The calorimeter subsystem of the Fermi-LAT instrument provides information about the type, direction and energy of detected particles. The calorimeter portion of "Pass 8", the development version of the LAT event reconstruction and analysis, has been extensively revised from Pass 7, the current production version, which is largely unchanged since launch. In particular, in order to properly handle the signals from nearly coincident particles in the calorimeter, we added a clustering stage based on a Minimum Spanning Tree (MST) algorithm.
In addition to that, we developed a multivariate classification technique based on a Naive Bayes Classifier (NBC) algorithm, with the aim of making the full topological information from the calorimeter available to the following stages of the event reconstruction. Finally, we improved the accuracy of the calorimeter direction measurement, and recovered for science analysis a substantial fraction of the "CAL-only" events, for which there is no usable tracker information. Here we present a comprehensive overview of the Pass 8 calorimeter reconstruction, provide a summary of the current performance and discuss the prospects for using the LAT calorimeter as a stand-alone gamma-ray telescope.