Table 4

Camera/Outlining:

- High resolution low energy cast (non-foil) collimator [38,96,97].

- 128 × 128 matrix-dynamic, 256 × 256 matrix-static.

- Upwardly offset ^99mTc energy windows and separate ⁵⁷Co energy windows (122 kev) [38,43,77,96].

- Decayed ⁵⁷Co sheet source transmission outlining to limit exposure [38,96].

Injection:

- Anesthetic cream (EMLA) applied to injection sites for 30+ minutes [38,43,77].

- Hybrid radiotracer injection technique: Concurrent perilesional (2–4 ml biased away from the axilla) and areolar-cutaneous "junction" injections "LymphoBoost " (LB), (0.2–1.0 ml). Total dose: 150–400+ uCi ^99mTc sulfur colloid for same day injections and surgery, 500–1000+ uCi for next day surgery. Higher LB volumes towards 1.0 ml tend to visualize nodes quicker and brighter but delineate more echelon nodes compared to lower volumes of 0.2 ml [38,40,43,72,74].

- High specific activity preparation, 100% filtered [130].

- Lidocain added to sulfur colloid syringe for additional pain control [38,43,77].

- Mild/short massage only [131].

- Deeper sub-lesional injections for internal mammary SN visualization if deemed important [113].

- Contamination control [77].

Acquisition sequences:

- Optional post perilesional injection views.

- Dynamic lateral 100 frame 10 second images during areolar-cutaneous "junction" injection "LymphoBoost" (LB) [38,43,72,74].

- Optional immediate post dynamic early static sitting/standing views (see below).

- Delayed supine anterior and oblique 45° views with the arm out in the 90° surgical position and lateral views with the arm up towards the head with triangulated body marking of anterior and oblique 45° views.

- ⁵⁷Co sheet source transmission outlining of anterior and lateral views [38,43,96].

- Sitting/Standing views highly recommended (see below).

Additional optional maneuvers:

- Perform perilesional injection followed by 30 minute (or more) delayed views followed by LB injection (dynamic see above). Alternately delete perilesional injections altogether (only inject LB).

- Adaptive Injection Technique (AIT), re-inject different volumes of radiotracer based on imaging results [40],(data pending publication).

- Tape breast displacement for small breasts, for large/pendulous breasts use sitting views (see below) [38,43,96].

- Prone imaging [112], MOVA position [127], next day follow up views if two day.

- Avoid lead shielding the injection site [42,96,97].

Triangulated body marking:

- See figure 2, [38,40,43].

Sitting/Standing views:

- Highly recommended end of study anterior and lateral sitting/standing views with arm out in the 90° surgical position with chest pressed up against collimator (best resolution), two 1 minute frames each position to address motion if it occurs [38,40,43,67-71,96]. Works best in large breasted women.

Display:

- Adjustment of upper level, gamma curve, pre-display low level data enhancement (pre-scale/contrast/threshold) and appropriate image summation [96].

- Viewing dynamic sequences in cine mode [107].

Printing:

- Two sets of images for final supine views (marking views): with and without ⁵⁷Co transmission scan (when performed) [38,96].

- Print images large enough for surgeons to clearly see anatomy. Optionally print sitting views and/or dynamic sequences if important [38,96,107].

Reporting:

- Timely and detailed communications with surgeon before surgery to discuss findings, meaning/convention of markings and complex patterns. Number of SN based on supine and standing views, appearance sequence and perceived intensity, 3-D position in body, any extra-axillary or intramammary nodes, dilations/ectasias.