Added value of repeat sentinel lymph node biopsy in FDG-PET/CT node-negative patients with ipsilateral breast cancer recurrence.

PURPOSE: Repeat sentinel lymph node biopsy (rSLNB) has been suggested for axillary staging in clinically node-negative (cN0) patients with ipsilateral breast tumor recurrence (IBTR). Although rSLNB is technically feasible in this group of patients, the clinical value has not been established. We aimed to assess the added value of rSLNB in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT. METHODS: This retrospective single-center cohort study included 119 patients with IBTR-staged cT1-4N0M0 with FDG-PET/CT who underwent rSLNB between 2006 and 2020. Overall recurrence-free survival (RFS) and overall survival (OS) were calculated for subgroups with tumor-positive, tumor negative, and unsuccessful rSLNB. RESULTS: rSLNB was successful in 79 (66%) of the 119 included patients, of whom 70 (59%) had a tumor negative and 9 (8%) a tumor-positive rSLNB; rSLNB was unsuccessful in the remaining 40 (34%) patients. Patients with a tumor-positive rSLNB had poorer overall 5-year RFS compared to patients with a tumor negative or unsuccessful rSLNB (44% vs. 86% vs. 90%, p = 0.004). Although patients with a tumor-positive rSLNB had worse RFS, the 10-year OS was comparable to a tumor negative or unsuccessful rSLNB (89% vs. 89% vs. 95%, p = 0.701). CONCLUSION: The incidence of a tumor-positive rSLNB in patients with a negative FDG-PET/CT is low and does not change survival. Therefore, in cN0 patients with IBTR who underwent optimal clinical staging with FDG-PET/CT, we support a patient- and tumor-tailored treatment strategy in which rSLNB may be omitted.

Determining the diagnostic value of PSMA-PET/CT imaging in patients with persistent high prostate specific antigen levels and negative prostate biopsies.

PURPOSE: To assess the diagnostic performance of prostate specific membranous antigen (PSMA) positron emission tomography/computed tomography (PET/CT) imaging to localize primary prostate cancer (PCa) in men with persistent elevated prostate-specific antigen (PSA) levels and previous prostate biopsies that were negative for PCa. METHODS: In this study, 34 men with persistently elevated PSA-levels, previous negative for PCa biopsies and who subsequently underwent diagnostic PSMA-PET/CT imaging were retrospectively evaluated. Men were divided into 3 groups: 1. 12 men with a previous negative mpMRI scan (PI-RADS 1-2) 2. 17 men with a positive mpMRI scan (PI-RADS 3-5), but negative MRI-targeted biopsies and 3. Four men in whom mpMRI was contraindicated. If PSMA-avid lesions were seen, patients underwent 2-4 cognitive targeted biopsies in combination with systematic biopsies. The detection rate of PSMA-PET/CT for PCa, and the accuracy of (possible) targeted biopsies were calculated. RESULTS: Included men had a median PSA-level of 22.8 ng/mL (Interquartile Range 15.6-30.0) at the time of PSMA-PET/CT. Elevated PSMA-ligand uptake in the prostate suspicious for PCa was observed in 22/34 patients (64.7%). In 18/22 patients (54.5%), PSMA-targeted prostate biopsies were performed. In 3/18 patients (16.6%), the targeted biopsies showed International Society of Urological Pathology (ISUP) score 1-2 PCa. The other men had inflammation or benign findings after histopathological examination of the biopsy cores. CONCLUSION: In this study, the clinical value of PSMA-PET/CT for patients with an elevated PSA-level, and negative for PCa biopsies was low. Only very few men were diagnosed with PCa, and no clinically significant PCa was found.

Nodal recurrence patterns on PET/CT after RTOG-based nodal radiotherapy for prostate cancer.

PURPOSE: Biochemical failure after external beam radiotherapy (RT) for node-positive prostate cancer (PCN+) frequently involves nodal recurrences, in most cases out of field. This raises the question if current RTOG-based elective nodal fields can still be considered optimal. Modern diagnostic tools like PSMA PET/CT and choline PET/CT can visualize nodal recurrences with unprecedented accuracy. We evaluated recurrence patterns on PET/CT after RT for PCN+, with the aim to explore options for improved nodal target definition. METHODS AND MATERIALS: Data of all patients treated with curative intent EBRT for PCN+ in NKI-AVL from 2008 to 2018 were retrospectively reviewed. EBRT comprised 70 Gy to the prostate or 66-70 Gy to the prostate bed, 60 Gy to involved nodes, and 52,5-56 Gy (46 Gy EQD2) to RTOG-based elective nodal fields, in 35 fractions. Locations of recurrences on PET/CT were noted, and nodal locations were correlated with the applied EBRT fields. RESULTS: 42 patients received PSMA (28) or choline (14) PET/CT at biochemical recurrence. 35 patients (83%) had a positive scan. At their first positive scan 17 patients had nodal metastasis, in some cases together with a local recurrence or distant disease. In-field nodal recurrences were uncommon (n = 3). Out-field nodal recurrences occurred more frequently (n = 14), with the majority (n = 12) just above the elective nodal field. These nodes were the single area of detectable failure in 6 patients (14%). CONCLUSIONS: Current RT with RTOG-based nodal fields for PCN+ provides good in-field tumour control, but frequent out-field nodal recurrences suggest missed microscopic locations. Expanding elective fields to include the aorta bifurcation may prolong recurrence-free survival. Future research must address whether the potential benefits of this strategy outbalance additional toxicity.

Adjuvant hepatic arterial infusion pump chemotherapy and resection versus resection alone in patients with low-risk resectable colorectal liver metastases - the multicenter randomized controlled PUMP trial.

BACKGROUND: Recurrences are reported in 70% of all patients after resection of colorectal liver metastases (CRLM), in which half are confined to the liver. Adjuvant hepatic arterial infusion pump (HAIP) chemotherapy aims to reduce the risk of intrahepatic recurrence. A large retrospective propensity score analysis demonstrated that HAIP chemotherapy is particularly effective in patients with low-risk oncological features. The aim of this randomized controlled trial (RCT) --the PUMP trial-- is to investigate the efficacy of adjuvant HAIP chemotherapy in low-risk patients with resectable CRLM. METHODS: This is an open label multicenter RCT. A total of 230 patients with resectable CRLM without extrahepatic disease will be included. Only patients with a clinical risk score (CRS) of 0 to 2 are eligible, meaning: patients are allowed to have no more than two out of five poor prognostic factors (disease-free interval less than 12 months, node-positive colorectal cancer, more than 1 CRLM, largest CRLM more than 5 cm in diameter, serum Carcinoembryonic Antigen above 200 µg/L). Patients randomized to arm A undergo complete resection of CRLM without any adjuvant treatment, which is the standard of care in the Netherlands. Patients in arm B receive an implantable pump at the time of CRLM resection and start adjuvant HAIP chemotherapy 4-12 weeks after surgery, with 6 cycles of floxuridine scheduled. The primary endpoint is progression-free survival (PFS). Secondary endpoints include overall survival, hepatic PFS, safety, quality of life, and cost-effectiveness. Pharmacokinetics of intra-arterial administration of floxuridine will be investigated as well as predictive biomarkers for the efficacy of HAIP chemotherapy. In a side study, the accuracy of CT angiography will be compared to radionuclide scintigraphy to detect extrahepatic perfusion. We hypothesize that adjuvant HAIP chemotherapy leads to improved survival, improved quality of life, and a reduction of costs, compared to resection alone. DISCUSSION: If this PUMP trial demonstrates that adjuvant HAIP chemotherapy improves survival in low-risk patients, this treatment approach may be implemented in the standard of care of patients with resected CRLM since adjuvant systemic chemotherapy alone has not improved survival. TRIAL REGISTRATION: The PUMP trial is registered in the Netherlands Trial Register (NTR), number: 7493 . Date of registration September 23, 2018.

A novel semi-robotized device for high-precision 18F-FDG-guided breast cancer biopsy.

PURPOSE: To assess the 3D geometric sampling accuracy of a new PET-guided system for breast cancer biopsy (BCB) from areas within the tumour with high 18F-FDG uptake. MATERIALS AND METHODS: In the context of the European Union project MammoCare, a prototype semi-robotic stereotactic prototype BCB-device was incorporated into a dedicated high resolution PET-detector for breast imaging. The system consists of 2 stacked rings, each containing 12 plane detectors, forming a dodecagon with a 186mm aperture for 3D reconstruction (1mm3 voxel). A vacuum-assisted biopsy needle attached to a robot-controlled arm was used. To test the accuracy of needle placement, the needle tip was labelled with 18F-FDG and positioned at 78 target coordinates distributed over a 35mm×24mm×28mm volume within the PET-detector field-of-view. At each position images were acquired from which the needle positioning accuracy was calculated. Additionally, phantom-based biopsy proofs, as well as MammoCare images of 5 breast cancer patients, were evaluated for the 3D automated locating of 18F-FDG uptake areas within the tumour. RESULTS: Needle positioning tests revealed an average accuracy of 0.5mm (range 0-1mm), 0.6mm (range 0-2mm), and 0.4mm (range 0-2mm) for the x/y/z-axes, respectively. Furthermore, the MammoCare system was able to visualize and locate small (<10mm) regions with high 18F-FDG uptake within the tumour suitable for PET-guided biopsy after being located by the 3D automated application. CONCLUSIONS: Accuracy testing demonstrated high-precision of this semi-automatic 3D PET-guided system for breast cancer core needle biopsy. Its clinical feasibility evaluation in breast cancer patients scheduled for neo-adjuvant chemotherapy will follow.

T2*-weighted MRI versus oxygen extraction fraction PET in acute stroke.

BACKGROUND: Mapping high oxygen extraction fraction (OEF) in acute stroke is of considerable interest to depict the at-risk tissue. Being sensitive to deoxyhemoglobin, T2*-weighted MRI has been suggested as a potential marker of high OEF. METHODS: We compared T2*-weighted images from pre-contrast arrival perfusion scans against quantitative positron emission tomography in 5 patients studied 7-21 h after onset of carotid territory stroke. OEF and T2* signal were obtained in the voxels with significantly high OEF. RESULTS: All patients showed increased OEF. No significant relationship between OEF and T2*-weighted signal was found either within or between subjects. CONCLUSION: We found no indication that T2*-weighted MRI in the way implemented in this investigation was sensitive to high OEF in acute stroke.