Lymphatic mapping after prior sentinel node negative breast surgery

Like in primary breast cancer, prognosis of recurrent breast cancer is also
correlated with the regional lymph node status.
However, although lymphatic mapping with sentinel node biopsy is generally
implemented in the clinical approach of primary breast cancer, this is not
the case for recurrent breast cancer. In the latter situation, lymphatic
pathways could have been altered due to prior surgery and/or radiotherapy.
However, several small studies have suggested that it is feasible to perform a
SNB in women who have undergone prior SNB. If lymphatic mapping and SNB truly
is a valid staging procedure in locally recurrent breast cancer, it might be an
alternative for complete ALND and patients may be spared a more invasive
procedure and its associated morbidity. Furthermore, alternative pathways could
be identified, which could lead to better staging and subsequent
administration of adjuvant systemic therapy.

Primary objective: To assess technical feasibility of lymphatic mapping in
patients previously treated for primary breast cancer with prior surgery with a
negative SNB.
Secondary objectives:
To determine lymphatic drainage pathways in patients with (grossly) intact
axillary lymph nodes after prior breast surgery.

This study is a prospective cohort study. Because of the descriptive instead
of comparative nature of the study, randomization is not necessary.
After determining that a patient meets the inclusion criteria, informed consent
is being obtained and an appointment for lymphatic mapping will be made. To
minimalize patient effort this outpatient appointment will be scheduled as much
as possible on the same day with regular follow-up appointments.
Lymcoscintigraphic findings will be documented for further research.

The procedure itself consists of performing lymphoscintigraphy, similarly to
the procedure done as part of the sentinel node procedure in patients with
primary breast cancer, which has long been validated.
In our hospital lymphatic mapping is carried out using 99mTc-colloidal
albumin (Nanocoll). Since there is no need for a SNB in this study,
radioactivity won*t have to last that long and we expect one can suffice with a
dose of 60Mbq of radioactive colloid.
The albumin will be injected subdermally and parenchymally at the site of the
skin scar. Two hours after injection a lymphoscintigram is made. If necessary,
additional recordings will be made after a greater time span has passed. The
identified lymphatic drainage pathways and/or the location of the sentinel
node(s) will be registered for further analysis. These lymphoscintigrams will
be compared with pre-operative lymphoscintigrams of the same patient.

Lymphatic drainage could have been altered due to former surgery and/or
radiotherapy. These aberrant drainage pathways could be detected with lymphatic
mapping, which might be a useful tool for more accurate regional staging in the
setting of recurrent breast cancer. Currently, ipsilateral axillary lymph node
dissection is thought to be common clinical practice in recurrent breast
cancer. If it appears to be technically feasible and valid to do lymphatic
mapping and a sentinel node biopsy instead, patients could be spared a
significant amount of additional morbidity in case of a negative sentinel node.
In this study, patients undergo lymphatic mapping (but no SNB) to identify
changes in lymphatic drainage after prior surgery and/or radiotherapy. Outcome
will be used for study purposes only and will not affect the patients possible
current treatment. Radiation exposure due to lymphatic mapping consists of a
dose of 0.46mSv. This is well under the constraint of 5mSv/year which is
documented in the code of practice involving human research.