Targetability of cervical cancer by magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU)-mediated hyperthermia (HT) for patients receiving radiation therapy.
PURPOSE
To evaluate the targetability of late-stage cervical cancer by magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU)-induced hyperthermia (HT) as an adjuvant to radiation therapy (RT).


METHODS
Seventy-nine cervical cancer patients (stage IIIB-IVA) who received RT with lesions visible on positron emission tomography-computed tomography (PET-CT) were retrospectively analyzed for targetability using a commercially-available HT-capable MRgHIFU system. Targetability was assessed for both primary targets and/or any metastatic lymph nodes using both posterior (supine) and anterior (prone) patient setups relative to the transducer. Thirty-four different angles of rotation along subjects' longitudinal axis were analyzed. Targetability was categorized as: (1) Targetable with/without minimal intervention; (2) Not targetable. To determine if any factors could be used for prospective screening of patients, potential associations between demographic/anatomical factors and targetability were analyzed.


RESULTS
72.15% primary tumors and 33.96% metastatic lymph nodes were targetable from at least one angle. 49.37% and 39.24% of primary tumors could be targeted with patient laying in supine and prone positions, respectively. 25°-30° rotation and 0° rotation had the highest rate of the posterior and anterior targetability, respectively. The ventral depth of the tumor and its distance to the coccyx were statistically correlated with the anterior and posterior targetability, respectively.


CONCLUSION
Most late-stage cervical cancer primaries were targetable by MRgHIFU HT requiring either no/minimal intervention. A rotation of 0° or 25°-30° relative to the transducer might benefit anterior and posterior targetability, respectively. Certain demographic/anatomic parameters might be useful in screening patients for treatability.
['Zhu|Lifei|L|', 'Huang|Yi|Y|', 'Lam|Dao|D|', 'Gach|H Michael|HM|', 'Zoberi|Imran|I|', 'Hallahan|Dennis E|DE|', 'Grigsby|Perry W|PW|', 'Chen|Hong|H|', 'Altman|Michael B|MB|']
D005260:Female D057086:High-Intensity Focused Ultrasound Ablation D006801:Humans D000084462:Hyperthermia D008279:Magnetic Resonance Imaging D009682:Magnetic Resonance Spectroscopy D000072078:Positron Emission Tomography Computed Tomography D011446:Prospective Studies D012189:Retrospective Studies D002583:Uterine Cervical Neoplasms
hyperthermia MRgHIFU HIFU interventional oncology thermal therapy treatment planning