Flexible Segmented Surface Coil Resonator for In Vivo EPR Measurements in Human Subjects

Petryakov, Sergey; Schreiber, Wilson; Kmiec, Maciej M.; Swartz, Harold M.; Schaner, Philip E.; Kuppusamy, Periannan; Williams, Benjamin B.

doi:10.1007/s00723-021-01408-0

Cited by 3 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Patients were positioned on a gurney within the magnetic field, and the EPR surface-coil detector was placed over the site of the implanted OxyChip (Supp. Figure 2B) (53). In some patients, ultrasound imaging was used to locate the OxyChip prior to placement of the detector.…”

Section: Epr Measurementsmentioning

confidence: 99%

“…She had EPR measurements over 7 visits spanning a period of 124 days while undergoing dose-dense chemotherapy (doxorubicin/cyclophosphamide followed by paclitaxel). Figures 2F-H shows the site of implantation in a left axillary node, OxyChip implantation using ultrasound guidance, and EPR measurement using the flexible surface-coil detector (53). Repeated measurements of tumor pO 2 and response to hyperoxygen breathing during the treatment period showed a progressive decline of baseline pO 2 for about 3 months (36.3 ± 3.7 mmHg on day 13 to 4.4 ± 0.5 mmHg on day 86) followed by an increase for a brief period (15.7 ± 1.5 on day 112) and eventually dropping to 7.6 ± 0.4 mmHg on day 124 (Figure 2I).…”

Section: Oxychip Measurements In the Long Termmentioning

confidence: 99%

See 1 more Smart Citation

First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip

et al. 2021

Self Cite

View full text Add to dashboard Cite

ObjectiveThe overall objective of this clinical study was to validate an implantable oxygen sensor, called the ‘OxyChip’, as a clinically feasible technology that would allow individualized tumor-oxygen assessments in cancer patients prior to and during hypoxia-modification interventions such as hyperoxygen breathing.MethodsPatients with any solid tumor at ≤3-cm depth from the skin-surface scheduled to undergo surgical resection (with or without neoadjuvant therapy) were considered eligible for the study. The OxyChip was implanted in the tumor and subsequently removed during standard-of-care surgery. Partial pressure of oxygen (pO2) at the implant location was assessed using electron paramagnetic resonance (EPR) oximetry.ResultsTwenty-three cancer patients underwent OxyChip implantation in their tumors. Six patients received neoadjuvant therapy while the OxyChip was implanted. Median implant duration was 30 days (range 4–128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6–73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5–144.6 mmHg). In 83% of the measurements, there was a statistically significant (p ≤ 0.05) response to hyperoxygenation.ConclusionsMeasurement of baseline pO2 and response to hyperoxygenation using EPR oximetry with the OxyChip is clinically feasible in a variety of tumor types. Tumor oxygen at baseline differed significantly among patients. Although most tumors responded to a hyperoxygenation intervention, some were non-responders. These data demonstrated the need for individualized assessment of tumor oxygenation in the context of planned hyperoxygenation interventions to optimize clinical outcomes.

show abstract

Section: Epr Measurementsmentioning

confidence: 99%

Section: Oxychip Measurements In the Long Termmentioning

confidence: 99%