Mitochondrial dysfUnction: a Key Player in Doxorubicin-induced Skeletal and Cardiac muscLE Damage

The goal of this observational study is to demonstrate the ability of using non-invasive Phosphorus (31P) Magnetic Resonance Spectroscopy (MRS) to monitor changes of in-vivo markers of mitochondrial function in skeletal and cardiac muscles in muscles in large B- or T-cell lymphoma patients during treatment with (R-)CHOP. The main question it aims to answer is: • Can 31P-MRS be used to monitor changes of in vivo markers of mitochondrial function in skeletal and cardiac muscles in large B- or T-cell lymphoma patients during treatment with (R-)CHOP? To be able to answer this main question, participants will undergo 31P-MRS imaging of the calf muscles and of the heart 3 times during the study period.

Rationale: Patients with large B-cell lymphoma or T-cell lymphoma are often treated with (R-)CHOP chemotherapy with the intent to cure the disease, but this treatment can also lead to serious toxicities, which may last for many years. (R-)CHOP contains doxorubicin, which has detrimental effects on skeletal and cardiac muscles. Loss of skeletal muscle mass is associated with treatment modifications (i.e., dose delay/reduction/discontinuation), increased levels of fatigue, decreased quality of life (QoL) and shorter survival. Cardiomyopathy might lead to chronic heart failure in the long-term, which negatively affects prognosis as well. Preclinical studies investigating underlying mechanisms of these detrimental effects suggest that mitochondrial dysfunction plays a key role. However, human data is lacking due to the need of invasive repeated muscle biopsies. Phosphorus (31P) Magnetic Resonance Spectroscopy (MRS) is an innovative, non-invasive technique, which enables repeated measures of skeletal and cardiac muscle mitochondrial energy metabolism. Hypothesis: In this study the investigators hypothesize that patients with large B-cell lymphoma or T-cell lymphoma treated with (R-)CHOP will show decreased mitochondrial function in skeletal and cardiac muscle tissue following chemotherapy treatment. Objective: To demonstrate the ability of using non-invasive 31P-MRS to monitor changes of in vivo markers of mitochondrial function in skeletal and cardiac muscles (i.e., skeletal muscle PCr recovery rate constant and cardiac PCr/ATP ratio) in patients with large B-cell lymphoma or T-cell lymphoma during treatment with (R-)CHOP. Furthermore, the investigators will assess the feasibility of undergoing the study measurements for patients with large B-cell lymphoma or T-cell lymphoma during intensive (R-)CHOP treatment and explore the association between changes in in vivo measured mitochondrial function in skeletal and cardiac muscle tissue and changes in muscle mass, physical fitness, muscle strength, physical activity levels measured by Fitbit, chemotherapy completion rate and patient-reported outcomes, including physical activity, fatigue and quality of life. Study design: Cohort study. Study population: Patients with large B-cell lymphoma or T-cell lymphoma scheduled for 6 full-dose cycles of 1st line immunochemotherapy with cyclophosphamide, doxorubicin, vincristine and prednisone with or without rituximab ((reversed) (R-)CHOP). Main study parameters/endpoints: The main study parameters are differences in skeletal muscle PCr recovery rate constant and cardiac PCr/ATP ratio. These parameters will be compared within-patients before, halfway during and after completion of chemotherapy treatment. Nature and extent of the burden and risks associated with participation and benefit: Included patients will visit the UMC Utrecht 3 times (i.e., before, halfway during and after completion of chemotherapy treatment). During these visits, participants will undergo 31P-MRS imaging of the calf muscles and of the heart at 7 Tesla. During the calf muscle scan, patients will be asked to perform a mild exercise challenge (i.e., dynamic plantar flexions). 7T 31P-MRS is a safe and reliable technique for subjects without contra-indications for undergoing MRI. Possible side-effects are limited to short-term vertigo and nausea. In addition, anthropometrics will be measured and small tests to evaluate muscle strength and physical performance will be performed. Participants will be asked to complete questionnaires regarding physical activity, quality of life and fatigue. Finally, patients will be asked to wear a Fitbit, provided by the study team, to objectively assess their levels of physical activity. Subjects will not experience direct benefits by participating in this study. By the end of the study, the investigators will demonstrate the ability to non-invasively monitor skeletal and cardiac muscle mitochondrial damage using 31P-MRS, which is a pre-requisite to assess the efficacy of (non-)pharmacological interventions.