Prospective of ³¹P MR Spectroscopy in Hepatopancreatobiliary Cancer: A Systematic Review of the Literature

Abstract

Background: The incidence of liver and pancreatic cancer is rising. Patients benefit from current treatments, but there are limitations in the evaluation of (early) response to treatment. Tumor metabolic alterations can be measured noninvasively with phosphorus ( 31 P) magnetic resonance spectroscopy (MRS). Purpose: To conduct a quantitative analysis of the available literature on 31 P MRS performed in hepatopancreatobiliary cancer and to provide insight into its current and potential for therapy (non-) response assessment. Population: Patients with hepatopancreatobiliary cancer. Field Strength/Sequence: 31 P MRS. Assessment: The PubMed, EMBASE, and Cochrane library databases were systematically searched for studies published to 17 March 17, 2022. All 31 P MRS studies in hepatopancreatobiliary cancer reporting 31 P metabolite levels were included. Statistical Tests: Relative differences in 31 P metabolite levels/ratios between patients before therapy and healthy controls, and the relative changes in 31 P metabolite levels/ratios in patients before and after therapy were determined. Results: The search yielded 10 studies, comprising 301 subjects, of whom 132 (44%) healthy volunteers and 169 (56%) patients with liver cancer of various etiology. To date, 31 P MRS has not been applied in pancreatic cancer. In liver cancer, alterations in levels of 31 P metabolites involved in cell proliferation (phosphomonoesters [PMEs] and phosphodiesters [PDEs]) and energy metabolism (ATP and inorganic phosphate [Pi]) were observed. In particular, liver tumors were associated with elevations of PME/PDE and PME/Pi compared to healthy liver tissue, although there was a broad variety among studies (elevations of 2%-267% and 21%-233%, respectively). Changes in PME/PDE in liver tumors upon therapy were substantial, yet very heterogeneous and both decreases and increases were observed, whereas PME/Pi was consistently decreased after therapy in all studies (À13% to À76%). Data Conclusion: 31 P MRS has great potential for treatment monitoring in oncology. Future studies are needed to correlate the changes in 31 P metabolite levels in hepatopancreatobiliary tumors with treatment response.

Measurement of metabolite levels and treatment‐induced changes in hepatic metastases of gastro‐esophageal cancer using 7‐T phosphorus magnetic resonance spectroscopic imaging

“…As a result, the PME/PDE ratio showed more variable changes and was only elevated in the liver metastases of patient 1, but not in patient 2. In previous studies of 31 P MRS in liver cancer, elevated PME/ATP (34%-200%), PME/PDE (2%-267%), and PME/Pi (21%-233%) ratios were found in liver tumors compared with healthy liver tissue (reviewed in 26 ). The heterogeneous results may be related to the different etiologies of liver tumors (e.g., primary origin or liver metastasis of colorectal cancer) included in these studies, but are largely in agreement with the elevated PMEs observed in the metastases from the current study.…”

“…The application of 31 P MRS in liver tumors has recently been reviewed 26 . 31 P MRS of liver tumors has been performed at magnetic field strengths of 1.5 and 3 T and, because of the low intrinsic sensitivity of 31 P MRS, rather large voxel sizes have been used (up to 560 mL).…”

Intelligent tumor tissue classification for Hybrid Health Care Units

“…fMRI, indicating brain activity through blood flow, offers high sensitivity (80%–90%) and specificity in identifying key brain areas but is susceptible to motion artifacts and variable interpretation ( 22 ). MRS provides a window into the biochemical makeup of tissues, yielding crucial data on tumor metabolism and types ( 23 ). Each modality contributes uniquely to tumor diagnosis, balancing specific advantages and inherent challenges.…”

Multinuclear MRI in Drug Discovery

“…More recently, the method has also been used to study neurological disorders [ 57 , 58 ]. 31 P MRS has potential for use in studies in hepatopancreatobiliary cancer [ 59 ].…”