Purpose: Watchful waiting (WW) can be considered for patients with metastatic clear-cell renal cell carcinoma (mccRCC) with good or intermediate prognosis, especially those with <2 International Metastatic RCC Database Consortium criteria and ≤2 metastatic sites [referred to as watch and wait (“W&W”) criteria]. The IMaging PAtients for Cancer drug SelecTion-Renal Cell Carcinoma study objective was to assess the predictive value of [18F]FDG PET/CT and [89Zr]Zr-DFO-girentuximab PET/CT for WW duration in patients with mccRCC. Experimental Design: Between February 2015 and March 2018, 48 patients were enrolled, including 40 evaluable patients with good (n = 14) and intermediate (n = 26) prognosis. Baseline contrast-enhanced CT, [18F]FDG and [89Zr]Zr-DFO-girentuximab PET/CT were performed. Primary endpoint was the time to disease progression warranting systemic treatment. Maximum standardized uptake values (SUVmax) were measured using lesions on CT images coregistered to PET/CT. High and low uptake groups were defined on the basis of median geometric mean SUVmax of RECIST-measurable lesions across patients. Results: The median WW time was 16.1 months [95% confidence interval (CI): 9.0–31.7]. The median WW period was shorter in patients with high [18F]FDG tumor uptake than those with low uptake (9.0 vs. 36.2 months; HR, 5.6; 95% CI: 2.4–14.7; P < 0.001). Patients with high [89Zr]Zr-DFO-girentuximab tumor uptake had a median WW period of 9.3 versus 21.3 months with low uptake (HR, 1.7; 95% CI: 0.9–3.3; P = 0.13). Patients with “W&W criteria” had a longer median WW period of 21.3 compared with patients without: 9.3 months (HR, 1.9; 95% CI: 0.9–3.9; Pone-sided = 0.034). Adding [18F]FDG uptake to the “W&W criteria” improved the prediction of WW duration (P < 0.001); whereas [89Zr]Zr-DFO-girentuximab did not (P = 0.53). Conclusions: In patients with good- or intermediate-risk mccRCC, low [18F]FDG uptake is associated with prolonged WW. This study shows the predictive value of the “W&W criteria” for WW duration and shows the potential of [18F]FDG-PET/CT to further improve this.

Background: In metastatic breast cancer (MBC), [¹⁸F]fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]FDG-PET/CT) can be used for staging. We evaluated the correlation between BC histopathological characteristics and [¹⁸F]FDG uptake in corresponding metastases. Patients and Methods: Patients with non-rapidly progressive MBC of all subtypes prospectively underwent a baseline histological metastasis biopsy and [¹⁸F]FDG-PET. Biopsies were assessed for estrogen, progesterone, and human epidermal growth factor receptor 2 (ER, PR, HER2); Ki-67; and histological subtype. [¹⁸F]FDG uptake was expressed as maximum standardized uptake value (SUV_max) and results were expressed as geometric means. Results: Of 200 patients, 188 had evaluable metastasis biopsies, and 182 of these contained tumor. HER2 positivity and Ki-67 ≥ 20% were correlated with higher [¹⁸F]FDG uptake (estimated geometric mean SUV_max 10.0 and 8.8, respectively; p = 0.0064 and p = 0.014). [¹⁸F]FDG uptake was lowest in ER-positive/HER2-negative BC and highest in HER2-positive BC (geometric mean SUV_max 6.8 and 10.0, respectively; p = 0.0058). Although [¹⁸F]FDG uptake was lower in invasive lobular carcinoma (n = 31) than invasive carcinoma NST (n = 146) (estimated geometric mean SUV_max 5.8 versus 7.8; p = 0.014), the metastasis detection rate was similar. Conclusions: [¹⁸F]FDG-PET is a powerful tool to detect metastases, including invasive lobular carcinoma. Although BC histopathological characteristics are related to [¹⁸F]FDG uptake, [¹⁸F]FDG-PET and biopsy remain complementary in MBC staging (NCT01957332).

Medical students at the UMCG are introduced to the basic principles of medical research during the 3-year bachelor's period. These experiences increase awareness of the importance of research and give them the competency to explore the literature and to find the gaps and limits of health science. In the 3-year master's period, students practice these skills during a research clerkship of 26 weeks. Many opportunities are offered locally, but students can also choose to go abroad. Personally, I wanted to go to a famous oncology research center in the world, because I want to pursue a career in oncology. I was lucky to find a supervisor who knew about The University of Texas MD Anderson Cancer Center, and I was immediately enthusiastic. A great advantage to Texas was having a family member living close to Houston. In March 2014, I had the first encounter with my supervisor at UMCG and soon after that I contacted my supervisor in Houston. In June, I started writing my proposal and organizing the required documents and could start my elective in November. Planning a research project abroad is not easy. You need sponsorship letters from your university and from your * Bertha Eisses

Background/Objectives: Outcome prediction in patients with estrogen (ER)-positive metastatic breast cancer (MBC) remains challenging. We investigated whether circulating tumor cell (CTC) count adds prognostic value in ER-positive MBC using immunohistochemical (IHC) or 16α-[¹⁸F]-fluoro-17β-estradiol (FES)-PET imaging. Methods: Patients with newly diagnosed non-rapidly progressive MBC receiving first-line endocrine monotherapy, with ER-positive IHC (biopsy) or FES-PET and available CTC count, were included. Associations of CTC count and CTC-ER status based on ESR1 mRNA expression with progression-free survival (PFS) and overall survival (OS) were analyzed, and the added prognostic value of CTC count (<5 vs. ≥5/7.5 mL) beyond a positive ER result was assessed. Results: In patients with ER-positive IHC (n = 98) or FES-PET (n = 99) out of 106 endocrine-treated patients, ≥5 CTCs were associated with shorter PFS (HR 1.86; p = 0.0047 and 1.75; p = 0.011) and OS (HR 3.19 and 3.22; both p < 0.01), respectively, compared with <5 CTCs. Adding CTC count to ER-positive IHC or FES-PET improved prognostic accuracy for PFS (p = 0.006 and 0.012) and OS (both p < 0.001). CTC-ER status (ESR1 RNA) was not associated with outcomes. Conclusions: CTC count adds prognostic value to PET- or biopsy-based ER analysis in endocrine-treated MBC.

Flow-chart patients according to RECIST-defined PD. *All patients had clinical disease progression; no CT-imaging was performed before initiation of systemic treatment ** In total 7 patients choose best supportive care. Three other patients underwent radiotherapy or surgery of all target lesions.