Abstract Background One of the most used treatments for breast cancer is radiation therapy (RT) which is a standard treatment after breast conserving surgery because it is associated with a reduction of about 50% of local recurrences; after mastectomy RT improves loco-regional control and breast cancer mortality especially with positive lymph nodes.Most of the patients show themselves worried when they find out they will receive RT as part of their treatment, experiencing fear and anxiety since the first consultation and before the RT starts, because they do not have adequate information about RT. Even if the information is given, this could be ununderstandable, unclear, with medical technicism or do not accomplish the patient´s expectatives. Most of the time this information is provided verbally despite the fact it being known that up to half of the patients prefer written information to have it and refer to it later as needed. Currently at the National Cancer Institute of Mexico (INCan), breast cancer patients who need RT, receive only verbal information during the initial consultation by the radiation oncologist, we do not have printed material to complement the information and satisfy patient’s needs. Material and Methods We performed a booklet with written information about the whole process of RT, which has general concepts, detailed information of each part of the treatment, adverse effects and self-care. We performed a pilot study with 38 breast cancer patients receiving RT. The aim was to evaluate the guide content. We asked them to read it and after we evaluated the booklet content with a mixed questionnaire of 5 elements to know the patient's opinion. Satisfaction with the information provided was evaluated using a subscale of the BREAST-Q questionnaire to quantify the results. Results Thirty eight patients were interviewed, with an average of 50 years (29-72) diagnosed between 2016 to 2019, all patients had formal education; 18.4% were first time RT patients, 7.9% were during treatment and 73.7% were at the follow up consults, were I, II, III and IV Clinical Stage (23.7%, 31.6%, 10.5% and 10.5% respectively); for 100% of the patients the booklet had clear, adequate, enough, precise and easy to understand information, within the commentaries they said: “Works like a guide”, “Detail explained like a consult, explain my difficulties”, “Totally clear”; 6 (15.8%) would like to add another information like nutrition tip; related to precise moment for receive the booklet 34 (89.5%) prefer prior first consult in RT service, 3 (7.9%) prefer to have the booklet after RT consult and 1 (2.6%) patient said that the best moment to receive it was during the treatment. Most patients considered RT’s booklet as complete, well explained and helped them to understand all the process. During the evaluation of Satisfaction with the information provided by Radiation Oncologist (SIRO) we obtained 77% (37-100) in global satisfaction. ConclusionOur booklet could be used to ameliorate the effective communication and as a complementary tool for patients who are going to receive RT and will allow us to improve the quality of care, upgrading the satisfaction with the information for the patients. Citation Format: Daniel Rivera-Sánchez, Luz M Gutiérrez-Zacarías, Juan A Torres-Domínguez, Paulina Guerra-Vázquez, Juan E Bargalló-Rocha. Pilot study for the use of a booklet for breast cancer patients who receive radiation therapy at national cancer institute of Mexico [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-66.