Materials and Methods
This study was approved by the local Ethical Committee and was performed in accordance with the ethical standards of the 1964 Declaration of Helsinki and its later amendments. All patients signed a written Informed Consent. The present single-center prospective study enrolled 173 consecutive patients affected by symptomatic bone metastases from mCRPC, eligible for 223Ra-therapy7,19 and treated in our Nuclear Medicine Unit, from September 2013 to the time of the analysis (July 2018). Currently, 223Ra-therapy consists of an intravenous injection of 55 KBq/Kg of body weight, dispensed every 28 days, for a total of 6 cycles6. QoL was evaluated by asking patients to answer both the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30, version 3.0), and the EORTC Bone Metastasis Module (QLQ-BM22). The unavailability of the baseline QoL assessment represented an exclusion criterion from the study. The QLQ-C30 questionnaire represents a specific tool for the assessment of QoL in cancer patients20. The QLQ‐C30 (version 3.0) is composed of both multi-item scales and single‐item measures. These include 5 functional scales (cognitive, CF; emotional, EF; physical, PF; role, RF; and social functioning, SF), 3 symptom scales (fatigue, FA; nausea/vomiting, NV; and pain, PA), a global health status/QoL scale and 5 single items assessing additional symptoms (appetite loss, AP; constipation, CO; diarrhea, DI; dyspnea, DY; and sleep disturbance, SL) and perceived financial impact, FI. Each of the multi-item scales includes a different set of items—no item occurs in more than 1 scale. All scales and single‐item measures range in score from 0–100. A high scale score represents a higher response level. Thus, a high score for a functional scale represents a high/healthy level of functioning. A high score for the global health status/QoL represents a high QoL. A high score for a symptom scale/item represents a high level of symptomatology/problems. The Bone Metastasis Module (QLQ-BM22) consists of an additional disease-specific module for patients with bone metastases21. The 22‐item EORTC QLQ‐BM22 questionnaire assesses disease symptoms related to bone metastasis, including painful sites, functional interference, painful characteristics, and psychosocial aspects as multi‐item scales. We scaled all items from one (not at all) to four (very much). In this questionnaire, a higher score in the case of symptom scales is indicative of greater distress, while a higher score in the case of functional scales indicates greater functional ability. Questionnaires were completed by patients without any kind of conditioning from relatives or medical staff, and were submitted at baseline, at the end of each treatment cycle, and at each follow-up evaluation, performed at 3 months, 6 months and 12 months after the end of 223Ra-therapy. Among 173 patients enrolled, 5 were excluded from the study because of the unavailability of the baseline QoL assessment. Other baseline clinical data relevant to the OS analysis, specifically age, height, weight, Hb, platelets (PLT), ECOG-PS, PSA and tALP, have been collected and taken into account in the statistical analysis. OS was established from the date of the first administration of 223Ra until the date of death from any cause.