Caren van Roekel

89 Quality of life in patients treated with 166 Ho-radioembolization BACKGROUND Radioembolizaton (RE) is an intra-arterial therapeutic option for patients with unresectable hepatic malignancies. Tumors within the liver receive their blood supply almost entirely from the hepatic artery whereas the normal liver is supplied mainly from the portal vein. Therefore, infusion of radiolabeled microspheres into the arterial system results in delivery of effective doses of radiation to the tumor without causing intolerable toxicity to the normal liver (1). Holmium-166-poly(L-lactic acid) ( 166 Ho)-microspheres (QuiremSpheres ® , Quirem Medical B.V., The Netherlands) have been developed as an alternative to yttrium-90 ( 90 Y) microspheres. The main advantage of 166 Ho-microspheres is the ability to be visualized in-vivo by SPECT and MRI, which enables quantitative biodistribution imaging (2). 166 Ho-microspheres have a mean diameter of 30 µm (range 15-60 µm). Overall, RE is safe and well tolerated, with primarily short-term toxicity. Mild clinical side effects of RE consist mainly of abdominal pain, nausea, vomiting, fatigue and fever and usually occur within 4-6 weeks after treatment (post-embolic syndrome) (3, 4). Palliative chemotherapy in the same setting, however, is known to be associated with substantial side effects (5). With the advances in cancer treatment and increased survival, quality of life (QoL) has become increasingly important (6). Tumor-specific therapy can potentially prolong life, but, due to its possible toxicity, may considerably reduce QoL (7). The majority of patients (82-95%) value the impact on QoL of the treatment at least as much as the survival benefit (8, 9). Factors known to influence QoL in cancer patients are, among others, age, gender, cancer type, performance status, and high symptomburden (10-13) In patients with hepatic malignancies, specifically, extrahepatic recurrence is of significant influence on QoL (14). To form an impression of the influence of RE on QoL, we performed a systematic review of the literature (See Figure S1 for the search strategies). The effect of Y90-RE on QoL was investigated in 14 studies (15-28). In most studies, QoL did not change significantly after Y90-RE (Table 1) (15, 17, 19-21, 23, 25, 27). In a minority, QoL either improved (16, 26) or worsened after 90 Y-RE (18, 24). The purpose of the current study was to evaluate the effect of 166 Ho-RE on QoL. Based on the literature, our hypothesis was that QoL would not be significantly affected by 166 Ho-RE, similar to what is known for 90 Y-RE. Furthermore, the hypothesis was that QoL may be impaired by the known short-term side-effects of 90 Y-RE, i.e. the post-embolization syndrome. 3