WINSTON-SALEM, NC - The length of a patient's survival after surgery for a brain tumor is most accurately predicted by answering one question.
Did the surgery leave residual tumor?
From residual tumor comes tumor regrowth.
But the best way to evaluate whether surgery leaves behind residual tumor has no simple answer. Brain surgeons themselves often make unreliable evaluations.
Researchers at the University of Wurzburg in Germany compared the sensitivity of transcranial sonography with MRI and CT for revealing residual tumor and tumor regrowth and found that transcranial sonography was more sensitive than MRI or CT.
In an interview preceding the International Neurosonology '97 conference sponsored by the Bowman Gray School of Medicine of Wake Forest University, the lead researcher, Dr. Georg Becker, said that although both MRI and CT are more often used, transcranial sonography deserves a wider application.
On follow-up imaging in 26 patients who had undergone surgery for high-grade gliomas (tumors of the nervous system), Becker and his colleagues found that, on average, transcranial sonography revealed tumor regrowth 6 weeks before MRI and 2 weeks before CT.
Based on data from this study, Becker has proposed a combination of transcranial sonography and CT for follow-up of patients who are at risk for tumor regrowth from high-grade gliomas.
"Beyond our study, we feel that transcranial sonography has great value during surgery," Becker said. "We also see transcranial sonography being used to differentiate complications like radionecrosis from complications like tumor regrowth."
Becker cataloged other advantages of transcranial sonography over MRI and CT:
Transcranial sonography is less expensive.
It's portable. Sonographic scanners can be brought to a patient's bedside.
It's easy to customize. Sonographic transducers, which fit in a person's palm, allow freehand scanning of the patient. With freehand scanning, the sonographer can customize the imaging of a patient's head to find the best window to see inside the very bony and difficult-to-image adult cranium.
While Becker admits that MRI and CT have higher diagnostic specificity, he praised transcranial sonography for its sensitivity, which includes its ability to reveal residual tumor in tissue adjacent to the site of surgery.
For further information, call Mark Wright (email: mwright@bgsm.edu) or Bob Conn (email: rconn@bgsm.edu) at 910-716-4587.
Once the International Neurosonology '97 has begun on August 13, call the conference press room at 910-724-6923.