Plasma osteopontin levels in patients with head and neck cancer undergoing chemoradiotherapy.

OBJECTIVES: To explore the prognostic role of plasma levels of osteopontin (OPN), a phosphoglycoprotein with adhesive properties, in patients with head and neck squamous cell carcinoma (HNSCC) undergoing concomitant chemoradiotherapy. Previous studies have proposed OPN level as a prognostic factor in several cancers. DESIGN: Prospective analysis of plasma OPN levels, before and within 12 weeks after treatment, in a cohort of patients with HNSCC undergoing platinum-based chemoradiotherapy at our center. SETTING: Academic center. PATIENTS: Sixty-nine patients diagnosed as having HNSCC. INTERVENTIONS: Plasma levels of OPN were assessed before the start and after the conclusion of chemoradiotherapy by using an enzyme-linked immunosorbency assay kit. Chemoradiotherapy was exclusive (n = 52) or adjuvant to surgery (n = 17). MAIN OUTCOME MEASURES: Levels of OPN were correlated with clinicopathological characteristics, response to treatment, and overall survival. RESULTS: Pretreatment plasma OPN levels were higher in patients with advanced T and N stages compared with patients with early stages (P = .009 and .07, respectively). Mean (SD) plasma levels of OPN measured before (102.5 [68.1] ng/mL) and after (104.0 [53.6] ng/mL) treatment did not differ (P = .18, paired t test). Pretreatment and posttreatment levels of OPN were lower in patients who achieved a complete response compared with those who failed to respond (75.0 [41.5] vs 131.2 [82.9] ng/mL [P = .005] and 86.8 [40.5] vs 141.6 [58.4] ng/mL [P = .004], respectively). Patients with high pretreatment OPN levels (>82.1 ng/mL) had shorter survival time (P < .001). Posttreatment OPN levels were marginally (P = .10) associated with survival time in univariate analysis. CONCLUSIONS: In patients with HNSCC undergoing chemoradiotherapy, a low pretreatment plasma OPN level is associated with treatment response and better survival. Modulation of OPN levels by chemoradiotherapy may also be associated with outcome. Further studies with serial measurement of OPN levels are warranted in these patients.

Radiocirurgia e radioterapia estereotáxica: princípios e aplicações / Radiosurgery and stereotactic radiotherapy: principles and utilizations

É feita revisão sobre radiocirurgia e radioterapia estereotáxica desde os primeiros trabalhos de Leksell, em 1951, o desenvolvimento do gamma knife, em 1983, até os resultados terapêuticos obtidos publicados maisn recentemente. As indicações, os requisitos necessários e as complicações dessa modalidade de tratamento são discutidos.