ReSECT is a project promoted by the Spanish Society of Thoracic Surgery with the aim not only to become an indefinite, dynamic and inclusive registry, but also to establish a common structural framework for the development of future multicentre projects in the field of thoracic surgery in Spain.

The goal of this nationwide prospective observational registry is:

• To develop and validate forecasting tools based on powerful computational methods with the goal of assisting in decision-making and improving quality of care.
• To evaluate the progressive implementation of certain surgical techniques that are on the rise, new technologies and future health programs.
• To be aware of our results as specialty and professionals and to serve as a permanent benchmarking instrument in thoracic surgery.

The first part of ReSECT, based on a personal registry design, will contemplate any thoracic surgical procedure performed by thoracic surgeons and residents in thoracic surgery in our country. Additionally, the Spanish thoracic surgery departments that voluntarily accept to collectively participate will contribute to specific surgical processes focused on certain procedures with specific objectives to be progressively implemented.

The first and only surgical process implemented since the start of the ReSECT project will focus on patients to undergo anatomical lung resection with special interest in those cases whose reason for intervention was lung cancer.

The main questions to answer in case of that first surgical process include:

• What is the performance of current predictive models for perioperative and oncological outcomes in our country?
• How could we modify previous predictive models to improve their performance?
• What is the implementation of current guideline recommendations in our country and across institutions?
• What is the potential impact of deviations from current recommendations?
• What is my performance compared to the rest of the thoracic surgical departments in my country in terms of perioperative and oncological outcomes?

ReSECT does not consider prespecified comparison groups of patients.

ReSECT is intended for SECT members including thoracic surgery specialists and residents with professional practice in Spain, as well as thoracic surgery departments in our country.

Participation in ReSECT may be at the individual level (personal surgical registry) or by department (ReSECT surgical processes). Those thoracic surgery departments interested in participating in a surgical process implemented in ReSECT must be represented by a single responsible hospital user.

ReSECT will be a clinical registry based on surgical procedures. The retrospective and prospective nature of the personal surgical record will be determined by the user's ability to include records of patients who underwent surgery prior to the approval of the current project. However, the "retrospective patients" to be included must belong to the centre associated with each user at the time of registering on the platform. In other words, it will not be feasible to include patients operated on in other institutions where the professional had previously worked.

The first ReSECT surgical process about anatomical lung resections and the successive processes that are to be created in the future, will only contemplate patients operated on prospectively with respect to the date of approval of each surgical process.

The inclusion criteria will depend on the section of the registry to be considered.

• Personal registry: patients undergoing any type of surgical intervention.
• Registry of surgical processes by departments: patients undergoing an anatomical pulmonary resection as the first process to be implemented at the time ReSECT is to be established.

Exclusion Criteria:

• Patients who could reject to participate in this study.

All the patients that could requiere an intervention in the Spanish Thoracic Surgery Departments