Nitric oxide and cytokinin cross-talk and their role in plant hypoxia response

Nitric oxide (NO) and cytokinins (CKs) are known for their crucial contributions to plant development, growth, senescence, and stress response. Despite the importance of both signals in stress responses, their interaction remains largely unexplored. The interplay between NO and CKs emerges as particularly significant not only regarding plant growth and development but also in addressing plant stress response, particularly in the context of extreme weather events leading to yield loss. In this review, we summarize NO and CKs metabolism and signaling. Additionally, we emphasize the crosstalk between NO and CKs, underscoring its potential impact on stress response, with a focus on hypoxia tolerance. Finally, we address the most urgent questions that demand answers and offer recommendations for future research endeavors.

Prostate Cancer Nodal Staging: Using Deep Learning to Predict 68Ga-PSMA-Positivity from CT Imaging Alone

Lymphatic spread determines treatment decisions in prostate cancer (PCa) patients. 68Ga-PSMA-PET/CT can be performed, although cost remains high and availability is limited. Therefore, computed tomography (CT) continues to be the most used modality for PCa staging. We assessed if convolutional neural networks (CNNs) can be trained to determine 68Ga-PSMA-PET/CT-lymph node status from CT alone. In 549 patients with 68Ga-PSMA PET/CT imaging, 2616 lymph nodes were segmented. Using PET as a reference standard, three CNNs were trained. Training sets balanced for infiltration status, lymph node location and additionally, masked images, were used for training. CNNs were evaluated using a separate test set and performance was compared to radiologists' assessments and random forest classifiers. Heatmaps maps were used to identify the performance determining image regions. The CNNs performed with an Area-Under-the-Curve of 0.95 (status balanced) and 0.86 (location balanced, masked), compared to an AUC of 0.81 of experienced radiologists. Interestingly, CNNs used anatomical surroundings to increase their performance, "learning" the infiltration probabilities of anatomical locations. In conclusion, CNNs have the potential to build a well performing CT-based biomarker for lymph node metastases in PCa, with different types of class balancing strongly affecting CNN performance.

Only strongly enhanced residual FDG uptake in early response PET (Deauville 5 or qPET ≥ 2) is prognostic in pediatric Hodgkin lymphoma: Results of the GPOH-HD2002 trial

PURPOSE

In 2014, we published the qPET method to quantify fluorodeoxyglucose positron emission tomography (FDG-PET) responses. Analysis of the distribution of the quantified signals suggested that a clearly abnormal FDG-PET response corresponds to a visual Deauville score (vDS) of 5 and high qPET values ≥ 2. Evaluation in long-term outcome data is still pending. Therefore, we analyzed progression-free survival (PFS) by early FDG-PET response in a subset of the GPOH-HD2002 trial for pediatric Hodgkin lymphoma (PHL).

PATIENTS/METHODS

Pairwise FDG-PET scans for initial staging and early response assessment after two cycles of chemotherapy were available in 93 PHL patients. vDS and qPET measurement were performed and related to PFS.

RESULTS

Patients with a qPET value ≥ 2.0 or vDS of 5 had 5-year PFS rates of 44%, respectively 50%. Those with qPET values < 2.0 or vDS 1 to 4 had 5-year PFS rates of 90%, respectively 80%. The positive predictive value of FDG-PET response assessment increased from 18% (9%; 33%) using a qPET threshold of 0.95 (vDS ≤ 3) to 30% (13%; 54%) for a qPET threshold of 1.3 (vDS ≤ 4) and to 56% (23%; 85%) when the qPET threshold was ≥ 2.0 (vDS 5). The negative predictive values remained stable at ≥92% (CI: 82%; 98%).

CONCLUSION

Only strongly enhanced residual FDG uptake in early response PET (vDS 5 or qPET ≥ 2, respectively) seems to be markedly prognostic in PHL when treatment according to the GPOH-HD-2002 protocol is given.

Die quantitative Sialoszintigraphie -eine sinnvolle Untersuchung im Vorfeld und in der Nachsorge der Radiojodtherapie

Ziel: Mit einer standardisierten, quantitativen Sialoszintigraphie (qSZ) sollte geprüft werden, ob auch durch relativ niedrige, im Rahmen gutartiger Schilddrüsenerkrankungen applizierte Aktivitäten von Radiojod subtile Speicheldrüsenschäden meßbar sind. Zusätzlich wurde die Prävalenz von Sialopathien bei Schilddrüsenpatienten ermittelt. Methoden: Im Rahmen der Schilddrüsenszintigraphie wurde eine qSZ nach i.v Injektion von 36-126 MBq 99mTc-Pertechnetat durchgeführt. Referenzbereiche für den 99mTc-Uptake und die Exkretionsfraktion nach Stimulation wurden an 312 Speicheldrüsengesunden ermittelt. 144 Patienten wurden vor und 3 Monate nach einer Radiojodtherapie untersucht. Bei weiteren 674 Schilddrüsenpatienten wurden die Ergebnisse der qSZ zur Erfassung der Prävalenz von Speicheldrüsenschäden ausgewertet. Ergebnisse: Im Referenzkollektiv betrug der Uptake 0,45 ± 0,14% bzw. 0,39 ± 0,12% und die Exkretionsfraktion 49,5 ± 10,6% bzw. 39,1 ± 9,2% in den GH. parotides bzw. submandibulares. Trotz intratherapeutischer Gabe von Sialogoga war eine signifikante und mit der Aktivität korrelierende Einschränkung der Parenchymfunktion von 14-90% nach Applikation von 0,4 bis 24 GBq 1-131 meßbar. Die Prävalenz prätherapeutischer Sialopathien betrug an singulären Speicheldrüsen 77/674 = 11,4%, die der globalen Speicheldrüseninsuffizienzen lag bei 52/674 = 7,7%. Schlußfolgerung: Die im Rahmen der Schilddrüsenszintigraphie durchführbare qSZ ist ein einfach durchzuführendes Verfahren ohne zusätzliche Strahlenbelastung. Sie sollte zur Dokumentation der Speicheldrüsenfunktion vor jeder Radiojodtherapie durchgeführt und zum Ausschluß bzw. zur Quantifizierung einer schon bei niedrigen 131I-Aktivitäten nachweisbaren Parenchymschädigung nach

Szintigraphischer Nachweis einer stillen Aspiration nach beidseitiger Lungentransplantation

Vorgestellt wird der Fall einer 25jährigen Patientin nach beidseitiger Lungentransplantation und rezidivierenden Pneumonien. Klinisch bestand der Verdacht auf eine stille Aspiration. Szintigraphisch gelang sowohl der Aspirationsnachweis als auch eine Differenzierung hinsichtlich der Genese: direkte oro-pulmonale Aspiration versus Aspiration nach gastro-öspohagealem Reflux.

Wirksamkeit der Radiosynoviorthese bei degenerativ-entzündlichen und chronisch-entzündlichen Gelenkerkrankungen

Ziel: Der Therapieerfolg der Radiosynoviorthese (RSO) sollte bei aktivierter Arthrose und anderen chronisch-entzündlichen Gelenkerkrankungen anhand der subjektiven Befindlichkeit und objektiver Parameter evaluiert werden. Methoden: Es wurden insgesamt 98 Gelenke bei 61 Patienten behandelt. Entsprechend der Grunderkrankung umfaßte die erste Gruppe 35 Patienten mit einer therapieresistenten, aktivierten Arthrose (46 Gelenke). Die zweite Patientengruppe beinhaltete 26 Patienten (52 Gelenke) mit peripherem Gelenkbefall bei Morbus Bechterew, reaktiver Arthritis, undifferenzierter Kollagenose mit Gelenkbeteiligung, Psoriasis-assoziierter Arthritis, pigmentierter villo-nodulärer Synoviales und chronisch-entzündliche Reizzustände nach vorangegangener Operation. Die Veränderung der Beschwerdesymptomatik wurde anhand eines standardisierten Fragebogens entsprechend den ARA-Kriterien subjektiv erfaßt und mit T/B-Quotienten in der Blutpoolphase der Skelettszintigraphie vor und nach der RSO quantifiziert. Ergebnisse: In der ersten Gruppe berichteten die Patienten über eine deutliche Besserung der Beschwerdesymptomatik in 40% der Fälle. In 51 % fand sich eine Beschwerdekonstanz, in 9% eine Verschlechterung des Beschwerdebildes. Analoge Verhältnisse fanden sich in der zweiten Patientengruppe. Die Mehrzahl der als unverändert beschriebenen Gelenke waren kleine Fingergelenke. Hingegen zeigten Hand- und Kniegelenke bessere Ergebnisse. Eine Übereinstimmung zwischen szintigraphischem Befund und subjektiver Einschätzung fand sich in der ersten Gruppe bei 38% und in der zweiten Gruppe bei 67%. Schlußfolgerung: Die Radiosynoviorthese stellt auch bei der aktivierten Arthrose und den nicht durch eine rheumatoide Arthritis verursachten Synovialitiden eine nebenwirkungsarme, gut nutzbare lokal anwendbare Therapieoption dar.

Radiation exposure to the personnel in the operating room and in the pathology due to SLN detection with Tc-99m-nanocolloid in breast cancer patients

Aim of this study was to assess the radiation exposure for the personnel in the operating room and in the pathology laboratories caused by radioguided SLN localization in breast cancer. Methods: In 15 patients dose rates were measured at various distances from the breast and tumor specimens during operation and pathological work-up at 3-5 h after peritumoral injection of 30 MBq Tc-99m-nanocolloid. Results: The dose rates were 84.1 ± 46.4 μGy/h at 2.5 cm, 3.57 ± 2.14 μGy/h at 30 cm, 0.87 ± 0.51 μGy/h at 100 cm, and 0.40 ± 0.20 μGy/h at 150 cm in the operating room and 44.4 ± 27.8 μGy/h at 2.5 cm, and 1.66 ± 1.34 μGy/h at 30 cm in the pathology laboratories. From these data the radiation exposure was calculated for 250 operations per year assuming a mean exposure time of 30 min for the surgical team members and of 10 min for the pathology staff. Under these conditions the finger dose is 10.5 mGy for the surgeon, and 5.55 mGy for the pathologist. The wholebody doses are 0.45 mSv, 0.11 mSv, 0.05 mSv, and 0.21 mSv for the surgeon, the operating room nurse, the anesthetist, and the pathologist, respectively. Conclusion: Since the radiation risk to staff members is low, a classification of the personnel in the operating room and in the pathology laboratories as occupational radiation exposed workers is not necessary.

Decisive Diagnosis of Infected Mandibular Osteoradionecrosis with a Tc-99m-labelled Anti-granulocyte Fab′-fragment

The accepted golden standard for detection of inflammatory bone disease is conventional three-phase bone scanning. Hyperperfusion, a high blood-pool activity and elevated bone metabolism are typical signs for an acute osteomyelitis. However, in case of subacute, chronic inflammation, neither elevated blood flow nor high blood-pool activity may be seen. This may cause difficulties in differentiating such cases from neoplastic or postoperative changes. This case report verifies the possible advantage of immunoscintigraphy with Tc-99m-labelled antigranulocyte Fab′-fragments (LeukoScan®) in a patient with infected mandibular osteoradionecrosis, who had equivocal clinical symptomes and questionable radiographic results. LeukoScan® is shown to be more sensitive in case of subacute bone inflammation compared with three-phase bone scanning. However, acquisition of delayed images after 24 hours including SPECT is inevitable in case of negative scans during the first hours of investigation.

Lymph Scintigraphy and Pre- and Intraoperative Gamma Prone Measurements for Localization of Sentinel Lymph Nodes (SLN) in Breast Cancer

Aim of this study was to prove the clinical value of nuclear medicine procedures to detect the sentinel lymph node (SLN) for SLN biopsy. Methods: In 132 patients with breast cancer we performed lymph scintigraphy of the breast as well as both pre- and intraoperative gamma probe measurements correlating the results with the findings of histopathology. Results: SLN were detectable in 62 of 110 patients according to a sensitivity of 56% when scanning was performed only at 1-2 h p.i. while the sensitivity increased to 86% (19 of 22 pts.) if sequential images were acquired up to 2 h p.i. One or more SLN were identified by a handheld gamma probe transcutaneously prior to surgery in 96% (113 of 118 pts.) of the patients who showed up with no clinically suspected lymph node metastases. Intraoperatively, in additionally 2 patients the SLN could be found resulting in a sensitivity of 97% (115 of 118 pts.). In only 3 patients with clinically no tumor spread to axillary lymph nodes no SLN could be identified by the probe. Skip lesions, i.e. lymph node metastases in patients with tumorfree SLN, occured in 2 cases: due to SLN biopsy in these patients lymph node staging was false negative compared to conventional staging by means of axillary lymph node dissection. Conclusion: The results demonstrate a high preoperative detection rate of SLN in patients with breast cancer using lymph scintigraphy and gamma probe measurements. Thus, nuclear medicine is capable of providing the basic requirements for SLN biopsy in the daily routine.

Verfahrensanweisung für die nuklear medizinische Wächter-Lymphknoten-Diagnostik

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma and other skin tumours, in breast cancer, in head and neck cancer, and in prostate and penile carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure < 1 mSv/year so that they do not require occupational radiation surveillance.

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

Aim: FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (> 7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is ≤ 7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure. Methods: The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease. Results: The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data. Conclusion: The proposed management protocol for acute correction of hyper glycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients.

Skelettszintigraphie

Diese Leitlinie soll eine an der Praxis orientierte Hilfestellung bei der Indikationsprüfung, Durchführung und Beurteilung der Skelettszintigraphie liefern. Ausgehend von den pathophysiologischen und pharmakologischen Grundlagen wird eine Übersicht über die methodischen Variationen der Skelett - szintigraphie incl. der Anwendung neuer Messtechniken gegeben, an die sich eine detaillierte Aufzählung der gesicherten Indikationen anschließt. Es folgt die Beschreibung der konkreten Vorgehensweise, zu der die Patientenvorbereitung, Anamnese-Erhebung, Beachtung der Kontraindikationen, Auswahl des geeigneten Radiopharmakons (incl. Dosierung und Abschätzung der Strahlenexposition) sowie die Festlegung der Datenakquisition unter Einschluss etwaiger Interventionen gehört. Komplettiert wird diese Beschreibung durch Angaben zur Datenauswertung (Nachbearbeitung), Befundung und Berichterstellung incl. Dokumentation. Schließlich werden auch die Qualitätssicherung und mögliche Quellen für Fehlbefunde dargestellt sowie Zukunftsperspektiven anhand offener Fragen beleuchtet.

Detection of metastases in breast cancer patients

Distant metastases at primary diagnosis are a prognostic key factor in breast cancer patients and play a central role in therapeutic decisions. To detect them, chest X-ray, abdominal ultrasound, and bone scintigraphy are performed as standard of care in Germany and many centers worldwide. Although FDG PET detects metastatic disease with high accuracy, its diagnostic value in breast cancer still needs to be defined. The aim of this study was to compare the diagnostic performance of FDG PET with conventional imaging. Patients, methods: A retrospective analysis of 119 breast cancer patients who presented for staging was performed. Whole-body FDG-PET (n=119) was compared with chest X-ray (n=106) and bone scintigraphy (n=95). Each imaging modality was independently assessed and classified for metastasis (negative, equivocal and positive. The results of abdominal ultrasound (n=100) were classified as negative and positive according to written reports. Imaging results were compared with clinical follow-up including follow-up imaging procedures and histopathology. Results: FDG-PET detected distant metastases with a sensitivity of 87.3% and a specificity of 83.3%. In contrast, the sensitivity and specificity of combined conventional imaging procedures was 43.1% and 98.5%, respectively. Regarding so-called equivocal and positive results as positive, the sensitivity and specificity of FDG-PET was 93.1% and 76.6%, respectively, compared to 61.2% and 86.6% for conventional imaging. Regarding different locations of metastases the sensitivity of FDG PET was superior in the detection of pulmonary metastases and lymph node metastases of the mediastinum in comparison to chest x-ray, whereas the sensitivity of FDG PET in the detection of bone and liver metastases was comparable with bone scintigraphy and ultrasound of the abdomen. Conclusions: FDG-PET is more sensitive than conventional imaging procedures for detection of distant breast cancer metastases and should be considered for additional staging especially in patients with high risk primary breast cancer.

Global scaling for semi-quantitative analysis in FP-CIT SPECT

Semi-quantitative characterization of dopamine transporter availability from single photon emission computed tomography (SPECT) with 123I-ioflupane (FP-CIT) is based on uptake ratios relative to a reference region. The aim of this study was to evaluate the whole brain as reference region for semiquantitative analysis of FP-CIT SPECT. The rationale was that this might reduce statistical noise associated with the estimation of non-displaceable FP-CIT uptake. Patients, methods: 150 FP-CIT SPECTs were categorized as neurodegenerative or non-neurode- generative by an expert. Semi-quantitative analysis of specific binding ratios (SBR) was performed with a custom-made tool based on the Statistical Parametric Mapping software package using predefined regions of interest (ROIs) in the anatomical space of the Montreal Neurological Institute. The following reference regions were compared: predefined ROIs for frontal and occipital lobe and whole brain (without striata, thalamus and brainstem). Tracer uptake in the reference region was characterized by the mean, median or 75th percentile of its voxel intensities. The area (AUC) under the receiver operating characteristic curve was used as performance measure. Results: The highest AUC of 0.973 was achieved by the SBR of the putamen with the 75th percentile in the whole brain as reference. The lowest AUC for the putamen SBR of 0.937 was obtained with the mean in the frontal lobe as reference. Conclusion: We recommend the 75th percentile in the whole brain as reference for semi-quantitative analysis in FP-CIT SPECT. This combination provided the best agreement of the semi-quantitative analysis with visual evaluation of the SPECT images by an expert and, therefore, is appropriate to support less experienced physicians.

FDG PET/CT in cancer therapy monitoring

Objectives: We developed and tested a software tool for computer-assisted analysis of FDG-PET/CT in cancer therapy monitoring. The tool provides automatic semi-quantitative analysis of a baseline scan together with up to two follow-up scans (standardized uptake values, glycolytic volume). The tool also supports visual analysis by local spatial registration which allows display of tumor lesions with the same orientation in all scans. The tool’s stability and accuracy was tested at typical everyday image quality. Patients, methods: Ten unselected cancer patients in whom three FDG PET/CT scans had been performed were included. A total of 18 lesions were analyzed. Results: Automatic lesion tracking worked properly in all lesions but one. In this lesion local coregistration had to be adjusted manually tuwhich, however, is easily performed with the tool. Semi-automatic lesion segmentation and fully automatic semi-quantitative analysis worked properly in all cases. Computer-assisted analysis was significantly less time consuming than manual analysis. Conclusions: The novel software tool appears useful for analysis of FDGPET/ CT in cancer therapy monitoring in clinical routine patient care.

Evaluation of bone viability in patients after girdlestone arthroplasty: comparison of bone SPECT/CT and MRI

PURPOSE

To test the diagnostic performance of bone SPECT/CT and MRI for the evaluation of bone viability in patients after girdlestone-arthroplasty with histopathology used as gold standard.

MATERIALS AND METHODS

In this cross-sectional study, patients after girdlestone-arthroplasty were imaged with single-photon-emission-computed-tomography/computed-tomography (SPECT/CT) bone-scans using 99mTc-DPD. Additionally, 1.5 T MRI was performed with turbo-inversion-recovery-magnitude (TIRM), contrast-enhanced T1-fat sat (FS) and T1-mapping. All imaging was performed within 24 h prior to revision total-hip-arthroplasty in patients with a girdlestone-arthroplasty. In each patient, four standardized bone-tissue-biopsies (14 patients) were taken intraoperatively at the remaining acetabulum superior/inferior and trochanter major/minor. Histopathological evaluation of bone samples regarding bone viability was used as gold standard.

RESULTS

A total of 56 bone-segments were analysed and classified as vital (n = 39) or nonvital (n = 17) by histopathology. Mineral/late-phase SPECT/CT showed a high sensitivity (90%) and specificity (94%) to distinguish viable and nonviable bone tissue. TIRM (sensitivity 87%, specificity 88%) and contrast-enhanced T1-FS (sensitivity 90%, specificity 88%) also achieved a high sensitivity and specificity. T1-mapping achieved the lowest values (sensitivity 82%, specificity 82%). False positive results in SPECT/CT and MRI resulted from small bone fragments close to metal artefacts.

CONCLUSIONS

Both bone SPECT/CT and MRI allow a reliable differentiation between viable and nonviable bone tissue in patients after girdlestone arthroplasty. The findings of this study could also be relevant for the evaluation of bone viability in the context of avascular bone necrosis.

Thiourea derivatives as chelating agents for bioconjugation of rhenium and technetium

A^99mTc complex with a tetradentate thiocarbamoylbenzamidine group was used for the conjugation of angiotensin-II. The resulting bioconjugate is stablein vivoandin vitro.

Ventilation/perfusion SPECT/CT in patients with pulmonary emphysema. Evaluation of software-based analysing

The purpose of this study was to evaluate the reproducibility of a new software based analysing system for ventilation/perfusion single-photon emission computed tomography/computed tomography (V/P SPECT/CT) in patients with pulmonary emphysema and to compare it to the visual interpretation.

PATIENTS, MATERIAL AND METHODS

19 patients (mean age: 68.1 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. Data were analysed by two independent observers in visual interpretation (VI) and by software based analysis system (SBAS). SBAS PMOD version 3.4 (Technologies Ltd, Zurich, Switzerland) was used to assess counts and volume per lung lobe/per lung and to calculate the count density per lung, lobe ratio of counts and ratio of count density. VI was performed using a visual scale to assess the mean counts per lung lobe. Interobserver variability and association for SBAS and VI were analysed using Spearman's rho correlation coefficient.

RESULTS

Interobserver agreement correlated highly in perfusion (rho: 0.982, 0.957, 0.90, 0.979) and ventilation (rho: 0.972, 0.924, 0.941, 0.936) for count/count density per lobe and ratio of counts/count density in SBAS. Interobserver agreement correlated clearly for perfusion (rho: 0.655) and weakly for ventilation (rho: 0.458) in VI.

CONCLUSIONS

SBAS provides more reproducible measures than VI for the relative tracer uptake in V/P SPECT/CTs in patients with pulmonary emphysema. However, SBAS has to be improved for routine clinical use.

[Perioperative Outcomes in Correlation to the Learning Curve for Robotic Assisted Partial Nephrectomy: The First 109 Cases of our Clinic]

BACKGROUND

In contrast to conventional laparoscopic partial nephrectomy, the approach of robot-assisted partial nephrectomy (RAPN) shows a steep learning curve with shorter warm ischaemia times (WIT) and comparable postoperative outcomes. Therefore RAPN is considered a good minimally-invasive surgical procedure for patients presenting with a renal cell carcinoma in clinical stage cT1a. The aim of the presented study was to evaluate the perioperative outcomes of our patients after RAPN and to illustrate the learning curve based on characteristic perioperative parameters such as WIT.

MATERIAL AND METHODS

The data of 109 patients treated by RAPN in our clinic between January 2010 and April 2015 were retrospectively analysed regarding perioperative, laboratory and oncological outcomes. Postoperative complications until 30 days after surgery were documented. We analysed the data of the largest patient population treated by a single urologist, comparing WIT, operating time, blood loss and decline of the glomerular filtration rate between the first and the second 30 consecutive cases.

RESULTS

Mean WIT was 18.4 min (SD±10.2), mean operating time was 199 min (SD±20), and mean estimated blood loss was 657 millilitres (SD±715 ml). Mean loss of GFR was reported to be 4.99 mg/dl/1.73 m (2) (SD±15.44). 83 (76%) malignant lesions were removed. 11 patients (10%) had a R1 resection, one patient had a R2 resection and in 2 cases the resection status was Rx. 22% of patients developed postoperative complications. Intraoperative complications were documented in 2 cases. According to the Clavien-Dindo Classification, 6% of patients had grade 1 and 2 complications and 13% developed grade 3 and 4 complications. WIT was significantly lower after 30 consecutive cases treated by one urologist. Regarding operating time, GFR or blood loss no significant correlation was found.

CONCLUSION

Our data is in line with the surgical outcomes described in the literature. RAPN is a safe surgical technique with a steep learning curve. In our experience, 30 surgical cases provide a urologist with sufficient expertise to achieve good perioperative results. Weaknesses of this report include the retrospective design and insufficient documentation in some cases.

Detection of pancreatic neuroendocrine tumors (PNET) using semi-quantitative [68Ga]DOTATOC PET in combination with multiphase contrast-enhanced CT

AIM

Pancreatic neuroendocrine tumors (PNETs) pose a diagnostic challenge with respect to the physiologic somatostatin receptor expression in the uncinate process representing a potential pitfall for receptor imaging with PET/CT.

METHODS

We identified 49 PNETs from a total of 316 consecutive [68Ga]DOTATOC PET/CT examinations for whom the detections rates of PET and multiphase contrast enhanced (CE-) CT could be retrospectively compared and 38 PNETs for which SUVmax and SUVmax target-to-liver ratios could be calculated for the tumors and the uncinate process.

RESULTS

The detection rate of PET (83.7%) was higher than of the different CT phases (arterial: 59.2%, P=0.017; portal-venous: 38.8%, P<0.001; venous: 46.9%, P=0.001; multiphase: 71.4%, P=0.286). Compared to the other method PET revealed 28.6% additional lesions and multiphase CE-CT 16.3%. The portal-venous phase revealed only lesions that were also detected in the arterial or venous phase. The detection rate for PNETs in the uncinate process (N.=9) was 66.7% for PET versus 55.6% for multiphase CE-CT. SUVmax and SUVmax target-to-liver ratios differed significantly (P<0.001) for PNETs (mean, range: SUVmax, 14.6, 1.4-69.3; SUVmax target-to-liver ratio, 3.2, 0.69-23.1) and uncinate process (4.32, 0.8-13.5; 0.94, 0.51-1.56), however with a wide overlap.

CONCLUSION

Patients with PNETs should undergo [68Ga]DOTATOC PET/CT with at least an arterial and venous phase CT scan. SUVmax and SUVmax target-to-liver ratios provide additional information but do no reliably separate PNETs from normal tracer uptake in the uncinate process.

Detection of pancreatic neuroendocrine tumors (PNET) using semi-quantitative [68Ga]DOTATOC PET in combination with multiphase contrast-enhanced CT

Aim: Pancreatic neuroendocrine tumors (PNETs) pose a diagnostic challenge with respect to the physiologic somatostatin receptor expression in the uncinate process representing a potential pitfall for receptor imaging with PET/CT. Methods: We identified 49 PNETs from a total of 316 consecutive [68Ga]DOTATOC PET/CT examinations for whom the detections rates of PET and multiphase contrast enhanced (CE-) CT could be retrospectively compared and 38 PNETs for which SUV max and SUV max target-to-liver ratios could be calculated for the tumors and the uncinate process. Results: The detection rate of PET (83.7%) was higher than of the different CT phases (arterial: 59.2%, P=0.017; portal-venous: 38.8%, P<0.001; venous: 46.9%, P=0.001; multiphase: 71.4%, P=0.286). Compared to the other method PET revealed 28.6% additional lesions and multiphase CE-CT 16.3%. The portal-venous phase revealed only lesions that were also detected in the arterial or venous phase. The detection rate for PNETs in the uncinate process (N.=9) was 66.7% for PET versus 55.6% for multiphase CE-CT. SUV max and SUV max target-to-liver ratios differed significantly (P<0.001) for PNETs (mean, range: SUV max,14.6, 1.4-69.3; SUV max target-to-liver ratio, 3.2, 0.69-23.1) and uncinate process (4.32, 0.8-13.5; 0.94, 0.51-1.56), however with a wide overlap. Conclusion: Patients with PNETs should undergo [68Ga]DOTATOC PET/CT with at least an arterial and venous phase CT scan. SUV max and SUV max target-to-liver ratios provide additional information but do no reliably separate PNETs from normal tracer uptake in the uncinate process.

[Bone scintigraphy. German Guideline S1]

The purpose of this guideline is to provide comprehensive state-of-the-art information about indication and how to perform and analyze bone scintigraphy. Based upon pathophysiology and pharmacology current acquisition techniques including new methodologies are summarized followed by a detailed list of indications. In the main part all relevant practical aspects such as patient preparation, anamnestic information, appropriate choice and dosage of the radiopharmaceutical, and data acquisition including interventions are discussed. Data processing and analysis, interpretation, reporting and documentation are described in the next chapters. Quality control, typical pitfalls and a short outlook to future developments complete the guideline.

SDF1β expression in renal cell carcinoma correlates with grading and infiltration by CD8+ T-cells

For several tumor entities, a significant correlation between the chemokine stromal cell-derived factor 1 (SDF1) and its receptor C-X-C chemokine receptor type 4 (CXCR4), metastasis and tumor proliferation, as well as prognosis, has been described. In this study, a series of 105 renal cell carcinoma patients were analyzed in terms of expression of SDF1α and SDF1β and infiltration by CD4+ and CD8+ T-cells and the data correlated with TNM category, grading and survival. While the splice variant SDF1α had no impact on tumor grading, T-cell invasion or overall survival, expression of SDF1β showed a significant correlation with tumor grading and also suggested a correlation with metastasis, as well as CD8+ T-cell invasion. These results indicate a potential T-cell-mediated antitumor response induced by SDF1β up-regulation. Therefore targeting the SDF1β-CXCR4 signaling pathway may be a promising means for new therapeutic strategies in advanced tumor stages.

Comparison of F-18 FET-PET with F-18 FDG-PET for biopsy planning of non-contrast-enhancing gliomas

OBJECTIVE

The management of non-contrast-enhancing brain tumours largely depends on biopsy, which allows a differentiation of low-grade gliomas (LGG) from high-grade gliomas (HGG). The aim of this study was to compare positron emission tomography using 2-[(18)F]-fluoro-2-deoxy-D: -glucose (FDG-PET) and O-(2-[(18)F]-fluoroethyl)-L: -tyrosine (FET-PET) in terms of providing target regions for biopsies.

MATERIALS AND METHODS

Fifteen consecutive patients with newly diagnosed brain tumours (n = 11) or suspected recurrence of a known LGG (n = 4), in whom MRI demonstrated no contrast enhancement, were studied by both FET-PET and FDG-PET. FET-PET, FDG-PET and MRI data were fused, and then transferred to the neurosurgical navigation system, prior to neurosurgical interventions.

RESULTS

Histology showed HGG (WHO grade III) in 6/15 and LGG (WHO grade II) in 9/15 patients. FET-PET revealed an increased intratumoural tracer uptake in 8/9 LGG and in 5/6 HGG. FDG-PET depicted hypermetabolic spots in 2/9 LGG and in 4/6 HGG. In 6 patients we observed an increased intratumoural uptake of both tracers. In 4 of them, the area of highest FET accumulation in the tumour corresponded to the focus of increased FDG uptake.

CONCLUSIONS

FET-PET appears to be superior to FDG-PET for biopsy planning in non-contrast-enhancing brain tumours. FDG-PET does not provide any additional information in this issue.

Imperative and elective indications for nephron-sparing surgery for renal tumors: long-term oncological follow-up

INTRODUCTION

Nephron-sparing surgery (NSS) is mandatory for patients with renal tumors in both kidneys or in a solitary kidney in order to preserve renal function (imperative indication). NSS has also become the gold standard (elective indication) for small unilateral renal tumors (< 4 cm) with a normal contralateral kidney. We report the oncological long-term follow-up of NSS of our own series and discuss the results of the current literature.

PATIENTS AND METHODS

From 1979 until 2006, a total of 851 patients was treated at our institution by NSS. The mean tumor diameter was 3 cm (0.5-11 cm) for elective cases and 4.2 cm (1.2-11 cm) for imperative cases. The median follow-up for elective cases is 4.7 years (0.1-24.1 years) and imperative cases 8 years (0.1-25.8 years). Cancer-specific survival (CSS) and local recurrence-free survival (RFS) were estimated.

RESULTS

Estimated CSS at 5 and 10 years for elective indications were 98.5% and 96.7% and for imperative indications (solitary kidney) 89.6% and 76%. RFS after 5 and 10 years for elective indications were 98.3% and 95.7%; and for imperative indications (solitary kidney) 89.4% and 79.9%. Chronic renal failure requiring haemodialysis developed after NSS in a solitary kidney in nine patients (11.2%).

CONCLUSION

NSS can be performed with oncologically safe and good functional results in imperative indications. In elective indications the resectability of a tumour rather than size and location is the limiting factor.

Independent validation of the 2002 UICC TNM staging system for papillary renal cell carcinoma in a multicenter cohort

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Background: Papillary renal cell carcinoma (pRCC) is the second most malignant histologic subtype in nephrectomy specimens. To date, the most recognized staging system to stratify renal cancer patients is the 2002 UICC TNM classification system. Its accuracy for predicting patient outcome for pRCC is unknown. Methods: From ten urologic institutions in Germany follow-up data on 675 patients with pRCC were collected. In most cases histologic slides were available and central pathologic review was performed. The Kaplan-Meier method was used to derive the cumulative cancer-specific survival. For multivariate analysis of prognostic factors, a Cox regression analysis was performed. Results: 498 (74.1%) patients had organ-confined tumor stages (≤pT2). Synchronous distant metastases in the entire group occurred in 58 (8.7%) patients and 69 (11.2%) others developed metastatic disease during follow-up. Cancer-specific survival (CSS) was significantly related to TNM stage and histologic grading in univariate as well as in multivariate analysis (all p < 0.0001). 5-year CSS in pT1b tumors (90.0%) was significantly shorter compared to pT1a tumors (98.3%) (p = 0.017). Patients with ≥pT3 were at high risk for metastases (50.6%), while metastatic disease associated with ≤pT2 tumors occurred in 7.8% (p < 0.0001). Once metastatic disease was present, prognosis was poor (5-year CSS: 7.2%). Age was associated with a worse prognosis in the subgroup of ≥pT3 tumors in univariate (p = 0.026), but not in multivariate analysis. Conclusions: The 2002 UICC TNM staging system is applicable for pRCC. Clinical and radiologic follow-ups should be offered in frequent intervals to patients with venous thrombus and/or locally advanced disease. The role of age remains unclear, but should not be underestimated at risk stratification after tumor resection.

No significant financial relationships to disclose.

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

AIM

FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (>7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is <or=7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure.

METHODS

The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease.

RESULTS

The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data.

CONCLUSION

The proposed management protocol for acute correction of hyper glycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients.

[Elective organ-sparing surgery for renal tumors in patients with a normal contralateral kidney: long-term results]

Continuous improvements in radiological imaging techniques have enabled an earlier diagnosis of incidental renal tumors. The share of small renal tumors (<or=4 cm, T1a) amongst the incidentally detected renal masses is reported to be as high as 60%. Fortunately, the classic clinical triad of pain, hematuria, and a palpable flank mass is nowadays the exception of clinical presentation. Concerns regarding development of chronic renal failure after radical nephrectomy have resulted in an increasing use and steady improvement of organ-sparing surgical techniques for patients with small unilateral renal tumors in the presence of a normal contralateral kidney (elective indication). Nephron-sparing surgery has become the gold standard for treating these small tumors. Newer long-term oncological results have demonstrated that carefully selected patients with unilateral renal tumors >4 cm can also be treated with nephron-sparing surgery. We report in this article our long-term oncological results of nephron-sparing surgery in patients with an elective indication.