Periradicular Infiltration of the Cervical Spine: How New CT Scanner Techniques and Protocol Modifications Contribute to the Achievement of Low-Dose Interventions

Abstract

Purpose CT-guided periradicular infiltration of the cervical spine is an effective symptomatic treatment in patients with radiculopathy-associated pain syndromes. This study evaluates the robustness and safety of a low-dose protocol on a CT scanner with iterative reconstruction software.

Materials and Methods A total of 183 patients who underwent periradicular infiltration therapy of the cervical spine were included in this study. 82 interventions were performed on a new CT scanner with a new intervention protocol using an iterative reconstruction algorithm. Spot scanning was implemented for planning and a basic low-dose setup of 80 kVp and 5 mAs was established during intermittent fluoroscopy. The comparison group included 101 prior interventions on a scanner without iterative reconstruction. The dose-length product (DLP), number of acquisitions, pain reduction on a numeric analog scale, and protocol changes to achieve a safe intervention were recorded.

Results The median DLP for the whole intervention was 24.3 mGy*cm in the comparison group and 1.8 mGy*cm in the study group. The median pain reduction was –3 in the study group and –2 in the comparison group. A 5 mAs increase in the tube current-time product was required in 5 patients of the study group.

Conclusion Implementation of a new scanner and intervention protocol resulted in a 92.6 % dose reduction without a compromise in safety and pain relief. The dose needed here is more than 75 % lower than doses used for similar interventions in published studies. An increase of the tube current-time product was needed in only 6 % of interventions.

Key Points: 

• The presented ultra-low-dose protocol allows for a significant dose reduction without compromising outcome.

• The protocol includes spot scanning for planning purposes and a basic setup of 80 kVp and 5 mAs.

• The iterative reconstruction algorithm is activated during fluoroscopy.

Citation Format

• Elsholtz FH, Kamp JE, Vahldiek JL et al. Periradicular Infiltration of the Cervical Spine: How New CT Scanner Techniques and Protocol Modifications Contribute to the Achievement of Low-Dose Interventions. Fortschr Röntgenstr 2019; 191: 54 – 61

Zusammenfassung

Ziel Die CT-gestützte periradikuläre Infiltrationstherapie der Halswirbelsäule stellt eine effektive symptomatische Behandlungsmethode bei Patienten mit Radikulopathie-bedingtem Schmerzsyndrom dar. Diese Studie evaluiert die Robustheit und Sicherheit eines low-dose-Protokolls bei einem CT Scanner mit iterativer Rekonstruktionssoftware.

Material und Methoden 183 Patienten nach periradikulärer Infiltrationstherapie der Halswirbelsäule wurden in diese Studie eingeschlossen. 82 Interventionen wurden auf einem neuem CT Scanner mit neuem Protokoll und Einsatz eines iterativen Rekonstruktionsalgorithmus durchgeführt. Spot Scanning wurde zur Planung eingesetzt und während der Fluoroskopie ein Basis-Setup von 80 kVp und 5 mAs verwendet. Die Vergleichsgruppe umfasste 101 zuvor durchgeführte Interventionen mit einem CT Scanner ohne iterative Rekonstruktionssoftware. Das Dosis-Längen-Produkt, die Anzahl der Akquisitionen, die Schmerzreduktion anhand einer numerischen Analogskala und eventuelle Protokolländerungen zur sicheren Durchführung der Intervention wurden registriert.

Ergebnisse Das mediane DLP für die gesamte Intervention betrug 24,3 mGy*cm in der Vergleichsgruppe und 1,8 mGy*cm in der Studiengruppe. Die mediane Schmerzreduktion betrug –3 in der Studiengruppe und –2 in der Vergleichsgruppe. Eine Erhöhung des Röhrenstrom-Zeit-Produktes um 5 mAs war bei 5 Patienten der Studiengruppe erforderlich.

Schlussfolgerung Die Einführung eines neuen CT Scanners mit einem neuen Interventionsprotokoll führte zur einer Dosisreduktion um 92,6 % ohne Einbußen in Sicherheit und Schmerzreduktion. Die benötigte Dosis liegt mehr als 75 % unter den benötigten Dosen vergleichbarer Interventionen, die in bisherigen Studien veröffentlicht wurden. Eine Erhöhung des Röhrenstrom-Zeit-Produktes war in nur 6 % der Interventionen notwendig.

Kernaussagen: 

• Das vorgestellte Ultra-low-dose-Protokoll ermöglicht eine signifikante Dosisreduktion ohne Minderung des Therapieerfolges.

• Das Protokoll beinhaltet Spot Scanning zur Interventionsplanung und ein Basis Setup von 80 kVp und 5 mAs.

• Während der Fluoroskopie ist ein iterativer Rekonstruktionsalgorithmus aktiviert.

Key words

interventional radiology - computed tomography - spine - cervical - injection - radiation dosage

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