailored at answering the need to quantify a large variety of real oncological lesions by means of PET. Validation of the PVE correction method resulted to be accurate (>89%) in clinical realistic conditions for lesion diameter > 1 cm, recovering >76% of radioactivity for lesion diameter < 1 cm. Results from patient studies showed that the proposed PVE correction method is suitable and feasible and has an impact on a clinical environment.

Nonpalpable breast lesions: preoperative radiological guidance in radioguided occult lesion localisation (ROLL).

PURPOSE: This study evaluated the methods, technical aspects and impact of preoperative radiological guidance in radioguided occult lesion localisation (ROLL) for single nonpalpable breast lesions. MATERIALS AND METHODS: A total of 288 patients underwent ROLL before surgery. Human serum albumin macroaggregates labelled with 3.7-7.4 MBq of technetium(99) were injected into the lesion. In the case of ultrasonographic guidance (221/288 patients), inoculum positioning resulted in a change of echogenicity at the lesion site. In the case of mammographic guidance (67/288 patients), iodinated contrast medium was injected following the radiotracer for subsequent mammographic evaluation. Patients underwent surgery within 24 h from ROLL. A gamma-detecting probe was used to locate the lesion during surgery and guide its removal. After excision, the specimen was examined by either ultrasonography or mammography to verify complete lesion removal before histological evaluation. RESULTS: The lesion was correctly localised in 281/288 patients (97.5%). One ROLL procedure failed because surgery could not be performed within 24 h and the radioactivity decayed. Of the six incorrect localisations, 2 were due to the radiological guidance and 4 to technetium(99) dispersion. CONCLUSIONS: Radiological guidance in ROLL ensured the outcome of the procedure of localisation and removal of single, nonpalpable breast lesions in the majority of cases.

Glutamate uptake is decreased in platelets from Alzheimer's disease patients.

Because excitotoxicity may be involved in neurodegeneration in Alzheimer's disease, we investigated possible modifications of platelet glutamate uptake in AD patients. High-affinity glutamate uptake was studied in platelets from 35 Alzheimer's disease patients, 10 multi-infarct dementia patients, and 35 age-matched normal controls; it was decreased by 40% in platelets from Alzheimer's disease patients compared with controls and with multi-infarct dementia patients. Platelet glutamate uptake could be used as peripheral marker of glutamatergic involvement and as adjunctive diagnostic tool in Alzheimer's disease patients.