Pre-Radiation Therapy Fluorine 18 Fluorodeoxyglucose PET Helps Identify Patients with Esophageal Cancer at High Risk for Radiation Pneumonitis.

PURPOSE: To examine the association between pre-radiation therapy (RT) fluorine 18 fluorodeoxyglucose (FDG) uptake and post-RT symptomatic radiation pneumonitis (RP). MATERIALS AND METHODS: In accordance with the retrospective study protocol approved by the institutional review board, 228 esophageal cancer patients who underwent FDG PET/CT before chemotherapy and RT were examined. RP symptoms were evaluated by using the Common Terminology Criteria for Adverse Events, version 4.0, from the consensus of five clinicians. By using the cumulative distribution of standardized uptake values (SUVs) within the lungs, those values greater than 80%-95% of the total lung voxels were determined for each patient. The effect of pre-chemotherapy and RT FDG uptake, dose, and patient or treatment characteristics on RP toxicity was studied by using logistic regression. RESULTS: The study subjects were treated with three-dimensional conformal RT (n = 36), intensity-modulated RT (n = 135), or proton therapy (n = 57). Logistic regression analysis demonstrated elevated FDG uptake at pre-chemotherapy and RT was related to expression of RP symptoms. Study subjects with elevated 95% percentile of the SUV (SUV95) were more likely to develop symptomatic RP (P < .000012); each 0.1 unit increase in SUV95 was associated with a 1.36-fold increase in the odds of symptomatic RP. Receiver operating characteristic (ROC) curve analysis resulted in area under the ROC curve of 0.676 (95% confidence interval: 0.58, 0.77), sensitivity of 60%, and specificity of 71% at the 1.17 SUV95 threshold. CT imaging and dosimetric parameters were found to be poor predictors of RP symptoms. CONCLUSION: The SUV95, a biomarker of pretreatment pulmonary metabolic activity, was shown to be prognostic of symptomatic RP. Elevation in this pretreatment biomarker identifies patients at high risk for posttreatment symptomatic RP.

Vaginal oligometastatic disease of colorectal primary: Report of a novel therapeutic approach.

Vaginal oligometastatic disease of colorectal primary is a rare malignancy with few reported cases in the literature and no standardized treatment paradigm. We report on the definitive management of an unusual case of an elderly woman with the aforementioned disease. A 78-year-old African-American woman presented with vaginal spotting and was found to have a vaginal lesion. Final pathology was consistent with moderately differentiated adenocarcinoma of colorectal primary. Extensive work up, which included endoscopies, pathologic analyzes, and imaging workup, did not reveal a primary gastrointestinal malignancy. The patient underwent partial vaginectomy and final pathology once again confirmed moderately differentiated adenocarcinoma of colorectal primary (CDX 2 and CEA positive, ER/PR, and CK 7 negative) with negative margins. She went on to receive adjuvant concurrent chemoradiation with 5-FU based chemotherapy. She received 45 Gy in 25 fractions to the whole pelvis followed by an HDR brachytherapy boost to 12 Gy in two fractions. Unfortunately, 10 months after completing radiation, she was found to have adenocarcinoma arising from a hepatic flexure colon polyp on colonoscopy. She required definitive surgical resection and was staged as mpT3N0M1. She received 12 cycles of 5-FU and at 2-year follow-up was found to be disease free with no evidence of locoregional recurrence or distant metastatic disease. Continued long-term follow up is warranted.

Pre-radiotherapy FDG PET predicts radiation pneumonitis in lung cancer.

BACKGROUND: A retrospective analysis is performed to determine if pre-treatment [18 F]-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) image derived parameters can predict radiation pneumonitis (RP) clinical symptoms in lung cancer patients. METHODS AND MATERIALS: We retrospectively studied 100 non-small cell lung cancer (NSCLC) patients who underwent FDG PET/CT imaging before initiation of radiotherapy (RT). Pneumonitis symptoms were evaluated using the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) from the consensus of 5 clinicians. Using the cumulative distribution of pre-treatment standard uptake values (SUV) within the lungs, the 80th to 95th percentile SUV values (SUV(80) to SUV(95) were determined. The effect of pre-RT FDG uptake, dose, patient and treatment characteristics on pulmonary toxicity was studied using multiple logistic regression. RESULTS: The study subjects were treated with 3D conformal RT (n=23), intensity modulated RT (n=64), and proton therapy (n=13). Multiple logistic regression analysis demonstrated that elevated pre-RT lung FDG uptake on staging FDG PET was related to development of RP symptoms after RT. A patient of average age and V(30) with SUV(95)=1.5 was an estimated 6.9 times more likely to develop grade ≥ 2 radiation pneumonitis when compared to a patient with SUV(95)=0.5 of the same age and identical V(30). Receiver operating characteristic curve analysis showed the area under the curve was 0.78 (95% CI=0.69 - 0.87). The CT imaging and dosimetry parameters were found to be poor predictors of RP symptoms. CONCLUSIONS: The pretreatment pulmonary FDG uptake, as quantified by the SUV(95), predicted symptoms of RP in this study. Elevation in this pre-treatment biomarker identifies a patient group at high risk for post-treatment symptomatic RP.