Diagnostic value of [99mTc]Tc-PSMA-I&S-SPECT/CT for the primary staging and restaging of prostate cancer

Background

A large number of studies have proved that prostate-specific membrane antigen-positron emission tomography/computer tomography (PSMA-PET/CT) provides excellent accuracy in primary staging and restaging of prostate cancer. Less data exist with PSMA-single photon emission computed tomography (SPECT)/CT investigations.

Objective

The aim of this study was to evaluate the performance of [99mTc]Tc-PSMA-I&S (for imaging and surgery) in prostate cancer.

Design and methods

We retrospectively analysed PSMA-SPECT/CT scans of 20 healthy volunteers and 100 male patients with prostate cancer. All of them had histologically confirmed prostate cancer. In all, 28 patients were examined for primary staging and 72 for biochemical recurrence or progressive disease. Whole body SPECT/CT imaging was carried out 6 h after the intravenous administration of 666 ± 102 MBq [99mTc]Tc-PSMA-I&S. Images were evaluated visually and semi-quantitatively.

Results

Patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy for primary prostate cancer were 86%, 100%, 100%, 83% and 92%, respectively. For detecting metastases in primary staging, these values were 88%, 100%, 100%, 85% and 93%, respectively. The radiopharmaceutical uptake of primary prostate cancer was significantly higher than in normal prostate. The patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the method in the visualization of local recurrence were 67%, 100%, 100%, 86% and 89%, and for detecting metastases in restaging were 91%, 92%, 98%, 75% and 91%, respectively. In restaging, detection rates were 37% under prostate-specific antigen level of 1 ng/mL, 74% between 1 and 5 ng/mL and 80% >5 ng/mL.

Conclusion

[99mTc]Tc-PSMA-I&S-SPECT/CT can be easily integrated into the routine diagnostic practice, and it provides usable data in primary staging and restaging of prostate cancer. Quantitative assessment of PSMA-SPECT/CT has the potential to be used to differentiate between physiological and pathological intraprostatic tracer uptake.

Prostate-specific membrane antigen-based imaging for stereotactic irradiation of low-volume progressive prostate cancer: a single-center experience

Introduction

Prostate-specific membrane antigen (PSMA) is a transmembrane protein that may be expressed on the surface of prostate cancer (PC) cells. It enables a more sensitive and specific diagnosis PC, compared to conventional anatomical imaging.

Aim

The integration of PSMA-based imaging in the personalized radiotherapy of PC patients and the evaluation of its impact on target volume definition if stereotactic body radiotherapy (SBRT) is planned for locally recurrent or oligometastatic disease.

Patients and methods

The data from 363 examinations were analyzed retrospectively. Inclusion criteria were histologically verified PC and clinical data suggesting local recurrence or distant metastasis. Whole-body 99mTc-PSMA-I&S single-photon emission computed tomography (SPECT)/CT or 18F-JK-PSMA-7 positron emission tomography/computer tomography (PET/CT) was carried out, and the evaluation of the scans and biological tumor volume contouring was performed at the Department of Nuclear Medicine. The target volume delineation on topometric CT (TCT) scan was performed at the Department of Oncotherapy. The comparison of the two volumes was performed by image fusion and registration.

Results

From 363 PSMA isotope-based examinations, 84 lesions of 64 patients were treated with SBRT. In 50 patients, 70 lesions were examined for intermodality comparison. The target volume defined by the PSMA density was significantly smaller than the tumor size defined by the TCT scan: GTVCT (gross tumor volume on the TCT), 27.58 ± 46.07 cm3; BTVPSMA (biological target volume on the PSMA-based examination), 16.14 ± 29.87 cm3. During geometrical analyses, the Dice similarity coefficient (DSC) was 0.56 ± 0.20 (0.07-0.85). Prostate-specific antigen (PSA) control was performed to evaluate the response: mean pre-radiotherapy (pre-RT) PSA was 16.98 ng/ml ( ± SD: 33.81), and post-RT PSA at 3 months after SBRT was 11.19 ng/ml ( ± SD: 32.85). Three-month post-therapy PSMA-based imaging was performed in 14 cases, in which we observed a decrease or cessation of isotope uptake. Conventional imaging control was performed in 42 cases (65.6% of all cases): 22 (52.4%) complete remissions, 14 (33.3%) partial remissions, four (9.5%) stable diseases, and two (4.8%) progressive diseases were described.

Conclusion

PSMA-based imaging is a promising diagnostic method for specifying the stage and detecting the low-volume progression. Our results suggest that PSMA-based hybrid imaging can influence treatment decisions and target volume delineation for SBRT.

Identification of similar epitopes between severe acute respiratory syndrome coronavirus-2 and Bacillus Calmette-Guérin: potential for cross-reactive adaptive immunity

Objectives

Bacillus Calmette–Guérin (BCG) vaccination has been implicated in protection against severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) and as a non‐specific immunisation method against the virus. We therefore decided to investigate T‐cell and B‐cell epitopes within the BCG‐Pasteur strain proteome for similarity to immunogenic peptides of SARS‐CoV‐2.

Methods

We used NetMHC 4.0 and BepiPred 2.0 epitope prediction methods for the analysis of the BCG‐Pasteur proteome to identify similar peptides to established and novel SARS‐CoV‐2 T‐cell and B‐cell epitopes.

Results

We found 112 BCG MHC‐I‐restricted T‐cell epitopes similar to MHC‐I‐restricted T‐cell SARS‐CoV‐2 epitopes and 690 BCG B‐cell epitopes similar to SARS‐CoV‐2 B‐cell epitopes. The SARS‐CoV‐2 T‐cell epitopes represented 16 SARS‐CoV‐2 proteins, and the SARS‐CoV‐2 B‐cell epitopes represented 5 SARS‐CoV‐2 proteins, including the receptor binding domain of the spike glycoprotein.

Conclusion

Altogether, our results provide a mechanistic basis for the potential cross‐reactive adaptive immunity that may exist between the two microorganisms.

Radiation Dosimetry of 99mTc-PSMA I&S: A Single-Center Prospective Study

^99mTc-PSMA I&S is a prostate-specific membrane antigen (PSMA) tracer that can be used for planar and SPECT/CT γ-imaging and radioguided surgery. The primary aim of this study was to estimate the dosimetry of ^99mTc-PSMA I&S using a hybrid method (sequential γ-planar imaging and 1 single SPECT/CT) in healthy volunteers. The secondary aim was to depict the tracer biodistribution and tumor-to-background ratios (TBRs) in patients with prostate cancer (PCa). Methods: Dosimetry of ^99mTc-PSMA I&S was investigated in 4 healthy volunteers. Whole-body planar imaging was acquired at 1, 2, 3, 6, and 24 h and SPECT/CT at 6 h after tracer injection. Contours of organs were drawn on all acquisitions to determine organ activity at each time point. Absorbed dose was estimated using 2 methods: independent curve-fitting manual method (Levenberg-Marquardt-based algorithm using dose factors from RAdiation Dose Assessment Resource [RADAR] website) and OLINDA/EXM software (version 2.0; HERMES Medical Solutions). Biodistribution of ^99mTc-PSMA I&S was assessed in 10 patients with PCa on SPECT/CT images at 6 h. Tumor uptake (SUV_max), and TBR (tumor SUV_max/background organ SUV_mean) using muscle (T/M), bladder (T/B), and intestine (T/I) as background organs were determined. Results: The mean injected activity of ^99mTc-PSMA I&S was 717 MBq (range: 562-828 MBq). No adverse events related to the injection of ^99mTc-PSMA I&S were reported. The average radiation effective dose was 0.0055 mSv/MBq with the RADAR manual method and 0.0052 mSv/MBq with OLINDA/EXM. Total body effective dose ranged between 3.33-4.42 and 3.11-4.23 mSv, respectively. All PCa patients showed high tracer uptake in primary and metastatic lesions with T/M, T/B, and T/I ranging from 5.29-110, 0.11-7.02, and 0.96-16.30, respectively. Conclusion: Effective doses of ^99mTc-PSMA I&S were comparable to those known for most of the ^99mTc tracers and was lower than for the ⁶⁸Ga-labeled and ¹⁸F-labeled agents. ^99mTc-PSMA I&S SPECT/CT showed high TBR in PCa patients. This study can provide required data for translation and approval of ^99mTc-PSMA I&S by regulatory agencies.

18F-FDG-PET/CT in the evaluation and differential diagnosis of active large-vessel vasculitis. A prospective study

Introduction: Large-vessel vasculitis has non-specific clinical symptoms, which can delay the diagnosis. Early recognition and treatment of the disease can help to avoid late complications. ¹⁸ F-FDG-PET can detect the inflammation of the vessel wall in the early stage of the disease with high sensitivity. CT is used to localize vasculitis. Aim: To examine the performance of ¹⁸F-FDG-PET/CT in patients with suspected large-vessel vasculitis, during relapse and remission, focusing on disease activity and extent. Method: 43 patients were evaluated. They were classified according to the clinical questions: steroid-naive suspected vasculitis, suspected vasculitis on steroid treatment, patients with relapse and in remission. We examined 10 cancer patients in control. We carried out visual and quantitative analysis of the ¹⁸F-FDG uptake of vessel walls. During quantitative evaluation, we determined standardised uptake values (SUVmax) of vessel wall segments compared to liver. Results: We found active disease in 5 patients examined for primary diagnosis, moreover, in 5 patients with relapse. The disease involved 3 or more vessel segments in fifty percent of the active cases. In the visually active group, the SUVmax was significantly lower in patients on steroid treatment than in steroid-naive cases (1.17 ± 0.11 vs. 1.43 ± 0.29; p = 0.005). We confirmed remission in 2 cases after therapy. In the inactive group, we found other types of inflammatory disorders in 8 cases. Conclusion: ¹⁸F-FDG-PET/CT is an effective diagnostic tool for large-vessel vasculitis, and can be used to determine the activity and extent of the disease. Steroid treatment influences the ¹⁸F-FDG-uptake of vessel wall. Orv Hetil. 2020; 161(20): 829-838.

Efficacy and safety of long pulse 1064 and 2940 nm lasers in noninvasive lipolysis and skin tightening

Noninvasive body shaping is becoming a growing demand. The aim of this study was to investigate the efficacy and safety of the combined treatments of 1064 nm Nd:YAG and 2940 nm Er:YAG in noninvasive lipolysis and skin tightening. Ten females were enrolled, and all women's side of the waist or the lower part of the abdomen were treated. In the first step, the 1064 nm Nd:YAG was used. As a second step, the 2940 nm Er:YAG laser was applied. Each woman was treated four times, once every 2 weeks. The effects were determined by comparative photo documentation, waist circumference measurement, two-dimensional B-mode ultrasonography and low-dose native computer tomography (CT), whereas body fat was monitored with bioelectric impedance. The tissue firmness was measured by ultrasound shear wave elastography. Combined laser treatment significantly reduced waist circumference and total body fat. Ultrasonography has revealed that the treatment considerably decreased fat thickness and improved skin stiffness in the treated region. Subcutaneous fat volume, measured by low-dose CT, displayed a moderate decrease in the waist region. The combined 1064 nm Nd:YAG and 2940 nm Er:YAG laser treatment results in the reduction of fat tissue and tightens the skin as confirmed by objective measurements.

New data for the application of the Post Critical Belief Scale – Theory and methodology

A Kritika Utáni Vallásosság Skála (Horváth-Szabó , 2003; Hutsebaut , 1996) a vallásosság mérőeszköze, mely a valláshoz való viszonyt két dimenzióban, a Transzcendens Bevonása vs. Kizárása és a Szimbolikus vs. Konkrét értelmezésmód szerint helyezi el. A skálát egyre gyakrabban alkalmazzák olyan módon, hogy főkomponens-elemzéssel kinyerik a két alapvető és független dimenziót, majd ezt a két dimenziót hozzák összefüggésbe további változókkal. A tanulmányban bemutatjuk az ezzel kapcsolatos újabb külföldi eredményeket, valamint az eljárás elméletét és gyakorlatát, melynek hazai alkalmazhatóságát 1820 fős magyar minta adatain ellenőriztük. Eredményeink szerint a flamand és a magyar változat tételeinek struktúrája jelentős mértékben megegyezik. A két alapdimenzió megléte nemtől, vallási hovatartozástól függetlenül a magyar mintán is kimutatható volt, és az egyes mintákban magas volt a kérdőív belső struktúrájának stabilitása. A tanulmányban javaslatot teszünk egy 18 tételes rövidített változatra is, mely jól helyettesítheti a 33 tételes eredeti változatot. Összességében azt találtuk, hogy Kritika Utáni Vallásosság Skála kétdimenziós kiértékelése megbízható eljárás, mely új szempontokkal gazdagíthatja a vallásossággal kapcsolatos pszichológiai kutatásokat.