Standardized PSMA-PET Imaging of Advanced Prostate Cancer.

Imaging of advanced prostate cancer is a challenging task, as it requires longitudinal characterization of disease extent in a standardized way to enable appropriate treatment selection and evaluation of treatment efficacy. In the last years, prostate-specific membrane antigen (PSMA)-PET/CT has become the reference standard examination for patients with advanced prostate cancer. Together with the rise of PSMA-PET, standardized frameworks for the reporting of image findings have been proposed, eg, the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) and the structured reporting system for PSMA targeted PET imaging (PSMA-RADS) framework. Therefore, recent evidence on PSMA-PET derived tumor volume as useful a biomarker for outcome prognostication and related frameworks will be discussed in the article. The PROMISE framework recommends quantifying the tumor volume per-organ system, which accounts for the fact that the location of the metastases greatly influence its biological aggressiveness. In addition, changes in PSMA-PET derived tumor volume have been shown to be promising biomarkers for response assessment. Limitations of PSMA-PET will also be discussed because the tumor volume might not always be suited for response assessment. As a pitfall of PSMA-based systems, decreasing PSMA-expression might erroneously be interpreted as response to therapy. Also, especially for patients with limited disease, the tumor volume might not be ideal for response assessment. Therefore, various frameworks have been introduced to objectively measure response to therapy with PSMA-PET. Amongst these, the PSMA-PET progression (PPP) criteria and the response evaluation criteria in PSMA (RECIP) are optimized for earlier and later phenotypes of advanced prostate cancer, respectively. Variables needed to determine PPP or RECIP outcome on PSMA-PET are recorded under the umbrella of PROMISE recommendations. In this article, various reporting and response assessment frameworks are explained and discussed. Also, recent evidence for the relevance of PSMA-PET biomarkers for clinical management and outcome prognostication are shown.

Next generation radiotheranostics promoting precision medicine.

Radiotheranostics is a field of rapid growth with some approved treatments including 131I for thyroid cancer, 223Ra for osseous metastases, 177Lu-DOTATATE for neuroendocrine tumors, and 177Lu-PSMA (prostate-specific membrane antigen) for prostate cancer, and several more under investigation. In this review, we will cover the fundamentals of radiotheranostics, the key clinical studies that have led to current success, future developments with new targets, radionuclides and platforms, challenges with logistics and reimbursement and, lastly, forthcoming considerations regarding dosimetry, identifying the right line of therapy, artificial intelligence and more.

[68Ga]/[90Y]FAPI-46: Automated production and analytical validation of a theranostic pair.

INTRODUCTION: With respect to the broad application of FAPI-46 in therapy and diagnostics, there is a need for an efficient as well as convenient way for routine production and quality control of the theranostic pair [90Y]Y/[68Ga]Ga-FAPI-46, since no monograph is currently available for radiolabelled FAPI derivatives. The aim of the current work is to create a GMP compliant theranostic set up for the production and quality control of the diagnostic [68Ga]Ga-FAPI-46 as well as the therapeutic drug [90 Y]Y-FAPI-46, which can be the basis for future monographic standards. METHODS: Sterile [90Y]yttrium chloride solution and a pharmaceutical grade 68Ge/68Ga generator were applied for the labelling of FAPI-46 using the cassette based synthesis module Trasis EASYONE. All chemicals were GMP-grade and excipients were with marketing authorisation. The quality control included test procedures according to Ph. Eur. RESULTS: Fully automated synthesis of the theranostic pair [90Y]Y/[68Ga]Ga-FAPI-46 was achieved on the Trasis EasyOne synthesizer with a radiochemical yield of 88 ± 7% and 56 ± 5% with a radiochemical purity of >99%. Stability experiments showed a durability for [68Ga]Ga-FAPI-46 within 4 h and for [90Y]Y-FAPI-46 within 24 h. All obtained specifications and validations were compliant with the European Pharmacopoeia and regulatory guidelines. Both products were successfully applied in cancer patients. CONCLUSION: In the present work, efficient and robust procedures for the automated production and quality control of the theranostic pair [68Ga]/[90Y]FAPI 46 were developed and validated using the same synthetic platform. The described methods were evaluated in accordance with existing guidelines and toxicological limits, which can be a valuable basis for future monographic standards.

EANM procedure guideline for the treatment of liver cancer and liver metastases with intra-arterial radioactive compounds.

Primary liver tumours (i.e. hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC)) are among the most frequent cancers worldwide. However, only 10-20% of patients are amenable to curative treatment, such as resection or transplant. Liver metastases are most frequently caused by colorectal cancer, which accounts for the second most cancer-related deaths in Europe. In both primary and secondary tumours, radioembolization has been shown to be a safe and effective treatment option. The vast potential of personalized dosimetry has also been shown, resulting in markedly increased response rates and overall survival. In a rapidly evolving therapeutic landscape, the role of radioembolization will be subject to changes. Therefore, the decision for radioembolization should be taken by a multidisciplinary tumour board in accordance with the current clinical guidelines. The purpose of this procedure guideline is to assist the nuclear medicine physician in treating and managing patients undergoing radioembolization treatment. PREAMBLE: The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association that facilitates communication worldwide among individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985. These guidelines are intended to assist practitioners in providing appropriate nuclear medicine care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals taking into account the unique circumstances of each case. Thus, there is no implication that an approach differing from the guidelines, standing alone, is below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set out in the guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources or advances in knowledge or technology subsequent to publication of the guidelines. The practice of medicine involves not only the science but also the art of dealing with the prevention, diagnosis, alleviation and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognised that adherence to these guidelines will not ensure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources and the needs of the patient to deliver effective and safe medical care. The sole purpose of these guidelines is to assist practitioners in achieving this objective.

Budget impact of the Oncotype DX® test compared to other gene expression tests in patients with early breast cancer in Germany.

PURPOSE: Gene expression tests can inform decisions on whether to recommend chemotherapy for patients with HR+, HER2- early breast cancer. The goal of this analysis was to compare treatment costs by an expanded budget impact model of reimbursed gene expression tests in Germany. METHODS: A cost comparison was constructed as an expanded budget impact model to calculate average total costs per patient covered by public health insurance. Based on the strong clinical evidence from the prospective randomized controlled trial TAILORx including more than 10,000 patients with HR+ and node negative breast cancer, the assumption was made that the Oncotype DX® test accurately predicts chemotherapy benefit and clinical outcomes. For the further reimbursed tests (EndoPredict®, MammaPrint®, Prosigna®), results from comparative studies - aligned with prognosis studies - as analyzed in IQWiG Rapid Report D19-01 were applied. RESULTS: The use of the Oncotype DX test led to estimated average savings per patient of 2,500 € vs. EndoPredict, 1,936 € vs. MammaPrint, and 649 € vs. Prosigna. Savings were achieved by reduction of unnecessary chemotherapy use, a consequence of false-positive test results (EndoPredict 73%, MammaPrint 42%, Prosigna 20%). False-negative test results (EndoPredict 5%, MammaPrint 22%, Prosigna 49%) reduced necessary chemotherapies, which initially results in cost savings, but may lead to increased long-term costs associated with management of progressive disease. CONCLUSION: The results from this model suggest that the use of the Oncotype DX test reduces the cost of health care in Germany making it the most cost effective test compared to the further tests.

Can a ToF-PET photon attenuation reconstruction test stopping-power estimations in proton therapy? A phantom study.

Objective. The aim of the phantom study was to validate and to improve the computed tomography (CT) images used for the dose computation in proton therapy. It was tested, if the joint reconstruction of activity and attenuation images of time-of-flight PET (ToF-PET) scans could improve the estimation of the proton stopping-power.Approach. The attenuation images, i.e. CT images with 511 keV gamma-rays (γCTs), were jointly reconstructed with activity maps from ToF-PET scans. Theß+activity was produced with FDG and in a separate experiment with proton-induced radioactivation. The phantoms contained slabs of tissue substitutes. The use of theγCTs for the prediction of the beam stopping in proton therapy was based on a linear relationship between theγ-ray attenuation, the electron density, and the stopping-power of fast protons.Main results. The FDG based experiment showed sufficient linearity to detect a bias of bony tissue in the heuristic look-up table, which maps between x-ray CT images and proton stopping-power.γCTs can be used for dose computation, if the electron density of one type of tissue is provided as a scaling factor. A possible limitation is imposed by the spatial resolution, which is inferior by a factor of 2.5 compared to the one of the x-ray CT.γCTs can also be derived from off-line, ToF-PET scans subsequent to the application of a proton field with a hypofractionated dose level.Significance. γCTs are a viable tool to support the estimation of proton stopping with radiotracer-based ToF-PET data from diagnosis or staging. This could be of higher potential relevance in MRI-guided proton therapy.γCTs could form an alternative approach to make use of in-beam or off-line PET scans of proton-inducedß+activity with possible clinical limitations due to the low number of coincidence counts.

Photoacoustic thermal characterization of low thermal diffusivity thin films.

The photoacoustic measurement technique is a powerful yet underrepresented method to characterize the thermal transport properties of thin films. For the case of isotropic low thermal diffusivity samples, such as glasses or polymers, we demonstrate a general approach to extract the thermal conductivity with a high degree of significance. We discuss in particular the influence of thermal effusivity, thermal diffusivity, and sample layer thickness on the significance and accuracy of this measurement technique. These fundamental thermal properties guide sample and substrate selection to allow for a feasible thermal transport characterization. Furthermore, our data evaluation allows us to directly extract the thermal conductivity from this transient technique, without separate determination of the volumetric heat capacity, when appropriate boundary conditions are fulfilled. Using silica, poly(methyl methacrylate) (PMMA) thin films, and various substrates (quartz, steel, and silicon), we verify the quantitative correctness of our analytical approach.

Dose-escalated radiotherapy with PET/CT based treatment planning in combination with induction and concurrent chemotherapy in locally advanced (uT3/T4) squamous cell cancer of the esophagus: mature results of a phase I/II trial.

BACKGROUND: This prospective phase I/II trial assessed feasibility and efficacy of dose-escalated definitive chemoradiation after induction chemotherapy in locally advanced esophageal cancer. Primary study endpoint was loco-regional progression-free survival at 1 year. METHODS: Eligible patients received 2 cycles of induction chemotherapy with irinotecan, folinic acid and 5-fluorouracil weekly and cisplatin every 2 weeks (weeks 1-6, 8-13) followed by concurrent chemoradiation with cisplatin and irinotecan (weeks 14, 15, 17, 18, 20). Radiotherapy dose escalation was performed in three steps (60 Gy, 66 Gy, 72 Gy) using conventional fractionation, planning target volumes were delineated with the aid of 18F-FDG-PET/CT scans. During follow-up, endoscopic examinations were performed at regular intervals. RESULTS: Between 09/2006 and 02/2010, 17 patients were enrolled (male/female:13/4, median age: 59 [range 48-66] years, stage uT3N0/T3N1/T4N1: 4/12/1). One patient progressed during induction chemotherapy and underwent surgery. Of 16 patients treated with definitive chemoradiotherapy, 9 (56%) achieved complete response after completion of chemoradiation. One-, 2-, 3- and 5-year overall survival rates (OS) were 77% [95%CI: 59-100], 53% [34-83], 41% [23-73], and 29% [14-61], respectively. Loco-regional progression-free survival at 1, 3, and 5 years was 59% [40-88], 35% [19-67], and 29% [14-61], corresponding cumulative incidences of loco-regional progressions were 18% [4-39%], 35% [14-58%], and 41% [17-64%]. No treatment related deaths occurred. Grade 3 toxicities during induction therapy were: neutropenia (41%), diarrhoea (41%), during combined treatment: neutropenia (62%) and thrombocytopenia (25%). CONCLUSIONS: Dose-escalated radiotherapy and concurrent cisplatin/irinotecan after cisplatin/irinotecan/5FU induction chemotherapy was tolerable. The hypothesized phase II one-year loco-regional progression free survival rate of 74% was not achieved. Long-term survival compares well with other studies on definitive radiotherapy using irinotecan and cisplatin but is not better than recent trials using conventionally fractionated radiotherapy ad 50 Gy with concurrent paclitaxel or 5FU and platinum compound. Trial registration The present trial was registered as a phase I/II trial at the EudraCT database: Nr. 2005-006097-10 ( https://www.clinicaltrialsregister.eu/ctr-search/trial/2005-006097-10/DE ) and authorized to proceed on 2006-09-25.

Longer-term recurrence rate after low versus high dose radioiodine ablation for differentiated thyroid Cancer in low and intermediate risk patients: a meta-analysis.

BACKGROUND: Regarding the longer-term recurrence rate the optimal activity for the remnant thyroid ablation in patients with differentiated thyroid cancer (DTC) is discussed controversially. For the short-term ablation success rate up to 12 months there are already several meta-analyses. In this study we performed the first meta-analysis regarding the longer-term recurrence rate after radioactive 131-I administration. METHODS: We conducted an electronic search using PubMed/MEDLINE, EMBASE and the Cochrane Library. All randomized controlled trials (RCTs) assessed the recurrence rate after radioactive iodine ablation in patients with DTC, with a follow-up of at least two years were selected. Statistics were performed by using Review Manager version 5.3 and Stata software. RESULTS: Four RCTs were included in the study, involving 1501 patients. There was no indication for heterogeneity (I2 = 0%) and publication bias. The recurrence rate among patients who had a low dose 131-iodine ablation was not higher than for a high dose activity (odds ratio (OR) 0.93 [95% confidence interval (CI) 0.53-1.63]; P = 0.79). The mean follow-up time was between 4.25 and 10 years. The subgroup analysis regarding the TSH stimulated thyroglobulin values (< 10 ng/mL versus < 2 ng/mL versus ≤1 ng/mL) showed no influence on recurrence rate. CONCLUSIONS: For the first time we showed that the longer-term, at least 2-year follow-up, recurrence rate among patients who had 131-iodine ablation with 1.1 GBq was not higher than with 3.7 GBq.

Correction to: Nuclear medicine services after COVID-19: gearing up back to normality.

The authors P. Orellana and N. El-Haj were inadvertently deleted in the original paper.

[PSMA radioligand therapy in patients with advanced prostate cancer]. / Radionuklidtherapie mit PSMA-Liganden bei fortgeschrittenem Prostatakarzinom.

BACKGROUND: Based on significant progress in recent years, metastatic castration-resistant prostate cancer (mCRPC) patients can be treated better and better. The medications include androgen signaling inhibitors, chemotherapy, 223Ra, and sipuleucel-T. Most patients treated with these agents will still develop primary or secondary resistance against any given drug. The 177Lutetium-PSMA radioligand therapy (177Lu-PSMA-RLT) represents a good reserve option and can be used within compassionate use provisions demonstrating promising efficacy in the majority of patients in Germany. OBJECTIVES: Establishment of status quo of 177Lu-PSMA-RLT in mCRPC in 2020. MATERIALS AND METHODS: Presentation of the therapy landscape in mCRPC and the current evidence on 177Lu-PSMA-RLT after PubMed based literature search. RESULTS: Several larger retrospective studies and the first prospective trials on 177Lu-PSMA-RLT show premature but encouraging evidence on 177Lu-PSMA-RLT to be a promising new option in mCRPC patients. The toxicity profile seems to be favorable. The phase III trial VISION aims to provide evidence for the approval of 177Lu-PSMA-RLT in combination with abiraterone or enzalutamide in patients having been pretreated with enzalutamide or abiraterone and docetaxel. CONCLUSIONS: Despite the promising preliminary results of 177Lu-PSMA-RLT, the efficacy results of VISION need to be awaited prior to using the therapy outside of compassionate use provisions.

Correction for hyperfunctioning radiation-induced stunning (CHRIS) in benign thyroid diseases.

PURPOSE: Radioiodine-131 treatment has been a well-established therapy for benign thyroid diseases for more than 75 years. However, the physiological reasons of the so-called stunning phenomenon, defined as a reduced radioiodine uptake after previous diagnostic radioiodine administration, are still discussed controversially. In a recent study, a significant dependence of thyroid stunning on the pre-therapeutically administered radiation dose could be demonstrated in patients with goiter and multifocal autonomous nodules. A release of thyroid hormones to the blood due to radiation-induced destruction of thyroid follicles leading to a temporarily reduced cell metabolism was postulated as possible reason for this indication-specific stunning effect. Therefore, the aim of this study was to develop dose-dependent correction factors to account for stunning and thereby improve precision of radioiodine treatment in these indications. METHODS: A retrospective analysis of 313 patients (135 with goiter and 178 with multifocal autonomous nodules), who underwent radioiodine uptake testing and radioiodine treatment, was performed. The previously determined indication-specific values for stunning of 8.2% per Gray in patients with multifocal autonomous nodules and 21% per Gray in patients with goiter were used to modify the Marinelli equation by the calculation of correction factors for hyperfunctioning radiation-induced stunning (CHRIS). Subsequently, the calculation of the required activity of radioiodine-131 to obtain an intra-therapeutic target dose of 150 Gy was re-evaluated in all patients. Furthermore, a calculation of the hypothetically received target dose by using the CHRIS-calculated values was performed and compared with the received target doses. RESULTS: After integrating the previously obtained results for stunning, CHRIS-modified Marinelli equations could be developed for goiter and multifocal autonomous nodules. For patients with goiter, the mean value of administered doses calculated with CHRIS was 149 Gy and did not differ from the calculation with the conventional Marinelli equation of 152 Gy with statistical significance (p = 0.60). However, the statistical comparison revealed a highly significant improvement (p < 0.000001) of the fluctuation range of the results received with CHRIS. Similar results were obtained in the subgroup of patients with multifocal autonomous nodules. The mean value of the administered dose calculated with the conventional Marinelli equation was 131 Gy and therefore significantly below the CHRIS-calculated radiation dose of 150 Gy (p < 0.05). Again, the fluctuation range of the CHRIS-calculated radiation dose in the target volume was significantly improved compared with the conventional Marinelli equation (p < 0.000001). CONCLUSIONS: With the presented CHRIS equation it is possible to calculate a required individual stunning-independent radioiodine activity for the first time by only using data from the radioiodine uptake testing. The results of this study deepen our understanding of thyroid stunning in benign thyroid diseases and improve precision of dosimetry in radioiodine-131 therapy of goiter and multifocal autonomous nodules.

Immunohistochemical Profile and 47-Gene Next-Generation Sequencing (NGS) Solid Tumor Panel Analysis of a Series of 13 Strumal Carcinoids.

Strumal carcinoid is an extraordinary rare tumor of the ovary consisting of thyroid tissue intermixed with neuroendocrine tumor component. The cellular origin of strumal carcinoids has been an area of debate. There is also little data on detailed immunohistochemical and molecular characteristics of these neoplasms. For this reason, this series investigated the characteristics of a series of 13 strumal carcinoids using immunohistochemical markers and a 47-gene next-generation sequencing (NGS) solid tumor panel analysis. Both cellular components showed thyroglobulin expression in all tumors. TTF-1 expression was noted in both cellular components of 11 cases. Chromogranin A was positive in both components of most tumors (n = 12, 92.3% in the neuroendocrine component and n = 10, 76.9% in the thyroid follicular component). Synaptophysin stained the neuroendocrine component of all cases, and it was also identified in the follicular thyroid component of a single case. All tumors were negative for CDX2 and calcitonin. ISLET1 was positive in the neuroendocrine component of 8 cases (6.5%). With the exception of one case, all tumors were positive for SSTR2a. The tumors were associated with a low Ki67 labeling index. All cases were microsatellite stable and no pathogenic mutations were identified using a 47-gene NGS solid tumor analysis. This series underscored that strumal carcinoids are distinct neuroendocrine tumors. The synchronous expression for thyroid follicular epithelial and neuroendocrine differentiation biomarkers may suggest a precursor cell origin displaying mixed-amphicrine differentiation. While strumal carcinoids can be diagnosed by their typical morphology and immunohistochemical profile, frequent SSTR expression may serve as a potential theranostic biomarker in the management of affected patients. In addition, the absence of common driver mutations in the NGS solid tumor panel may suggest that these neoplasms seem to be genetically unrelated to follicular epithelial-derived thyroid tumors and potentially different than other commonly identified well-differentiated neuroendocrine neoplasms. Therefore, further studies focusing on molecular characteristics of this entity are still needed.