A phase I/II trial of 125I methylene blue for one-stage sentinel lymph node biopsy.

BACKGROUND: Sentinel lymph node biopsy can be associated with delays in operating room schedule and with significant pain during the preoperative Tc colloid injection. To avoid these problems, we developed a novel radiolabeled blue dye that can be injected intraoperatively. METHODS: We performed a phase I/II trial (IND#70627) of sterile pyrogen-free I-methylene blue to identify sentinel nodes in patients with breast cancer. Twelve women were studied. Two women each were given peritumoral or circumareolar injections of 100, 200, 300, 400, 500, or 1000 microCi of I methylene blue. RESULTS: Sentinel nodes were detected in 11 of 12 patients, with a low-dose 200 microCi patient being the single exception. The number of sentinel nodes detected per patient ranged from 0 to 3 (mean = 1.66 nodes/case). Radioactivity at the tumor injection site [counts per second (cps) averaged over 10 seconds] ranged from 3346 to 47,300 cps and was highly dose-dependent (r = 0.90, P = 0.0002). In contrast, the in vivo node counts ranged from 0 to 1228 cps, while ex vivo counts ranged from 0 to 1516 cps. The in vivo nodal counts were dose-dependent (r = 0.67, and P = 0.0231). Radiation was carefully monitored inside the operating room and in pathology. Even with the 1-mCi dose, the radioactive blue dye produced significantly lower personnel exposure than historically seen with Tc. CONCLUSIONS: This method eliminates the painful preoperative injections of Tc colloid, is performed by the surgeon in the operating room, is associated with lower radiation exposures for personnel, and avoids the delays caused by nonoperating room personnel. These observations warrant a more extensive trial of this method using the 1000-microCi dose of I methylene blue dye for sentinel lymph node biopsies.

Effect of a supplemental plate on the stiffness of a type I external fixator.

OBJECTIVE: To assess the effect of a supplemental plate on the stiffness of a six-pin unilateral external skeletal fixator. STUDY DESIGN: Mechanical testing performed on models. METHODS: Wooden (birch) dowels were used to create five models of a fracture. A commercially available external fixation system was applied to the model with a uniform unilateral six-pin fixator design. The models were mechanically tested with and without a supplemental plate attached to the 2 clamps adjacent to the fracture gap. Testing was conducted in axial loading, medial to lateral bending, and cranial to caudal bending. RESULTS: Results showed a 4.42-fold increase in stiffness in axial load, a 4.23-fold increase in stiffness in medial to lateral bending, and a 1.94-fold increase in stiffness in cranial to caudal bending with the addition of the plate. CONCLUSIONS: The addition of a supplemental plate increases the mechanical stiffness of unilateral fixators. This was especially true in axial load and medial to lateral bending. CLINICAL RELEVANCE: A supplemental plate can be used with unilateral fixators to increase stiffness of the fixator. Conversely, the plate can be removed to decrease stiffness without the removal of fixation pins.