న్యూక్లియర్ మెడిసిన్ & రేడియేషన్ థెరపీ

Purpose: To evaluate the effects of radiation to the anterior visual pathway in locally advanced nasopharyngeal carcinoma (NPC) patients after low energy photon external beam radiation. Design: A cross-sectional, observational case series.

Methods: Fifty- one patients treated with the same radiotherapy were assessed in visual acuity (VA), color vision, visual field (VF), and contrast sensitivity. The patients with post radiation interval of ≤ 3 years were defined as group 1, of > 3 years as group 2, and healthy volunteers as control group 3. The visual functions were analyzed between the three groups.

Results: One patient in group 1 developed radiation-induced optic neuropathy (RION) with decreased VA, color vision defect, decreased contrast sensitivity, and VF defect. No RION was detected in group 2. There was no statistical significance in color vision defect (P = 0.303) or mean contrast sensitivity (P = 0.235) between the three groups. There was statistical significance in mean contrast sensitivity value (P = 0.044) between the irradiated and non-irradiated group.

Conclusions: This study reported the acceptable incidence of RION in 1.96% of locally advanced NPC patients after external beam radiotherapy. Significant decrease in contrast sensitivity was the subclinical anterior visual pathway abnormality, observed among the irradiated group. Monitoring subjective and objective visual changes is helpful for irradiated patients in detecting and assessing treatment for minimizing long term devastating results on the visual conditions.

Purpose: Positron Emission Tomography (PET) scan is a vital tool in the staging, prognosis and response evaluation of gastrointestinal malignancies. The purpose of this study is to determine the prognostic significance of PET standardized uptake values (SUV) in esophageal cancer treated with chemoradiotherapy (CRT).

Methods: An IRB approved esophageal cancer database was queried for patients who completed treatment for esophageal cancer with CRT between 2006 and 2010. Patients were included in the analysis if they had nonmetastatic esophageal cancer that completed definitive or preoperative CRT and had pre- and post-CRT PET scans. Patients treated with induction chemotherapy were excluded. The pre-and post-CRT SUV maximum values were obtained. Univariate analysis for overall survival (OS) was performed with Kaplan-Meier and log-rank analysis or hazard ratio model. Multivariate analysis (MVA) for OS was performed with a Cox proportional hazard ratio model.

Results: We identified 77 patients who met inclusion criteria with a median followup of 16 months (range 4 - 43 months). Univariate analysis demonstrated that post-CRT SUV max and percent change SUV max were prognostic for OS, while pre-CRT SUV was not prognostic. In addition, there were no deaths in patients with a post-CRT SUV max of ≤3. MVA demonstrated that only post-CRT SUV max (HR 1.401; 95% CI: 1.061-1.850) was prognostic for OS, while age, gender, surgery, histology, tumor length and stage, were not.

Conclusions: Our series demonstrates that post-CRT maximum SUV was the strongest predictor of survival in esophageal cancer while pre-CRT SUV was not. Percent change SUV max was prognostic on univariate analysis but not on multivariate analysis. Prospective studies to evaluate the role of post-CRT SUV in the management of esophageal cancer are needed.