Short summary

Stereotactic body radiation therapy of lung tumors located less than 1 cm from the thoracic wall yields an increased risk of developing chest wall pain or rib fracture. Often it is necessary to reduce the radiation dose to reduce the risk of these side effects, but the patients are seldom asked for their opinion. In this study we want to directly involve the patients in the choice of a high or lower dose and to test whether a Patient Decision Aid improves the consultation regarding the decision.

Rationale

Lung cancer is common with more than 4600 new cases in Denmark each year. Mortality is high with a 5-year survival less than 20%. Curative treatment in the form of surgery is only possible if the patient has localized disease (i.e. stage I or II), is fit for surgery, and has adequate lung function allowing for removal of a lung lobe or even a whole lung. In the event of localized non-small cell disease with inadequate lung function or other reasons for not offering surgery, curative stereotactic body radiation therapy (SBRT) is often feasible. SBRT is an advanced radiation technique in which one or few tumors are irradiated with high doses delivered precisely from many angles, sparing the surrounding normal tissue. The technique is applied for tumors in different organs such as the brain, lungs, liver and bone. For lung tumors up to 5 cm SBRT can be delivered in different dose-fraction regimens such as 66 Gray (Gy) in 3 fractions, 45 Gy in 3 fractions, and 50 Gy in 5 fractions. Local tumor control for non-small cell lung cancer treated with SBRT is as high as 93% during 5-year follow-up. Metastases to the lung from other primary malignancies such as breast, colorectal, bladder, and kidney cancer occur frequently. In the case of oligometastastic disease, these metastases can often be treated with SBRT with comparably high local tumor control. When the lung tumor is located close to the thoracic wall, there is an increased risk of developing chest wall pain or rib fracture following SBRT of the tumor. A meta-analysis has shown the pooled risk of chest wall pain to be 11% and that of rib fracture to 6.3% with significant differences between individual studies. These side effects may occur several years after the treatment. In order to avoid violation of the thoracic wall radiation constraints, and hereby reduce the risk of side effects from the thoracic wall, it is often necessary to lower the dose delivered to a tumor located adjacent to the thoracic wall. This may increase the risk of local failure. Planning the radiation treatment of a lung tumor located adjacent to the thoracic wall involves conflicting interests, namely 1) offering as high a radiation dose as possible to obtain local tumor control versus 2) balancing the dose to reduce the risk of side effects from the thoracic wall and surrounding ribs. Whether 1 or 2 is more important depends on the individual patient's situation and preferences, but the patients are seldom involved in the decision while in fact they should be. The concept of shared decision making (SDM) offers a solution to this problem. SDM is a collaborative process allowing patients and healthcare professionals to make decisions together taking into account the best scientific evidence as well as patients' values, preferences, life situation, and knowledge about disease process and prognosis. Patient decision aids (PtDAs) are tools designed to assist caregivers in the process of informing patients about relevant treatment options. PtDAs contain factual and balanced information about the options and the pertaining pros, cons, and probabilities. The tools are relevant when the decision is preference-sensitive, that is, the right treatment cannot be decided based on professional knowledge alone. They can be digital, paper-based, videos, etc., and are often designed to a specific situation. The use of PtDAs has shown to provide a number of positive effects on the patients, including increased knowledge of options, better understanding of risks, and clarity as to what matters most in their life situation. Other effects are decreased decisional conflict, less indecision about personal values, and a higher degree of involvement in decision making. The Regional Center for Shared Decision Making at Vejle Hospital has developed a generic PtDA ("Beslutningshjælperen") in collaboration with the School of Design in Kolding. This platform can be tailored to any clinical situation. Radiotherapy is an important treatment modality in oncology, and approximately 50% of all cancer patients will receive it during their disease course. Radiotherapy and especially SBRT is complex science and it can be difficult for some patients to understand how the treatment works. This may lead the patients to be passive during the consultation and accept the suggested treatment without further thought. Due to the potentially serious side effects it is necessary to better involve the patients in the decision making process. SDM with a PtDA can help facilitate this. Hypothesis The use of a PtDA will increase the extent of SDM occurring in the consultation compared to consultations without the PtDA and result in patients being more directly involved in the planning of their treatment. Objective By increasing the extent of SDM the objective is to tailor SBRT treatment to the individual patient with peripheral non-small cell lung cancer or lung metastasis from another primary tumor.

Description of the cohort

Adult patients with newly diagnosed early stage non-small cell lung cancer or lung metastasis from other primary cancer located less than 1 cm from the thoracic wall and eligible for stereotactic body radiation therapy can be offered enrollment in the study. The included patients are randomized to either consultation as usual or consultation using the PtDA.

Data and biological material

Clinical and demographic data. The questionnaires OPTION, SDM-Q9, SDM_P4, CollaboRATE, DCS, DRS, FCRI-SF, EORTC QLQ-L30 & QLQ-LC29 up to 5 years after the treatment. Occurence of chest wall pain or rib fractures.

Collaborating researchers and departments

Department of Oncology, Vejle Hospital

• Associate professor Torben Frøstrup Hansen, MD, PhD
• Charlotte Kristiansen, MD
• Torben Schjødt Hansen, MD
• Rune Slot Thing, Physicist
• Professor Karina Dahl Steffensen, MD, PhD

Regional Center for Shared Decision Making