Thesis defence in the University of Oulu

Doctoral Candidate

Licentiate of Medicine Tiina Remes

Faculty and research unit

University of Oulu Graduate School, Faculty of Medicine, University of Oulu Graduate School, Department of Children and Adolescents

Field of study

Medicine

Date and time of the thesis defence

22.11.2019 12:00

Place of the thesis defence

Auditorium 12 of the Department of Paediatrics in Oulu University Hospital

Topic of the dissertation

Signs of Radiation-Induced Accelerated Ageing in Survivors of Childhood Brain Tumors – The Incidence of Cerebrovascular Disease, Neurocognitive Impairment, Secondary Neoplasms, and Low Bone Mineral Density after 18 Years of Follow-up

Opponent

Docent Anne Mäkipernaa, Helsinki University

Custos

Professor Heikki Rantala, Oulu University

Signs of Radiation-Induced Accelerated Ageing in Survivors of Childhood Brain Tumors

Young adult survivors of childhood brain tumor treated with radiotherapy have a high risk of late-effects that are generally associated with ageing.

This doctoral thesis has investigated cerebrovascular disease, neurocognitive impairment, secondary neoplasms and bone mineral density in the survivors.

After 20 years of follow-up, cerebrovascular disease was diagnosed in half of the survivors using magnetic resonance imaging. Small-vessel disease and large-vessel disease were found in 38 % and 16 %, respectively. Ischemic infarcts, lacunar infarcts and cerebral hemorrhages had occurred in many survivors who were at a mean age of 28 years (range 16 – 43 years). Half of the survivors had white matter lesions in magnetic resonance imaging. High blood pressure increased the radiation-induced vascular injury, and it was associated with cerebrovascular disease, large-vessel disease, white matter lesions, and lacunar infarcts.

Cognitive impairment was common in the survivors with highest impairment in executive functions, processing speed and attention. Lower performance intelligent quotient, higher impairment in executive functions, processing speed and attention were associated with lower educational level, unemployment or retirement, not having intimate relationship or driving license.

A tenth of the survivors were diagnosed with secondary meningiomas at 25-year follow-up using the clinical data, and secondary neoplasms were registered in 2.4 % of the register-cases in the Finnish Cancer Registry data. Meningiomas developed in the radiation field area, where the dose was not the highest.

Fifth of the survivors had low bone mineral density. Bone mineral density was associated with body mass index and hormonal factors, such as sex hormone and thyroid hormone dysfunction. Low bone mineral density increased the risk of fractures in long-bones in the survivors.

A total of 74 survivors participated to the present study conducted in the five university hospitals in Finland. The researchers warmly thank all the participants, their families and group homes for their devotion in the present study. The results of the study have been described in the doctoral thesis of Licentiate of Medicine Tiina Remes named “Signs of Radiation-Induced Accelerated Ageing in Survivors of Childhood Brain Tumors”. The aim of the study was to further develop the follow-up clinics for the survivors.

These results increase the knowledge of late-effects and thus can be applied while developing new treatment strategies and in future research concerning the prevention of the late-effects.

Dissertation

Last updated: 14.11.2019