Prevalence and clinical impact of incidental findings on the unenhanced CT images of PET/CT scan in patients with multiple myeloma: the value of radiological reporting in the multimodal hybrid imaging

OBJECTIVE

In the hybrid Positron Emission Tomography/Computed Tomography (PET/CT) method, the functional evaluation is integrated with the morphological information provided by co-registered CT, still performed for attenuation correction and lesion localization. However, co-registered CT images could provide additional diagnostic information that PET alone could underestimate. To optimize the diagnostic potential of this hybrid examination, we evaluated the prevalence and the clinical significance of incidental findings detected on co-registered CT images in a cohort of multiple myeloma (MM) patients.

PATIENTS AND METHODS

We evaluated 112 MM patients (mean age 65.8 y), who underwent [18F]FDG-PET/CT during their regular workup. All co-registered CT images were retrospectively reviewed by two expert radiologists and each non-myelomatous incidental finding (nM-IF) was collected and clinically graded according to a nM-IF Reporting and Data System (nM-RADS). In addition, nM-IFs were classified according to anatomic localization (skull, lung, mediastinum, abdomen, breast, gastrointestinal, genitourinary and cardiovascular system and muscle/soft tissue).

RESULTS

163 nM-IFs were detected in 94/112 patients (83.9%) (mean value: 1.5 IFs per patient). The most interested anatomic districts were the lung (n=33; 20.2%), genitourinary (n=33; 20.2%) and gastrointestinal (n=30; 18.4%) systems. Focusing on the clinically significant findings (nM3+nM4), 92/163 (56.4%) IFs could have been required further investigations, of which 38/163 (23.3%) were potentially important and detected in 33/112 (29.5%) patients.

CONCLUSIONS

The high percentage of potentially clinically significant IFs detected in MM patients emphasizes that co-registered CT images hold precious information often missed. Giving more relevance to co-registered CT with tailored acquisition and reconstruction protocols and dedicated reporting could optimize the potentiality of this multimodality imaging method with impact on clinical management.

Impact of pre-treatment variables on the completion of 223radium-dichloride therapy in mCRPC patients with bone metastases

INTRODUCTION

Radium-223 dichloride (²²³Ra) is an alpha-particle-emitter radiopharmaceutical, approved for metastatic castration-resistant prostate cancer (mCRPC) patients with symptomatic bone metastases and no visceral involvement. Its administration is based on a schedule of intravenous injection (55kBq/kg) every four weeks for up to six cycles. Because the biological effectiveness of ²²³Ra-therapy is dose-dependent, the main goal is to complete the entire treatment to achieve a better patient outcome. This study aims to identify potential pre-treatment variables that could impact on ²²³Ra-treatment completion and then be used to improve the clinical and supportive management of mCRPC patients.

MATERIALS AND METHODS

30 consecutive mCRPC patients (mean age 77 years old), who were admitted for Ra223-therapy at our Department from February 2016 to October 2018, were enrolled for the analysis. The population was grouped as patients who completed ²²³Ra-therapy (group Ra223-C) and patients who do not (group ²²³Ra-U). For each group, we analyzed the effects of potential pre-treatment variables (age, Gleason Score, tumor burden, "Time From Diagnosis To ²²³Ra therapy", type and number of previous treatments, hemoglobin level, Alkaline Phosphatase, Prostate Specific Antigen and pain) on the Ra223-therapy completion. Statistical analysis was performed to evaluate the association between the completion of ²²³Ra therapy and the variables examined.

RESULTS

16/30 (53%) patients were ²²³Ra-C, conversely 14/30 (47%) patients were ²²³Ra-U because of an early interrupted treatment. A statistically significant association was found only with tumor burden: 68.7% of patients who completed ²²³-therapy had less than 20 bone metastases (χ²=4.821, p=0.028).

CONCLUSION

Our preliminary analysis demonstrates that the high tumor burden represents the most important pre-treatment factor that could affect treatment completion and that needs to be considered before starting ²²³Ra-therapy to achieve a better outcome in mCRPC patients.

The paleoradiology importance in the study of relics: the unique densitometric analysis of a bone relic of Saint Nicholas

INTRODUCTION

DXA have greatly contributed to the development of paleoradiology, a branch of diagnostic imaging that allows to obtain information about human remains in contexts of archaeological and/or forensic interest. In this manuscript we report the unique experience of DXA performed on the relic of a Saint; in particular we analyzed a skeletal fragment of St. Nicholas, kept in the Basilica of Bari (Italy) since 1087.

MATERIALS AND METHODS

The bone to be examined consisted of the posterior arch of the ninth left rib that was 12cm long, 1.2cm maximum width and 1.7cm thick at the body. The data acquired from the densitometric study were performed using the anthropometric measures reported in historical records of St. Nicholas' life: sex (male), age (75 years), weight (70kg), height (167cm), and ethnicity (Caucasian). In addition to the examination of the relic, a comparison assessment was made with the rib of a healthy 60 years old man (height of 170cm, without known skeletal pathologies). This sample had a length of 19cm, maximum width at the head 1cm, and 0.7cm thick at the body. The analysis of bone fragments is different from the analysis of bones in the context of the human body (where soft tissues are placed around the skeleton); for this reason, one of the most critical issues was to create a support that would allow the analysis of bone fragments. We simulated conditions similar to those occurring in patients: a density scale was established, using a specific plexiglass phantom on which the bone fragments to be examined were placed. From the analysis it was calculated the parameter bone mineral density (BMD), express in g/cm², that indicates the relation between mass of bone mineral content and area of examined bone segment. BMD data was compared to a range normalized by age, sex and ethnicity (BMD-N).

RESULTS

The results of the scannnig of St. Nicholas' rib showed a BMD of 0.97g/cm² with a BMD-N between 0.77 and 1.08g/cm². Simultaneous measurements of the relic compared with a reference rib showed highlighted BMD of 0.84g/cm² for the relic and 0.50g/cm² for the reference rib. The St. Nicholas data are 168% higher than reference bone. All our measurements of the relic indicated a high bone mineral density, most likely due to the presence of a high concentration of calcium salts. A relatively higher mineral density of the relic was seen compared to the healthy subject's rib. From the history of St Nicholas' life, we know of the long imprisonment at the age of 51 in damp and unhealthy environment. The results of this study suggest that a good bone mineral density was maintained by the Saint even in old age. An additional element that can influence bone mineral density is diet, certainly different during the time of St. Nicholas. The good bone densitometry indicates that the Saint maintained a proper diet, with a generally fair state of health.

CONCLUSION

For this first DXA analysis of the rib relic of Saint Nicholas was necessary a long and complex experimental work to modify standard technique procedure to particular and unusual sample and Create specific supports and complementary instruments. Perform DXA analysis on relics permit to obtain additional information to living conditions, economical situation, behaviours, diet, diseaes, conservations conditions of remains, change of life style in different age. Our experimental work, the first of its kind, creates the way to analyze precious relics that often include only few bone fragments and data obtained by our work can be useful for a better management and movement of fragile relics. We ourselves are working on a new challenge for the analysis of bone finds from shipwrecks found at the bottom of the sea.

Use of amyloid PET/CT with 18F-Florbetaben in the management of patients with Alzheimer's disease

INTRODUCTION AND AIM

Amyloid PET/CT is an "in vivo" imaging that may radically change management of Alzheimer's disease (AD) thanks to its ability to identify AD at the earliest stage. A diagnosis of dementia is currently made in terms of probability and is based on clinical evaluation (neuropsycological tests) as well as on the results of morphological imaging investigations (MRI) that can be supported by biohumoral (CSF analysis), and functional imaging only in the case of uncertain diagnosis of disease. The present study aimed to evaluate the role of amyloid PET/CT in the management of patients with suspicion of AD, through comparison with instrumental and clinical evaluation.

METHODS

38 consecutive patients with suspicion of AD (23 female, 15 male; median age 63 years old, range 46-72), who performed ¹⁸F-florbetaben PET/CT, were retrospectively reviewed. All of them performed a previous instrumental evaluation. A subgroup of patients (24/38) were evaluated with Mini Mental State Examination (MMSE). Cohen's K test was used as a measure of agreement between previous instrumental examinations/clinical evaluation and beta-amyloid PET results.

RESULTS

Twenty-five/38 (65.8%) amyloid PET/CT scans resulted positive for amyloid deposition. Among the four target regions, precuneus was the most frequently involved. Previous instrumental evaluation was: MRI in 26/38 patients (24/26 positive for atrophy), CT in 9/38 (8/9 positive for atrophy), perfusion SPECT in 12/38 (8/12 areas of hypo-perfusion), ¹⁸F-FDG PET/CT in 2/38 (1/2 hypometabolism in frontal cortex). The agreement between previous instrumental examinations and beta-amyloid PET results was low (K= 0.084). In the subgroup of 24/38 patients, MMSE was scored positive (MMSE<24) in 14/24 (58.4%) and negative (MMSE>24) in 10/24 (41.6%). The agreement between clinical evaluation (MMSE) and beta-amyloid PET results was fair (K= 0.217).

CONCLUSION

The low agreement between amyloid PET/CT and previous clinical and instrumental assessments that we found in our study suggests that the amyloid PET/CT provides additional and early information. To perform an early and differential diagnosis of AD could have a great impact on the patient's management and cost of care in order to perform the correct therapeutic interventions and to allow family members to manage adequately the patient's demanding care.