Factors	Emblematic Quotes
Supporting or opposing factors
Opinion of the physician	“When the doctor is convinced of the benefit of the treatment, his or her opinion strongly influences the patient’s choice.” (P5) “Some colleagues may be more reticent and so I think that this plays into the patient’s choice.” (P15) “Some patients don’t want to choose and when the different solutions are presented, they are lost and say: no, I trust you and will do what is best for me.” (P12)
One-day treatment	“When fewer sessions are offered, patients are immediately willing to accept.” (P1)
Public image and experience among relatives	“Conventional radiotherapy is a treatment that is still frightening, that is a bit mysterious, patients don’t know what to expect. There is a lot of talk about the side effects, so it is a treatment that is sometimes misunderstood, with a negative attitude on the part of patients. Possibility of not doing postoperative conventional radiotherapy can influence the choice.” (P15) “Women are influenced by what they have seen, heard, about the different techniques, what some people around them may have told them as a personal experience, a bad experience of external radiotherapy or IORT.” (P11)
Supporting factors
Preservation of quality of life	“Older women will opt for the least burdensome, least aggressive treatment that has the least impact on their autonomy. Older patients want to remain independent”. (P9) “One of the criteria that can influence patients is their own experience and what they expect from the treatment in terms of its impact on their quality of life.” (P11)
Less travel time	“It is difficult to have a medical transport…the transporter is not under control, that is stressful for the patient… in the context of radiotherapy there may be unexpected waiting times, you are scheduled for a given time, but this is shifted for reasons of patient flow, independently of everyone’s goodwill. You wait for an hour, a few minutes under the machine, you wait again for your ambulance driver, and then you are back home. In fact, the days are centered on the half-day needed to do all this.” (P9)
Opposing factors
Fear of relapse	“I have patients who tell me, I want the whole thing, the longest, heaviest treatment, because I am afraid.” (P15)
Delay before treatment initiation	“With IORT, the delay in management is sometimes longer, which can lead to a refusal of the intraoperative procedure and the choice of the treatment that begins most quickly.” (P13)
Refusal of adjuvant endocrine therapy	“There are many women who for X or Y reasons do not want anti-hormonal treatment or do not take it correctly, I insist on the fact that it is the whole procedure that allows a better chance of cure.” (P15) “I propose IORT with the only constraint that the woman agrees to take the anti-hormone therapy. This seems to be the major determinant, and this is what I insist on a lot with patients, saying that I agree to do the IORT, but if they agree to take this anti-hormonal treatment. If they are reluctant at the beginning, I think it is not a good treatment because the few cases of relapse that we have had were in patients who had not taken the anti-hormonal treatment.” (P11)
Poorer aesthetic result	“To install the intrabeam, the surgeon must make a direct approach. If you have a tumor on the edge of the breast, you cannot go through the nipple, you will have to go directly, which is not as pretty… in women aged 55-60, I have seen some recently who have refused the intraoperative procedure for this reason.” (P13)