First report on extended distance between tumor lesion and adjacent organs at risk using interventionally applied balloon catheters: a simple procedure to optimize clinical target volume covering effective isodose in interstitial high-dose-rate brachytherapy of liver malignomas

Peter Hass; Ingo G Steffen; Maciej Powerski; Konrad Mohnike; Max Seidensticker; Frank Meyer; Thomas Brunner; Robert Damm; Christoph Willich; Mathias Walke; Efstratios Karagiannis; Jazan Omari; Jens Ricke

doi:10.5114/jcb.2019.84798

First report on extended distance between tumor lesion and adjacent organs at risk using interventionally applied balloon catheters: a simple procedure to optimize clinical target volume covering effective isodose in interstitial high-dose-rate brachytherapy of liver malignomas

J Contemp Brachytherapy. 2019 Apr;11(2):152-161. doi: 10.5114/jcb.2019.84798. Epub 2019 Apr 29.

Authors

Peter Hass^{1

2}, Ingo G Steffen³, Maciej Powerski^{2

4}, Konrad Mohnike^{2

5}, Max Seidensticker^{2

6}, Frank Meyer⁷, Thomas Brunner¹, Robert Damm⁴, Christoph Willich¹, Mathias Walke¹, Efstratios Karagiannis⁸, Jazan Omari⁴, Jens Ricke^{2

6}

Affiliations

¹ Department of Radiation Oncology, University Hospital, Magdeburg, Germany.
² International School of Image-Guided Interventions, Magdeburg, Germany.
³ Department of Nuclear Medicine, University Medical Center Charité, Berlin, Germany.
⁴ Department of Radiology and Nuclear Medicine, University Hospital, Magdeburg, Germany.
⁵ DTZ am Frankfurter Tor, Center for Radiology, Berlin, Germany.
⁶ Department of Clinical Radiology, Ludwig-Maximilians-University (LMU), Munich, Germany.
⁷ Department of General, Abdominal, Vascular, and Transplant Surgery, University Hospital, Magdeburg, Germany.
⁸ Department of Radiation Oncology, German Oncology Center, Limassol, Cyprus.

Abstract

Purpose: Organs at risk (OARs), which are very close to a clinical target volume (CTV), can compromise effective tumor irradiation. The present study investigated the feasibility and safety of a novel approach, in particular, the extent of the dosimetric effect of distancing CTV from adjacent OARs by means of interventionally applied balloon catheters.

Material and methods: Patients with peripheral hepatic malignancies, in whom the critical proximity of an OAR to the CTV in the assessment by contrast-enhanced magnetic resonance imaging (MRI) scans and the preplanning process were included. Additionally, patients underwent placement of an interventional balloon catheter during computed tomography (CT)-guided application of interstitial brachytherapy (iBT) catheters inserted into the tissue between hepatic capsule and adjacent OAR. The virtual position of an OAR without balloon catheter was anticipated and contoured in addition to contouring of CTV and OAR. The calculated dose values for CTV as well as 1 cc of the relevant OAR (D_1cc) with and without balloon were recorded. The D_1cc of the realized irradiation plan was statistically compared to the D_1cc of the virtually contoured OARs.

Results: In 31 cases, at least one balloon catheter was administered. The mean D_1cc of the OAR in the group with balloon(s) was 12.6 Gy compared with 16 Gy in the virtual cohort without the device, therefore significantly lower (p < 0.001). Overall, there were no acute complications. Severe (> 2 CTCAEv4.03) late complications observed in 3/31 (9.6%) patients during follow-up period after brachytherapy were most certainly not due to the balloon application. Side effects were probably associated with pre-existing serious diseases and potentially additional local late effects of the irradiation in general rather than with the balloon catheters.

Conclusions: The distancing of the adjacent OARs allows a higher D₁₀₀ value of CTV, therefore allowing for more efficient local control.

Keywords: balloon catheters; clinical target volume (CTV); dose per 1 cc (D1cc); dose volume histogram (DVH); interstitial high-dose-rate (HDR) brachytherapy (iBT); liver malignancies; organ at risk (OAR).