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Primary liver cancers (i.e. hepatocellular carcinoma or cholangiocarcinoma) are worldwide some of the most frequent cancers, with rapidly fatal liver failure in a large majority of patients. Curative therapy consists of surgery (i.e. resection or liver transplantation), but only 10-20% of patients are candidates for this. In other patients, a variety of palliative treatments can be given, such as chemoembolization, radiofrequency ablation or recently introduced tyrosine kinase inhibitors, e.g. sorafenib. Colorectal cancer is the second most lethal cancer in Europe and liver metastases are prevalent either at diagnosis or in follow-up. These patients are usually treated by a sequence of surgery, chemotherapy and antibody therapy [Okuda et al. (Cancer 56:918-928, 1985); Schafer and Sorrell (Lancet 353:1253-1257, 1999); Leong et al. (Arnold, London, 1999)]. Radioembolization is an innovative therapeutic approach defined as the injection of micron-sized embolic particles loaded with a radioisotope by use of percutaneous intra-arterial techniques. Advantages of the use of these intra-arterial radioactive compounds are the ability to deliver high doses of radiation to small target volumes, the relatively low toxicity profile, the possibility to treat the whole liver including microscopic disease and the feasibility of combination with other therapy modalities. Disadvantages are mainly due to radioprotection constraints mainly for (131)I-labelled agents, logistics and the possibility of inadvertent delivery or shunting [Novell et al. (Br J Surg 78:901-906, 1991)]. The Therapy, Oncology and Dosimetry Committees have worked together in order to revise the European Association of Nuclear Medicine (EANM) guidelines on the use of the radiopharmaceutical (131)I-Lipiodol (Lipiocis®, IBA, Brussels, Belgium) and include the newer medical devices with (90)Y-microspheres. (90)Y is either bound to resin (SIR-Spheres®, Sirtex Medical, Lane Cove, Australia) or embedded in a glass matrix (TheraSphere®, MDS Nordion, Kanata, ON, Canada). Since (90)Y-microspheres are not metabolized, they are not registered as unsealed sources. However, the microspheres are delivered in aqueous solution: radioactive contamination is a concern and microspheres should be handled, like other radiopharmaceuticals, as open sources. The purpose of this guideline is to assist the nuclear medicine physician in treating and managing patients undergoing such treatment.

Introduction: (32)P phosphate was the first therapeutic radioisotope, used in leukaemia about 70 years ago. Since then, many new agents for haematological proliferations have been introduced successfully. Today there remains a distinct subgroup of elderly patients with polycythaemia vera and essential thrombocythaemia for whom (32)P is the most optimal treatment option, an assertion supported by two large studies with long follow-up., Purpose: The purpose of this guideline is to assist the nuclear medicine physician in treating and managing patients who may be candidates for (32)P phosphate therapy.

Introduction: The pituitary gland has a high expression of somatostatin receptors and is therefore a potential organ at risk for radiation-induced toxicity after 177Lu-DOTATATE treatment. Objective: To study changes in pituitary function in patients with neuroendocrine tumors (NETs) treated with dosimetry-based 177Lu-DOTATATE to detect possible late toxicity. Methods: 68 patients from a phase II clinical trial of dosimetry-based, individualized 177Lu-DOTATATE therapy were included in this analysis. Patients had received a median of 5 (range 3–9) treatment cycles of 7.4 GBq/cycle. Median follow-up was 30 months (range 11–89). The GH/IGF-1 axis, gonadotropins, and adrenal and thyroid axes were analyzed at baseline and on a yearly basis thereafter. Percent changes in hormonal levels over time were analyzed statistically using a linear mixed model and described graphically using box plots. The absorbed radiation dose to the pituitary was estimated based on post-therapeutic imaging, and the results analyzed versus percent change in IGF-1 levels over time. Results: A statistically significant decrease in IGF-1 levels was found (p < 0.005), which correlated with the number of treatment cycles (p = 0.008) and the absorbed radiation dose (p = 0.03). A similar decrease, although non-significant, was seen in gonadotropins in postmenopausal women, while in men there was an increase during the first years after therapy, after which the levels returned to baseline. No change was observed in the adrenal or thyroid axes. Conclusions: No signs of severe endocrine disorders were detected, although a significant decrease in the GH/IGF-1 axis was found, where dosimetric analyses indicated radiation-induced damage to the pituitary gland as a probable cause. [ABSTRACT FROM AUTHOR]

Purpose: To present data from an interim analysis of a Phase II trial designed to determine the feasibility, safety, and efficacy of individualising treatment based on renal dosimetry, by giving as many cycles as possible within a maximum renal biologically effective dose (BED). Method: Treatment was given with repeated cycles of 7.4 GBq Lu-DOTATATE at 8-12-week intervals. Detailed dosimetry was performed in all patients after each cycle using a hybrid method (SPECT + planar imaging). All patients received treatment up to a renal BED of 27 ± 2 Gy (α/β = 2.6 Gy) (Step 1). Selected patients were offered further treatment up to a renal BED of 40 ± 2 Gy (Step 2). Renal function was followed by estimation and measurement of the glomerular filtration rate (GFR). Results: Fifty-one patients were included in the present analysis. Among the patients who received treatment as planned, the median number of cycles in Step 1 was 5 (range 3-7), and for those who completed Step 2 it was 7 (range 5-8); 73% were able to receive >4 cycles. Although GFR decreased in most patients after the completion of treatment, no grade 3-4 toxicity was observed. Patients with a reduced baseline GFR seemed to have an increased risk of GFR decline. Five patients received treatment in Step 2, none of whom exhibited a significant reduction in renal function. Conclusions: Individualising PRRT using renal dosimetry seems feasible and safe and leads to an increased number of cycles in the majority of patients. The trial will continue as planned. [ABSTRACT FROM AUTHOR]

Red marrow dosimetry is essential during radioimmunotherapy and a reliable method is essential in order to find a measure correlated to the toxic effect observed. The aim of this study was to calculate the absorbed dose to red marrow with different methods for the same patients and to compare the results. Patients diagnosed with B-cell lymphoma were treated with 131 I-labelled monoclonal antibodies (LL2, anti-CD22). Blood samples were collected, scintillation camera images were taken and single probe measurements were carried out at different points in time after administration of the radiopharmaceutical. The absorbed dose to red marrow per unit activity administered was calculated using four varieties of the blood method and from activity quantification in the sacrum in the scintillation camera images. The absorbed dose to the total body per unit activity, sometimes used as a measure for determining the toxic effect in red marrow, was calculated from both the scintillation camera images and the single probe measurements. The results from the different methods of calculating the absorbed dose for the same patient and treatment were compared. The ratio of the maximum and the minimum absorbed dose to red marrow calculated using the four variations of the blood method and the sacrum imaging method for one and the same patient varied between 1.8 and 2.8. The correlation coefficients for all the possible combinations of the dosimetry methods, including total body measurements, varied from 0.51 to 0.99. The results show that the variability of the absorbed dose to the bone marrow is dependent on both method and patient. [ABSTRACT FROM AUTHOR]

Material and methods: The present study investigates the safety and efficacy of 2590 MBq rhenium-186 ([sup 186]Re) etidronate (i.e. twice the activity normally used) administered intravenously in 15 patients with disseminated prostatic carcinoma and bone pain. Results: Pain relief was observed in 11 of 14 evaluable patients (79%), 4 of whom became completely free from pain. Five of the responding patients also noted an improvement in daily activity and two found it possible to reduce or discontinue morphine medication. Pain relief occurred within one week in four patients, and within two weeks in eight of the responding patients. The mean duration of pain relief after the first course of [sup 186]Re-etidronate was 6 weeks (range 4-10). The toxicity was mild (≤ grade 2), transient, and restricted to hematological toxicity. Conclusions: [sup 186]Re-etidronate provided rapid pain-relief and had mild toxicity in most patients with disseminated hormone-refractory prostatic carcinoma, but doubling the activity did not markedly improve the efficacy. [ABSTRACT FROM AUTHOR]