FDG-PET/CT is a powerful tool to predict and evaluate response to chimeric antigen receptor (CAR) T-cell therapy in Non-Hodgkin-Lymphoma (NHL)

Chimeric antigen receptor (CAR) T-cell therapy has dramatically shifted the landscape of treatment especially for Non-Hodgkin-Lymphoma (NHL). This study evaluates the role of fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) in NHL treated with CAR T-cell therapy concerning response assessment and prognosis.We evaluated 34 patients with NHL who received a CAR T-cell therapy between August 2019 and July 2022. All patients underwent a pre-therapeutic FDG-PET/CT (PET-0) 6 days prior and a post-therapeutic FDG-PET/CT (PET-1) 34 days after CAR T-cell therapy. Deauville score (DS) was used for evaluation of response to therapy and compared to a minimum follow-up of 5 months.19/34 (55.9%) patients achieved DS ≤ 3 on PET-1, the remaining 15 (44.1%) patients had DS > 3 on PET-1. 14/19 patients with DS ≤ 3 on PET-1 had no relapsed or refractory (r/r)-disease and were still alive at last follow-up. The other 5 patients had r/r-disease and 4 of these died. Except for two patients who had no r/r-disease, all other patients (13/15) with DS > 3 on PET-1 had r/r-disease and 12 of these subsequently died. Patients with DS ≤ 3 on PET-1 had significantly better progression free survival (PFS; HR: 5.7; p < 0.01) and overall survival (OS; HR: 5.0; p < 0.01) compared to patients with DS > 3 on PET-1. In addition, we demonstrated that patients with DS ≤ 4 on PET-0 tended to have longer PFS (HR: 3.6; p = 0.05).Early FDG-PET/CT using the established DS after CAR T-cell therapy is a powerful tool to evaluate response to therapy.

Volumetric Parameters Derived from CXCR4-Directed PET/CT Predict Outcome in Patients with Gastrointestinal Neuroendocrine Carcinomas

BACKGROUND

Gastro-entero-pancreatic neuroendocrine carcinomas (GEP-NECs) are an aggressive subgroup of neuroendocrine neoplasms (NENs). In patients affected with NEN, there is a growing body of evidence that increased C-X-C motif chemokine receptor (CXCR4) expression is linked to decreasing overall survival (OS) in an ex-vivo setting. Thus, we aimed to determine whether the in-vivo-derived CXCR4-directed whole-body PET signal can also determine GEP-NEC patients with shorter OS.

METHODS

We retrospectively included 16 patients with histologically proven GEP-NEC, who underwent CXCR4-directed PET/CT for staging and therapy planning. We assessed maximum, peak, and mean standardized uptake values as well as whole-body tumor volume (TV) and total-lesion uptake (TLU = SUVmean × TV) using a semi-automatic segmentation tool with a 50% threshold. Association of PET-based biomarkers and OS or radiographic progression-free survival (rPFS; according to RECIST 1.1 criteria) was analyzed using univariable and multivariable cox regression.

RESULTS

Median OS and rPFS was 7.5 and 7 months, respectively. A significant correlation between TV and TLU was found for OS (TV: hazard ratio (HR) 1.007 95% confidence interval (CI) 1.000-1.014, p = 0.0309; TLU: HR 1.002 95% CI 1.000-1.003, p = 0.0350) and rPFS (TV: HR 1.010 95% CI 1.002-1.021; p = 0.0275; TLU: HR 1.002 95% CI 1.000-1.004, p = 0.0329), respectively. No significant correlation with OS or rPFS was found for non-volumetric parameters (p > 0.4). TV remained a significant predictive marker for OS and rPFS in multivariable analysis (OS: HR 1.012 95%, CI 1.003-1.022, p = 0.0084; rPFS: HR 1.009, 95% CI 0.9999-1.019, p = 0.0491), whereas TLU remained only prognostic for OS (HR 1.009, 95% CI 0.9999-1.019, p = 0.0194) but narrowly failed significance for rPFS (p = 0.0559).

CONCLUSION

In-vivo assessment of CXCR4 PET-derived volumetric parameters is predictive for outcome of patients with GEP-NEC and could be used as a risk stratification tool, which detects patients prone to early progression.

Prognostic Performance of RECIP 1.0 Based on [18F]PSMA-1007 PET in Prostate Cancer Patients Treated with [177Lu]Lu-PSMA I&T

In metastatic castration-resistant prostate cancer (mCRPC) patients treated with prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT), the recently proposed criteria for evaluating response to PSMA PET (RECIP 1.0) based on 68Ga- and 18F-labeled PET agents provided prognostic information in addition to changes in prostate-specific antigen (PSA) levels. Our aim was to evaluate the prognostic performance of this framework for overall survival (OS) in patients undergoing RLT and imaged with [18F]PSMA-1007 PET/CT and compare the prognostic performance with the PSA-based response assessment. Methods: In total, 73 patients with mCRPC who were scanned with [18F]PSMA-1007 PET/CT before and after 2 cycles of RLT were retrospectively analyzed. We calculated the changes in serum PSA levels (ΔPSA) and quantitative PET parameters for the whole-body tumor burden (SUVmean, SUVmax, PSMA tumor volume, and total lesion PSMA). Men were also classified following the Prostate Cancer Working Group 3 (PCWG3) criteria for ΔPSA and RECIP 1.0 for PET imaging response. We performed univariable Cox regression analysis, followed by multivariable and Kaplan-Meier analyses. Results: Median OS was 15 mo with a median follow-up time of 14 mo. Univariable Cox regression analysis provided significant associations with OS for ΔPSA (per percentage, hazard ratio [HR], 1.004; 95% CI, 1.002-1.007; P < 0.001) and PSMA tumor volume (per unit, HR, 1.003; 95% CI, 1.000-1.005; P = 0.03). Multivariable Cox regression analysis confirmed ΔPSA (per percentage, HR, 1.004; 95% CI, 1.001-1.006; P = 0.006) as an independent prognosticator for OS. Kaplan-Meier analyses provided significant segregation between individuals with versus those without any PSA response (19 mo vs. 14 mo; HR, 2.00; 95% CI, 0.95-4.18; P = 0.04). Differentiation between patients with or without progressive disease (PD) was also feasible when applying PSA-based PCWG3 (19 mo vs. 9 mo for non-PD and PD, respectively; HR, 2.29; 95% CI, 1.03-5.09; P = 0.01) but slightly failed when applying RECIP 1.0 (P = 0.08). A combination of both response systems (PCWG3 and RECIP 1.0), however, yielded the best discrimination between individuals without versus those with PD (19 mo vs. 8 mo; HR, 2.78; 95% CI, 1.32-5.86; P = 0.002). Conclusion: In patients with mCRPC treated with RLT and imaged with [18F]PSMA-1007, frameworks integrating both the biochemical (PCWG3) and PET-based response (RECIP 1.0) may best assist in identifying subjects prone to disease progression.

Comparison of PET/CT-based eligibility according to VISION and TheraP trial criteria in end-stage prostate cancer patients undergoing radioligand therapy

BACKGROUND

Two randomized clinical trials demonstrated the efficacy of prostate-specific membrane antigen (PSMA) radioligand therapy (PSMA RLT) in metastatic castration-resistant prostate cancer (mCRPC). While the VISION trial used criteria within PSMA PET/CT for inclusion, the TheraP trial used dual tracer imaging including FDG PET/CT. Therefore, we investigated whether the application of the VISION criteria leads to a benefit in overall survival (OS) or progression-free survival (PFS) for men with mCRPC after PSMA RLT.

METHODS

Thirty-five men with mCRPC who had received PSMA RLT as a last-line option and who had undergone pretherapeutic imaging with FDG and [68Ga]Ga-PSMA I&T or [18F]PSMA-1007 were studied. Therapeutic eligibility was retrospectively evaluated using the VISION and TheraP study criteria.

RESULTS

26 of 35 (74%) treated patients fulfilled the VISION criteria (= VISION+) and only 17 of 35 (49%) fulfilled the TheraP criteria (= TheraP+). Significantly reduced OS and PFS after PSMA RLT was observed in patients rated VISION- compared to VISION+ (OS: VISION-: 3 vs. VISION+: 12 months, hazard ratio (HR) 3.1, 95% confidence interval (CI) 1.0-9.1, p < 0.01; PFS: VISION-: 1 vs. VISION+: 5 months, HR 2.7, 95% CI 1.0-7.8, p < 0.01). For patients rated TheraP-, no significant difference in OS but in PFS was observed compared to TheraP+ patients (OS: TheraP-: 5.5 vs. TheraP+: 11 months, HR 1.6, 95% CI 0.8-3.3, p = 0.2; PFS: TheraP-: 1 vs. TheraP+: 6 months, HR 2.2, 95% CI 1.0-4.5, p < 0.01).

CONCLUSION

Retrospective application of the inclusion criteria of the VISION study leads to a benefit in OS and PFS after PSMA RL, whereas TheraP criteria appear to be too strict in patients with end-stage prostate cancer. Thus, performing PSMA PET/CT including a contrast-enhanced CT as proposed in the VISION trial might be sufficient for treatment eligibility of end-stage prostate cancer patients.

PSMA PET/CT for Response Assessment of 177Lu-PSMA Therapy

Prostate-specific membrane antigen (PSMA) PET/CT has been widely integrated into the management of prostate cancer (PCa) patients with biochemical recurrence, is increasingly used for initial staging in high-risk patients prior to surgery or to identify candidates for PSMA-targeted radioligand therapy (RLT). To date, monitoring response in PCa patients in prospective studies remains the domain of conventional imaging, such as magnetic resonance/CT or bone scintigraphy. With the increasing use of PSMA-targeted PET/CT in PCa, however, varying criteria based on molecular imaging have been established to define progressive disease, including "PSMA PET Progression Criteria," "Response evaluation criteria in PSMA PET/CT (RECIP 1.0)" or consensus statements of respective societies. In the present review, we will discuss the current status of PSMA PET/CT for response monitoring, focusing on PSMA RLT with [177Lu]Lu-labeled PSMA ligands, along with a head-to-head comparison of recently published response criteria.

Radiopharmaceuticals for Treatment of Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) represents a rare tumor entity with limited treatment options and usually rapid tumor progression in case of metastatic disease. As further treatment options are needed and ACC metastases are sensitive to external beam radiation, novel theranostic approaches could complement established therapeutic concepts. Recent developments focus on targeting adrenal cortex-specific enzymes like the theranostic twin [123/131I]IMAZA that shows a good image quality and a promising therapeutic effect in selected patients. But other established molecular targets in nuclear medicine such as the C-X-C motif chemokine receptor 4 (CXCR4) could possibly enhance the therapeutic regimen as well in a subgroup of patients. The aims of this review are to give an overview of innovative radiopharmaceuticals for the treatment of ACC and to present the different molecular targets, as well as to show future perspectives for further developments since a radiopharmaceutical with a broad application range is still warranted.

SUVmean on baseline [18F]PSMA-1007 PET and clinical parameters are associated with survival in prostate cancer patients scheduled for [177Lu]Lu-PSMA I&T

BACKGROUND

Quantification of [68 Ga]-labeled PSMA PET predicts response in patients with prostate cancer (PC) who undergo PSMA-targeted radioligand therapy (RLT). Given the increasing use [18F]-labeled radiotracers, we aimed to determine whether the uptake derived from [18F]PSMA-1007 PET can also identify responders and to assess its prognostic value relative to established clinical parameters.

METHODS

We retrospectively analyzed 103 patients with metastatic, castration-resistant PC who were treated with [177Lu]Lu-PSMA I&T. We calculated SUVmean, SUVmax, PSMA-avid tumor volume (TV), and total lesion PSMA (defined as PSMA-TV*SUVmean) on pre-therapeutic [18F]PSMA-1007 PET. Laboratory values for hemoglobin, C-reactive protein (CRP), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alkaline phosphatase (AP) were also collected prior to RLT. We performed univariable Cox regression followed by multivariable and Kaplan-Meier analyses with overall survival (OS) serving as endpoint. Last, we also computed a risk factor (RF) model including all items reaching significance on multivariable analysis to determine whether an increasing number of RFs can improve risk stratification.

RESULTS

A total of 48 patients died and median OS was 16 months. On univariable Cox regression, SUVmean, CRP, LDH, hemoglobin, and the presence of liver metastases were significantly associated with OS. On multivariable Cox regression, the following significant prognostic factors for OS were identified: SUVmean (per unit, HR, 0.91; P = 0.04), the presence of liver metastases (HR, 2.37; P = 0.03), CRP (per mg/dl, HR, 1.13; P = 0.003), and hemoglobin (per g/dl, HR, 0.76; P < 0.01). Kaplan-Meier analysis showed significant separation between patients with a SUVmean below or above a median SUVmean of 9.4 (9 vs 19 months, HR 0.57; P = 0.03). Of note, patients with only one RF (median OS not reached) showed longest survival compared to patients with two (11 months; HR 2.43 95% CI 1.07-5.49, P = 0.02) or more than two RFs (7 months; HR 3.37 95% CI 1.62-7.03, P < 0.001).

CONCLUSION

A lower SUVmean derived from [18F]PSMA-1007, higher CRP, lower hemoglobin, and the presence of liver metastases are associated with reduced OS in patients undergoing RLT. An early RF model also demonstrated that an increasing number of those factors is linked to worse outcome, thereby emphasizing the importance of clinical and imaging parameters for adequate risk stratification.

Molecular imaging of arterial fibroblast activation protein: association with calcified plaque burden and cardiovascular risk factors

PURPOSE

We aimed to assess prevalence, distribution, and intensity of in-vivo arterial wall fibroblast activation protein (FAP) uptake, and its association with calcified plaque burden, cardiovascular risk factors (CVRFs), and FAP-avid tumor burden.

METHODS

We analyzed 69 oncologic patients who underwent [68 Ga]Ga-FAPI-04 PET/CT. Arterial wall FAP inhibitor (FAPI) uptake in major vessel segments was evaluated. We then investigated the associations of arterial wall uptake with calcified plaque burden (including number of plaques, plaque thickness, and calcification circumference), CVRFs, FAP-positive total tumor burden, and image noise (coefficient of variation, from normal liver parenchyma).

RESULTS

High focal arterial FAPI uptake (FAPI +) was recorded in 64/69 (92.8%) scans in 800 sites, of which 377 (47.1%) exhibited concordant vessel wall calcification. The number of FAPI + sites per patient and (FAPI +)-derived target-to-background ratio (TBR) correlated significantly with the number of calcified plaques (FAPI + number: r = 0.45, P < 0.01; TBR: r =  - 0.26, P = 0.04), calcified plaque thickness (FAPI + number: r = 0.33, P < 0.01; TBR: r =  - 0.29, P = 0.02), and calcification circumference (FAPI + number: r = 0.34, P < 0.01; TBR: r =  - 0.26, P = 0.04). In univariate analysis, only body mass index was significantly associated with the number of FAPI + sites (OR 1.06; 95% CI, 1.02 - 1.12, P < 0.01). The numbers of FAPI + sites and FAPI + TBR, however, were not associated with other investigated CVRFs in univariate and multivariate regression analyses. Image noise, however, showed significant correlations with FAPI + TBR (r = 0.30) and the number of FAPI + sites (r = 0.28; P = 0.02, respectively). In addition, there was no significant interaction between FAP-positive tumor burden and arterial wall FAPI uptake (P ≥ 0.13).

CONCLUSION

[68 Ga]Ga-FAPI-04 PET identifies arterial wall lesions and is linked to marked calcification and overall calcified plaque burden, but is not consistently associated with cardiovascular risk. Apparent wall uptake may be partially explained by image noise.

PET/CT reading for relapse in non-small cell lung cancer after chemoradiotherapy in the PET-Plan trial cohort

BACKGROUND

Current studies indicate that fluorine-18-fluorodeoxyglucose positron emission tomography/ computed tomography ([¹⁸F]FDG PET/CT) is the most accurate imaging modality for the detection of relapsed locally advanced non-small cell lung cancer (NSCLC) after curatively intended chemoradiotherapy. To this day, there is no objective and reproducible definition for the diagnosis of disease recurrence in PET/CT, the reading of which is relevantly influenced by post radiation inflammatory processes. The aim of this study was to evaluate and compare visual and threshold-based semi-automated evaluation criteria for the assessment of suspected tumor recurrence in a well-defined study population investigated during the randomized clinical PET-Plan trial.

METHODS

This retrospective analysis comprises 114 PET/CT data sets of 82 patients from the PET-Plan multi-center study cohort who underwent [¹⁸F]FDG PET/CT imaging at different timepoints for relapse, as suspected by CT. Scans were first analyzed visually by four blinded readers using a binary scoring system for each possible localization and the associated reader certainty of the evaluation. Visual evaluations were conducted repeatedly without and with additional knowledge of the initial staging PET and radiotherapy delineation volumes. In a second step, uptake was measured quantitatively using maximum standardized uptake value (SUVmax), peak standardized uptake value corrected for lean body mass (SULpeak), and a liver threshold-based quantitative assessment model. Resulting sensitivity and specificity for relapse detection were compared to the findings in the visual assessment. The gold standard of recurrence was independently defined by prospective study routine including external reviewers using CT, PET, biopsies and clinical course of the disease.

RESULTS

Overall interobserver agreement (IOA) of the visual assessment was moderate with a high difference between secure (ĸ = 0.66) and insecure (ĸ = 0.24) evaluations. Additional knowledge of the initial staging PET and radiotherapy delineation volumes improved the sensitivity (0.85 vs 0.92) but did not show significant impact on the specificity (0.86 vs 0.89). PET parameters SUVmax and SULpeak showed lower accuracy compared to the visual assessment, whereas threshold-based reading showed similar sensitivity (0.86) and higher specificity (0.97).

CONCLUSION

Visual assessment especially if associated with high reader certainty shows very high interobserver agreement and high accuracy that can be further increased by baseline PET/CT information. The implementation of a patient individual liver threshold value definition, similar to the threshold definition in PERCIST, offers a more standardized method matching the accuracy of experienced readers albeit not providing further improvement of accuracy.

Impact of 68 Ga-FAPI-04 PET/CT on Staging and Therapeutic Management in Patients With Digestive System Tumors

PURPOSE

We aimed to determine the impact of fibroblast activation protein inhibitor (FAPI)-directed molecular imaging on staging and therapeutic management in patients affected with digestive system tumors when compared with guideline-compatible imaging (GCI).

PATIENTS AND METHODS

Thirty-two patients with tumors of the digestive system were included: colon adenocarcinoma, 2/32 (6.3%); hepatocellular carcinoma (HCC), 6/32 (18.8%); pancreatic duct adenocarcinoma (PDAC), 6/32 (18.8%), and gastroenteropancreatic neuroendocrine neoplasms, 18/32 (56.3%). All patients underwent GCI and 68 Ga-FAPI-04 PET/CT within median 4 days. Staging outcomes and subsequent treatment decisions were compared between GCI and 68 Ga-FAPI-04 PET/CT.

RESULTS

Compared with GCI, 68 Ga-FAPI-04 PET/CT led to staging changes in 15/32 patients (46.9%). Among those, downstaging was recorded in 3/15 cases (20.0%) and upstaging in the remaining 12/15 patients (HCC, 4/12 [33.3%]; PDAC, 4/12 [33.3%]; neuroendocrine neoplasms, 3/12 [25%]; colon adenocarcinoma, 1/12 [8.3%]). Therapeutic management was impacted in 8/32 patients (25.0%), including 4 instances of major and 4 instances of minor therapeutic changes. The highest proportion of treatment modifications was observed in patients diagnosed with PDAC and HCC in 6/8 (75%).

CONCLUSIONS

In patients affected with digestive system tumors, 68 Ga-FAPI-04 PET/CT resulted in staging changes in more than 46% and therapeutic modifications in 25% of the cases, in particular in patients with HCC and PDAC. In clinical routine, such findings may favor a more widespread adoption of FAP-directed imaging in those tumor types.

Prognostic value of tumor volume assessment on PSMA PET after177Lu-PSMA radioligand therapy evaluated by PSMA PET/CT consensus statement and RECIP 1.0

Quantitative evaluation of prostate-specific membrane antigen (PSMA)-targeting PET/CT remains challenging but is urgently needed for the use of standardized PET-based response criteria, such as the PSMA PET/CT consensus statement or Response Evaluation Criteria in PSMA PET/CT (RECIP 1.0). A recent study evaluated the prognostic value of whole-body tumor volume using a semiautomatic method relying on a 50% threshold of lesion SUV_max (PSMA_TV50). In the present study, we analyzed the suitability of this approach comparing ¹⁸F-PSMA-1007 with ⁶⁸Ga-PSMA-11 PET/CT scans and the potential of PSMA_TV50 for the prediction of overall survival (OS) in patients before ¹⁷⁷Lu-PSMA radioligand therapy (RLT). Moreover, PSMA_TV50 was integrated into the PSMA PET/CT consensus statement as well as RECIP 1.0, and the prognostic value of these response classification systems was compared. Methods: This retrospective study included 70 patients with metastatic castration-resistant prostate cancer undergoing PSMA RLT. Thirty-three patients were monitored by ⁶⁸Ga-PSMA-11 PET/CT, and 37 patients by ¹⁸F-PSMA-1007 PET/CT. PET/CT scans before (baseline) and at the end of PSMA RLT after 2-4 cycles (follow-up) were separately analyzed by 2 readers. PSMA_TV50 at baseline and its change at the time of follow-up (ΔPSMA_TV50, expressed as a ratio) were correlated with OS using Cox proportional-hazards regression. The results of both subgroups were compared. The integration of ΔPSMA_TV50 in existing response classification systems was evaluated. To assess and compare the discriminatory strength of these classification systems, Gönen and Heller concordance probability estimates were calculated. Results: PSMA_TV50 determination was technically feasible in all examinations. A higher PSMA_TV50 at baseline and a higher ΔPSMA_TV50 were strongly associated with a shorter OS for both ⁶⁸Ga-PSMA-11 (PSMA_TV50: hazard ratio [HR] of 1.29 [95% CI, 1.05-1.55], P = 0.009; ΔPSMA_TV50: HR of 1.83 [95% CI, 1.08-3.09], P = 0.024) and ¹⁸F-PSMA-1007 (PSMA_TV50: HR of 1.84 [95% CI, 1.13-2.99], P = 0.014; ΔPSMA_TV50: HR of 1.23 [95% CI, 1.04-1.51], P = 0.03). Response assessment provided high discriminatory power for OS for the PSMA PET/CT consensus statement (concordance probability estimate, 0.73) as well as RECIP 1.0 (concordance probability estimate, 0.74). Conclusion: PSMA_TV50 and ΔPSMA_TV50 proved to be predictive of OS not only for ⁶⁸Ga-PSMA-11 but also for ¹⁸F-PSMA-1007 PET/CT scans. Subsequent integration of ΔPSMA_TV50 into the PSMA PET/CT consensus statement and RECIP 1.0 provided equally high prognostic value for both classification systems.

Bone marrow impairment during early [177Lu]PSMA-617 radioligand therapy: Haematotoxicity or tumour progression?

Background

The recent phase III VISION-trial confirms the treatment efficacy of radioligand therapy with [¹⁷⁷Lu]PSMA-617 (PSMA-RLT) in metastatic castration-resistant prostate cancer (mCRPC). In PSMA-RLT, the relatively low absorbed bone marrow dose allows for multiple therapy cycles with relatively low risk of haematological adverse events (hAE). However, as disease progression itself may be a cause of bone marrow impairment, the aim of this study was to assess potential relations between impairment of haematological status and response to PSMA-RLT.

Methods

In this retrospective analysis, haematological parameters (HP) of 64 patients with mCRPC were systematically acquired over two cycles (12–16 weeks) of PSMA-RLT from baseline to restaging. Changes in HP were analysed qualitatively (CTCAE 5.0) and quantitatively. The HP changes from baseline were compared to quantitative and qualitative biochemical and imaging response, using PCWG3 and PROMISE criteria.

Results

All grade 3/4 hAE observed were associated with disseminated or diffuse bone involvement as well as biochemical non-response at restaging. Quantitatively, at baseline, HP inversely correlated with biochemical and volumetric (on PET) tumour burden as well as bone involvement pattern (p ≤ 0.043). Among patients with disseminated or diffuse bone involvement, percentage changes in HP (%HP) at restaging inversely correlated with serological and imaging tumour burden (p ≤ 0.017). Biochemical non-responders showed a significant decrease in %HP (p ≤ 0.001) while HP in biochemical responders remained stable (p ≥ 0.079).

Conclusion

During early cycles of PSMA-RLT, qualitative and quantitative bone marrow impairment appears to be closely associated with osseous tumour burden as only patients with advanced bone involvement and non-response to therapy exhibited high-grade haematological adverse events, showing a significant decline of haematological parameters. This implies that in patients with advanced mCRPC, non-response to PSMA-RLT may be a major cause of bone marrow impairment during early treatment cycles.

German Clinical Trial Register DRKS00013665. Registered 28 December 2017, retrospectively registered (www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00013665)

Expression of Prostate Specific Membrane Antigen (PSMA) in Breast Cancer

Background Prostate specific membrane antigen (PSMA) is a promising protein for breast cancer patients. It has not only been detected in prostate cancer but is also expressed by tumor cells and the endothelial cells of tumor vessels in breast cancer patients. PSMA plays a role in tumor progression and tumor angiogenesis. For this reason, a number of diagnostic and therapeutic methods to target PSMA have been developed. Method This paper provides a general structured overview of PSMA and its oncogenic potential, with a special focus on its role in breast cancer. This narrative review is based on a selective literature search carried out in PubMed and the library of Freiburg University Clinical Center. The following key words were used for the search: "PSMA", "PSMA and breast cancer", "PSMA PET/CT", "PSMA tumor progression". Relevant articles were explicitly read through, processed, and summarized. Conclusion PSMA could be a new diagnostic and therapeutic alternative, particularly for triple-negative breast cancer. It appears to be a potential predictive and prognostic marker.

Assessing Response to [177Lu]PSMA Radioligand Therapy using modified PSMA PET Progression Criteria

Introduction: Positron emission tomography/computer tomography (PET/CT) targeting the prostate specific membrane antigen (PSMA) plays a key role in staging of patients with prostate cancer (PCa). Moreover, it is not only used for the assessment of adequate PSMA expression of PCa cells before PSMA-targeting radioligand therapy (PSMA RLT) but also for re-staging during the course of therapy to evaluate response to treatment. Whereas no established criteria exist for systematic response evaluation so far, recently proposed PSMA PET Progression (PPP) criteria might fill this gap. The aim of this study was to assess the feasibility of PPP criteria in patients undergoing PSMA RLT and their prognostic implications. Methods: In this retrospective analysis, PSMA PET/CT scans of 46 patients acquired before and after completion of PSMA RLT were analyzed separately by two readers using modified PPP criteria. After interobserver agreement assessment, consensus results (progressive vs. non-progressive disease) were compared in a multivariate cox regression model (endpoint overall survival, OS). Results: Interobserver agreement on modified PPP criteria was substantial (Cohens κ = 0.73) with a concordance in 87% of patients. Median OS of all patients after PSMA RLT (n = 46) was 9.0 [95% confidence interval (CI) 7.8 - 10.2] months. Progression according to modified PPP criteria was found in 32 patients and was a significant (p ≤0.001) prognostic marker for OS with a hazard ratio of 15.5 [95% CI 3.4 - 70.2]. Conclusion: Response assessment in patients undergoing PSMA RLT using modified PPP criteria are reproducible and highly prognostic for OS. Modified PPP criteria should be validated in future prospective trials.

Prognostic implications of dual tracer PET/CT: PSMA ligand and [18F]FDG PET/CT in patients undergoing [177Lu]PSMA radioligand therapy

BACKGROUND

Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) with ¹⁷⁷Lu-labeled PSMA ligands has achieved remarkable results in advanced disease stages of metastatic castration-resistant prostate cancer (mCRPC). However, not all patients benefit from this therapy. Different treatment responses could be explained by tumor heterogeneity triggered by progression and the number of prior treatments. PSMA-negative lesions can be missed on PSMA ligand PET/CT, which subsequently results in an underestimation of tumor burden. Conversely, high FDG uptake may also be an indicator of tumor aggressiveness and thus a poor prognostic marker for response to RLT and overall survival (OS). The aim of this analysis was to investigate the prognostic value of combined PSMA ligand PET/CT and [¹⁸F]fluorodeoxyglucose (FDG) PET/CT for outcome prediction in patients undergoing RLT.

MATERIALS AND METHODS

This bicentric analysis included 54 patients with mCRPC who underwent both FDG and PSMA ligand PET/CT imaging before RLT. In all patients, the pattern of PSMA ligand and FDG uptake was visually assessed. Patients with at least one FDG-positive, but PSMA-negative (FDG+/PSMA-) lesions were compared to patients without any FDG+/PSMA- lesions. A log-rank analysis was used to assess the difference in OS between subgroups.

RESULTS

Median OS was 11 ± 1.8 months (95% CI 7.4-14.6). A significantly lower OS (p < 0.001) was found in patients with at least one FDG+/PSMA- lesion at baseline PET/CTs (n = 18) with a median OS of 6.0 ± 0.5 months (95% CI: 5.0-7.0 months). In comparison, patients without any FDG+/PSMA- lesions (n = 36) had a median OS of 16.0 ± 2.5 months (95% CI: 11.2-20.8 months).

CONCLUSION

FDG+/PSMA- lesions are a negative predictor of overall survival in patients with mCRPC undergoing RLT. However, it remains to be determined if patients with FDG+/PSMA- lesions should be excluded from PSMA RLT.

Association between gastrin-releasing peptide receptor expression as assessed with [68Ga]Ga-RM2 PET/CT and histopathological tumor regression after neoadjuvant chemotherapy in primary breast cancer

INTRODUCTION

The gastrin-releasing peptide receptor is overexpressed in breast cancer (BC) tissue and can be visualized by positron emission tomography (PET) using the GRPR antagonist [⁶⁸Ga]Ga-RM2. This study assessed tumor binding of RM2 before and after neoadjuvant chemotherapy (NAC) in primary BC with reference to residual tumor size in the resected specimen.

MATERIALS AND METHODS

In this retrospective study, five female patients with biopsy-confirmed estrogen receptor (ER)-positive primary BC (one with bilateral tumors) underwent [⁶⁸Ga]Ga-RM2 PET/CT before and after NAC. PET/CT was acquired 1 h after injection of 143-224 MBq [⁶⁸Ga]Ga-RM2. Time from pre-NAC PET to beginning of NAC was 23 ± 4.9 days, from end of NAC to post-NAC PET 18.7 ± 6.3 days, and from post-NAC PET to surgery 9.5 ± 10.8 days. In vivo tumor uptake of [⁶⁸Ga]Ga-RM2 was assessed before and after NAC and correlated with histopathological response.

RESULTS

All tumors (6/6) showed strongly increased [⁶⁸Ga]Ga-RM2 uptake compared to normal breast tissue on pre-NAC PET (mean SUVmax 13.2 ± 7.3; mean SUVpeak 9.4 ± 4.4). [⁶⁸Ga]Ga-RM2 uptake was significantly reduced on post-NAC PET in all primary tumors (mean SUVmax 2.3 ± 0.8, -79 ± 11%; p = 0.0125; mean SUVpeak 1.6 ± 0.4, -79 ± 10%; p = 0.0096). Residual tumor size in resected specimens correlated well with SUVmax (r = 0.91, p = 0.0057) and SUVpeak (r = 0.88, p = 0.0196) on [⁶⁸Ga]Ga-RM2 PET/CT after NAC.

CONCLUSION AND IMPLICATIONS FOR PATIENT CARE

In this pilot study, residual uptake of [⁶⁸Ga]Ga-RM2 in ER-positive primary BC correlated well with residual vital tumor size after NAC. This suggests that [⁶⁸Ga]Ga-RM2 PET/CT merits further investigation for response assessment to NAC in patients with ER-positive BC.

Determination of whole-body tumour burden on [68Ga]PSMA-11 PET/CT for response assessment of [177Lu]PSMA-617 radioligand therapy: a retrospective analysis of serum PSA level and imaging derived parameters before and after two cycles of therapy

AIM

 In patients with metastasized castration-resistant prostate cancer a reliable imaging-based therapy response assessment in addition to PSA kinetics is desirable. Recently, measurements of whole-body tumour burden by [⁶⁸Ga]PSMA-11 PET/CT have been reported for response assessment in oligometastasic patients. The present study investigated the association of PSMA PET derived parameters and serum PSA level before and after [¹⁷⁷Lu]PSMA-617 radioligand therapy (RLT).

METHODS

 This retrospective study assessed whole-body PSMA tumour volume (PSMA-TV) in 10 patients with multifocal to diffuse metastases before and after 2 cycles of RLT using volume of interest (VOI) analysis. A standardized uptake value (SUV) threshold-based approach was used to semi-automatically delineate all voxels with a SUV ≥ 2.0 g/ml using the software ROVER^® (ABX Radeberg, Germany). Voxels with physiological tracer uptake (e. g. kidneys) were excluded manually. Correlations between PSMA-TV and serum PSA level before and after two cycles of RLT as well as changes thereof (ΔPSMA-TV and ΔPSA, respectively) were calculated.

RESULTS

 Changes of ΔPSMA-TV and ΔPSA were concordant in 7 of 10 patients. Whereas a good correlation was found between PSMA-TV and PSA before RLT (ρ = 0.81, p = 0.0049), this correlation was attenuated after RLT (ρ = 0.64, p = 0.0479). Consequently, no association was found between ΔPSMA-TV and ΔPSA (ρ = 0.39, p = 0.26).

CONCLUSION

 The attenuation of the correlation of PSA and PSMA-TV after RLT suggests that in patients with advanced disease the comparison of imaging based parameters such as PSMA-TV and PSA level might be useful for an adequate monitoring of treatment response.

Dealing with foreign cultural paradigms: A systematic review on intercultural challenges of international medical graduates

OBJECTIVES

An increasing number of International Medical Graduates (IMG), who are defined to be physicians working in a country other than their country of origin and training, immigrate to Western countries. In order to ensure safe and high-quality patient care, they have to take medical and language tests. This systematic review aims to (1) collect all empiric research on intercultural communication of IMGs in medical settings, (2) identify and categorize all text passages mentioning intercultural issues in the included studies, and (3) describe the most commonly reported intercultural areas of communication of IMGs.

METHODS

This review was based on the PRISMA-Guidelines for systematic reviews. We conducted a broad and systematic electronic literature search for empiric research in the following databases: MEDLINE, BIOSIS Citation Index, BIOSIS Previews, KCI-Korean Journal Database and SciELO Citation Index. The search results were synthesized and analyzed with the aid of coding systems. These coding systems were based on textual analysis and derived from the themes and topics of the results and discussion sections from the included studies. A quality assessment was performed, comparing the studies with their corresponding checklist (COREQ or STROBE). Textual results of the studies were extracted and categorized.

RESULTS

Among 10,630 search results, 47 studies were identified for analysis. 31 studies were qualitative, 12 quantitative and 4 studies used mixed methods. The quality assessment revealed a low level of quality of the studies in general. The following intercultural problems were identified: IMGs were not familiar with shared decision-making and lower hierarchies in the health care system in general. They had difficulties with patient-centered care, the subtleties of the foreign language and with the organizational structures of the new health care system. In addition, they described the medical education in their home countries as science-oriented, without focusing on psychosocial aspects.

CONCLUSION

There is a need for a better training of IMGs on culture-related and not culture-related topics in the new workplace country. The topics that emerged in this review constitute a basis for developing these courses. Further empiric research is needed to describe the findings of this review more precisely and should be in accordance with the existing reporting guidelines.

[Comorbidity of diabetes mellitus and eating disorders. A comparison of psychological features of eating disordered and non-eating disordered patients with diabetes mellitus]

As part of a multicentre study on the comorbidity of diabetes mellitus and eating disorders, the following paper compares the psychological features of diabetic patients with and without an eating disorder. In a sample of 663 diabetic patients (type 1: n = 341 type 2: n = 322), eating disorder related variables, self-esteem, body acceptance and emotional distress, especially depression in diabetic patients with and without an eating disorder, were compared. A possible relationship to diabetic control was investigated. Type 2 diabetics revealed more pronounced psychopathology in comparison to type 1 diabetics. According to our assumption, diabetic patients with an eating disorder and diabetic patients who deliberately reduced insulin in order to loose weight (insulin purging) revealed a much more severe psychopathology compared to diabetics without an eating disorder. The type of diabetes was of no importance. With the exception of the variable body and figure satisfaction in the sample of type 1 diabetes and the variable self-acceptance in the sample of type 2 diabetes, no relationship to diabetic control could be found.

Identification, counselling, and outcome of two cases of prenatally diagnosed supernumerary small ring chromosomes

De novo supernumerary small ring chromosomes have mainly been reported in pediatric patients with clinical abnormalities, thus, there may be bias of ascertainment. Reports on prenatally diagnosed cases with postnatal follow-up are rare. With the availability of chromosome specific alpha-satellite centromeric probes, the interest in these previously unidentifiable supernumerary small ring chromosomes has been rekindled [Callen et al.: J Med Genet 27: 155-159, 1990; Callen et al.: Am J Hum Genet 48:769-782, 1991; Callen et al.: Am J Med Genet 43:709-715, 1992]. We report on 2 prenatal diagnosis cases, where a ring was noted in 25 and 60% of the amniocytes, respectively. The initial G- and C-banding in Case 1 allowed an assumption of a chromosome 1 origin of the extra chromosome. This was confirmed by fluorescence in situ hybridization (FISH) studies using the appropriate probes. No similar initial assumption could be made in Case 2; thus, random trials with multiple probes were performed. A chromosome 19 origin in Case 2 was eventually concluded. The large amount of C-band positive material on the extra chromosome and the normal level 2 fetal ultrasound examination suggested a favorable outcome in both cases, but the possibility of mental retardation could not be ruled out. An empiric risk figure with regard to prenatally diagnosed de novo supernumerary small ring chromosomes is not available. Although the decision making processes of the parents were different, they both decided to continue the pregnancy. At age 9 months and 1 1/2 years both children, a girl and a boy, showed normal growth and development.

Cytogenetics of bilateral renal cell carcinoma

We analyzed cytogenetically 6 tumors from 4 patients with bilateral renal cell carcinoma. Comparison among findings in these patients with bilateral disease and previously reported cases of unilateral tumor demonstrates that bilaterality is associated with a more frequent loss of a sex chromosome, and gain of chromosomes 7 and 3, whereas unilateral tumors often are associated with loss of chromosome 3 material. It is proposed that bilateral tumors are distinct genetically from unilateral tumors and that most bilateral tumors have a genetic propensity to either enhanced metastatic spread to other renal tissue or spontaneous degeneration.

Genomic defects in nonfamilial renal cell carcinoma. Possible specific chromosome change

Using a newly developed combined method of enzymatic technique and short-term tissue culture, 30 tumor specimens from 26 patients with nonfamilial renal cell carcinoma were subjected to cytogenetic analysis. Of the 26 patients, 19 had chromosomally abnormal tumors, four (including two oncocytomas) were normal, and three did not grow. The modal chromosome numbers ranged from 44 to 98 (including two pseudotetraploids). Banding analysis revealed 38 clonal aberrations and ten nonclonal aberrations. Abnormalities were of structure and number. The most consistent clonal abnormality was a trisomy or tetrasomy chromosome 7 occurring in tumors from 15 of the 19 patients with cytogenetically abnormal tumors. In four cases, trisomy 7 was the only visible abnormality observed, and in an additional five it was the only abnormality in two or more cells. An abnormal chromosome 3 was found in ten (38%) of the cases. Two were trisomic for #3, two were monosomic, three were hyperdiploid, and three had interstitial deletions with breakpoints clustered from p11 to p25. In only one case was a deleted #3 the only abnormality observed in a clone of cells. Loss of the sex chromosome was seen in eight (35%) of the 23 chromosomally abnormal cases including all four (100%) patients with bilateral disease. One of the patients with bilateral disease had an abnormal clone with monosomy X as the only abnormality. These data suggest that trisomy or tetrasomy 7 more often represents the specific primary abnormality than abnormalities of either chromosome 3 or the sex chromosomes. From this, a model of chromosomal progression may be constructed for nonfamilial renal cell carcinoma, which could assist in pathologic classification and prognostic and therapeutic considerations.

Cytogenetic analysis in renal cell carcinoma: correlation with tumor aggressiveness

Twenty-eight tissue specimens from 26 patients with renal cell carcinoma were subjected to cytogenetic analysis using a newly developed combined method of enzymatic technique and short term tissue culture. Of the 28 tumor samples studied, 21 were chromosomally abnormal. Four (including two oncocytomas) were normal, and three did not grow in tissue culture. Of the 21 tumors with abnormal chromosomes, the most frequent abnormality was either trisomy or tetrasomy of chromosome 7 (18 of 21 tumors). In four of these tumors, trisomy 7 was the only visible abnormality. Ten tumors contained abnormalities of chromosome 3. Three showed a previously reported chromosome 3 interstitial deletion, five were hyperdiploid, and two revealed a monosomy 3. Of these 10 patients, six have had disease progression, compared to one of the 16 remaining patients without an abnormal chromosome 3. These data suggest that abnormalities of chromosome 7 represent a primary abnormality, and that when these abnormalities are present in association with abnormalities involving chromosome 3, they may correlate with a more aggressive clinical course and a corresponding higher stage of disease at diagnosis.

Cutaneous lymphosarcoma with abnormal chromosomes in a dog

A poorly differentiated cutaneous lymphosarcoma with delayed multicentric anatomical distribution was diagnosed in a dog. The neoplasm had cells with chromosome numbers of 58 or 67 and the former cells lacked the subtelocentric marker chromosome seen in cells of canine transmissible venereal tumour with 58 chromosomes.

Translocation (4;11) in acute myelogenous leukemia

A child with acute myelogenous leukemia is presented. Cytogenetic analysis of her leukemic cells revealed a (4;11)(q12;q23) translocation. The slight difference in the breakpoint on chromosome #4 from previously reported cases of t(4;11) may account for the degree of myeloid differentiation expressed. Acute leukemia associated with t(4;11) is a unique subgroup that originates in an early myeloid stem cell and carries a poor prognosis.

Partial trisomy 6p and partial monosomy 9p from a de novo translocation 46,XY, -9, +DER(9)T(6:9)(p211:p24)

This report describes an adult male with a partial trisomy 6p(p211-pter) and a partial monosomy 9p(9p24-pter) resulting from a de novo unbalanced translocation. This patient does not show the classical featured of the 9p partial monosomy syndrome, thus disputing the claim of Hoo et al. (1982) that 9p24 is the critical segment for the monosomy syndrome. Partial trisomy for 6p has only been previously reported in children. In addition to the chromosomal anomalies, the patient has autosomal recessive spinal muscular atrophy with a different age of onset than two affected sibs. Finally, he shows unusual audiologic and ophthalmologic signs nor previously reported as part of the 9p monosomy or 6p trisomy syndromes.

Neurofibromatosis and fragile-X syndrome in the same patient

We report on an 11 1/2-year-old boy with neurofibromatosis and the fragile-X syndrome. Clinical manifestation of neurofibromatosis include multiple cafe-au-lait spots, axillary freckles, congenital glaucoma, relative macrocephaly, radiologic findings of overtubulation of the long bones, and precocious puberty. The fragile-X syndrome manifests itself as mental retardation with behavior problems, macro-orchidism, and specific cytogenetic findings. The boy has normal serum hormone levels, but a greatly elevated FSH on a first morning void, which contains the nocturnally secreted gonadotropins. This seems to be the first reported occurrence of the fragile-X syndrome with another inherited disease.