Tumor Burden of Iodine-Avid Bone Metastatic Thyroid Cancer Identified via 18F-Sodium Fluoride PET/CT Imaging.

BACKGROUND: Patients with differentiated thyroid cancer (DTC) are referred to radioactive 131I (RAI) therapy and post-therapy 131I whole-body scintigraphy (WBS) to identify local and/or remote metastases. Positron emission tomography (PET)/computed tomography (CT) imaging with 18F-fluoro-D-glucose (FDG) or 18F-sodium fluoride (NaF) may also be used with these patients for the evaluation of bone metastases. We compared the role of 18F-NaF PET/CT and 18F-FDG-PET/CT in patients with DTC and documented bone metastases at post-therapy WBS. METHODS: Ten consecutive DTC patients with iodine avid bone metastasis at post-therapy WBS referred to 18F-NaF PET/CT and 18F-FDG PET/CT were studied. The findings of the three imaging procedures were compared for abnormal detection rates and concordance. RESULTS: At post-therapy 131I WBS, all patients had skeletal involvement with a total of 21 bone iodine avid lesions. At 18F-FDG PET/TC, 19 bone lesions demonstrated increased tracer uptake and CT pathological alterations, while 2 lesions did not show any pathological finding. At 18F-NaF PET/CT, the 19 bone lesions detected at 18F-FDG PET/TC also demonstrated abnormal tracer uptake, and the other 2 bone iodine avid foci did not show any pathological finding. CONCLUSIONS: In patients with DTC, 18F-NaF PET/CT did not obtain more information on the metastatic skeletal involvement than post-therapy 131I WBS and 18F-FDG PET/CT.

Efficacy of Empirical Radioiodine Therapy in Patients with Differentiated Thyroid Cancer and Elevated Serum Thyroglobulin without Evidence of Structural Disease: A Propensity Score Analysis.

We assessed the outcome of administration of empiric radioactive iodine (RAI) therapy to patients with differentiated thyroid cancer (DTC), in a propensity-score-matched cohort of patients with biochemical incomplete response (BIR) and without evidence of structural disease. We retrospectively evaluated 820 DTC patients without distant metastases, who underwent total thyroidectomy followed by RAI therapy, with available BIR at 12 months and follow-up evaluations. The patients were categorized according to the administration of empiric therapy (ET). To account for differences between patients with (n = 119) and without (n = 701) ET, a propensity-score-matched cohort of 119 ET and 119 no-ET patients was created. The need for additional therapy and the occurrence of structural disease were considered as end-points. During a median follow-up of 53 months (range 3-285), 57 events occurred (24% cumulative event rate). The rate of events was significantly higher in the no-ET compared to the ET patients (30% vs. 18% p < 0.001). The multivariate Cox analysis identified age (p < 0.01), pre-therapy Tg (p < 0.05) and empiric RAI therapy (p < 0.01) as predictors of outcome. The Kaplan-Meier analysis found that progression-free survival was lower in no-ET patients compared to the ET group (p < 0.01). In patients with DTC treated with surgery and RAI, and with biochemical incomplete response at the 12-month evaluation, their prognosis seemed to be affected by Tg values and the empiric treatment. The identification of candidates for this approach may improve prognosis.

Prognostic value of 12-month response to therapy in pediatric patients with differentiated thyroid cancer.

PURPOSE: In pediatric patients with differentiated thyroid cancer (DTC) we assessed the prognostic value of the 12-month response to therapy after initial treatment with surgery and radioactive iodine (RAI). METHODS: We retrospectively evaluated 94 pediatric patients with DTC, treated with surgery and RAI who were initially classified as low, intermediate or high risk of relapse of disease according to the American Thyroid Association (ATA) guidelines. Twelve months after RAI administration the response to therapy was assessed by serum thyroglobulin (Tg) measurement and neck ultrasound and patients were classified as having excellent response (ER) or no-ER. RESULTS: At the 12 months evaluation, 62 (66%) patients had ER and 32 (34%) no-ER. During a mean follow-up time of 86 months (range 9-517), 19 events occurred (20% cumulative event rate). Events occurred more frequently in younger patients (p < 0.05), in those at ATA intermediate/high risk (p < 0.01) and with a pre-RAI therapy Tg level > 10 ng/mL (p < 0.001), and in those with no-ER (p < 0.001). At multivariate analysis, the evidence of no-ER was the only independent predictor of events. CONCLUSION: In pediatric patients with DTC, the response to therapy evaluated 12 months after initial treatment has an independent prognostic impact and is able to predict mid-term outcome. Patients with no-ER at 12 months after RAI therapy should be closely followed-up.

Prognostic Value of Hybrid PET/MR Imaging in Patients with Differentiated Thyroid Cancer.

Background: Hybrid positron emission tomography (PET)/magnetic resonance (MR) is an emerging imaging modality with great potential to provide complementary data acquired at the same time, under the same physiological conditions. The aim of this study was to evaluate the prognostic value of hybrid 18F-fluorodeoxyglucose (FDG) PET/MR in patients with differentiated thyroid cancer (DTC) who underwent total thyroidectomy and radioactive iodine therapy for suspicion of disease relapse. Methods: Between November 2015 and February 2017, 55 patients underwent hybrid 18F-FDG PET/MR. Assessment of positive MR was made considering all sequences in terms of malignancy based on the morphological T2-weighted features and the presence of restricted diffusivity on diffusion-weighted imaging images and both needed to be positive on the same lesion. Both foci with abnormal 18F-FDG uptake, which corresponded to tissue abnormalities on the MR, and tracer accumulation, which did not correspond to normal morphological structures, were considered positive. Results: During follow-up (mean 42 ± 27 months), 29 patients (53%) had disease recurrence. In the Cox univariate regression analysis age, serum Tg level ≥ 2 ng/mL, positive short tau inversion recovery (STIR), and positive PET were significant predictors of DTC recurrence. Kaplan−Meier survival analyses showed that patients with Tg ≥ 2 ng/mL had poorer outcomes compared to those with serum Tg level < 2 ng/mL (p < 0.05). Similarly, patients with positive STIR and positive PET had a worst outcome compared to those with negative STIR (p < 0.05) and negative PET (p < 0.005). Survival analysis performed in the subgroup of 36 subjects with Tg level ≥ 2 ng/mL revealed that patients with positive PET had a worst outcome compared to those with negative PET (p < 0.05). Conclusions: Age, serum Tg level ≥ 2 ng/mL, positive STIR, and positive 18F-FDG PET were significant predictors of DTC recurrence. However, the serum Tg level was the only independent predictor of DTC. Hybrid PET/MR imaging may have the potential to improve the information content of one modality with the other and would offer new opportunities in patients with DTC. Thus, further studies in a larger patient population are needed to understand the additional value of 18F-FDG PET/MR in patients with DTC.

A Complex Radiomic Signature in Luminal Breast Cancer from a Weighted Statistical Framework: A Pilot Study.

Radiomics is rapidly advancing in precision diagnostics and cancer treatment. However, there are several challenges that need to be addressed before translation to clinical use. This study presents an ad-hoc weighted statistical framework to explore radiomic biomarkers for a better characterization of the radiogenomic phenotypes in breast cancer. Thirty-six female patients with breast cancer were enrolled in this study. Radiomic features were extracted from MRI and PET imaging techniques for malignant and healthy lesions in each patient. To reduce within-subject bias, the ratio of radiomic features extracted from both lesions was calculated for each patient. Radiomic features were further normalized, comparing the z-score, quantile, and whitening normalization methods to reduce between-subjects bias. After feature reduction by Spearman's correlation, a methodological approach based on a principal component analysis (PCA) was applied. The results were compared and validated on twenty-seven patients to investigate the tumor grade, Ki-67 index, and molecular cancer subtypes using classification methods (LogitBoost, random forest, and linear discriminant analysis). The classification techniques achieved high area-under-the-curve values with one PC that was calculated by normalizing the radiomic features via the quantile method. This pilot study helped us to establish a robust framework of analysis to generate a combined radiomic signature, which may lead to more precise breast cancer prognosis.

The best prostate biopsy sampling system-fusion and systematic biopsy: A single center experience.

BACKGROUND: Prostate cancer is the second most commonly diagnosed cancer in men. The diagnostic accuracy in prostate cancer can be increased by employing a preliminary multiparametric MRI followed by a fusion-targeted biopsy. METHODS: To compare the diagnostic accuracy of fusion-targeted biopsy with the standard systematic biopsy in prostate cancer patients, we enrolled 139 patients on which we performed 139 prostate biopsies consisting of three targeted samples followed by 12 regular systematic samples. Based on histology, we analyzed the diagnostic performance of the two methods. RESULTS: Both methods were equally good at detecting clinically significant cancer (83.3%, 50/60), while systematic biopsy detected more clinically insignificant cancers. However, the best diagnostic performance is obtained by combining the two methods. CONCLUSION: The two methods are best seen as synergistic, and the addition of fusion biopsy can be used to detect more clinically significant prostate cancers than systematic biopsy alone.

Second Primary Malignancies in Patients with Differentiated Thyroid Cancer after Radionuclide Therapy: A Retrospective Single-Centre Study.

Second primary malignancies (SPM) are described as any primary, not synchronous, malignancy arising in a different anatomical district, with confirmed histological diagnosis. Age at diagnosis, previous non-thyroidal primary malignancy, and radioactive iodine (RAI) therapy have been proposed as independent risk factors for SPM. RAI therapy is a standard treatment for moderate-high risk differentiated thyroid cancer (DTC), and its effect on the development of SPM has become a critical topic in DTC treatment. The purpose of this retrospective single-center study was to investigate the occurrence and the possible association of non-thyroidal SPM diagnosed after DTC and RAI therapy in a cohort of 1326 consecutive DTC patients referred at our Institution for RAI treatment from 1993 to 2009. Eighty-nine patients with ages ≤ 18 years at the time of DTC diagnosis or with a follow-up of ≤12 months were excluded from the final analysis. All patients underwent a complete clinical and hematological follow-up every 6 months for a minimum of 12 months. During follow-up (mean 89 ± 73 months), 25 patients (2%) had an SPM diagnosis (mean 133 ± 73 months). The most common site of the second malignancy was the breast, accounting for 32% of all SPM, followed by colon-rectal cancer (16%), leukemia, and gynecological and kidney cancer (4%). At Cox univariable regression analysis, age at DTC diagnosis (p < 0.001), age ≥55 years (p < 0.001) and follow-up duration (p < 0.004) were associated with SPM onset, while no significant association was observed with the administered activity of radioiodine. In conclusion, our data suggest that the older a person gets, the more sharply the likelihood of developing additional diseases, such as PMS, increases. Similarly, for follow-up, the more a patient is followed up clinically over time, the higher the risk of new diagnoses increases.

Long-Term Prognostic Value of the Response to Therapy Assessed by Laboratory and Imaging Findings in Patients with Differentiated Thyroid Cancer.

This study assessed the long-term predictive value of the response to therapy, evaluated by serum thyroglobulin (Tg) determination and neck ultrasound, and estimated the potential additional impact of diagnostic whole-body scan (WBS) in patients with differentiated thyroid cancer (DTC) treated with surgery and radioactive iodine (RAI) therapy. We retrospectively evaluated 606 DTC patients treated with surgery and RAI. Response to 131I therapy at 12 months was assessed by serum Tg measurement, neck ultrasound, and diagnostic WBS. According to American Thyroid Association (ATA) guidelines, patients were classified as having a low, intermediate or high risk of recurrence and at 12 months as having an excellent response (ER) or no-ER. Follow-up was then performed every 6-12 months with serum Tg determination and imaging procedures. With a median follow-up of 105 months (range 10-384), 42 (7%) events requiring further treatments occurred. Twenty-five patients had additional RAI therapy, 11 with structural disease in the thyroid bed, eight in both thyroid bed and neck lymph nodes, four had lung metastases and two had bone metastases. The other 17 patients had additional surgery for nodal disease followed by RAI therapy. The ATA intermediate and high risk of recurrence, post-operative and pre-RAI therapy Tg ≥ 10 ng/mL, and the absence of ER at 12 months were independent predictors of events. Diagnostic WBS at 12 months permitted the identification of only five recurrences among the 219 ER patients according to serum Tg levels and ultrasound. In DTC patients, the response to therapy at 12 months after RAI therapy could rely on serum Tg measurement and neck ultrasound, while diagnostic WBS was not routinely indicated in patients considered in ER.

Combined bone scintigraphy and fluorocholine PET/computed tomography predicts response to radium-223 therapy in patients with prostate cancer.

AIM: To assess the value of bone scintigraphy and 18F-fluorocholine PET/computed tomography (CT) in predicting outcome in patients with prostate cancer and bone metastases treated with 223radium. MATERIALS & METHODS: Retrospective analysis of 48 patients that underwent 223radium therapy. End points were pain relief and overall survival. RESULTS: After therapy, pain relief was observed in 27 patients. Patients without pain relief had more bone lesions at PET/CT than at bone scintigraphy (pretherapy imaging mismatch). In 39 patients who completed treatment protocol, post-therapy alkaline phosphatase and pretherapy imaging mismatch were independent predictors of poor overall survival. CONCLUSION: Patients with more lesions at 18F-fluorocholine PET/CT than at bone scintigraphy had a poor prognosis. The combined imaging approach could be useful to predict outcome after 223radium therapy.

PET/CT in the management of differentiated thyroid cancer.

The standard treatment of differentiated thyroid cancer (DTC) consists of surgery followed by iodine-131 (131I) administration. Although the majority of DTC has a very good prognosis, more aggressive histologic subtypes convey a worse prognosis. Follow-up consists of periodically measurements of serum thyroglobulin, thyroglobulin antibodies and neck ultrasound and 123I/131I whole-body scan. However, undifferentiated thyroid tumors have a lower avidity for radioiodine and the ability of DTC to concentrate 131I may be lost in metastatic disease. Positron emission tomography (PET)/computed tomography (CT) has been introduced in the evaluation of patients with thyroid tumors and the 2-[18F]-fluoro-2-deoxyd-glucose (18F-FDG) has been largely validated as marker of cell's metabolism. According to the 2015 American Thyroid Association guidelines, 18F-FDG PET/CT is recommended in the follow-up of high-risk patients with elevated serum thyroglobulin and negative 131I imaging, in the assessment of metastatic patients, for lesion detection and risk stratification and in predicting the response to therapy. It should be considered that well-differentiated iodine avid lesions could not concentrate 18F-FDG, and a reciprocal pattern of iodine and 18F-FDG uptake has been observed. Beyond 18F-FDG, other tracers are available for PET imaging of thyroid tumors, such as Iodine-124 (124I), 18F-tetrafluoroborate and Gallium-68 prostate-specific membrane antigen. Moreover, the recent introduction of PET/MRI, offers now several opportunities in the field of patients with DTC. This review summarizes the evidences on the role of PET/CT in management of patients with DTC, focusing on potential applications and on elucidating some still debating points.

MRI to assess deep myometrial invasion in patients with endometrial cancer:A multi-reader study to evaluate the diagnostic role of different sequences.

OBJECTIVE: The identification of deep myometrial invasion (DMI) represents a fundamental aspect in patients with endometrial cancer (EC) for accurate disease staging. It can be detected on MRI using T2-weighted (T2-w), diffusion weighted (DWI) and dynamic contrast enhanced sequences (DCE). Aim of the study was to perform a multi-reader evaluation of such sequences to identify the most accurate and its reliability for the best protocol. METHODS: In this multicenter retrospective study, MRI were independently evaluated by 4 radiologists (2 senior and 2 novice) with a sequence-based approach to identify DMI. The performance of the entire protocol was also evaluated. A comparison between the different sequences assessed by the same reader was performed using receiver operating curve and post-hoc analysis. Intraclass Correlation Coefficient (ICC) was used to assess inter- and intra-observer variability. RESULTS: A total of 92 patients were included. The performance of the readers did not show significant differences among DWI, DCE and the entire protocol. For only one senior radiologist, who reached the highest diagnostic accuracy with the entire protocol (82,6 %), both DWI (p = 0,0197) and entire protocol (p = 0,0039) were found significantly superior to T2-w. The highest inter-observer agreement was obtained with the entire protocol by expert readers (ICC = 0,77). CONCLUSIONS: For the detection of DMI, the performances of DWI and DCE alone and that of a complete protocol do not significantly differ, even though the latter ensures the highest reliability particularly for expert readers. In cases in which T2-w and DWI are consistent, an unenhanced protocol could be proposed.

Prognostic value of 18F-FDG PET/MRI in patients with advanced oropharyngeal and hypopharyngeal squamous cell carcinoma.

OBJECTIVE: The aim of this study was to evaluate the prognostic value of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) parameters provided by simultaneous 18F-fluorodeoxyglucose (FDG) PET/MRI in patients with locally advanced oropharyngeal and hypopharyngeal squamous cell carcinomas (OHSCC). METHODS: Forty-five patients with locally advanced OHSCC who underwent simultaneous FDG PET/MRI before (chemo)radiotherapy were retrospectively enrolled. Peak standardized uptake value (SULpeak), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were obtained on PET data. On MRI scans, primary tumor size, diffusion and perfusion parameters were assessed using pre-contrast and high-resolution post-contrast images. Ratios between metabolic/metabolo-volumetric parameters and ADC were calculated. Comparisons between groups were performed by Student's t test. Survival analysis was performed by univariate Cox proportional hazard regression analysis. Overall survival curves were obtained by the Kaplan-Meier method and compared with the log-rank test. Survivors were censored at the time of the last clinical control. p < 0.05 was considered statistically significant RESULTS: During follow-up (mean 31.4 ± 21 months), there were 15 deaths. Univariate analysis shows that SULpeak and SULpeak/ADCmean were significant predictors of overall survival (OS). At multivariate analysis, only SULpeak remained a significant predictor of OS. Kaplan-Meier survival analyses showed that patients with higher SULpeak had poorer outcome compared to those with lower values (HR: 3.7, p = 0.007). CONCLUSION: Pre-therapy SULpeak of the primary site was predictive of overall survival in patients with oropharyngeal or hypopharyngeal cancer treated with (chemo)radiotherapy.

Risk of structural persistent disease in pediatric patients with low or intermediate risk differentiated thyroid cancer.

PURPOSE: In pediatric patients with differentiated thyroid cancer (DTC), the risk of recurrence is high and the indication for postoperative 131I administration is still debated. The aim of this study was to assess the outcome in low and intermediate risk pediatric DTC patients. METHODS: We retrospectively evaluated 45 pediatric patients with low or intermediate risk DTC, treated with surgery and 131I between 1992 and 2002 and with no detectable antithyroglobulin (Tg) antibodies. Follow-up was performed every 6-12 months with Tg blood level determination and imaging procedures. RESULTS: During follow-up (64 ± 53 months), 15 events occurred (33% cumulative event rate, with an annual event rate of 5% person years). Five of these patients were submitted to additional surgery and all these 15 patients underwent a second 131I treatment course. All patients were alive at the end of the follow-up. Structural persistent disease occurred more frequently in patients at intermediate risk (p < 0.01) and in those with Tg values after thyroid hormone withdrawal >10 ng/ml before 131I therapy (p < 0.01). At multivariate analysis, only a postoperative thyroid stimulating hormone-stimulated Tg level >10 ng/ml was an independent predictor of persistent disease. CONCLUSIONS: In pediatric patients with DTC, postoperative high stimulated Tg values (>10 ng/ml) should be taken into account for deciding the extent of both initial treatment and follow-up.

MR-enterography in Crohn's disease: what MRE mural parameters are associated to one-year therapeutic management outcome?

OBJECTIVE: To investigate the association of mural parameters of MR-enterography (MRE) with one-year therapeutic management of Crohn's disease (CD) patients. METHODS: CD patients, undergone MRE with diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps between January 2017 and June 2018, were retrospectively enrolled. Extramural complications represented an exclusion criterion because of their potential influence on the intrinsic characteristic of the bowel wall. Two groups of patients were defined on the base of the therapeutic management adopted at 1-year follow-up: Medical-group and surgical-group. The following MRE parameters were evaluated: wall-thickening, longitudinal-extension, T2-fat-suppression-mural-signal, ulcers, mural-oedema, wall-enhancement-rate/pattern, DWI-scores, ADC-values, strictures. RESULTS: 70 CD patients were enrolled. 57/70 (81.4%) were included in Medical-group and 13/70 (18.6%) in Surgical-group. ADCmean and strictures resulted to be significantly (p < 0.01) different between the two groups. The ADCmean showed to be significantly associated to conservative management [p < 0.01; OR: 0.0003; 95% CI (0.00-0.13)], while the strictures to surgical management [p < 0.01; OR: 29.7; 95% CI (4.9-179.7)]. ROC curves for ADCmean showed that AUC was 0.717 [95% CI (0.607-0.810), p < 0.01] with an optimal cut-off value of 1.081 × 10-3 mm2 s-1. A negative predictive value of 90.2% was observed associating ADCmean values > 1.081 × 10-3 mm2 s-1 to conservative therapy. 13/17 (76%) strictures with an ADCmean > 1.081 × 10-3 mm2 s-1 benefited of conservative therapy. CONCLUSION: ADCmean values calculated on DWI-MRE may be associated to 1-year conservative medical therapy in patients with CD without extramural complications. ADVANCES IN KNOWLEDGE: ADC maps may be proposed to select CD patients with a lower burden of mural active inflammatory cells and/or fibrosis benefiting of 1-year conservative treatment.

Comparison of simultaneous 18F-2-[18F] FDG PET/MR and PET/CT in the follow-up of patients with differentiated thyroid cancer.

AIMS: 18F-FDG PET/CT is the most accurate imaging modality in differentiated thyroid cancer (DTC) patients with either an aggressive histology, an absence of radioiodine uptake in neoplastic foci, or in the absence of imaging abnormalities in patients with an elevated serum thyroglobulin (Tg) level that progresses with time. We evaluated the diagnostic performance of FDG PET/MR in comparison with that of PET/CT. METHODS AND RESULTS: Following the injection of a single 18F-FDG activity, PET/MR and PET/CT were sequentially performed in 40 consecutive patients with DTC previously treated with total thyroidectomy and radioiodine ablation. All patients were then followed up for at least 6 months. PET/MR was positive in 11 patients and PET/CT in 10. PET/MR detected 33 tumor foci and PET/CT 30. During the follow-up of the 12 patients with negative initial PET studies and with a detectable serum Tg, only one patient had a neck recurrence and the administration of an empiric high activity of 131I in the other 11 patients did not reveal any tumor focus. In the 17 patients with an initial serum Tg level < 2 ng/mL, no recurrence occurred. CONCLUSION: This study confirms the high diagnostic accuracy of FDG PET studies in DTC patients with elevated serum Tg levels and shows that PET/MR brings similar information as compared to PET/CT imaging.

Brown Adipose Tissue in Breast Cancer Evaluated by [18F] FDG-PET/CT.

PURPOSE: Recently brown adipose tissue (BAT) activation has been proposed to have a possible role in breast cancer. The aim of this study was to evaluate BAT activation in patients with breast cancer and its relationship with molecular characteristics of tumor. PROCEDURES: The study group comprised 79 patients with histologically proven ductal breast carcinoma (51 ± 13 years). Data on distribution, intensity (SUVmax), and total metabolic activity (TMA) of BAT were obtained from [18F] FDG-PET/CT. Clinical and biochemical data were obtained from the database. RESULTS: BAT activation was present in 12 of the 79 patients (15.2 %). Patients with BAT activation were younger and had a lower body mass index (BMI) (p < 0.05 and p < 0.0005, respectively) and showed less frequently metastasis (p < 0.05). No significant differences were found in estrogen receptor (ER), progesterone receptor (PgR), Ki67, grade, and in molecular subtypes. In patients younger than 55 years and with a BMI < 26, no significant differences were observed between patients with and without BAT activation. In the 12 patients with BAT activation, a significant inverse correlation was observed between TMA and BMI (r = - 0.64, p < 0.05). TMA and SUVmax were higher in grade 2 than in grade 3 patients. No significant differences were found in both TMA and SUVmax between patients with and without lymph node metastases. A significant difference in both TMA and SUVmax was observed among different molecular types, with luminal B patients showing higher values. CONCLUSIONS: In conclusion, the present study suggests a relation between BAT activation and positive known prognostic factor in breast cancer, such as intermediate tumor grade and luminal B cancer type.

2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography in primary extranodal lymphomas: treatment response evaluation and prognosis.

BACKGROUND: We evaluated the role of [18F]FDG PET/CT in tumor response assessment and prognosis of primary extranodal lymphoma (PEL) patients. METHODS: We examined retrospectively, 56 PEL patients: 31 with aggressive diffuse large B cell lymphoma (DLBCL) and 25 with indolent lymphoma (20 mucosa-associated lymphoid tissue lymphoma and five follicular lymphoma). All patients had undergone [18F]FDG PET/CT at diagnosis (PET-I) and 50 of them also after therapy (PET-II). Moreover, 52 patients were subjected to a mean follow-up period of 76 months. RESULTS: PET-I was positive in 50 (89%) patients (mean SUVmax 10.3±6.7). In the assessment of tumor response, according to Lugano classification, 45 patients showed complete metabolic response (CMR), four patients had partial metabolic response (PMR) and one had progressive metabolic disease (PMD). Based on 66% ΔSUVmax cut-off, among CMR patients, 41 showed a ΔSUVmax>66% whereas among non-responders, four patients showed a ΔSUVmax<66%. At follow-up, univariate analysis showed that age, performance status, prognostic index, ΔSUVmax and Lugano classification predicted progression-free survival (PFS) (P<0.05), while, performance status, prognostic index, ΔSUVmax and Lugano classification predicted overall survival (OS) (P<0.05). At multivariate analysis only Lugano classification was retained in the model for prediction of both PFS (P<0.05) and OS (P<0.05). By Kaplan-Meier analysis and log-rank testing both PFS and OS were significantly better in patients in CMR as compared to patients in PMR or PMD according to Lugano classification (P<0.01). CONCLUSIONS: [18F]FDG PET/CT represents a useful tool in the detection of disease response and in the evaluation of outcome in PEL patients.

Visual and volumetric parameters by 18F-FDG-PET/CT: a head to head comparison for the prediction of outcome in patients with multiple myeloma.

In multiple myeloma (MM) patients, 18F-FDG-PET/CT allows either the detection of disease spread by using visual parameters based on the Italian Myeloma criteria for PET Use (IMPeTUs) or the direct measurement of metabolic tumor burden by volume-based parameters such as metabolic tumor volume (MTV). The purpose is to evaluate the contribution of visual and volumetric parameters in the prediction of progression-free survival (PFS) and overall survival (OS) in MM patients. Forty-seven patients in stage IIIA who had undergone whole-body 18F-FDG-PET/CT were retrospectively evaluated. In each patient, visual parameters were determined and compared with volumetric parameters for PFS and OS prediction after a mean follow-up period of 53 months. Among the visual and volumetric parameters tested, a statistically significant difference was found between maximum standardized uptake value, MTV, total lesion glycolysis, and number of lytic lesions of patients with (n = 26) or without (n = 21) progression (p = 0.0400, p = 0.0065, p = 0.015, and p = 0.0220, respectively) and of dead (n = 24) vs survivors (n = 23) (p = 0.0171, p = 0.0037, p = 0.0060, and p = 0.0270, respectively). At univariate and multivariate analysis, MTV and hemoglobin were predictive of both PFS (p = 0.008) and OS (p = 0.0026). The best MTV discriminative value assessed by receiver operating characteristic curve analysis for predicting both PFS and OS was 39.4 ml. By Kaplan-Meier analysis and log-rank test, PFS and OS were significantly better in patients with MTV ≤ 39.4 ml (p = 0.0004 and p = 0.0001, respectively) as compared with those having an MTV higher than the cutoff. The volume-based parameter MTV determined by 18F-FDG-PET/CT may be used in the prediction of PFS and OS in myeloma patients.

Clinically significant prostate cancer detection on MRI: A radiomic shape features study.

PURPOSE: Prostate multiparametric MRI (mpMRI) is the imaging modality of choice for detecting clinically significant prostate cancer (csPCa). Among various parameters, lesion maximum diameter and volume are currently considered of value to increase diagnostic accuracy. Quantitative radiomics allows for the extraction of more advanced shape features. Our aim was to assess which shape features derived from MRI index lesions correlate with csPCa presence. MATERIALS AND METHODS: We retrospectively enrolled 75 consecutive subjects, who underwent mpMRI on a 3 T scanner, divided based on MRI index lesion Gleason Score in a csPCa group (GS > 3 + 4, n = 41) and a non-csPCa one (n = 34). Ten shape features were extracted both from axial T2-weighted and ADC maps images, after lesion tridimensional segmentation. Univariable and multivariable logistic analysis were used to evaluate the relationship between shape features and csPCa. Diagnostic performance was assessed measuring the area under the curve of the receiver operating characteristic (ROC) analysis. Diagnostic accuracy, sensitivity, and specificity were determined using the best cut-off on each ROC. A P value < 0.05 was considered statistically significant. RESULTS: Univariable analysis demonstrated that almost every shape feature was statistically significant between csPCa e non-csPCa groups. However, multivariable analysis revealed that the parameter defined as surface area to volume ratio (SAVR), especially when extracted from ADC maps is the strongest independent predictor of csPCa among tested shape features. CONCLUSION: The radiomic shape feature SAVR, extracted from ADC maps after index lesion segmentation, appears as a promising tool for csPCa detection.

Outcome of Patients With Differentiated Thyroid Cancer Treated With 131-Iodine on the Basis of a Detectable Serum Thyroglobulin Level After Initial Treatment.

Background: In patients with differentiated thyroid cancer (DTC) and raising serum thyroglobulin (Tg) after total or near-total thyroidectomy and 131I remnant ablation an empiric 131I therapy may be considered. However, outcome data after empiric therapy in did not show a clear evidence of improved survival. We assessed the efficacy of such empiric 131I therapy in patients with DTC and evaluated the long-term outcome. Methods: A total of 100 patients with DTC showing raised Tg level during follow-up after thyroidectomy and 131I ablation were treated with a further 131I therapy (6.1 ± 1.7 GBq). Whole-body scan (WBS) was performed 5-7 days after therapy. Tg value at 12 months after 131I therapy was considered as an indicator of treatment response: ≤1.5 ng/ml complete remission (CR), >50% decrease partial remission (PR), higher than pre-therapy progression disease (PD), all other cases stable disease (SD). Patients were followed-up for 96 ± 75 months. Results: After 12 months, 62% of patients were in CR, 16% in PR, 8% in SD, and 14% in PD. WBS was positive in 41% of patients and negative in 59% (P = NS). Among patients with local recurrences at WBS 89% showed either CR or PR, while 71% of patients with distant metastases were in SD or PD (P < 0.001). Distant metastases at WBS (P < 0.05), CR (P < 0.0001), and CR + PR (P < 0.0001) were predictors of both progression free survival and overall survival. Conclusion: There is a beneficial effect of 131I therapy on outcome of patients with DTC treated on the basis of elevated Tg value. In these patients, survival is affected by achievement of CR or PR at 12 months evaluation after 131I therapy and by the presence of distant metastases at WBS.