Single institution implementation of permanent 131Cs interstitial brachytherapy for previously irradiated patients with resectable recurrent head and neck carcinoma

Abstract

Purpose: Permanent interstitial brachytherapy is an appealing treatment modality for patients with locoregional recurrent, resectable head and neck carcinoma (HNC), having previously received radiation. Cesium-131 (131 Cs) is a permanent implant brachytherapy isotope, with a low average photon energy of 30 keV and a short half-life of 9.7 days. Exposure to medical staff and family members is low; patient isolation and patient room shielding are not required. This work presents a single institution's implementation process of utilizing an intraoperative, permanent 131 Cs implant for patients with completely resected recurrent HNC. Material and methods: Fifteen patients receiving 131 Cs permanent seed brachytherapy were included in this analysis. The process of pre-planning, selecting the dose prescription, seed ordering, intraoperative procedures, post-implant planning, and radiation safety protocols are described. Results: Tumor volumes were contoured on the available preoperative PET/CT scans and a pre-implant treatment plan was created using uniform source strength and uniform 1 cm seed spacing. Implants were performed intraoperatively, following tumor resection. In five of the fifteen cases, intraoperative findings necessitated a change from the planned number of seeds and recalculation of the pre-implant plan. The average prescription dose was 56.1 ±6.6 Gy (range, 40-60 Gy). The average seed strength used was 2.2 ±0.2 U (3.5 ±0.3 mCi). Patients returned to a recovery room on a standard surgical floor and remained inpatients, without radiation safety restrictions, based on standard surgical recovery protocols. A post-implant treatment plan was generated based on immediate post-operative CT imaging to verify the seed distribution and confirm delivery of the prescription dose. Patients were provided educational information regarding radiation safety recommendations. Conclusions: Cesium-131 interstitial brachytherapy is feasible and does not pose major radiation safety concerns; it should be considered as a treatment option for previously irradiated patients with recurrent, resectable HNC.

Permanent Interstitial Cesium-131 Brachytherapy in Treating High-Risk Recurrent Head and Neck Cancer: A Prospective Pilot Study

“…They reported overall and progression-free survival at 18 months were 45 and 37% respectively, similar to our report at 58 and 33% respectively at 24 months. Bar-ad et al reported 15 patients treated with Cs-131 brachytherapy for re-irradiation after surgical resection (29). The mean implant dose was 56.1 Gy, with similar treatment implementation to our approach, though no toxicity or tumor control endpoints were reported.…”

Adjuvant Cesium‐131 Brachytherapy for Patients Intolerant of External Beam Radiation Therapy

“…Dosing is designed to be at 60 Gy at 0.5 to 1 cm from the surface of the seed. 1 If two different planes of seeds are required to contour the surgical defect, then they do not collapse on each other upon closure, which prevents radiation hot spots. 4 Once the 1 x 1 cm grid of seeds are established, the mesh or individual strands are secured with sutures or clips to the surrounding fascia (Supporting Video 1).…”

“…Cesium (Cs)-131 is a permanent implantable brachytherapy with a half-life of 9.7 days and average photon energy of 30 keV. 1 Compared to external beam radiation or high dose rate brachytherapy using Iridium-192, the lower energy photons from Cs-131 decay allow for more localized deposition of dose, decreasing the dose delivered to nearby tissues and potentially reducing treatment complications. 1 The feasibility of Cs-131 implants for recurrent head and neck cancer (HNC) has been demonstrated with acceptably low levels of exposure to staff during the procedure.…”

“…1 Compared to external beam radiation or high dose rate brachytherapy using Iridium-192, the lower energy photons from Cs-131 decay allow for more localized deposition of dose, decreasing the dose delivered to nearby tissues and potentially reducing treatment complications. 1 The feasibility of Cs-131 implants for recurrent head and neck cancer (HNC) has been demonstrated with acceptably low levels of exposure to staff during the procedure. 2 While patient isolation is not required, the therapeutic dose is delivered over 40 days, resulting in minimal restriction for patient interaction.…”

Multi-Institutional Study Validates Safety of Intraoperative Cesium-131 Brachytherapy for Treatment of Recurrent Head and Neck Cancer

“…Preplanning was completed by a head and neck cancer surgeon and radiation oncologist to determine the total area of risk to be covered, the prescribed radiation dose, the strength and number of the Cs-131 seeds, and the surrounding critical structures of concern. Cs-131 seeds were ordered prior to surgical resection (16). Source placement followed conventional planar implant techniques.…”