Intraoperative radiotherapy with low energy x-rays for primary and recurrent soft-tissue sarcomas

Abstract

Background: Soft tissue sarcomas (STS) treatment remains a therapeutic challenge. Intraoperative radiotherapy (IORT) resembles a safe and efficient for STS treatment. The first data on electronic-IORT (eIORT) using low-energy photons is herein presented. Methods: Thirty-one patients with newly and recurrent STS were retrospectively assessed. EIORT was applied with low-energy photons during surgery. The dose was either prescribed to the applicator surface (spherical applicators) or 5 mm depth (flat applicators). Overall progression-free survival (O-PFS), local progression-free survival (L-PFS), overall survival (OS) and adverse events were evaluated. Results: Median follow-up was 4.88 (1.0-8.95) years. Twenty-five patients (80.6%) had recurrent STS with prior treatment. The resection status was R1 in 25.8% and R2 in 6.5%. The distribution was 51.7% for extremities, 35.5% for abdomen and pelvis, 9.7% for thorax and 3.2% for head and neck tumors. The median O-PFS was 11.0 months, with 42.6% 5-year estimated O-PFS. The only local recurrence in the primary setting occurred after 22 months. Median L-PFS in recurrent STS was 12.5 months, with 65.5% 5-year estimated L-PFS. The 5-year OS estimated rate was 94.7% (3 events after 7 years). No G3 toxicity related to eIORT was observed. Two patients exhibited G2 acute neuropathic pain. Late neuropathic pain was seen in 6 patients being 3 graded as G1 and 3 as G2. No woundrelated toxicity was found. Conclusion: Electronic IORT with low-energy photons is a safe treatment option for STS, yielding similar outcomes as historical series reporting IORT with electrons or HDR brachytherapy.

Single-Fraction Adjuvant Electronic Brachytherapy after Resection of Conjunctival Carcinoma

“…The latter feature yields a special benefit, as high influx facilities struggle permanently in matters of extended waiting lists for EBRT slots [ 24 ]. The versatility of this device could be as well regarded as a potential logistic advantage, as different entities and anatomical regions could be as well treated with it [ 25 , 26 , 27 , 28 ].…”

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

“…New advancements to IORT include the exploration of electronic-IORT (eIORT), which utilizes low-energy photons and was deemed a safe alternative in a retrospective review. 84 Importantly, a panel of experts completed a systematic literature review of IORT, leading to the development of guidelines based on patient selection and multimodal treatment plans. 85…”

“…From 2010 to 2017, one study showed improved local control of STS with intraoperative brachytherapy, 81 while a trial for DDLS 82 and a retrospective review by the University of Heidelberg 83 showed no difference, emphasizing the need for randomized trials. New advancements to IORT include the exploration of electronic‐IORT (eIORT), which utilizes low‐energy photons and was deemed a safe alternative in a retrospective review 84 . Importantly, a panel of experts completed a systematic literature review of IORT, leading to the development of guidelines based on patient selection and multimodal treatment plans 85 …”

Comparison of the Medical Uses and Cellular Effects of High and Low Linear Energy Transfer Radiation

“…The X-ray generation technology (using voltages of 10–150 KV) produced low-energy photons (3–50 KeV), and although these X-rays could produce some cancer cell killing, adverse effects included severe injury to the skin due to the deposition of energy primarily in the surface tissues [ 1 ]. As a result of the low penetration of the low-energy X-rays, effective cancer eradication could only be achieved in surface tissues or when the cancerous tissue was exposed surgically [ 63 , 64 , 65 ].…”