Localized prostate cancer (LPC) is predominantly a tumor among older men, and few patients will get symptoms from the disease. All methods to treat LPC with a curative intent have different types and degrees of side effects. It is therefore very important to evaluate the side effects thoroughly to make sure that treatment complications will not decrease the quality of life more than the disease would have done. In search for new and better treatments, complications has to be registered and evaluated in relation to quality of life (QOL) for the patients. Few validated self-assessment questionnaires for evaluation of external radiotherapy (EBRT) induced side effects has yet been developed. The present project focus on the development of the PC-specific questionnaire, QUFW94, and evaluation of symptoms in patients treated with EBRT and un-treated (watchful waiting) patients with a LPC. In the newly developed LPC-specific questionnaire a reliability and responsiveness test was performed. Both the inter-rater test and the test-retest show high correlation coefficients (ICC), above 0.60 for all scales. The internal reliability exceeded the lower acceptable limit (Cronbach a >0.70). The questionnaire was proven to be valid for the evaluations of EBRT side effects in LPC patients. Late side effects were evaluated 4 years after treatment in 181 LPC patients, treated with conventional large field EBRT, and compared with 141 age-matched PC disease free men. The most prominent urinary side effects were urgency and leakage which were doubled in the patient group. A ten fold increase was seen in comparison to controls at the most prominent intestinal problems, blood, mucus and leakage. The results support the use 3-D conformai therapy to decrease irradiation dose to the rectum and the bladder and thereby decreased side effects. A prospective additional evaluation 8 years after EBRT did not show any changes in urinary problems between 4 and 8-yr follow-up in the patients or the controls. EBRT of LPC is also accompanied by disturbances in sexual function. These problems were therefore evaluated, 4 years after EBRT, in relation to the function in PC free men. Patients treated with EBRT indicated higher levels of sexual dysfunction than age-matched controls. No erection was reported from 12% of the control subjects, 56% of the patients who had only received radiotherapy (RT) and 87% of the RT+castration (RT+A) patients. The extended evaluation 8 years after EBRT show similar sexual function in all groups. QOL and late side effects/symptoms were evaluated in the first and only randomized trial between RT and deferred treatment (DT) and compared to age-matched controls. QOL was evaluated with the general QOL formula, EORTC's QLQ-C30 (+3), and LPC specific side effects with QUFW94 in 108 randomized patients with LPC 3 years after diagnosis. Social functioning was the only QOL scale where a significant difference was found between the two patient groups and in comparison with the control group. Multivariate regression analysis showed that hematuria, incontinence, mucus, and planning of the daily activities due to intestinal problems caused this decrease in QOL in the RT group. In conclusion, the LPC specific QUFW94 questionnaire was proven to be valid for evaluation of side effects and showed increased intestinal problems in the patients treated with conventional large field EBRT in comparison to untreated LPC patients. No difference in urinary and intestinal late side effects or sexual function was seen between a 4 year vs. 8 year follow-up. / digitalisering@umu