The value of yttrium-90 PET/CT after hepatic radioembolization : a pictorial essay

Introduction: Distribution of microspheres after radioembolization can be accurately visualized using PET/CT. In this pictorial essay, we aim to demonstrate the value of 90Y-PET/CT after radioembolization. Methods: 90Y-PET/CT imaging was routinely performed after radioembolization at our institute. Patients were scanned the same day or the day after treatment, using a scanner with time-of-flight technology. We retrospectively reviewed all 90Y-PET/CTs from patients treated with radioembolization (both glass and resin microspheres) between January 2011 and January 2019. Five cases were selected that are illustrative of the added value of PET/CT after radioembolization. Results: 90Y-PET/CT allows for distribution assessment and dosimetry of 90Y-microspheres. It was used for the assessment of treatment success by visualization of tumor targeting, quantification of the absorbed dose, prediction of complications such as radioembolization-induced liver disease, and determining the required dosage for retreatment. Conclusion: PET/CT is an excellent modality for post-treatment imaging of 90Y-microspheres and could lead to improved dose planning and more personalized treatment

Inflammatory markers and long term hematotoxicity of holmium-166-radioembolization in liver-dominant metastatic neuroendocrine tumors after initial peptide receptor radionuclide therapy

Purpose: In patients with neuroendocrine tumor liver metastases, additional tumor reduction can be achieved by sequential treatment with [166Ho]-radioembolization after peptide receptor radionuclide therapy (PRRT). The aim of this study was to analyze hematotoxicity profiles, (i.e. lymphocyte and neutrophile toxicity) and the prognostic value of neutrophil-to-lymphocyte ratio (NLR) and thrombocyte-to-lymphocyte ratio (TLR). Methods: All patients included in the prospective HEPAR PLuS study were included in this study. Blood testing was performed at baseline (before radioembolization) and at regular intervals during 1-year follow-up. Radiological response was assessed at 3, 6, 9, and 12 months according to RECIST 1.1. Logistic regression was used to analyze the prognostic value of NLR and TLR on response. Results: Thirty-one patients were included in the toxicity analysis; thirty were included in the response analysis. Three weeks after radioembolization, a significant decrease in lymphocyte count (mean change − 0.26 × 109/L) was observed. Ten patients (32.2%) experienced grade 3–4 lymphocyte toxicity. This normalized at 6 weeks and 3 months after treatment, while after 6 months a significant increase in lymphocyte count was observed. An increase in NLR and TLR at 3 weeks, compared to baseline, significantly predicted response at 3 months (AUC = 0.841 and AUC = 0.839, respectively) and at 6 months (AUC = 0.779 and AUC = 0.765). No significant relation with survival was found. Conclusions: Toxicity after sequential treatment with PRRT and [166Ho]-radioembolization is limited and temporary, while significant additional benefit can be expected. Change in NLR and TLR at 3-weeks follow-up may be valuable early predictors of response. Trial registration ClinicalTrials.gov, NCT02067988. Registered 20 February 2014, https://clinicaltrials.gov/ct2/show/record/NCT02067988

Case report. Toepassing van 177Lu-PSMA bij een patiënt met gemetastaseerd castratieresistent prostaatcarcinoom

In December 2016, the first patient in the Netherlands was treated with lutetium-177 prostate specific membrane antigen (177Lu-PSMA); a promising application of radionuclide therapy in prostate carcinoma. This case report discusses the working mechanism of 177Lu-PSMA therapy. Furthermore, an overview of the published literature on this specific subject is presented

Impact of external cooling with icepacks on 68Ga-PSMA uptake in salivary glands

Background: External cooling of the salivary glands is advised to prevent xerostomia in lutetium-177-PSMA treatment for advanced prostate cancer. Since evidence addressing this subject is sparse, this study aims to determine impact of icepacks application on uptake in salivary glands. Eighty-nine patients referred for gallium-68-PSMA PET/CT for (re)staging of prostate cancer were prospectively included. Twenty-four patients were scanned with unilateral (solely left-sided) icepacks; 20 with bilateral icepacks; 45 without icepacks. Icepacks were applied approximately 30 minutes prior to tracer injection. PET/CT acquisition started 1 hour postinjection. Radiotracer uptake was measured in the parotid- and submandibular glands. Results: When comparing the intervention group with the control group, uptake in the left parotid gland significantly differed: SUVmax: 11.07 ± 3.53 versus 12.95 ± 4.16; p = 0.02. SUVpeak: 9.91 ± 3.14 versus 11.45 ± 3.61; p = 0.04. SUVmax and SUVpeak were reduced with 14.52% and 13.45%. All other SUV values did not significantly differ. Patients with bilateral icepacks showed no significant differences in PSMA uptake compared to the control group (all: p > 0.05). Intra-patient analysis revealed some significant differences in SUVmax and SUVpeak between the cooled and non-cooled parotid gland (SUVmax: 11.12 ± 3.71 versus 12.69 ± 3.75; p = 0.00. SUVpeak: 9.93 ± 3.32 versus 11.25 ± 3.25; p = 0.00). Conclusions: Impact of icepacks on PSMA uptake seems to be limited to the parotid glands. As clinical relevance of these findings is debatable, structural application of icepacks in the setting of lutetium-177 PSMA therapy needs careful consideration

Case report. Toepassing van 177Lu-PSMA bij een patiënt met gemetastaseerd castratieresistent prostaatcarcinoom

In December 2016, the first patient in the Netherlands was treated with lutetium-177 prostate specific membrane antigen (177Lu-PSMA); a promising application of radionuclide therapy in prostate carcinoma. This case report discusses the working mechanism of 177Lu-PSMA therapy. Furthermore, an overview of the published literature on this specific subject is presented

Current status of yttrium-90 microspheres radioembolization in primary and metastatic liver cancer

Liver malignancy, including primary liver cancer and metastatic liver cancer, has become one of the most common causes of cancer-related death worldwide due to the high malignant degree and limited systematic treatment strategy. Radioembolization with yttrium-90 (90Y)-loaded microspheres is a relatively novel technology that has made significant progress in the local treatment of liver malignancy. The different steps in the extensive work-up of radioembolization for patients with an indication for treatment with 90Y microspheres, from patient selection to follow up, both technically and clinically, are discussed in this paper. It describes the application and development of 90Y microspheres in the treatment of liver cancer