A Comparison of Dose Metrics to Predict Local Tumor Control for Photofrin-mediated Photodynamic Therapy.

This preclinical study examines light fluence, photodynamic therapy (PDT) dose and "apparent reacted singlet oxygen," [1 O2 ]rx , to predict local control rate (LCR) for Photofrin-mediated PDT of radiation-induced fibrosarcoma (RIF) tumors. Mice bearing RIF tumors were treated with in-air fluences (50-250 J cm-2 ) and in-air fluence rates (50-150 mW cm-2 ) at Photofrin dosages of 5 and 15 mg kg-1 and a drug-light interval of 24 h using a 630-nm, 1-cm-diameter collimated laser. A macroscopic model was used to calculate [1 O2 ]rx and PDT dose based on in vivo explicit dosimetry of the drug concentration, light fluence and tissue optical properties. PDT dose and [1 O2 ]rx were defined as a temporal integral of drug concentration and fluence rate, and singlet oxygen concentration consumed divided by the singlet oxygen lifetime, respectively. LCR was stratified for different dose metrics for 74 mice (66 + 8 control). Complete tumor control at 14 days was observed for [1 O2 ]rx ≥ 1.1 mm or PDT dose ≥1200 µm J cm-2 but cannot be predicted with fluence alone. LCR increases with increasing [1 O2 ]rx and PDT dose but is not well correlated with fluence. Comparing dosimetric quantities, [1 O2 ]rx outperformed both PDT dose and fluence in predicting tumor response and correlating with LCR.

Sarcoma miofibroblástico posradioterapia / Radiation-induced myofibroblastic sarcoma

Paciente de 51 años, varón, fumador y alcohólico moderado, con síntomas de disfonía intermitente que debuta con una adenopatía cervical metastásica de carcinoma epidermoide, sin hallazgos del tumor primario. Es intervenido quirúrgicamente siéndole realizada una disección cervical unilateral y posteriormente es tratado con quimiorradioterapia concomitante. A los 4 años del final del tratamiento oncológico, sin recidiva local ni aparición del tumor primario, el paciente debuta con disnea de presentación subaguda. Tras la exploración física y pruebas diagnósticas, se constata una nueva tumoración en laringe que resulta ser un "sarcoma miofibroblástico de bajo grado". Según los criterios de Cahan, este tumor, de estirpe histológica poco frecuente en laringe, hace pensar que probablemente podría ser inducido por la radiación. Se discuten los criterios de causalidad entre radiación y oncogenesis y se resumen las características de los tumores radioinducidos.

We report a clinical case about a male patient, smoker and alcoholic, that debuts with a neck metastasis of an epidermoid carcinoma of unknown origin. He was submitted to a cervical dissection and treated with adjuvant combined chemo and radio therapy. Four years after finishing the oncologic treatment without tumor recurrence or appearence of the primary tumor, he begins with sub acute dyspnea. After physical examination and imaging, a new larynx tumor was found, "low grade myofibroblastic sarcoma". Under Cahan criteria, this tumoral kind, rare in larynx, was probably induced by the local radiotherapy. We discuss briefly the causality between radiation and oncogenesis and the characteristics of the radio induced tumors.

Fibroma cutáneo postirradiación / Post-radiation cutaneous fibroma

Se presenta el caso de una paciente de sexo femenino con fibrosarcoma en cara anterior del tórax, secundario a la terapia radiante por adenocarcinoma de mama. Se realiza un breve comentario de los distintos factores etiopatogénicos que inducen estas proliferaciones neoplásicas luego de la terapia radiante

Fibroma cutáneo postirradiación / Post-radiation cutaneous fibroma

Se presenta el caso de una paciente de sexo femenino con fibrosarcoma en cara anterior del tórax, secundario a la terapia radiante por adenocarcinoma de mama. Se realiza un breve comentario de los distintos factores etiopatogénicos que inducen estas proliferaciones neoplásicas luego de la terapia radiante (AU)

Hepatic localization of a fibrosarcoma in a child with a liver transplant.

Two years after an orthotopic liver transplantation, a multifocal hepatic tumor with lymphonodular metastases, identified as a fibrosarcoma, developed in a 4-year-old girl being treated with cyclosporine. On a needle biopsy sample, genetic typing of the HLA-DR group revealed that tumoral cells were from the recipient.