68Ga-PSMA Cerenkov luminescence imaging in primary prostate cancer: first-in-man series.

PURPOSE: Currently, approximately 11-38% of prostate cancer (PCa) patients undergoing radical prostatectomy have a positive surgical margin (PSM) on histopathology. Cerenkov luminescence imaging (CLI) using 68Ga-prostate-specific membrane antigen (68Ga-PSMA) is a novel technique for intraoperative margin assessment. The aim of this first-in-man study was to investigate the feasibility of intraoperative 68Ga-PSMA CLI. In this study, feasibility was defined as the ability to distinguish between a positive and negative surgical margin, imaging within 45 min and low radiation exposure to staff. METHODS: Six patients were included in this ongoing study. Following perioperative i.v. injection of ~ 100 MBq 68Ga-PSMA, the prostate was excised and immediately imaged ex vivo. Different acquisition protocols were tested, and hotspots on CLI images from the intact prostate were marked for comparison with histopathology. RESULTS: By using an acquisition protocol with 150 s exposure time, 8 × 8 binning and a 550 nm shortpass filter, PSMs and negative surgical margins (NSMs) were visually correctly identified on CLI in 3 of the 5 patients. Two patients had a hotspot on CLI from cancer < 0.1 mm from the excision margin. CONCLUSION: Overall, the study showed that 68Ga-PSMA CLI is a feasible and low-risk technique for intraoperative margin assessment in PCa. The remaining patients in this ongoing study will be used to assess the diagnostic accuracy of the technique. TRIAL REGISTRATION: NL8256 registered at www.trialregister.nl on 04/11/20109.

Underestimation of pelvic organ prolapse in the supine straining position, based on magnetic resonance imaging findings.

OBJECTIVE: Pelvic organ prolapse (POP) is clinically diagnosed in the supine position, where the effect of gravity is simulated by having the patients put strain on their pelvic floor. The objective of this study was to determine the degree of POP underestimation in the supine position based on magnetic resonance imaging (MRI) findings. METHODS: This prospective study was conducted with symptomatic POP grade ≥ 2 patients. Fifteen female patients were examined with an MRI system that allows supine and upright imaging. The differences between supine and upright in distances of the bladder neck, cervix, and pouch of Douglas from the pubococcygeal line (PCL) were estimated, together with changes in the genital hiatal area. Patients were scanned at rest and during straining. All distances were compared using the Wilcoxon ranking test. RESULTS: All mean distances from the PCL increased from the supine-strain to the upright-rest and from the supine-strain to the upright-strain position. These distances were found in the supine and upright positions: the bladder descended 1.3 cm to 1.4 cm, the cervix 1.1 cm to 2.2 cm, and the pouch of Douglas 0.8 cm to 1.5 cm respectively (all p values <0.05). The hiatal area was larger in the upright-strain position (mean 42.0 cm2; SD ±14.8) than during the supine-strain position (mean 33.5 cm2; SD ±14.5), with a p value of 0.02. CONCLUSION: Upright MRI scanning of patients with POP grade ≥ 2 both at rest and during straining shows a significantly larger extent of the prolapse than that observed during supine straining.

Three cases of posttraumatic wrist problems solved with 3D-printed patient-specific guides.

Symptomatic malunion of the wrist is one of the most common posttraumatic wrist problems. This study demonstrates three patients with complex malunions of the wrist who benefited from a corrective osteotomy using preplanned 3D-printed patient-specific guides, by experiencing improvement in their wrist function, grip strength and a reduction in pain.

It is safe to use the ulnar length difference to correct the radial length difference in the 3D-planning process of a radius osteotomy in patients with a distal radius malunion.

BACKGROUND: A corrective radius osteotomy is often performed in patients with a symptomatic distal radius malunion. In 3D-planned osteotomies, the unaffected radius is mirrored over the malunited radius after adjusting for left-right length differences using both ulnae. This approach assumes that ulnar length differences in a malunion population are similar to those in a healthy population. This study was conducted to analyze the difference in ulnar length in a distal radius malunion population and to assess the potential influence of age, sex, or malunion side on this difference. METHODS: We evaluated 65 adult patients with distal radius malunion using bilateral forearm CT scans. 3D models of both ulnae were constructed, and length differences were determined along a standardized length axis. The results were compared to two populations without a radius malunion. RESULTS: The average absolute ulnar length difference was 2.57 mm (SD 1.81), which was comparable to the two healthy populations. This difference was not significantly affected by age, sex, or malunion side. CONCLUSION: This study demonstrated that using the ulnar length difference to correct for radial length difference in the current 3D planning process, before using the contralateral radius as a template for a corrective osteotomy in patients with radius malunion, is safe.

Bilateral trochlear subchondral insufficieny fracture of the knee in a professional cyclist.

This case report presents a rare case of subsequent ipsilateral and contralateral subchondral insufficiency fracture of the knee (SIFK) in the trochlea of the femur within months, manifested in a professional cyclist. SIFKs in the trochlea have not yet been reported in the literature; however, their appearance in a professional cyclist might be explained by the amount of repetitive pressure on the patellofemoral joint when cycling. In both instances, atraumatic anterior knee pain occurred, resolving after conservative treatment for 6-9 weeks. The patient reached their previous activity level. The authors believe SIFK in the younger population may be more common than currently perceived due to its self-limiting behaviour and a lack of performing immediate MRIs in this younger group whenever an overload injury is suspected.

State-of-the-art Intraoperative Imaging Technologies for Prostate Margin Assessment: A Systematic Review.

CONTEXT: The main challenge in radical prostatectomy is complete excision of malignant tissue, while preserving continence and erectile function. Positive surgical margins (PSMs) occur in up to 38% of cases, are associated with tumour recurrences, and may result in debilitating additional therapies. Despite surgical developments for prostate cancer (PCa), no technology is yet implemented to assess surgical margins of the entire prostatic surface intraoperatively. OBJECTIVE: The aim of this systematic review is to provide an overview of novel imaging methods developed for intraoperative margin assessment in PCa surgery, which are compared with standard postoperative histopathology. EVIDENCE ACQUISITION: A literature search of the last 10 yr was conducted in the Scopus, PubMed, and Embase (Ovid) databases. Eligible articles had to report the PSM rate according to their intraoperative margin assessment technology in comparison with standard histopathology. EVIDENCE SYNTHESIS: The search resulted in 616 original articles, of which 11 were included for full-text review. The main technical developments in PCa margin assessment included optical coherence tomography, photodynamic diagnosis with 5-aminolevulinic acid, spectroscopy, and enhanced microscopy. These techniques are described and their main advantages, limitations, and applications in the clinical setting are discussed. CONCLUSIONS: Several imaging methods are suggested in literature for the detection of positive margins during PCa surgery. Despite promising qualifications of the mentioned technologies, many struggle to find implementation in the clinic. Surgical conditions hampering the signal, long imaging times, and comparison with histopathology are mutual challenges. The next step towards reduction of PSMs in PCa surgery includes evaluation of these technologies in large clinical trials. PATIENT SUMMARY: In this review, new technologies are reported that can assist the surgeon by detecting insufficient removal of all tumorous tissue during surgery, instead of the standard postoperative histopathological assessment. Currently, it is not clear whether these technologies improve the patient outcome directly; however, the review shows potential future implementations.

Day-to-day variability of [68Ga]Ga-PSMA-11 accumulation in primary prostate cancer: effects on tracer uptake and visual interpretation.

PURPOSE: Prostate-specific membrane antigen (PSMA) agents, such as [68Ga]Ga-PSMA-11, have an unprecedented accuracy in staging prostate cancer (PCa) and detecting disease recurrence. PSMA PET/CT may also be used for response monitoring by displaying molecular changes, instead of morphological changes alone. However, there are still limited data available on the variability in biodistribution and intra-prostatic uptake of PSMA targeting radiotracers. Therefore, the aim of this study was to assess the repeatability of [68Ga]Ga-PSMA-11 uptake in primary PCa patients in a 4-week interval. METHODS: Twenty-four primary PCa patients were prospectively included, who already were scheduled for [68Ga]Ga-PSMA-11 PET/CT scan on clinical indication (≥ cT3, Gleason score ≥ 7 or PSA ≥ 20 ng/mL). These patients received two [68Ga]Ga-PSMA-11 PET/CT scans with a 4-week interval. No treatment was started in between the scans. Semiquantitative measurements (SULmax, SULmean, and SULpeak) were determined in the prostate tumor, normal tissues, and blood pool. The repeatability coefficient of every region was determined. All scans were visually analyzed by two nuclear medicine physicians. RESULTS: Within-subject coefficient of variation of [68Ga]Ga-PSMA-11 uptake between the two scans was on average 10% in the prostate tumor, normal tissues (liver, kidney, parotid), and blood pool. The repeatability coefficient of the prostate tumor was 18% for SULpeak and 22% for SULmax. Lesion uptake was visually different in 5 patients, though not clinically relevant. CONCLUSION: Results of test-retest [68Ga]Ga-PSMA-11 PET/CT scans in a 4-week interval show that [68Ga]Ga-PSMA-11 uptake is repeatable, with a clinical irrelevant variation in tumor and physiological distribution. Based on the presented repeatable uptake, [68Ga]Ga-PSMA-11 PET/CT scans can potentially be used for disease surveillance and therapy response monitoring. Changes in uptake larger than the RC are therefore likely to reflect actual biological changes in PSMA expression. Trial registration NL8263 at Trialregister.nl retrospectively registered on 03-01-2020. https://www.trialregister.nl/trial/8263.