Volumetric intensity modulated arc therapy for stereotactic body radiosurgery in oligometastatic breast and gynecological cancers: Feasibility and clinical results

Abstract

Abstract. In the present study, the preliminary results of the first stereotactic body radiosurgery (SRS) experience with volumetric intensity modulated arc therapy (VMAT) in oligometastatic breast and recurrent gynecological tumors (OBRGT) are reported in terms of feasibility, toxicity and efficacy. Patients were treated in a head-first supine treatment position on a customized body frame immobilization shell. SRS-VMAT treatment plans were optimized using the ERGO++ treatment planning system. Response assessment was performed 8-12 weeks after treatment by morphologic imaging modalities, or if feasible, also by functional imaging. Thirty-six lesions in 24 consecutive patients (median age, 63 years; range, 40-81) were treated: 13.9% had primary or metastatic lung lesions, 30.5% had liver metastases, 36.1% had bone lesions, 16.7% had lymph node metastases and 2.8% had a primary vulvar melanoma. The median dose was 18 Gy (BED 2 Gy, α/β: 10 =50.4 Gy), the minimal dose was 12 Gy (BED 2 Gy, α/β: 10 =26.4 Gy) and the maximal dose was 28 Gy (BED 2 Gy, α/β: 10 =106.4 Gy). Seven patients (29.2%) experienced acute toxicity, which however was grade 2 in only 1 case. Moreover, only 3 patients (12.5%) developed late toxicity of which only 1 was grade 2. Objective response rate was 77.7% including 16 lesions achieving complete response (44.4%) and 12 lesions achieving partial response (33.3%). The median duration of follow-up was 15.5 months (range, 6-50). Recurrence/progression within the SRS-VMAT treated field was observed in 6 patients (total lesions=7) with a 2-year inside SRS-VMAT field disease control expressed on a per lesion basis of 69%. Recurrence/progression of disease outside the SRS-VMAT field was documented in 15 patients; the 2-year outside SRS-VMAT field metastasis-free survival, expressed on a per patient basis, was 35%. Death due to disease was documented in 6 patients and the 2-year overall survival was 58%. Although the maximum tolerated dose was not reached, SRS-VMAT resulted in positive early clinical results in terms of tumor response, local control rate and toxicity.

BIT-ART: Multicentric Comparison of HDR-brachytherapy, Intensity-modulated Radiotherapy and Tomotherapy for Advanced Radiotherapy in Prostate Cancer

“…Using IRT it is possible to avoid patient and internal organ motion errors in treatment delivery also with the only expansion of 2 mm from clinical target volume (CTV) to planning target volume (PTV). The high-dose PTV in HDR-IRT is significantly smaller compared to that in EBRT (38)(39)(40)(41).…”

Dose escalation in extracranial stereotactic ablative radiotherapy (DESTROY-1): A multiarm Phase I trial

“…Treatment plans were optimized using the Precise-Plan treatment planning system (TPS) v. 2.16 and the ERGO ++ TPS for VMAT technique (Elekta, Crawley, England), as previously described. 14,15,18,20,21 In particular, the first 152 lesions were treated according to a class solution based on a tetrahedral static beam configuration. 15,20 Subsequently, 224 lesions were treated with the VMAT technique.…”

“…15,20 Subsequently, 224 lesions were treated with the VMAT technique. 14,18 According to the study design, the only dose-volume constraints were for spinal cord (Dmax <30 Gy; EQD 2Gy , α/β:3, = 54 Gy) and small bowel (V30Gy <1 cc; EQD 2Gy , α/β:3 = 54 Gy).…”

Epid‐based in vivo dose verification for lung stereotactic treatments delivered with multiple breath‐hold segmented volumetric modulated arc therapy

“…The technological advancements in immobilization and imaging, together with the ability to deliver high conformal doses and to account for organ motion have led to a widespread implementation of stereotactic body radiotherapy (SBRT) in a number of clinical settings . Over the last few years, different new techniques including volumetric modulated arc therapy (VMAT) have been successfully applied to SBRT treatments, owing to high‐dose conformity, improved sparing of healthy tissues and fast delivery time . In SBRT treatments effective tumor motion control must be considered much more compelling because reduced margins are needed to avoid the irradiation of a large amount of normal tissue to high doses.…”