Delayed Sentinel Lymph Node Biopsy in Ductal Cancer in Situ

d-SLND detection rate

Number of subjects in whom SPIO detected at least one node divided by the number of subjects who underwent the SLND procedure. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

l-SLND detection rate

Number of subjects in whom radioisotope detected at least one node divided by the number of subjects who underwent the SLND procedure. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

Nodal concordance

Number of nodes identified by both test (SPIO) and control (isotope) out of all nodes identified. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

SLND avoidance rate

Number of subjects with pure DCIS or microinvasive/invasive cancer on specimen pathology who did not undergo SLND out of total number recruited in the trial and injected. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

Per patient concordance

Number of subjects in whom at least one node was identified by both test and control out of subjects in whom at least one node was identified by control. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

Malignancy rate

Number of subjects in whom at least one malignant lymph node was identified by any method divided by the number of subjects who underwent the SLND procedure. Comparisons and analyses will be performed cumulatively and by type of tracer (SPIO+/-BD vs isotope +/-BD) and per type of surgery (BCT or mastectomy).

Nodal Malignancy rate

Number of malignant lymph nodes identified by any method divided by the number of nodes who retrieved during SLND procedure. Comparisons and analyses will be performed cumulatively and by type of tracer (SPIO+/-BD vs isotope +/-BD) and per type of surgery (BCT or mastectomy).

Shoulder Arm Morbidity

Shoulder Arm Morbidity, assessed by the Disease of the Arm, Shoulder and Hand (DASH) questionnaire. Higher values denote greater disability. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

Cost effectiveness

Cost of in-patient and out-patient care, including admission on an out-patient or in-patient basis, operation and anesthesia per minute and SLN pathology, either standard or intraoperative frozen section. Actual expenses will also be registered with respect to costs of admission, anesthesia time, operative time, pathology costs related to axillary procedure (frozen section and routine sectioning), leave of absence, complication related costs and rehabilitation costs. Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).

Quality-Adjusted-Life-Years (QALY)

Incremental cost-effectiveness ratios will be calculated based on the societal costs per Quality-Adjusted-Life-Years (QALY) within 12 months. For calculation of the QALY, the 5-level EQ-5D version (EQ-5D-5L) will be assessed at baseline, and at postoperative visits at 28 days, 6 and 12 months. The EQ-5D-5L consists of 2 pages: the EQ-5D descriptive system (5 level Likert items with higher score signifying hiugher problems) and the EQ visual analogue scale (EQ VAS).

Health Related Quality of Life (HR-QoL)

HR-QoL assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires core version 30 (EORTC-QLQ-C30). Analyses will be performed cumulatively and +/-BD and per type of surgery (BCT or mastectomy).