At a meeting of the Society of Nuclear Medicine in Washington in early June, German scientists reported that imaging with positron emission tomography (PET) can show esophageal cancer patients' responses to chemotherapy."This is the first study to apply PET results from early metabolic response assessment to clinical decision making in the treatment of common solid tumors, said Ken Herrmann of the Technical University in Munich, Germany. "The outcome for metabolic responders turned out to be remarkably favorable compared to metabolic non-responders."
According to Herrmann, the results can help select patients who are benefiting from chemotherapy and "circumvent the adminstration of inefficient chemotherapy to patients with no metabolic response."
1. Possible indications of whether chemotherapy benefits esophageal cancer patients could be provided by PET imaging. The biggest difference is that with PET imaging, you give the patient potentially toxic and ineffective drugs and wait six to eight weeks and then make tumor measurements. And then give more potentially toxic and ineffective drugs and wait another six to eight weeks and repeat measurements. You still have the patient getting potentially toxic and ineffective treatment and then you still have to wait weeks until you could try Plan B. And you may promote the onset of clinically acquired multi-drug resistance.
You measure the drug effects on tumors in the patient (one treatment at a time), rather than in the laboratory where as many as twenty treatments can be done to see which one works best. The outcome for metabolic responders and non-responders in PET imaging is basically what is going on with "functional profiling" assays, showing what patients are benefiting from what drug agents, "before" they are put in the patient.
However, if your criteria is that medical tests should only be used if they have been shown to improve treatment outcomes, then don't use Pet Scans, and don't use the Estrogen Receptor Test, which is used to make important decisions such as whether people with potentially curable diseases should receive adjuvant therapy and with which drugs, rather than simply used to decide between treatments which would produce equal results, given the choice by a coin flip. If that's your criteria, don't use Her2/neu, or immunohistochemical staining, electrocardiograms, chest xrays, CT scans, bacterial culture and sensitivity.
Posted at 11:22AM on Jul 2nd 2007 by Gregory D. Pawelski