Source: Doctor’s Guide (www.docguide.com)
Author: Arushi Sinha

Use of single-photon emission computed tomography (SPECT) may be indicated to monitor patients after skull-based surgery for head and neck tumours, according to research presented here at the American Head and Neck Society (AHNS) 7th International Conference on Head and Neck Cancer.

Balasubramanian Balaji, MBBS, Department of Surgical Oncology, Meenakshi Mission Hospital and Research Centre, Madurai, Tamil Nadu, India, presented research results on July 20 on methods to monitor potential adverse effects on carotid artery functioning for patients undergoing head and neck tumour surgery.

The study enrolled 20 patients undergoing surgery for a wide range of head and neck tumours: 7 patients with ear malignancies; 7 with tumours of the cranial nerves; 4 with parotid tumours; and 2 with salivary gland tumours.

The carotid artery is often located in close proximity to skull-based tumours, so its functionality may be compromised following tumour resection. Therefore, these patients were evaluated for the presence of possible carotid artery occlusion subsequent to surgery.

“We designed a stepwise study for carotid-artery occlusion based upon tolerance by the patients,” Dr. Balaji explained.

Patients were tested in stages for possible carotid-artery occlusion on the affected side using manual compression as the first step. If this was tolerated, a balloon catheter technique was used to look for signs of possible circulatory abnormalities. Following successful catheterisation, an additional SPECT scan using technetium-99 labelled ethylcysteinate dimer was performed to evaluate the severity and location of possible circulatory abnormalities.

“We used the technetium-99 labelled ethylcysteinate dimer SPECT scan as an adjunct to the other diagnostic techniques,” said Dr. Balaji.

The series of diagnostic procedures showed that 4 of 20 patients did not tolerate the balloon catheter, 5 patients had moderate hypoperfusion, and 11 patients were deemed to be normal. SPECT scan identified individuals with hypoperfusion who were previously found to be normal during the balloon catheterisation. In addition, 3 patients underwent carotid resection.

Based on these findings, Dr. Balaji concluded that SPECT scan may be indicated for monitoring patients after skull-based surgery. His study found that even though patients seemed normal during balloon catheterisation, they subsequently were revealed to have occlusions based on SPECT findings.

“Balloon occlusion test of carotid artery with only clinical monitoring is inadequate in evaluation of cerebral vascular reserve,” Dr. Balaji concluded.

[Presentation title: Assessment of at Risk Internal Carotid Artery in Skull Base Surgery. Abstract P203]