This study demonstrates that the role of DWI in defining tumor response and planning breast surgery after NCT is more than promising.
DWI resulted comparable to contrast enhanced MRI in the assessment of NCT response,
showing similar results in defining PR,
SD,
and PD.
DWI resulted inferior to DCE-MRI in defining CR (4 cases vs 10 cases) and this can be due to either different spatial resolution or presence of residual DCIS in the tumoral bed.
Our study demonstrates that,
despite this difference in the assessment of CR,
this fact had no impact on planning the surgical treatment which was correctly defined in 85% of cases.
Figure 1 and 2.
Otherwise,
DWI is not good performing in axillary lymph node status evaluation after NCT (accuracy value 51%).
This result was expected considering that similar findings have already been reported in the literature.
Figure 3.
This study confirm the emerging thesis that non-contrast MRI is suitable in clinical practice,
moreover these results were obtained in a real daily clinical practice situation.
Omitting the use of contrast agents could lead to a less invasive and less long exam for patients as an immediate consequence,
making MRI more easily tolerable.
Instead,
indirect consequences could affect the nullification of potential risks deriving from gadolinium administration.
First of all allergic reactions,
even though they are rare (0,03% of severe reaction in literature),
represent a concrete risk and a contraindication of further administration of intravenous paramagnetic contrast agent.
Secondly,
the risk of nephrogenic systemic fibrosis could be avoided,
which represents a contraindication to contrast agent administration,
even though it’s rare.
Moreover,
as recently demonstrated by many Authors,
after repeated administrations,
gadolinium deposits in basal ganglia; even though by now it is without clinical meaning,
it is still object of study,
but it is universally accepted the recommendation of selecting Patients to administrate with contrast agents.
Considering these advantages,
non-contrast MRI in selected Patients could bring a patient care targeted to not expose women to avoidable risks.
Considering our study,
contrast agents could be used in those patients who have a non-mass lesion pre-NCT: in fact our results shows that DWI is more performing in the assessment of the response of mass lesions.
Last but not least we have to consider the potential costs reduction.
The avoidance of contrast agent,
in the face of a comparable diagnostic accuracy to contrast enhanced MRI,
could reduce the total cost of the exam.
It has to be underlined,
that,
to use DWI in clinical practice,
the exams have to be performed with an equipment at the state of the art and by a highly qualified staff: this combination makes possible to obtain high quality images.
In conclusion,
taking into account the limitation of the study,
as the small series and the necessity of further investigations on this scenario,
our study demonstrates that DWI is suitable for clinical practice in defining NCT response and planning the surgical treatment at breast level but it does not demonstrate satisfactory diagnostic performance in the assessment of axillary nodal status after NCT.