Progression to Symptomatic Multiple Myeloma Predicted by Texture Analysis-Derived Parameters in Patients Without Focal Disease at 18F-FDG PET/CT.

This retrospective study is focused on the possible clinical implications of texture analysis-derived PET parameters in patients with smoldering multiple myeloma. Several texture features are significantly associated with progression to symptomatic multiple myeloma and with a shorter time to progression. The results of this study may lead to early identification of patients who could benefit from specific therapies. BACKGROUND: The aim of the study was to determine whether positron emission tomography parameters derived from texture analysis of axial and peripheral skeleton predict progression to symptomatic multiple myeloma (MM) in patients undergoing 18F-​fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) without evidence of focal sites of 18F-FDG uptake. PATIENTS AND METHODS: Patients with smoldering MM who underwent 18F-FDG PET/CT from May 2014 to June 2018 were retrospectively reviewed. Volumes of interest (VOIs) were placed on T5-T7 and L2-L4, iliac crests, and femoral diaphyses. Dedicated software (LIFEx) allowed us to obtain PET-derived first-, second-, and higher order texture features. Possible associations between PET parameters and progression to symptomatic MM were determined. Kaplan-Meier curves allowed to assess time to progression (TTP) based on the PET parameters. RESULTS: Forty-five patients were included: 26 patients (58%) did not meet the criteria for symptomatic MM, but 19 patients (42%) progressed to symptomatic MM. Several texture features extracted from VOIs placed on iliac crests and femoral diaphyses were significantly associated with progression to symptomatic MM and with a shorter TTP (P < .05); conversely, the above-mentioned parameters extracted from VOIs placed on T5-T7 and L2-L4 did not significantly differ among the patients with regard to their progression to symptomatic MM and length of TTP, except for the gray-level zone length matrix-short-zone low-gray-level emphasis and gray-level zone length matrix-low gray-level zone emphasis. Particularly, second- and higher order texture features showed a significant association with the above-mentioned outcomes. CONCLUSION: Texture features derived from PET may be an expression of subtle disease distribution in the axial and peripheral bone marrow.

A Case of Primary Localized Small Bowel Amyloidosis Studied by 18F-Choline and Contrast-Enhanced 18F-FDG PET/CT.

Amyloidosis is a rare hereditary or acquired protein deposition disorder with different etiologies, characterized by pathological protein deposition essentially in nearly any organs or tissues. There are 2 major forms: primary and secondary amyloidosis. Moreover, it is possible to have systemic or localized disease. The localized form of amyloidosis affecting the small intestine is rare, and it is characterized by the formation of precursor proteins at the site of the lesion. We report a case of localized small bowel amyloidosis studied by F-choline and F-FDG-iodinated PET/CT performed for staging an aggressive prostatic cancer.

The prognostic role of FDG PET/CT before combined radio-chemotherapy in anal cancer patients.

OBJECTIVE: We assessed the prognostic value of several FDG PET/CT parameters, measured within the primary tumor and the involved lymph nodes, before definitive radio-chemotherapy (RCT) in anal cancer patients. METHODS: Anal cancer patients with positive baseline FDG PET/CT who underwent definitive RCT from May 2011 to February 2018 were retrospectively assessed. Primary tumour (T)-SUVmax, T-SUVpeak, T-SUVmean, T-MTV, T-TLG, whole-body (WB) MTV, and WB-TLG were measured. Kaplan-Meier curves, Cox-regression analysis, and logistic regression machine-learning technique were used to test for associations between clinical data, metabolic parameters, and outcomes as overall survival (OS), disease-specific survival (DSS), metastatic-free survival (MFS), disease-free survival (DFS), local relapse-free survival (LRFS), and colostomy-free survival (CFS). RESULTS: Fifty-nine patients were included in the study. Median follow-up was 28 months. Higher pre-treatment WB-MTV, T-TLG, and WB-TLG were associated with worse OS (p = 0.025, 0.021, and 0.02, respectively). PET parameters resulted also statistically significant for DSS, DFS, and CFS (p = 0.032, 0.043, 9 × 10-4 for WB-TLG). Cox analysis showed that PET parameters are significant predictors of OS, DSS, DFS, CFS, and LRFS. On multivariate analysis, age, stage, T-SUVpeak, WB-MTV, and T-TLG resulted significantly related to OS. A further stratification for patients with advanced stage (cT3-4 any N or any cT, N + ) showed that MTV and TLG, measured within the primary tumor and the involved nodes, are significantly higher in patients with a worse prognosis. In this subgroup, cut-off values of T- and WB-TLG as well as T- and WB-MTV showed a statistically significant correlation with clinical outcomes. CONCLUSIONS: Pre-treatment metabolic parameters measured within the primary tumor and the involved nodes may represent additional new biomarkers for estimating prognosis in anal cancer patients, especially in advanced stage patients.

Prognostic significance of normalized FDG-PET parameters in patients with multiple myeloma undergoing induction chemotherapy and autologous hematopoietic stem cell transplantation: a retrospective single-center evaluation.

PURPOSE: The purpose of this study was to determine retrospectively, through a single-center evaluation, whether FDG PET-CT normalized semi-quantitative parameters may predict response to induction chemotherapy (iChT) and hematopoietic stem cell transplantation (HSCT), as well as disease progression and progression-free survival in multiple myeloma (MM) patients, thus becoming a tool of personalized medicine. METHODS: Patients undergoing iChT and HSCT with baseline and post-treatment FDG PET-CTs from January 2008 to July 2015 were included. The following baseline and post-treatment parameters were obtained: SUVmax, SUVmean, SUVpeak, MTVsum, TLGsum, rPET (lesion SUVmax/liver SUVmax) and qPET (lesion SUVpeak/liver SUVmean). Baseline-to-post-treatment changes (Δ) were also calculated. Metabolic and clinical laboratory progression or response at follow-up were noted; time-to-metabolic-progression (TMP) was defined as the interval from post-treatment scan to eventual progression at follow-up FDG PET-CTs. Possible association between each functional parameter and metabolic/clinical-laboratory progression or response was determined. Kaplan-Meier curves allowed to depict the TMP trend according to FDG PET-CT parameters. RESULTS: Twenty-eight patients were included. Significantly higher ΔrPET and ΔqPET values were observed in ten patients with "metabolic response", with respect to 18 patients having "metabolic progression" (median 0.62 [IQR 0.32 - 1.34] vs median 0.00 [IQR -0.25 - 0.49] for ΔrPET; P = 0.045; median 0.51 [IQR 0.32 - 1.13] vs median 0.00 [IQR -0.31 - 0.67] for ΔqPET; P = 0.035). Neither normalized nor non normalized parameters differed significantly between the 20 patients with "clinical-laboratory response" and the eight patients with "clinical-laboratory progression". ΔrPET value lower than 0.38 and ΔqPET value lower than 0.27 predicted a significantly shorter TMP (P = 0.003 and P = 0.005, respectively). CONCLUSIONS: Normalized semi-quantitative parameters are effective in predicting persistent response to treatment and shorter TMP in patients with MM undergoing iChT and HSCT.