Clinical outcomes of single or oligo-fractionated stereotactic radiotherapy for head and neck tumors using micromultileaf collimator-based dynamic conformal arcs

Abstract

DCA-based SRT can confer relatively long-term LC with acceptable toxicity in selected patients with HNTs. The patients with CN involvement or tumor volume ≥25.6 cm(3) were deemed unsuitable for this treatment regimen.

Long-Term Tumor Control despite Late Pseudoprogression on 18F-FDG-PET following Extremely Hypofractionated Stereotactic Radiotherapy for Retropharyngeal Lymph Node Metastasis from Esthesioneuroblastoma

“…At the time when we were considering SBRT for RPLNm in this case, the use of the micro-multileaf collimator as an add-on device for a non-dedicated linear accelerator and the machine capacity at our institution required us to use a very limited number of fractions, only 1 or 2 per week [1]. In this case, we used 2 fractions over 8 days.…”

“…Unfortunately, these analyses, including the histological verification of the RPLNm, were unavailable. The prognosis of patients with recurrent HNM, who are treated using a SBRT-based strategy, is largely determined by the presence of any disease outside the irradiated site [1]. In this case, a couple of locoregional recurrences, including RPLNm, occurred metachronously and reiteratively after the initial treatment, for which SBRT offered a less invasive and efficacious treatment as an integral part of salvage therapy, allowing the maintenance of a good quality of life.…”

“…We used the dynamic conformal arcs technique with the m3 ® (BrainLAB AG, Feldkirchen, Germany) micro-multileaf collimator as an add-on device on the Clinac 21EX linear accelerator (Varian Medical Systems, Palo Alto, Calif., USA) with a 6-MV X-ray output to deliver SBRT. The patient's immobilization was achieved using the BrainLAB thermoplastic mask [1]. BrainSCAN v5.3 (BrainLAB AG) was used to generate the dynamic conformal arcs plan.…”

“…Stereotactic body radiotherapy (SBRT), also referred to as stereotactic ablative radiotherapy, has emerged as a valuable treatment option, either alone or in conjunction with other radiotherapeutic approaches and/or pharmacotherapy, for oral as well as head and neck malignancies (HNM) [1]. Several issues have been under active investigation, including the optimal dose-fractionation scheme according to a wide variety of clinical scenarios, and long-term outcomes with respect to safety and durability of efficacy [1].…”

“…Several issues have been under active investigation, including the optimal dose-fractionation scheme according to a wide variety of clinical scenarios, and long-term outcomes with respect to safety and durability of efficacy [1]. …”