RESUMEN
Chemoradiation plays a core role in the definitive and preoperative management of esophageal cancer. Remarkable advances in technology now allow for the implementation of intensity modulated radiation therapy (IMRT) to minimize normal organ damage and to maximize coverage of tumorous targets. While IMRT is commonly accepted in the treatment of prostate and head and neck cancers, there have been clinical and dosimetric studies supporting the use of IMRT in esophagus cancer. In addition, the IMRT technique was recently enhanced by the availability of volumetric intensity modulated arc therapy (VMAT). VMAT may allow for faster delivery of IMRT with the advantage of normal organ protection compared to the stop-and-shoot IMRT, with faster delivery time and reduced monitor units. This review summarizes the use of chemoradiation in esophageal cancer, discusses current dosimetric data and clinical outcomes with the use of IMRT, and reviews IMRT as part of multi-modality treatment in esophageal cancer.
RESUMEN
BACKGROUND: Information on differential renal function following abdominal chemoradiation is limited. This study evaluated the association between renal function as measured by biochemical endpoints and scintigraphy and dose volume parameters in patients with gastrointestinal malignancies. MATERIALS AND METHODS: Patients who received abdominal chemoradiation between 2002 and 2009 were identified for this study. Technetium(99m) MAG-3 scintigraphy and laboratory data were obtained prior to and after chemoradiation in 6 month intervals. Factors assessed included age, gender, hypertension, diabetes, and dose volume parameters. Renal function was assessed by biochemical endpoints and renal scintigraphy. RESULTS: Significant reductions in relative renal function of the primarily irradiated kidney and creatinine clearance were seen. Split renal function decreased from 49.75% pre-radiation to 47.74% and 41.28% at 6-12 months and >12 months post-radiation (P=0.0184). Creatinine clearance declined from 90.67ml/min pre-radiation to 82.23ml/min and 74.54ml/min at 6-12 months and >12 months post-radiation (P<0.0001). Univariate analysis of patients who had at least one post-radiation renogram showed the percent volumes of the primarily irradiated kidney receiving ≥ 25 Gy (V(25)) and 40 Gy (V(40)) were significantly associated with ≥5% decrease in relative renal function (P=0.0387 and P=0.0438 respectively). CONCLUSION: Decline in split renal function using Technetium(99m) MAG-3 scintigraphy correlates with decrease in creatinine clearance and radiation dose-volume parameters following abdominal chemoradiation. Change in split perfusion can be detected as early as 6 months post-radiation. Scintigraphy may provide early determination and quantification of subclinical renal injury prior to clinical evidence of nephropathy.