Peptide Receptor Radionuclide Therapy in Patients With Advanced Progressive Medullary Thyroid Cancer: Efficacy, Safety, and Survival Predictors

PURPOSE

Progressive metastatic medullary thyroid carcinoma (MTC) is often characterized by rapid disease progression and poor prognosis, with only few therapeutic options available. Peptide receptor radionuclide therapy (PRRT) has demonstrated remarkable success in the management of gastroenteropancreatic neuroendocrine tumors and has also been suggested to treat MTC. However, evidence on its effectiveness and long-term outcome for this indication is still limited. The objective of this study was to assess the safety and efficacy of PRRT in patients with advanced, progressive MTC and to determine survival. Potential predictors of survival were also evaluated.

METHODS

From September 2003 to June 2019, 28 patients (15 men and 13 women; mean age, 49 ± 14 years) with progressive, somatostatin receptor-positive advanced MTC received PRRT with 177Lu- or 90Y-labeled somatostatin analogs at Zentralklinik Bad Berka, Germany. Toxicity was graded according to Common Terminology Criteria for Adverse Events version 5.0. Treatment response was evaluated according to RECIST (Response Evaluation Criteria in Solid Tumors) 1.1, as well as molecular imaging criteria (European Organisation for Research and Treatment of Cancer). Kaplan-Meier analysis was used to calculate progression-free survival (PFS) and overall survival (OS), defined from the start of PRRT. Univariate and multivariate Cox regression analyses were performed to identify parameters associated with PFS and OS.

RESULTS

Seventy-seven cycles of PRRT were administered (mean cumulative administered activity, 16.0 ± 7.8 GBq). No acute or long-term grade 3/4 toxicity was recorded with a follow-up of 3 to 140 months, except for 1 patient (4%) who suffered from grade 3 anemia (possibly related to disease progression). According to the RECIST criteria, the disease control rate after 3 to 4 months of PRRT was 56% (partial remission, 12%; stable disease, 44%). The disease control rate (72%) was higher by molecular response evaluation. Median OS and PFS were 63.7 and 10.1 months, respectively. The annual OS rates were 84% at 1 year, 65% at 3 years, 57% at 5 years, and 18% at 10 years. The annual PFS rates were 42% at 1 year, 21% at 2 years, and 13% at 5 years. Patients with bone metastases had poorer OS and PFS than those without metastases (median OS, 58.7 vs 92.3 months [P = 0.035; hazard ratio, 2.7; 95% confidence interval, 0.92-7.84]; median PFS, 8.5 vs 12.8 months [P = 0.592; hazard ratio, 1.2; 95% confidence interval, 0.56-2.76]).

CONCLUSIONS

Peptide receptor radionuclide therapy was well tolerated and effective in patients with advanced, aggressive MTC. Bone metastasis was an independent adverse prognostic factor for OS.

Ga-68 PSMA-11 impacting prostate cancer management in a real-world setting: A pilot experience using the total-body PET/CT scanner

62

Background: PET/CT using Ga-68 PSMA-11, which received FDA approval, can detect early biochemical recurrence of prostate cancer at greater sensitivity than conventional imaging, as well as more accurately clinical stage and impact treatment management, particularly vital for high-risk patients. We present our first experience with Ga-68 PSMA-11 PET/CT using the total-body PET/CT scanner (uExplorer). Methods: PET/CT imaging (1-bed acquisition of the entire body for 5 minutes) was performed on the uExplorer scanner 56-65 minutes after administering 150-200 MBq of Ga-68 PSMA-11 (Illucix) in 14 patients with prostate cancer at our clinic. The medical records of these patients were reviewed. Results: Of the 14 patients who underwent Ga-68 PSMA-11 total-body PET/CT, 6 had high risk, 6 had intermediate risk and 2 had low risk cancers. The scan was negative in 1 patient, whereas local recurrence and pelvic lymph nodes could be identified in the other patient with low-risk prostate cancer. The smallest size of the lymph node identified was 2 mm. All patients with intermediate and high-risk cancers had metastatic disease – 2 had metastases to the lymph nodes only. Of the 10 patients with widespread metastases to bones and lymph nodes, 4 had additional visceral metastases – in 3 patients to the lungs and in 1 to the liver. The line of management changed in 10/13 patients with a positive scan – 5 were treated with Lu-177 PSMA radioligand, 4 with chemotherapy and 1 with local irradiation. Conclusions: Our pilot experience is consistent with the clinical value of Ga-68 PSMA-11 PET/CT (Illucix) imaging to better inform patient management, in addition to demonstrating the role of rapid and high-resolution imaging with the total-body PET/CT scanner (uExplorer). With the availability of PSMA PET/CT, it should be considered the new standard of care for men who have prostate cancer for staging or localization of recurrence.

Salivary Gland Toxicity of PSMA-Targeted Radioligand Therapy with 177Lu-PSMA and Combined 225Ac- and 177Lu-Labeled PSMA Ligands (TANDEM-PRLT) in Advanced Prostate Cancer: A Single-Center Systematic Investigation

Purpose: PSMA-targeted radioligand therapy (PRLT) is a promising treatment option for patients with metastatic castration-resistant prostate cancer (mCRPC). However, a high uptake of the radiopharmaceutical in the salivary glands (SG) can lead to xerostomia and becomes dose-limiting for 225Ac-PSMA-617. This study investigated the sialotoxicity of 177Lu-PSMA-I&T/-617 monotherapy and co-administered 225Ac-PSMA-617 and 177Lu-PSMA-617 (Tandem-PPRLT). Methods: Three patient cohorts, that had undergone 177Lu-PSMA-I&T/-617 monotherapy or Tandem-PRLT, were retrospectively analyzed. In a short-term cohort (91 patients), a xerostomia assessment (CTCAE v.5.0), a standardized questionnaire (sXI), salivary gland scintigraphy (SGS), and SG SUVmax and the metabolic volume (MV) on 68Ga-PSMA-11-PET/CT were obtained before and after two cycles of 177Lu-PSMA-I&T/-617. In a long-term cohort, 40 patients were similarly examined. In a Tandem cohort, the same protocol was applied to 18 patients after one cycle of Tandem-PRLT. Results: Grade 1 xerostomia in the short-term follow-up was observed in 22 (24.2%) patients with a worsening of sXI from 7 to 8 at (p < 0.05). In the long-term cohort, xerostomia grades 1 to 2 occurred in 16 (40%) patients. SGS showed no significant changes, but there was a decline of the MV of all SGs. After Tandem-PRLT, 12/18 (66.7%) patients reported xerostomia grades 1 to 2, and the sXI significantly worsened from 9.5 to 14.0 (p = 0.005), with a significant reduction in the excretion fraction (EF) and MV of all SGs. Conclusion: 177Lu-PSMA-I&T/-617 causes only minor SG toxicity, while one cycle of Tandem-PRLT results in a significant SG impairment. This standardized protocol may help to objectify and quantify SG dysfunction.

Prostate-Specific Membrane Antigen Radioligand Therapy Using 177Lu-PSMA I&T and 177Lu-PSMA-617 in Patients with Metastatic Castration-Resistant Prostate Cancer: Comparison of Safety, Biodistribution, and Dosimetry

The objective of this study was to determine the safety, kinetics, and dosimetry of the ¹⁷⁷Lu-labeled prostate-specific membrane antigen (PSMA) small molecules ¹⁷⁷Lu-PSMA I&T and ¹⁷⁷Lu-PSMA-617 in a large cohort of patients with metastatic castration-resistant prostate cancer (mCRPC) undergoing PSMA radioligand therapy (PRLT). Methods: In total, 138 patients (mean age, 70 ± 9 y; age range, 46-90 y) with progressive mCRPC and PSMA expression verified by ⁶⁸Ga-PSMA-11 PET/CT underwent PRLT. Fifty-one patients received 6.1 ± 1.0 GBq (range, 3.4-7.6 GBq) of ¹⁷⁷Lu-PSMA I&T, and 87 patients received 6.5 ± 1.1 GBq (range, 3.5-9.0 GBq) of ¹⁷⁷Lu-PSMA-617. Dosimetry was performed on all patients using an identical protocol. The mean absorbed doses were estimated with OLINDA software (MIRD Scheme). Treatment-related adverse events were graded according to the Common Terminology Criteria for Adverse Events, version 5.0, of the National Cancer Institute. Results: The whole-body half-lives were shorter for ¹⁷⁷Lu-PSMA I&T (35 h) than for ¹⁷⁷Lu-PSMA-617 (42 h). The mean whole-body dose of ¹⁷⁷Lu-PSMA-617 was higher than that of ¹⁷⁷Lu-PSMA I&T (0.04 vs. 0.03 Gy/GBq, P < 0.00001). Despite the longer half-life of ¹⁷⁷Lu-PSMA-617, the renal dose was lower for ¹⁷⁷Lu-PSMA-617 than for ¹⁷⁷Lu-PSMA I&T (0.77 vs. 0.92 Gy/GBq, P = 0.0015). Both PSMA small molecules demonstrated a comparable dose to the parotid glands (0.5 Gy/GBq, P = 0.27). Among all normal organs, the lacrimal glands exhibited the highest mean absorbed doses, 5.1 and 3.7 Gy/GBq, for ¹⁷⁷Lu-PSMA-617 and ¹⁷⁷Lu-PSMA I&T, respectively. All tumor metastases exhibited a higher initial uptake when using ¹⁷⁷Lu-PSMA I&T than when using ¹⁷⁷Lu-PSMA-617, as well as a shorter tumor half-life (P < 0.00001). The mean absorbed tumor doses were comparable for both ¹⁷⁷Lu-PSMA I&T and ¹⁷⁷Lu-PSMA-617 (5.8 vs. 5.9 Gy/GBq, P = 0.96). All patients tolerated the therapy without any acute adverse effects. After ¹⁷⁷Lu-PSMA-617 and ¹⁷⁷Lu-PSMA I&T, there was a small, statistically significant reduction in hemoglobin, leukocyte counts, and platelet counts that did not need any clinical intervention. No nephrotoxicity was observed after either ¹⁷⁷Lu-PSMA I&T or ¹⁷⁷Lu-PSMA-617 PRLT. Conclusion: Both ¹⁷⁷Lu-PSMA I&T and ¹⁷⁷Lu-PSMA-617 PRLT demonstrated favorable safety in mCRPC patients. The highest absorbed doses among healthy organs were in the lacrimal and parotid glands-not, however, resulting in any significant clinical sequel. ¹⁷⁷Lu-PSMA-617 demonstrated a higher absorbed dose to the whole-body and lacrimal glands but a lower renal dose than did ¹⁷⁷Lu-PSMA I&T. The mean absorbed tumor doses were comparable for both ¹⁷⁷Lu-PSMA I&T and ¹⁷⁷Lu-PSMA-617. There was a large interpatient variability in the dosimetry parameters. Therefore, individual patient-based dosimetry seems favorable for personalized PRLT.

225Ac-DOTATOC-Targeted Somatostatin Receptor α-Therapy in a Patient With Metastatic Neuroendocrine Tumor of the Thymus, Refractory to β-Radiation

ABSTRACT

Somatostatin receptor-targeted α-therapy using α-emitter 225Ac-labeled somatostatin analogs has been suggested as a treatment option in advanced metastatic neuroendocrine tumors (NETs) failing treatment with β-emitters, such as 177Lu or 90Y. Thymus NETs are rare and usually more aggressive than other neuroendocrine tumor entities. We present here a case with β-radiation refractory metastatic thymus NET, who demonstrated an excellent therapy response (molecular and morphological remission, as well as significantly improved clinical symptoms) after 225Ac-DOTATOC-targeted α-therapy, without any adverse effects during the treatment or in the follow-up period.

Feasibility, Biodistribution and Preliminary Dosimetry in Peptide-Targeted Radionuclide Therapy (PTRT) of Diverse Adenocarcinomas using 177Lu-FAP-2286: First-in-Human Results

Fibroblast activation protein (FAP) is a promising target for diagnosis and therapy of numerous malignant tumors. FAP-2286 is the conjugate of a FAP-binding peptide, which can be labeled with radionuclides for theranostic applications. We present the first-in-human results using ¹⁷⁷Lu-FAP-2286 for peptide-targeted radionuclide therapy (PTRT). Methods: PTRT using ¹⁷⁷Lu-FAP-2286 was performed in 11 patients with advanced adenocarcinomas of pancreas, breast, rectum and ovary after prior confirmation of uptake on ⁶⁸Ga-FAP-2286/-FAPI-04- PET/CT. Results: Administration of ¹⁷⁷Lu-FAP-2286 (5.8 ± 2.0 GBq; range, 2.4-9.9 GBq) was well tolerated, with no adverse symptoms or clinically detectable pharmacologic effects being noticed or reported in any of the patients. The whole-body effective doses were 0.07 ± 0.02 Gy/GBq (range 0.04 - 0.1). The mean absorbed doses for kidneys and red marrow were 1.0 ± 0.6 Gy/GBq (range 0.4 - 2.0) and 0.05 ± 0.02 Gy/GBq (range 0.03 - 0.09), respectively. Significant uptake and long tumor retention of ¹⁷⁷Lu-FAP-2286 resulted in high absorbed tumor doses, e.g., 3.0 ± 2.7 Gy/GBq (range 0.5 - 10.6) in bone metastases. No grade (G) 4 adverse events were observed. G3 events occurred in 3 patients - 1 pancytopenia, 1 leukocytopenia and 1 pain flare-up; 3 patients reported pain-response. Conclusion: ¹⁷⁷Lu-FAP-2286 PTRT, applied in a broad spectrum of cancers, was relatively well-tolerated with acceptable side effects and demonstrated long retention of the radiopeptide. Prospective clinical studies are warranted.

First-in-Humans Application of 161Tb: A Feasibility Study Using 161Tb-DOTATOC

¹⁶¹Tb has decay properties similar to those of ¹⁷⁷Lu but, additionally, emits a substantial number of conversion and Auger electrons. The aim of this study was to apply ¹⁶¹Tb in a clinical setting and to investigate the feasibility of visualizing the physiologic and tumor biodistributions of ¹⁶¹Tb-DOTATOC. Methods: ¹⁶¹Tb was shipped from Paul Scherrer Institute, Villigen-PSI, Switzerland, to Zentralklinik Bad Berka, Bad Berka, Germany, where it was used for the radiolabeling of DOTATOC. In 2 separate studies, 596 and 1,300 MBq of ¹⁶¹Tb-DOTATOC were administered to a 35-y-old male patient with a metastatic, well-differentiated, nonfunctional malignant paraganglioma and a 70-y-old male patient with a metastatic, functional neuroendocrine neoplasm of the pancreatic tail, respectively. Whole-body planar γ-scintigraphy images were acquired over a period of several days for dosimetry calculations. SPECT/CT images were reconstructed using a recently established protocol and visually analyzed. Patients were observed for adverse events after the application of ¹⁶¹Tb-DOTATOC. Results: The radiolabeling of DOTATOC with ¹⁶¹Tb was readily achieved with a high radiochemical purity suitable for patient application. Planar images and dosimetry provided the expected time-dependent biodistribution of ¹⁶¹Tb-DOTATOC in the liver, kidneys, spleen, and urinary bladder. SPECT/CT images were of high quality and visualized even small metastases in bones and liver. The application of ¹⁶¹Tb-DOTATOC was well tolerated, and no related adverse events were reported. Conclusion: This study demonstrated the feasibility of imaging even small metastases after the injection of relatively low activities of ¹⁶¹Tb-DOTATOC using γ-scintigraphy and SPECT/CT. On the basis of this essential first step in translating ¹⁶¹Tb to clinics, further efforts will be directed toward the application of ¹⁶¹Tb for therapeutic purposes.

Therapy-related myeloid neoplasm after peptide receptor radionuclide therapy (PRRT) in 1631 patients from our 20 years of experiences: prognostic parameters and overall survival

PURPOSE

To determine prognostic factors and overall survival (OS) in therapy-related myeloid neoplasm (t-MN) of patients after receiving peptide receptor radionuclide therapy (PRRT).

METHODS

All patients treated from February 1999 until September 2019 at our center who had bone marrow biopsy-proven t-MN after PRRT were included. Patient characteristics, laboratory results, and all tumor-directed therapies before t-MN diagnosis were collected. Cox regression analysis was performed to identify parameters associated with OS. Receiver operating characteristic (ROC) curve analysis was used to define cutoff values as well as sensitivity and specificity of the parameters.

RESULTS

Out of 1631 patients treated with PRRT, 30 patients developed t-MN comprising myelodysplastic syndrome (MDS) in 23 patients (77%) and acute myeloid leukemia (AML) in 7 patients (23%). The median OS of t-MN patients was 13 months (range 9.1-16.9 months): 6 months for AML and 15 months for the MDS subgroup, respectively. Higher platelet level was a significant prognostic parameter for longer OS (hazard ratio (HR): 0.99, P < 0.05). Using ROC analysis, the best cutoff value for thrombocyte count was 183.5 Gpt/L, resulting in a sensitivity of 92.3% and a specificity of 50%. Other factors, such as hemoglobin level, did not show a significant correlation with OS.

CONCLUSION

Even rarely occurred, the OS is gravely compromised in t-MN patients after PRRT, and even less in the AML subgroup (6 months). Higher platelet value was a significant prognostic parameter for longer OS in t-MN patients.

Prior therapies as prognostic factors of overall survival in metastatic castration-resistant prostate cancer patients treated with [177Lu]Lu-PSMA-617. A WARMTH multicenter study (the 617 trial)

Introduction

The impact of prior therapies, especially chemotherapy, on overall survival (OS) in patients with castration-resistant prostate cancer (CRPC) receiving [¹⁷⁷Lu]Lu-PSMA-617 therapy has been the subject of controversy. Therefore, WARMTH decided to plan a multicenter retrospective analysis (the “617 trial”) to evaluate response rate and OS as well as the impact of prior therapies on OS in more than 300 patients treated with ¹⁷⁷Lu-PSMA-617.

Materials and methods

The data of 631 metastatic CRPC (mCRPC) patients from 11 different clinics were evaluated. According to the inclusion and exclusion criteria, all patients had to have received at least abiraterone or enzalutamide prior to [¹⁷⁷Lu]Lu-PSMA-617 therapy. The patients were divided into three groups: patients who had received prior chemotherapy, patients who avoided chemotherapy, and patients for whom a chemotherapy was contraindicated.

Results

The analysis included the data of 416 patients, with a median age of 71.9 years. At the time of analysis, 87 patients (20,9%) were still alive. A total of 53.6% of patients had received both abiraterone and enzalutamide; 75.5% and 26.4% had a history of chemotherapy with docetaxel and cabazitaxel, respectively. A total of 20.4% had had Ra-223. The median OS was 11.1 months. Prior chemotherapy, the existence of bone and liver metastases, as well as Eastern Cooperative Oncology Group (ECOG) status, were significant prognosticators of worse overall survival in both univariate and multivariate analyses. Patients without any prior chemotherapy showed a significantly longer OS (14.6 months). The median OS in patients who received one or two lines of chemotherapy with docetaxel or docetaxel followed by cabazitaxel, respectively, was 10.9 months and 8.9 months. There was no difference in OS between patients who had not received chemotherapy and patients for whom chemotherapy was contraindicated. The other prior therapies did not have any significant impact on OS.

Conclusion

In the present multicenter analysis, chemotherapy-naïve mCRPC patients receiving [¹⁷⁷Lu]Lu-PSMA-617 therapy had a significantly longer OS than patients with a history of chemotherapy. This remained independent in the multivariate analysis besides presence of bone and liver metastases as negative prognosticators for survival, whereas an ECOG of 0–1 is associated with a longer OS.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-04797-9) contains supplementary material, which is available to authorized users.

Metastatic extent predicts survival as patients with metastatic castration-resistant prostate cancer are treated with 177Lu-PSMA radioligand therapy

PSMA based radioligand is a new investigational drug for treatment of metastatic multidrug-resistant and castration-resistant prostate cancer. Prognostic factors point to above and below average overall survival (OS) after the treatment.

Kessel et al. [Theranostics 2019;9:4841-8] reported for the first time that two sites of visceral metastases, lungs and liver, differed in impact on OS after treatment with ¹⁷⁷Lu PSMA 617. Treatment with established drugs showed the same trend. The difference in OS between the sites is independent of the type of treatment and can reflect changes in tumor biology during the progression of metastatic prostate cancer.

Prognostic Value of 18F-FDG PET/CT in a Large Cohort of Patients with Advanced Metastatic Neuroendocrine Neoplasms Treated with Peptide Receptor Radionuclide Therapy

The objective of this retrospective study was to determine the role of ¹⁸F-FDG PET/CT in a large cohort of 495 patients with metastatic neuroendocrine neoplasms (NENs) who were treated with peptide receptor radionuclide therapy (PRRT) with a long-term follow-up. Methods: The 495 patients were treated with ¹⁷⁷Lu- or ⁹⁰Y-DOTATOC/DOTATATE PRRT between February 2002 and July 2018. All subjects received both ⁶⁸Ga-DOTATOC/TATE/NOC and ¹⁸F-FDG PET/CT before treatment and were followed 3-189 mo. Kaplan-Meier analysis, log-rank testing (Mantel-Cox), and Cox regression analysis were performed for overall survival (OS) and progression-free survival (PFS). Results: One hundred ninety-nine patients (40.2%) presented with pancreatic NENs, 49 with cancer of unknown primary, and 139 with midgut NENs, whereas the primary tumor was present in the rectum in 20, in the lung in 38, in the stomach in 8, and in other locations in 42. ¹⁸F-FDG PET/CT was positive in 382 (77.2%) patients and negative in 113 (22.8%) before PRRT, whereas 100% were ⁶⁸Ga-DOTATOC/TATE/NOC-positive. For all patients, the median PFS and OS, defined from the start of PRRT, were 19.6 mo and 58.7 mo, respectively. Positive ¹⁸F-FDG results predicted shorter PFS (18.5 mo vs. 24.1 mo; P = 0.0015) and OS (53.2 mo vs. 83.1 mo; P < 0.001) than negative ¹⁸F-FDG results. Among the cases of pancreatic NENs, the median OS was 52.8 mo in ¹⁸F-FDG-positive subjects and 114.3 mo in ¹⁸F-FDG-negative subjects (P = 0.0006). For all patients positive for ¹⁸F-FDG uptake, and a ratio of more than 2 for the highest SUV_max on ⁶⁸Ga-somatostatin receptor (SSTR) PET to the most ¹⁸F-FDG-avid tumor lesions, the median OS was 53.0 mo, compared with 43.4 mo in those patients with a ratio of less than 2 (P = 0.030). For patients with no ¹⁸F-FDG uptake (complete mismatch imaging pattern), the median OS was 108.3 mo versus 76.9 mo for an SUV_max of more than 15.0 and an SUV_max of 15.0 or less on ⁶⁸Ga-SSTR PET/CT, respectively. Conclusion: The presence of positive lesions on ¹⁸F-FDG PET is an independent prognostic factor in patients with NENs treated with PRRT. Metabolic imaging with ¹⁸F-FDG PET/CT complements the molecular imaging aspect of ⁶⁸Ga-SSTR PET/CT for the prognosis of survival after PRRT. High SSTR expression combined with negative ¹⁸F-FDG PET/CT results is associated with the most favorable long-term prognosis.

Preclinical investigations and first-in-human application of 152Tb-PSMA-617 for PET/CT imaging of prostate cancer

Background

For almost a decade, terbium radioisotopes have been explored for their potential theragnostic application in nuclear medicine: ¹⁵²Tb and ¹⁵⁵Tb are the radioisotopes identified for PET or SPECT imaging, while ¹⁴⁹Tb and ¹⁶¹Tb have suitable decay characteristics for α- and combined β⁻/Auger-e⁻-therapy, respectively. In the present study, the application of ¹⁵²Tb, in combination with PSMA-617 for imaging of prostate-specific membrane antigen (PSMA)-positive prostate cancer, was demonstrated in a preclinical setting and in a patient with metastatic castration-resistant prostate cancer (mCRPC).

Results

¹⁵²Tb was produced at the ISOLDE facility at CERN/Geneva, Switzerland, by spallation, followed by on-line mass separation. The chemical separation was performed at Paul Scherrer Institute using chromatographic methods, as previously reported. ¹⁵²Tb was employed for labeling PSMA-617, and the radioligand was extensively investigated in vitro to demonstrate similar characteristics to its ¹⁷⁷Lu-labeled counterpart. Preclinical PET/CT imaging studies performed with mice enabled visualization of PSMA-positive PC-3 PIP tumors, while uptake in PSMA-negative PC-3 flu tumors were absent. Based on these promising preclinical results, ¹⁵²Tb was shipped to Zentralklinik Bad Berka, Germany, where it was used for labeling of PSMA-617, enabling PET imaging of a patient with mCRPC. PET/CT scans were performed over a period of 25 h post injection (p.i.) of the radioligand (140 MBq). The images were of diagnostic quality, particularly those acquired at later time points, and enabled the detection of the same metastatic lesions and of local recurrent tumor as previously detected by ⁶⁸Ga-PSMA-11 PET/CT acquired 45 min p.i.

Conclusions

The results of this study demonstrate the successful preparation and preclinical testing of ¹⁵²Tb-PSMA-617 and its first application in a patient with mCRPC. This work could pave the way towards clinical application of other Tb radionuclides in the near future, most importantly ¹⁶¹Tb, which has promising decay characteristics for an effective treatment of mCRPC patients.

Electronic supplementary material

The online version of this article (10.1186/s13550-019-0538-1) contains supplementary material, which is available to authorized users.

From Bench to Bedside-The Bad Berka Experience With First-in-Human Studies

Precision oncology is being driven by rapid advances in novel diagnostics and therapeutic interventions, with treatments targeted to the needs of individual patients on the basis of genetic, biomarker, phenotypic, or psychosocial characteristics that distinguish a given patient from other patients with similar clinical presentations. Inherent in the theranostics paradigm is the assumption that diagnostic test results can precisely determine whether an individual is likely to benefit from a specific treatment. As part and integral in the current era of precision oncology, theranostics in the context of nuclear medicine aims to identify the appropriate molecular targets in neoplasms (diagnostic tool), so that the optimal ligands and radionuclides (therapeutic tool) with favorable labeling chemistry can be selected for personalized management of a specific disease, taking into consideration the specific patient, and subsequently monitor treatment response. Over the past two decades, the use of gallium-68 labeled peptides for somatostatin receptor (SSTR)-targeted PET/CT (or PET/MRI) imaging followed by lutetium-177 and yttrium-90 labeled SSTR-agonist for peptide receptor radionuclide therapy has demonstrated remarkable success in the management of neuroendocrine neoplasms, and paved the way to other indications of theranostics. Rapid advances are being made in the development of other peptide-based radiopharmaceuticals, small molecular-weight ligands and with newer radioisotopes with more favorable kinetics, potentially useful for theranostics strategies for the clinical application. The present review features the Bad Berka experience with first-in-human studies of new radiopharmaceuticals, for example, prostate-specific membrane antigen ligand, gastrin-releasing peptide receptor, neurotensin receptor 1 ligand, novel SSTR-targeting peptides and nonpeptide, and bone-seeking radiopharmaceuticals. Also new radioisotopes, for example, actinium (²²⁵Ac), copper (⁶⁴Cu), scandium (⁴⁴Sc), and terbium (¹⁵²Tb/¹⁶¹Tb) will be discussed briefly demonstrating the development from basic science to precision oncology in the clinical setting.

Semiquantitative Parameters in PSMA-Targeted PET Imaging with [18F]DCFPyL: Intrapatient and Interpatient Variability of Normal Organ Uptake

PURPOSE

Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging has impacted the management of patients with prostate cancer (PCa) in many parts of the world. PSMA-targeted endoradiotherapies are also being increasingly utilized and for these applications, the radiopharmaceutical distribution in normal organs is particularly important because it may limit the dose that can be delivered to tumors. In this study, we measured both interpatient and intrapatient variability of [¹⁸F]DCFPyL uptake in the most relevant normal organs.

PROCEDURES

Baseline and 6-month follow-up PSMA-targeted [¹⁸F]DCFPyL PET/computed tomography (CT) scans from 39 patients with PCa were reviewed. Volumes of interest were manually drawn using the best visual approximation of the organ edge for both lacrimal glands, all four major salivary glands, the liver, the spleen, and both kidneys for all patients. The average SUV_mean, the COVs, and intraclass correlation coefficients (ICCs) across scans were calculated. Bland-Altman analyses were performed for all organs to derive repeatability coefficients (RCs).

RESULTS

The liver demonstrated the lowest interpatient variability (13.0 and 16.6 % at baseline and follow-up, respectively), while the spleen demonstrated the largest interpatient variability (44.6 and 51.0 % at baseline and follow-up, respectively). The lowest intrapatient variability was found in the spleen (ICC 0.86) while the highest intrapatient variability was in the kidneys (ICCs 0.40-0.50). Bland-Altman analyses showed 95 % repeatability coefficients for mean uptake > 40 % for multiple organs and were highest for the lacrimal glands, kidneys, and spleen.

CONCLUSIONS

Normal organs demonstrate significant variability in uptake of the PSMA-targeted radiotracer [¹⁸F]DCFPyL. Depending on the organ, different contributions of interpatient and intrapatient factors affect the intrinsic variability. The RCs also vary significantly among the different organs were highest for the lacrimal glands, kidneys, and spleen. These findings may have important implications for the design of clinical protocols and personalized dosimetry for PSMA-targeted endoradiotherapies.

177Lu-PSMA radioligand therapy of predominant lymph node metastatic prostate cancer

¹⁷⁷Lu-PSMA radioligand therapy (LuPRLT) is mainly used for patients with metastatic castration-resistant prostate cancer who are resistant to established drugs. This study describes LuPRLT, either LuPSMA I&T or LuPSMA RLT-617, for 45 patients with predominant lymph node metastatic prostate cancer (LNM PC). Thirty-five patients had LNM and ten patients had LNM and one or two bone metastases. Before LuPRLT, the patients had prostate specific antigen (PSA) of median 18 µg/l (interquartile range (IQR): 3.3–39). LuPRLT was given with a cumulative injected ¹⁷⁷Lu activity of median 14.5 GBq (IQR: 12.2–20.4). Maximum percentage decline of PSA was median 92% (IQR: 70–99). Thirty-five patients with only LNM had a better overall survival (OS) than ten patients with LNM and one or two bone metastases. Thirty-three docetaxel-naïve patients had a longer PSMA PET/CT progression-free survival than twelve patients who were resistant to docetaxel. Twenty-two patients who received LuPRLT with a cumulative injected ¹⁷⁷Lu activity ≥ 14.8 GBq had a better PSMA PET/CT progression-free survival than 23 patients who received LuPRLT with a lower cumulative injected ¹⁷⁷Lu activity. Seventeen patients with relapse after LuPRLT who received rechallenge LuPRLT or ActPRLT had a better OS than five patients who received other forms for relapse treatment. LuPRLT gave mild and transitory adverse effects. The findings of the present study suggest that LuPRLT of patients with LNM may be effective and safe. The promising results motivate randomized phase II trials to further quantify the impact of LuPRLT as treatment of patients with LNM.

177Lu-PSMA-617 Radioligand Therapy in Metastatic Castration-Resistant Prostate Cancer Patients with a Single Functioning Kidney

The aim of this study was to assess the safety, tolerability, and effects on renal function as well as therapeutic efficacy of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (PRLT) using ¹⁷⁷Lu-labeled PSMA-617 in patients with metastatic castration-resistant prostate cancer and a single functioning kidney before PRLT. Methods: Sixteen patients (aged 53-78 y; mean age, 64.7 ± 6.5 y) with a single functioning kidney received PRLT with ¹⁷⁷Lu-PSMA-617 between March 2015 and October 2018. All parameters of renal function (serum creatinine, blood urea nitrogen, and electrolytes) were prospectively documented in a structured database and analyzed before each PRLT cycle and in follow-up. Renal function was further quantified by measuring tubular extraction rate (TER) using ^99mTc-mercaptoacetyltriglycine renal scintigraphy. Treatment-related adverse events were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. Kaplan-Meier analysis was performed to obtain the progression-free survival and overall survival. Results: The median administered activity was 22.1 GBq (range, 15.4-33.8 GBq). The calculated absorbed radiation dose to the kidney per cycle was 5.3 ± 2.1 Gy (0.81 ± 0.32 Gy/GBq). Renal function was already impaired at baseline in 43.7% of patients, including CTCAE grade 1 renal impairment in 25.0% and CTCAE grade 2 in 18.8%. Grade 1 and 2 renal impairment, respectively, were present in 37.5% and 6.3% of the patients after the first PRLT cycle and in 31.3% and 12.5% after the second cycle. No CTCAE grade 3 or 4 nephrotoxicity was observed during or after treatment. There was no significant change in either TER or the ratio of TER to lower-limit TER after the last cycle of treatment (P > 0.05). The median PFS was 8.1 mo based on both the criteria of the European Organization for Research and Treatment of Cancer and RECIST. The median overall survival has yet to be reached with a median follow-up time of 19.3 mo (range, 5.8-45.3 mo). Conclusion: In patients with a single functioning kidney, ¹⁷⁷Lu-PSMA-617 PRLT is feasible, seems to be effective, and is well tolerated, without any signs of acute or subacute nephrotoxicity during a mean follow-up of nearly 2 y (and up to 45.3 mo). Further long-term follow-up of this special patient group is warranted.

Clinical Outcomes of 177Lu-PSMA Radioligand Therapy in Earlier and Later Phases of Metastatic Castration-Resistant Prostate Cancer Grouped by Previous Taxane Chemotherapy

¹⁷⁷Lu-labeled prostate-specific membrane antigen (PSMA) radioligand therapy using PSMA-617 and PSMA-I&T ligands (¹⁷⁷Lu-PRLT) is an emerging treatment in metastatic castration-resistant prostate cancer (mCRPC). This retrospective study evaluates clinical outcomes of ¹⁷⁷Lu-PRLT in earlier and later phases of mCRPC grouped by previous taxane chemotherapy. Methods: A retrospective analysis was performed on 167 patients with mCRPC who underwent ¹⁷⁷Lu-PRLT between March 2013 and December 2016. Patients were classified as either taxane chemotherapy pretreated (T-pretreated) or naïve (T-naïve) depending on whether they had received taxane-based chemotherapy prior to ¹⁷⁷Lu-PRLT. Clinical outcome for T-pretreated and T-naïve patients was assessed by overall survival (OS), radiographic progression-free survival, and prostate-specific antigen (PSA) response rate. Univariate and multivariable analyses were performed for both T-pretreated and T-naïve patients to determine predictors of outcome. Toxicity was categorized by the Common Terminology Criteria for Adverse Events (version 4.03). Results: Of the 167 patients treated with ¹⁷⁷Lu-PRLT, 83 were T-pretreated and 84 were T-naïve. At baseline, T-pretreated patients had overall poorer performance status, a higher prevalence of bone metastases, higher PSA levels, lower hemoglobin levels, higher alkaline phosphatase (ALP) levels and had received more additional therapies compared with T-naïve patients. Median OS was 10.7 mo for T-pretreated patients and 27.1 mo for T-naïve patients. Median radiographic progression-free survival was 6.0 mo for T-pretreated patients and 8.8 mo for T-naïve patients. PSA response assessment was evaluable in 132 patients and seen in 25 of 62 (40%) T-pretreated patients and 40 of 70 (57%) T-naïve patients. Significant determinates of inferior OS in multivariable analysis for T-pretreated patients were poorer performance status, lower cumulative administered activity, and lower baseline hemoglobin. Higher baseline alkaline phosphatase was the only significant determinate of inferior OS in multivariable analysis for T-naïve patients. Overall ¹⁷⁷Lu-PRLT was safe, with minimal adverse effects evident during follow-up in both T-pretreated and T-naïve patients. Conclusion: ¹⁷⁷Lu-PRLT is a promising therapy in mCRPC, with encouraging outcomes and minimal associated toxicity seen in both our T-naïve and heavily pretreated patient cohorts.

Peptide Receptor Radionuclide Therapy in Grade 3 Neuroendocrine Neoplasms: Safety and Survival Analysis in 69 Patients

To date, limited data are available concerning peptide receptor radionuclide therapy (PRRT) of grade 3 (G3) neuroendocrine neoplasms (NENs) with a Ki-67 proliferation index of greater than 20%. The purpose of this study was to analyze the long-term outcome, efficacy, and safety of PRRT in patients with somatostatin receptor (SSTR)-expressing G3 NENs. Methods: A total of 69 patients (41 men; age, 28-81 y) received PRRT with ¹⁷⁷Lu- or ⁹⁰Y-labeled somatostatin analogs (DOTATATE or DOTATOC). Twenty-two patients had radiosensitizing chemotherapy. Kaplan-Meier analysis was performed to calculate progression-free survival (PFS) and overall survival (OS), defined from the start of PRRT, including a subgroup analysis for patients with a Ki-67 index of less than or equal to 55% and a Ki-67 index of greater than 55%. Treatment response was evaluated according to RECIST 1.1 as well as molecular imaging criteria (European Organization for Research and Treatment of Cancer). Short- and long-term toxicity was documented (Common Terminology Criteria for Adverse Events, v 5.0) using a structured database (comprising >250 items per patient) and retrospectively analyzed. Results: Forty-six patients had pancreatic NENs, 11 had unknown primary cancer, 6 had midgut NENs, 3 had gastric NENs, and 3 had rectal NENs. The median follow-up was 94.3 mo. The median PFS was 9.6 mo, and the median OS was 19.9 mo. For G3 NENs with a Ki-67 index of less than or equal to 55% (n = 53), the median PFS was 11 mo and the median OS was 22 mo. Patients with a Ki-67 index of greater than 55% (n = 11) had a median PFS of 4 mo and a median OS of 7 mo. For patients with positive SSTR imaging but no ¹⁸F-FDG uptake, the median PFS was 24 mo and the median OS was 42 mo. A significant difference was found for both PFS and OS, with median PFS of 16 mo and 5 mo and median OS of 27 mo and 9 mo for an SUV_max of greater than 15.0 and an SUV_max of less than or equal to 15.0, respectively, on SSTR PET. In the group with ¹⁸F-FDG uptake scored as 3 or 4, the median PFS was 7.1 mo and the median OS was 17.2 mo. In the group with ¹⁸F-FDG uptake scored as 0-2, the median PFS was 24.3 mo and the median OS was 41.6 mo. PRRT was well tolerated by all patients; no grade 3 or grade 4 hematotoxicity occurred, and no clinically significant decline in renal function was observed. There was no hepatotoxicity. Conclusion: PRRT was tolerated well, without significant adverse effects, and was efficacious in G3 NENs; the clinical outcome was promising, especially in patients with a Ki-67 index of less than or equal to 55% and even in patients for whom chemotherapy had failed. Baseline ¹⁸F-FDG along with SSTR molecular imaging was useful for stratifying G3 NEN patients with high uptake on SSTR PET/CT and no or minor ¹⁸F-FDG avidity-a mismatch pattern that was associated with a better long-term prognosis.

Abstract CT015: Safety and long-term efficacy of radioligand therapy using Lu-177 labeled PSMA ligands in metastatic prostate cancer: A single center experience over 5 years

Aim: Metastatic prostate cancer (mPC) has still a poor prognosis. First- and second-line chemotherapy with docetaxel or cabazitaxel is often toxic and prolongs life by only a few months. Also novel agents like abiraterone, enzalutamide or Ra-223-chloride confer a limited survival benefit. Prostate-specific membrane antigen (PSMA) is a glutamate carboxypeptidase II overexpressed especially in poorly differentiated prostate cancer (1) and is a very attractive target for diagnosis and therapy (theranostics) with radiolabeled small molecules. Internalization and retention within the tumor cell provides very promising and highly selective treatment effects of multiple metastases with PSMA radioligand therapy (PRLT) (2-5).

Methods: 224 mPC patients (mean age 71 years, mean Gleason score 8), screened by Ga-68 PSMA or F-18 DCFPyl PET/CT imaging, were treated with 1 - 9 cycles (3.5 - 12 GBq Lu-177 PSMA per cycle) between April 2013 and October 2017 and included in the intention to treat analysis with a median follow-up time of 16 months (3 - 55). Previous treatments were surgery (154), external beam radiation (151), chemotherapy (110), androgen deprivation (206) and Ra-223 chloride (19). The serum prostate antigen (PSA) levels were monitored before and after therapy. Response to therapy was also determined by RECIST as well as according to molecular imaging criteria using standardized uptake values (SUV) on Ga-68 PSMA PET/CT studies. Hematological and organ toxicity was documented according to CTCAE v4.03.

Results: Reduction in serum PSA was observed in 157/224 (70%) patients; 121/224 patients (54%) demonstrated a PSA decline by &gt;50%, best response was complete remission with undetectable PSA. Ga-68 PSMA PET/CT after at least 2 PRLT cycles in 200 patients demonstrated complete remission in 6 (3%), partial remission in 70 (35%), stable disease in 55 (27.5%) and progressive disease in 69 (34.5%) patients. RECIST revealed 46 (23%) partial remissions, 6 (3%) complete remissions, 84 (42%) with stable disease and 64 (32%) disease progressions. The median overall survival was 27 months. Median progression-free survival was 18 months. No severe (G3-4) bone marrow toxicity was observed and patients didn't show any evidence of nephrotoxicity or any other significant organ toxicity. Mild xerostomia occurred in less than 3% of all patients.

Conclusion: Lu-177 PSMA radioligand therapy appears to be effective for the treatment of metastatic prostate cancer with only minimal toxicity, offering a significant benefit in overall and progression-free survival even in patients whose disease had progressed despite all standard treatments. Randomized controlled studies are required to best determine the place of this theranostic approach in the management of mPC.

Citation Format: Harshad R. Kulkarni, Thomas Langbein, C Atay, Aviral Singh, Christiane Schuchardt, Coline Lehmann, Martin Pomper, Kenneth J. Pienta, Richard P. Baum. Safety and long-term efficacy of radioligand therapy using Lu-177 labeled PSMA ligands in metastatic prostate cancer: A single center experience over 5 years [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT015.

Theranostics of prostate cancer: from molecular imaging to precision molecular radiotherapy targeting the prostate specific membrane antigen

Alterations at the molecular level are a hallmark of cancer. Prostate cancer is associated with the overexpression of prostate-specific membrane antigen (PSMA) in a majority of cases, predominantly in advanced tumors, increasing with the grade or Gleason's score. PSMA can be selectively targeted using radiolabeled PSMA ligands. These small molecules binding the PSMA can be radiolabeled with γ-emitters like ^99mTc and ¹¹¹In or positron emitters like ⁶⁸Ga and ¹⁸F for diagnosis as well as with their theranostic pairs such as ¹⁷⁷Lu (β-emitter) or ²²⁵Ac (α-emitter) for therapy. This review summarizes the theranostic role of PSMA ligands for molecular imaging and targeted molecular radiotherapy, moving towards precision oncology.

Results and adverse events of personalized peptide receptor radionuclide therapy with 90Yttrium and 177Lutetium in 1048 patients with neuroendocrine neoplasms

Introduction

Peptide receptor radionuclide therapy (PRRT) of patients with somatostatin receptor expressing neuroendocrine neoplasms has shown promising results in clinical trials and a recently published phase III study.

Methods

In our center, 2294 patients were screened between 2004 and 2014 by ⁶⁸Ga somatostatin receptor (SSTR) PET/CT. Intention to treat analysis included 1048 patients, who received at least one cycle of ⁹⁰Yttrium or ¹⁷⁷Lutetium-based PRRT. Progression free survival was determined by ⁶⁸Ga SSTR-PET/CT and EORTC response criteria. Adverse events were determined by CTCAE criteria.

Results

Overall survival (95% confidence interval) of all patients was 51 months (47.0-54.9) and differed significantly according to radionuclide, grading, previous therapies, primary site and functionality. Progression free survival (based on PET/CT) of all patients was 19 months (16.9-21), which was significantly influenced by radionuclide, grading, and origin of neuroendocrine neoplasm. Progression free survival after initial progression and first and second resumption of PRRT after therapy-free intervals of more than 6 months were 11 months (9.4-12.5) and 8 months (6.4-9.5), respectively. Myelodysplastic syndrome or leukemia developed in 22 patients (2.1%) and 5 patients required hemodialysis after treatment, other adverse events were rare.

Conclusion

PRRT is effective and overall survival is favorable in patients with neuroendocrine neoplasms depending on the radionuclide used for therapy, grading and origin of the neuroendocrine neoplasm which is not exactly mirrored in progression free survival as determined by highly sensitive ⁶⁸Ga somatostatin receptor PET/CT using EORTC criteria for determining response to therapy.

Morphological and Functional Imaging for Detecting and Assessing the Resectability of Neuroendocrine Liver Metastases

This review evaluates the diagnostic efficacy of different morphological and functional imaging modalities (ultrasound [US], computed tomography [CT], magnetic resonance [MR] imaging, scintigraphy, and positron emission tomography [PET]) in detecting neuroendocrine liver metastases (NELM), assessing vascular and biliary involvement, and the presence of extrahepatic disease. MR imaging is superior for depicting NELM compared to US, CT, and somatostatin receptor scintigraphy. Diffusion-weighted MR imaging is more sensitive for detecting NELM than both T2-weighted and dynamic gadolinium-enhanced MR sequences, and should be systematically performed. Similarly, gadoxetic acid-enhanced MR imaging is more sensitive for detecting liver metastases than conventional extracellular gadolinium chelate-enhanced MR sequences. Its role in detecting NELM remains investigational but appears promising. Somatostatin receptor-targeted PET/CT is a highly effective approach in assessing the resectability of well-differentiated NELM due to very high specificity (and high sensitivity) and its ability to detect small volume extrahepatic disease; this molecular imaging modality is becoming increasingly available in and outside Europe after the recent approval of 6868-DOTATATE in the US. In addition, the information from multiphase, contrast-enhanced CT with 3D reconstruction - obtained concurrently with the information on somatostatin receptor expression of the metastases - is very helpful in planning the extent and type of resection of NELM.

Theranostics of Neuroendocrine Tumors

Somatostatin receptor positron emission tomography/computed tomography using ⁶⁸Ga-labeled somatostatin analogs is the mainstay for the evaluation of receptor status in neuroendocrine tumors (NETs). This translates towards better therapy options, with increasing evidence of peptide receptor radionuclide therapy (PRRT) as the treatment of choice for advanced or progressive NETs. There are benefits in progression-free and overall survival as well as a significant improvement in clinical condition. In patients with progressive NETs, fractionated, personalized PRRT results in good therapeutic responses with no significant severe hematological and/or renal toxicity, thus improving quality of life.

177Lu-3BP-227 for Neurotensin Receptor 1-Targeted Therapy of Metastatic Pancreatic Adenocarcinoma: First Clinical Results

Neurotensin receptor 1 (NTR1) is overexpressed in ductal pancreatic adenocarcinoma, which is still one of the deadliest cancers, with a very poor prognosis. Eligible patients were offered salvage radiopharmaceutical therapy with the novel NTR1 antagonist ¹⁷⁷Lu-3BP-227. Methods: Six patients with confirmed ductal pancreatic adenocarcinoma who had exhausted all other treatment options received ¹⁷⁷Lu-3BP-227 for evaluation of NTR1 expression in vivo. Three patients received treatment activities of 5.1-7.5 GBq. Results: Administration of ¹⁷⁷Lu-3BP-227 was well tolerated by all patients. The kidneys were identified as the dose-limiting organ. The most severe adverse event was reversible grade 2 anemia. One patient achieved a partial response and experienced significant improvement of symptoms and quality of life. This patient survived 13 mo from diagnosis and 11 mo from the start of ¹⁷⁷Lu-3BP-227 therapy. Conclusion: This initial report provides clinical evidence of the feasibility of treatment of ductal pancreatic adenocarcinoma using ¹⁷⁷Lu-3BP-227.

Abstract 944: Chemokine receptor signaling as a new tool to improve lung cancer diagnostics and therapy

Background: The tumor microenvironment plays a critical role in cancer development, progression, and control. We demonstrated in vitro and in vivo that a bidirectional crosstalk between tumor-associated macrophages and cancer cells via CCR2-CCL2 and CX3CR1-CXCL1 signaling is fundamental for lung cancer growth and metastasis offers new treatment concepts.

Aim: Our working hypothesis is to develop a new platform for specific chemokine receptor (CCR2) PET imaging and a range of theranostic applications in lung cancer. For this purpose, we planned to define the CCR2 expression in NSCLC as well as in SCLC, tumor cells as well as immune/inflammatory cells.

Material and Methods: This is a multicenter trial with patients from Zentralklinik Bad Berka GmbH (n =100 NSCLC, n=100 SCLC). All patients gave informed consent according to the declaration of Helsinki. FFPE material was available in all cases. CCR2 CXCR4 and CX3CR1 expression was determined by immunohistochemistry with the avidin-biotin-peroxidase-complex.

Results: Analyzing 96 NSCLC (47 adenocarcinoma, 49 squamous cell carcinoma) and 45 SCLC tumor samples, we found CXCR4 and CCR2 chemokine receptor expression in tumor, immune and inflammatory cells. In NSCLC, co-expression between CCR2 and CXCR4 staining was very high concerning their expression on tumor cells rising with higher tumor stages, proliferation rate and grading. CCR2 expression in immune cells was restricted to lower stages; the same pattern could be observed in 45 SCLC tumor samples where CCR2 expression on immune cells was found especially in limited disease rather than in metastatic disease; CXCR4 expression in tumor cells was found to be high in all stages of SCLC. To evaluate the therapeutic efficacy of CCR2 antagonism in vivo, we injected LLC1 s.c. into WT mice treated with CCR2 antagonist (RS504393) or vehicle. Notably, tumor growth was significantly inhibited in CCR2 antagonist-treated mice as compared with vehicle-treated mice.

Discussion: Our preliminary results show a significant portion of CCR2 positive tumors - NSCLC as well as SCLC which would qualify for a CCR2-based imaging as well as - demonstrated in our mice models - CCR2 inhibitory strategies. This should be evaluated in further preclinical trials.

Citation Format: Katalin Nagy-Major, Jörg Sänger, Harshad R. Kulkarni, Peter Fix, Almut Kunze, Amelie Lupp, Reiner Bonnet, Werner Seeger, Richard P. Baum, Patricia Grabowski, Rajkumar Savai. Chemokine receptor signaling as a new tool to improve lung cancer diagnostics and therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 944. doi:10.1158/1538-7445.AM2017-944

Advances in the Diagnosis of Neuroendocrine Neoplasms

Somatostatin receptor PET/CT using (68)Ga-labeled somatostatin analogs, is a mainstay for the evaluation of the somatostatin receptor status in neuroendocrine neoplasms. In addition, the assessment of glucose metabolism by (18)F-FDG PET/CT at diagnosis can overcome probable shortcomings of histopathologic grading. This offers a systematic theranostic approach for the management of neuroendocrine neoplasms, that is, patient selection for the appropriate treatment-surgery, somatostatin analogs, peptide receptor radionuclide therapy, targeted therapies like everolimus and sunitinib, or chemotherapy-and also for therapy response monitoring. Novel targets, for example, the chemokine receptor CXCR4 in higher-grade tumors and glucagon like peptide-1 receptor in insulinomas, appear promising for imaging. Scandium-44 and Copper-64, especially on account of their longer half-life (for pretherapeutic dosimetry) and cyclotron production (which favors mass production), might be the potential alternatives to (68)Ga for PET/CT imaging. The future of molecular imaging lies in Radiomics, that is, qualitative and quantitative characterization of tumor phenotypes in correlation with tumor genomics and proteomics, for a personalized cancer management.

PSMA-Based Radioligand Therapy for Metastatic Castration-Resistant Prostate Cancer: The Bad Berka Experience Since 2013

A potential milestone in personalized nuclear medicine is theranostics of metastatic castration-resistant prostate cancer (mCRPC) based on molecular imaging using PET/CT with ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA) ligands and molecular radiotherapy using PSMA-targeted radioligand therapy (PRLT) with ¹⁷⁷Lu-PSMA ligands. ⁶⁸Ga-PSMA PET/CT enables accurate detection of mCRPC lesions with high diagnostic sensitivity and specificity and provides quantitative and reproducible data that can be used to select patients for PRLT and therapeutic monitoring. Our comprehensive experience over the last 3 years using different radioligands indicates that PRLT is highly effective for the treatment of mCRPC, even in advanced cases, and potentially lends a significant benefit to overall and progression-free survival. Additionally, significant improvement in clinical symptoms and excellent palliation of pain can be achieved.

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

BACKGROUND

Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (¹⁷⁷Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors.

METHODS

We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either ¹⁷⁷Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (¹⁷⁷Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here.

RESULTS

At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the ¹⁷⁷Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the ¹⁷⁷Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the ¹⁷⁷Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the ¹⁷⁷Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame.

CONCLUSIONS

Treatment with ¹⁷⁷Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the ¹⁷⁷Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors

BACKGROUND

Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (¹⁷⁷Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors.

METHODS

We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either ¹⁷⁷Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (¹⁷⁷Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here.

RESULTS

At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the ¹⁷⁷Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the ¹⁷⁷Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the ¹⁷⁷Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the ¹⁷⁷Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame.

CONCLUSIONS

Treatment with ¹⁷⁷Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the ¹⁷⁷Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).

Clinical evaluation of the radiolanthanide terbium-152: first-in-human PET/CT with 152Tb-DOTATOC

The existence of theragnostic pairs of radionuclides allows the preparation of radiopharmaceuticals for diagnostic and therapeutic purposes.

German Multicenter Study Investigating 177Lu-PSMA-617 Radioligand Therapy in Advanced Prostate Cancer Patients

¹⁷⁷Lu-labeled PSMA-617 is a promising new therapeutic agent for radioligand therapy (RLT) of patients with metastatic castration-resistant prostate cancer (mCRPC). Initiated by the German Society of Nuclear Medicine, a retrospective multicenter data analysis was started in 2015 to evaluate efficacy and safety of ¹⁷⁷Lu-PSMA-617 in a large cohort of patients.

METHODS

One hundred forty-five patients (median age, 73 y; range, 43-88 y) with mCRPC were treated with ¹⁷⁷Lu-PSMA-617 in 12 therapy centers between February 2014 and July 2015 with 1-4 therapy cycles and an activity range of 2-8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (version 4.0) on the basis of serial blood tests and the attending physician's report. The primary endpoint for efficacy was biochemical response as defined by a prostate-specific antigen decline ≥ 50% from baseline to at least 2 wk after the start of RLT.

RESULTS

A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response in 99 patients as well as data for physician-reported and laboratory-based toxicity in 145 and 121 patients, respectively, were available. The median follow-up was 16 wk (range, 2-30 wk). Nineteen patients died during the observation period. Grade 3-4 hematotoxicity occurred in 18 patients: 10%, 4%, and 3% of the patients experienced anemia, thrombocytopenia, and leukopenia, respectively. Xerostomia occurred in 8%. The overall biochemical response rate was 45% after all therapy cycles, whereas 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and the presence of visceral metastases were negative predictors and the total number of therapy cycles positive predictors of biochemical response.

CONCLUSION

The present retrospective multicenter study of ¹⁷⁷Lu-PSMA-617 RLT demonstrates favorable safety and high efficacy exceeding those of other third-line systemic therapies in mCRPC patients. Future phase II/III studies are warranted to elucidate the survival benefit of this new therapy in patients with mCRPC.

German Multicenter Study Investigating 177Lu-PSMA-617 Radioligand Therapy in Advanced Prostate Cancer Patients

¹⁷⁷Lu-labeled PSMA-617 is a promising new therapeutic agent for radioligand therapy (RLT) of patients with metastatic castration-resistant prostate cancer (mCRPC). Initiated by the German Society of Nuclear Medicine, a retrospective multicenter data analysis was started in 2015 to evaluate efficacy and safety of ¹⁷⁷Lu-PSMA-617 in a large cohort of patients.

METHODS

One hundred forty-five patients (median age, 73 y; range, 43-88 y) with mCRPC were treated with ¹⁷⁷Lu-PSMA-617 in 12 therapy centers between February 2014 and July 2015 with 1-4 therapy cycles and an activity range of 2-8 GBq per cycle. Toxicity was categorized by the common toxicity criteria for adverse events (version 4.0) on the basis of serial blood tests and the attending physician's report. The primary endpoint for efficacy was biochemical response as defined by a prostate-specific antigen decline ≥ 50% from baseline to at least 2 wk after the start of RLT.

RESULTS

A total of 248 therapy cycles were performed in 145 patients. Data for biochemical response in 99 patients as well as data for physician-reported and laboratory-based toxicity in 145 and 121 patients, respectively, were available. The median follow-up was 16 wk (range, 2-30 wk). Nineteen patients died during the observation period. Grade 3-4 hematotoxicity occurred in 18 patients: 10%, 4%, and 3% of the patients experienced anemia, thrombocytopenia, and leukopenia, respectively. Xerostomia occurred in 8%. The overall biochemical response rate was 45% after all therapy cycles, whereas 40% of patients already responded after a single cycle. Elevated alkaline phosphatase and the presence of visceral metastases were negative predictors and the total number of therapy cycles positive predictors of biochemical response.

CONCLUSION

The present retrospective multicenter study of ¹⁷⁷Lu-PSMA-617 RLT demonstrates favorable safety and high efficacy exceeding those of other third-line systemic therapies in mCRPC patients. Future phase II/III studies are warranted to elucidate the survival benefit of this new therapy in patients with mCRPC.

Investigating the Effect of Ligand Amount and Injected Therapeutic Activity: A Simulation Study for 177Lu-Labeled PSMA-Targeting Peptides

In molecular radiotherapy with ¹⁷⁷Lu-labeled prostate specific membrane antigen (PSMA) peptides, kidney and/or salivary glands doses limit the activity which can be administered. The aim of this work was to investigate the effect of the ligand amount and injected activity on the tumor-to-normal tissue biologically effective dose (BED) ratio for ¹⁷⁷Lu-labeled PSMA peptides. For this retrospective study, a recently developed physiologically based pharmacokinetic model was adapted for PSMA targeting peptides. General physiological parameters were taken from the literature. Individual parameters were fitted to planar gamma camera measurements (¹⁷⁷Lu-PSMA I&T) of five patients with metastasizing prostate cancer. Based on the estimated parameters, the pharmacokinetics of tumor, salivary glands, kidneys, total body and red marrow was simulated and time-integrated activity coefficients were calculated for different peptide amounts. Based on these simulations, the absorbed doses and BEDs for normal tissue and tumor were calculated for all activities leading to a maximal tolerable kidney BED of 10 Gy_2.5/cycle, a maximal salivary gland absorbed dose of 7.5 Gy/cycle and a maximal red marrow BED of 0.25 Gy₁₅/cycle. The fits yielded coefficients of determination > 0.85, acceptable relative standard errors and low parameter correlations. All estimated parameters were in a physiologically reasonable range. The amounts (for 2⁵−2⁹ nmol) and pertaining activities leading to a maximal tumor dose, considering the defined maximal tolerable doses to organs of risk, were calculated to be 272±253 nmol (452±420 μg) and 7.3±5.1 GBq. Using the actually injected amount (235±155 μg) and the same maximal tolerable doses, the potential improvement for the tumor BED was 1–3 fold. The results suggest that currently given amounts for therapy are in the appropriate order of magnitude for many lesions. However, for lesions with high binding site density or lower perfusion, optimizing the peptide amount and activity might improve the tumor-to-kidney and tumor-to-salivary glands BED ratio considerably.

First-In-Human Study Demonstrating Tumor-Angiogenesis by PET/CT Imaging with (68)Ga-NODAGA-THERANOST, a High-Affinity Peptidomimetic for αvβ3 Integrin Receptor Targeting

(68)Ga-NODAGA-THERANOST™ is an αvβ3 integrin antagonist and the first radiolabeled peptidomimetic to reach clinical development for targeting integrin receptors. In this first-in-human study, the feasibility of integrin receptor peptidomimetic positron emission tomography/computed tomography (PET/CT) imaging was confirmed in patients with non-small-cell lung cancer and breast cancer.

METHODS

Patients underwent PET/CT imaging with (68)Ga NODAGA-THERANOST. PET images were analyzed qualitatively and quantitatively and compared to 2-deoxy-2-((18)F) fluoro-d-glucose ((18)F-FDG) findings. Images were obtained 60 minutes postinjection of 300-500 MBq of (68)Ga-NODAGA-THERANOST.

RESULTS

(68)Ga-NODAGA-THERANOST revealed high tumor-to-background ratios (SUVmax=4.8) and uptake at neoangiogenesis sites. Reconstructed fused images distinguished cancers with high malignancy potential and enabled enhanced bone metastasis detection. (18)F-FDG-positive lung and lymph node metastases did not show uptake, indicating the absence of neovascularization.

CONCLUSIONS

(68)Ga-NODAGA-THERANOST was found to be safe and effective, exhibiting in this study rapid blood clearance, stability, rapid renal excretion, favorable biodistribution and PK/PD, low irradiation burden (μSv/MBq/μg), and convenient radiolabeling. This radioligand might enable theranostics, that is, a combination of diagnostics followed by the appropriate therapeutics, namely antiangiogenic therapy, image-guided presurgical assessment, treatment response evaluation, prediction of pathologic response, neoadjuvant-peptidomimetic-radiochemotherapy, and personalized medicine strategies. Further clinical trials evaluating (68)Ga-NODAGA-THERANOST are warranted.

Preclinical and first clinical experience with the gastrin-releasing peptide receptor-antagonist [⁶⁸Ga]SB3 and PET/CT

PURPOSE

Gastrin-releasing peptide receptors (GRPR) represent attractive targets for tumor diagnosis and therapy because of their overexpression in major human cancers. Internalizing GRPR agonists were initially proposed for prolonged lesion retention, but a shift of paradigm to GRPR antagonists has recently been made. Surprisingly, radioantagonists, such as [(99m)Tc]DB1 ((99m)Tc-N4'-DPhe(6),Leu-NHEt(13)]BBN(6-13)), displayed better pharmacokinetics than radioagonists, in addition to their higher inherent biosafety. We introduce here [(68)Ga]SB3, a [(99m)Tc]DB1 mimic-carrying, instead of the (99m)Tc-binding tetraamine, the chelator DOTA for labeling with the PET radiometal (68)Ga.

METHODS

Competition binding assays of SB3 and [(nat)Ga]SB3 were conducted against [(125)I-Tyr(4)]BBN in PC-3 cell membranes. Blood samples collected 5 min postinjection (pi) of the [(67)Ga]SB3 surrogate in mice were analyzed using high-performance liquid chromatography (HPLC) for degradation products. Likewise, biodistribution was performed after injection of [(67)Ga]SB3 (37 kBq, 100 μL, 10 pmol peptide) in severe combined immunodeficiency (SCID) mice bearing PC-3 xenografts. Eventually, [(68)Ga]SB3 (283 ± 91 MBq, 23 ± 7 nmol) was injected into 17 patients with breast (8) and prostate (9) cancer. All patients had disseminated disease and had received previous therapies. PET/CT fusion images were acquired 60-115 min pi.

RESULTS

SB3 and [(nat)Ga]SB3 bound to the human GRPR with high affinity (IC50: 4.6 ± 0.5 nM and 1.5 ± 0.3 nM, respectively). [(67)Ga]SB3 displayed good in vivo stability (>85 % intact at 5 min pi). [(67)Ga]SB3 showed high, GRPR-specific and prolonged retention in PC-3 xenografts (33.1 ± 3.9%ID/g at 1 h pi - 27.0 ± 0.9%ID/g at 24 h pi), but much faster clearance from the GRPR-rich pancreas (≈160%ID/g at 1 h pi to <17%ID/g at 24 h pi) in mice. In patients, [(68)Ga]SB3 elicited no adverse effects and clearly visualized cancer lesions. Thus, 4 out of 8 (50 %) breast cancer and 5 out of 9 (55 %) prostate cancer patients showed pathological uptake on PET/CT with [(68)Ga]SB3.

CONCLUSION

[(67)Ga]SB3 showed excellent pharmacokinetics in PC-3 tumor-bearing mice, while [(68)Ga]SB3 PET/CT visualized lesions in about 50 % of patients with advanced and metastasized prostate and breast cancer. We expect imaging with [(68)Ga]SB3 to be superior in patients with primary breast or prostate cancer.

68Ga- and 177Lu-Labeled PSMA I&T: Optimization of a PSMA-Targeted Theranostic Concept and First Proof-of-Concept Human Studies

On the basis of the high and consistent expression of prostate-specific membrane antigen (PSMA) in metastatic prostate cancer (PC), the goal of this study was the development, preclinical evaluation, and first proof-of-concept investigation of a PSMA inhibitor for imaging and therapy (PSMA I&T) for (68)Ga-based PET and (177)Lu-based endoradiotherapeutic treatment in patients with metastatic and castration-resistant disease.

METHODS

PSMA I&T was synthesized in a combined solid phase and solution chemistry strategy. The PSMA affinity of (nat)Ga-/(nat)Lu-PSMA I&T was determined in a competitive binding assay using LNCaP cells. Internalization kinetics of (68)Ga- and (177)Lu-PSMA I&T were investigated using the same cell line, and biodistribution studies were performed in LNCaP tumor-bearing CD-1 nu/nu mice. Initial human PET imaging studies using (68)Ga-PSMA I&T, as well as endoradiotherapeutic treatment of 2 patients with metastatic PC using (177)Lu-PSMA I&T, were performed.

RESULTS

PSMA I&T and its cold gallium and lutetium analog revealed nanomolar affinity toward PSMA. The DOTAGA (1,4,7,10-tetraazacyclododecane-1-(glutamic acid)-4,7,10-triacetic acid) conjugate PSMA I&T allowed fast and high-yield labeling with (68)Ga(III) and (177)Lu(III). Uptake of (68)Ga-/(177)Lu-PSMA I&T in LNCaP tumor cells is highly efficient and PSMA-specific, as demonstrated by competition studies both in vitro and in vivo. Tumor targeting and tracer kinetics in vivo were fast, with the highest uptake in tumor xenografts and kidneys (both PSMA-specific). First-in-human (68)Ga-PSMA I&T PET imaging allowed high-contrast detection of bone lesions, lymph node, and liver metastases. Endoradiotherapy with (177)Lu-PSMA I&T in 2 patients was found to be effective and safe with no detectable side effects.

CONCLUSION

(68)Ga-PSMA I&T shows potential for high-contrast PET imaging of metastatic PC, whereas its (177)Lu-labeled counterpart exhibits suitable targeting and retention characteristics for successful endoradiotherapeutic treatment. Prospective studies on larger cohorts of patients are warranted and planned.

Peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors: current state and future perspectives

The heterogeneous nature of neuroendocrine tumors, their indolent course and lack of therapeutic options for the management of advanced cases – together form the Achilles heel for oncologists. Somatostatin receptor-specific imaging with Ga-68 labeled peptides has provided an opportunity for management of advanced cancers with their therapeutic radionuclide counterparts (Lu-177/Y-90 labeled peptides). Molecular imaging with positron emission tomography/computed tomography is accepted technique for treatment response assessment, since the radiolabels for imaging and therapy are same, thereby depicting accurate response. We have compiled and reviewed our experience of last 8–10 years in the use of these novel radiolabeled peptides in the treatment of neuroendocrine tumors, focusing on the survival, toxicity profiles and the recent advances and improvements.

Patient selection for personalized peptide receptor radionuclide therapy using Ga-68 somatostatin receptor PET/CT

Neuroendocrine tumors are malignant solid tumors originating from neuroendocrine cells dispersed throughout the body. Differentiated neuroendocrine tumors overexpress somatostatin receptors (SSTRs), which enable the diagnosis using radiolabeled somatostatin analogues. Internalization and retention within the tumor cell are important for peptide receptor radionuclide therapy using the same peptide. The use of the same DOTA-peptide for SSTR PET/CT using (68)Ga and for peptide receptor radionuclide therapy using therapeutic radionuclides like (177)Lu and (90)Y offers a unique theranostic advantage.

THERANOSTICS-clinical aimshots in surgical warfare against well-differentiated neuroendocrine neoplasms

Targeted, personalized or molecular medicine all imply maximal treatment with minimal side effects and requires definition and detection of molecular targets prior to therapy. THERANOSTICS in nuclear medicine utilizes the same vector with distinct radionuclides for diagnosis and treatment and has become innovative standard for the treatment of somatostatin receptor expressing neuroendocrine neoplasms.

[Pulmonary neuroendocrine neoplasms]

The pulmonary neuroendocrine neoplasms originate from the enterochromaffin cells which are diffusely distributed in the body. The incidence of these tumors has increased significantly in recent decades due to the available diagnostics. They make up about 1-2% of all lung tumors and 20-30% of all neuroendocrine neoplasms. The current WHO classification from 2004 divides them into typical carcinoids (TC), atypical carcinoids (AC), large cell neuroendocrine carcinomas (LCNEC) and small cell carcinomas (SCLC). The major neuroendocrine biomarkers are chromogranin A, synaptophysin and CD56. TC have a low mitotic rate of <2 mitoses/2mm(2) (10 HPF), whereas the mitotic rate of the AC is 2-10 mitoses/2 mm(2) (10 HPF). The Ki-67 staining is helpful to distinguish typical and atypical carcinoids from the highly malignant LCNEC and SCLC. Clinically, the patient presents usually with cough, hemoptysis or bronchial obstruction. The occurrence of a carcinoid or Cushing's syndrome and a tumor-associated acromegaly are rare. Surgical resection with radical lymph node dissection is the treatment of choice for achieving long-term survival. Endoscopic resection of the endobronchial tumor growth is a good alternative for inoperable endobronchially localized tumors. Peptide receptor radionuclide therapy (PRRT) is a promising treatment option for patients with metastatic or unresectable pulmonary neuroendocrine tumors. New targeted therapies using angiogenesis inhibitors, mTOR inhibitors, and tyrosine kinase inhibitors are being tested for their effectiveness in many previous studies. Typical carcinoid tumors metastasize less frequently than AC, the 5-year survival rate of patients with TC being over 90%. Patients with AC have a 5-year survival rate between 35% and 87%. The highly malignant LCNEC and SCLC, on the other hand, have a 5-year survival rate between 15% and 57%, and <5% respectively. The increasing number of therapeutic options and diagnostic procedures requires a multidisciplinary approach and decision-making in multidisciplinary tumor conferences to ensure a personalized treatment approach. Therefore patients with a neuroendocrine neoplasm of the lung should be treated in specialized centers.

[The relevance of PET/CT for the surgical management of neuroendocrine neoplasms]

Neuroendocrine neoplasms (NEN) are rare malignancies with a wide spectrum of metastatic potential which originate from the endocrine cells of the body and express somatostatin receptors. The (68)gallium somatostatin receptor positron emission tomography-computed tomography (PET/CT) technique is the most sensitive method of assessment of well-differentiated NENs and for the detection of cancer of unknown primary (CUP syndrome) NENs. Imaging with 18F-fluorodeoxyglucose (18F-FDG PET/CT) is indicated in poorly differentiated neuroendocrine carcinomas. The receptor-dependent imaging of NENs has a decisive impact on further management.