Prostate Cancer: Prediction of Biochemical Failure after External-Beam Radiation Therapy—Kattan Nomogram and Endorectal MR Imaging Estimation of Tumor Volume

Abstract

Purpose:To determine whether magnetic resonance (MR) imaging and MR spectroscopic imaging fi ndings can improve predictions made with the Kattan nomogram for radiation therapy. Materials and Methods:The institutional review board approved this retrospective HIPAA-compliant study. Ninety-nine men who underwent endorectal MR and MR spectroscopy before externalbeam radiation therapy for prostate cancer (January 1998 to June 2007) were included. Linear predictors were calculated with input variables from the study sample and the Kattan original coeffi cients. The linear predictor is a single weighted value that combines information of all predictor variables in a model, where the weight of each value is its association with the outcome. Two radiologists independently reviewed all MR images to determine extent of disease; a third independent reader resolved discrepancies. Biochemical failure was defi ned as a serum prostate-specifi c antigen level of 2 ng/mL (2 m g/L) or more above nadir. Cox proportional hazard models were used to determine the probabilities of treatment failure (biochemical failure) in 5 years. One model included only the Kattan nomogram data; the other also incorporated imaging fi ndings. The discrimination performance of all models was determined with receiver operating characteristics (ROC) curve analyses. These analyses were followed by an assessment of net risk reclassifi cation. Results:The areas under the ROC curve for the Kattan nomogram and the model incorporating MR imaging fi ndings were 61.1% (95% confi dence interval: 58.1%, 64.0%) and 78.0% (95% confi dence interval: 75.7%, 80.4%), respectively . Comparison of performance showed that the model with imaging fi ndings performed signifi cantly better than did the model with clinical variables alone ( P , .001).Overall, the addition of imaging fi ndings led to an improvement in risk classifi cation of about 28%, ranging from approximately a minimum of 16% to a maximum of 39%, depending on the risk change considered important.

Biochemical recurrence prediction after radiotherapy for prostate cancer with T2w magnetic resonance imaging radiomic features

“…Similar findings have been reported by Hegde et al [22] , stressing the importance of imaging in such a high-risk cohort. Literature reported values for the use of the Kattan nomogram are of AUC = 0.61 [23] and 0.58 [10] , higher than our clinical model performance. The Kattan nomogram was originally developed using a combined population of intermediate and high-risk patients and the literature values reported above are obtained when applied in similarly mixed cohorts.…”

A Predictive Nomogram for Recurrence of Carcinoma of the Major Salivary Glands<alt-title>Nomogram for Salivary Gland Carcinoma Recurrence</alt-title>

“…19 Nomograms are well established in the prediction of outcomes in patients with prostate cancer. 6,[20][21][22][23] In breast oncology, they have been used to predict nonsentinel node status after a positive sentinel lymph biopsy result for breast cancer and have assessed the risk of arm lymphedema after axillary dissection in breast cancer. 4,5,24 Within head and neck oncology, there has been the development of a nomogram for deciding adjuvant radiation treatment after surgery for oral cavity squamous cell carcinoma 25 and predicting malignancy in thyroid nodules.…”

PREDICT: model for prediction of survival in localized prostate cancer

“…Adding MRI-based T-staging may increase the predictive accuracy of a predictive model. Prediction of biochemical recurrence after EBRT indeed improved by MRI imaging in addition to the Kattan model, when compared to the Kattan model alone [ 29 ].…”