A registry study to collect data on tumor shrinkage resulting from radiation therapy

The treatment of large-volume tumors is complex and depends on numerous factors. One component of treatment may be radiation therapy, in which high-energy radiation is used to damage the tumor cells. The primary goal of treatment is to reduce the tumor’s size, which is intended to alleviate symptoms or improve the tumor’s resectability. Various radiation techniques are available within the framework of radiation therapy, including conventional and volumetric modulated arc therapy (VMAT). In conventional radiation therapy, the entire tumor is treated with the same radiation dose. In the case of large tumors, this can result in damage to a relatively large amount of surrounding healthy tissue. At the same time, the effectiveness in certain areas of the tumor may be limited due to the total radiation dose that must be adhered to. For this reason, spatially fractionated radiation therapy is increasingly being used for larger tumors. In this approach, specific sections of the tumor are treated with very high radiation doses, whereas other parts of the tumor receive only a small amount of radiation. The targeted destruction of cancer cells is thought to release various signaling molecules that can also damage surrounding cancer cells that have received lower doses of radiation (the so-called bystander effect). This method is intended to better spare the surrounding healthy tissue.

The aim of this registry study is the structured collection of long-term treatment data on various forms of radiation therapy for large-volume tumors. In particular, the study aims to compare tumor response and the occurrence of side effects between conventional and spatially fractionated radiation therapy. The treatment technique recommended by the treating physicians will be used as part of the study. No new therapeutic approach is being investigated. Clinical and imaging examinations will be performed before the start of therapy, on the last day of treatment, and at subsequent follow-up visits. As part of regular follow-up care, check-ups are scheduled approximately four to six weeks after the end of therapy and subsequently every three to six months. The study is being conducted as a single-center trial at Heidelberg University Hospital.

Women and men aged 18 and older with a large-volume tumor exceeding 150 ml and an indication for radiation therapy are eligible to participate in this study.