Combined approach evaluates breast cancer treatment progress

CONTEXT: Combining proton MR spectroscopic imaging, sodium MR, and PET/CT imaging may be an effective multimodality approach for detecting early response to chemotherapy in breast cancer patients, according to Dr. Michael Jacobs, a radiologist at Johns Hopkins School of Medicine. Jacobs and colleagues tested combined methods for examining molecular and metabolite activity in breast tumors during preoperative systemic therapy (PST).

RESULTS: Jacobs' team studied five patients with operable adenocarcinoma. Prior to PST and after the first cycle of taxane-based chemotherapy (seven to eight days), doctors performed gadolinium-enhanced, fat-suppressed T1- and T2-weighted MRI. Three-D twisted projection imaging was employed to acquire sodium MR images. PET/CT was then performed following a fluorine-18 FDG injection. In responders, multimodality monitoring revealed a significant decrease in tumor size, total sodium, and standard uptake values.

IMAGE: Combined multimodality images on a 35-year-old woman reveal changes in tumor volumes from 33 cc baseline MR volume to 28 cc after one cycle of chemotherapy and 12 cc before surgery. Changes in sodium concentration decreased from 42.8 mmol/kg before chemotherapy to 41 mmol/kg afterward. FDG standard uptake values dropped from 6.7 before therapy to 3.15 afterward.

IMPLICATIONS: Combined noninvasive imaging techniques (MR/PET/CT) have proven successful for identifying early tumor response to chemotherapy.

"If we can tell within the first cycle if a patient is going to respond or not to this treatment, we can avoid a lot of unnecessary toxicity to the patient," Jacobs said.