Effect of delay between nuclear medicine scanning and sentinel node biopsy on outcome in patients with cutaneous melanoma.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is an important staging tool for the management of melanoma. A multicentre study was done to validate previous findings that the timing of lymphoscintigraphy influences the accuracy of SLNB and patient outcomes, particularly survival. METHODS: Data were reviewed on patients undergoing SLNB for melanoma at three centres in the UK and Sweden, examining the effect of timing of SLNB after nuclear medicine scanning. Kaplan-Meier survival analysis was used to assess overall (OS), disease-specific (DSS) and progression-free (PFS) survival, stratified by timing of lymphoscintigraphy. Independent risk factors for survival were identified by Cox multivariable regression analysis. RESULTS: A total of 2270 patients were identified. Median follow-up was 56 months. Univariable analysis showed a 4·2 per cent absolute and 35·5 per cent relative benefit in DSS (hazard ratio 1·36, 95 per cent c.i. 1·05 to 1·74; P = 0·018) for 863 patients whose SLNB was performed up to 12 h after lymphoscintigraphy compared with 1407 patients who had surgery after more than 12 h. There were similar OS and PFS benefits (P = 0·036 and P = 0·022 respectively). Multivariable analysis identified timing of lymphoscintigraphy as an independent predictor of OS (P = 0·017) and DSS (P = 0·030). There was an excess of nodal recurrences as first site of recurrence in the group with delayed surgery (4·5 versus 2·5 per cent; P = 0·008). CONCLUSION: Delaying SLNB beyond 12 h after lymphoscintigraphy with 99 Tc-labelled nanocolloid has a significant negative survival impact in patients with melanoma.

ANTECEDENTES: La biopsia de ganglio centinela (sentinel lymph node biopsy, SLNB) es una técnica importante para la estadificación y tratamiento del melanoma. Se realizó un estudio multicéntrico para validar hallazgos previos según los cuales el momento de la linfogammagrafía (lymphoscintigraphy, LS) influye en la precisión de la SLNB y en los resultados de los pacientes, especialmente en la supervivencia. MÉTODOS: Se revisaron los datos de los pacientes a los que se realizó una SLNB por melanoma en 3 centros en el Reino Unido y Suecia, con especial atención al efecto del período entre la inyección el material radioactivo y la SLNB. Se realizó un análisis de supervivencia mediante el método de Kaplan-Meier para la supervivencia específica de la enfermedad (disease-specific survival, DSS), supervivencia global (overall survival, OS) y supervivencia libre de progresión (progression-free survival, PFS), todas ellas estratificadas por el momento de la LS. Los factores de riesgo independientes para la supervivencia se determinaron mediante un análisis de regresión multivariable de Cox. RESULTADOS: Se incluyeron 2.270 pacientes. La mediana de seguimiento fue de 49 meses. El análisis univariado mostró un beneficio absoluto del 4,2% y relativo del 35,5% (cociente de riesgos instantáneos, hazard ratio, HR: 1,36 (i.c. del 95% 1,05-1,74, P = 0.02)) en la DDS para los pacientes a los que la SLNB se realizó < 12 horas después de la LS (n = 863) en comparación con aquellos realizados > 12 horas (n = 1407). Se detectaron beneficios similares para la OS y la PFS (P = 0,04 y P = 0,02, respectivamente). El análisis multivariable identificó el tiempo entre la LS y la SLNB como un factor independiente de OS (P = 0,017) y DSS (P = 0,03). Hubo un aumento en las recidivas ganglionares como primer sitio de recidiva en el grupo de > 12 horas (2,5% versus 4,5%; P = 0,008). CONCLUSIÓN: Estos datos validan nuestra investigación previa y tienen implicaciones significativas para las unidades de melanoma, en el sentido de que retrasar la SLNB más allá de las 12 horas después de realizar la LS con nanocoloides marcados con Tc99 tiene un impacto negativo significativo en la supervivencia de los pacientes y debe evitarse. Se presenta la hipótesis de que la causa subyacente es la migración temporal del trazador que determina una SLNB incorrecta. .

Immune system phenotyping of radiation and radiation combined injury in outbred mice.

The complexity of a radionuclear event would be immense due to varying levels of radiation exposures and injuries caused by blast-associated trauma. With this scenario in mind, we developed a mouse model to mimic as closely as possible the potential consequences of radiation injury and radiation combined injury (RCI) on survival, immune system phenotype, and immune function. Using a mouse burn injury model and a (137)CsCl source irradiator to induce injuries, we report that the immunological response to radiation combined injury differs significantly from radiation or burn injury alone. Mice that underwent radiation combined injury showed lower injury survival and cecal ligation and puncture (CLP) induced polymicrobial sepsis survival rates than mice with single injuries. As anticipated, radiation exposure caused dose-dependent losses of immune cell subsets. We found B and T cells to be more radiation sensitive, while macrophages, dendritic cells and NK cells were relatively more resistant. However, radiation and radiation combined injury did induce significant increases in the percentages of CD4(+) regulatory T cells (Tregs) and a subset of macrophages that express cell-surface GR-1 (GR-1(+) macrophages). Immune system phenotyping analysis indicated that spleen cells from radiation combined injury mice produced higher levels of proinflammatory cytokines than cells from mice with radiation or burn injury alone, especially at lower dose radiation exposure levels. Interestingly, this enhanced proinflammatory phenotype induced by radiation combined injury persisted for at least 28 days after injury. In total, our data provide baseline information on differences in immune phenotype and function between radiation injury and radiation combined injury in mice. The establishment of this animal model will aid in future testing for therapeutic strategies to mitigate the immune and pathophysiological consequences of radionuclear events.