Intraoperative Full-Dose of Partial Breast Irradiation with Electrons Delivered by Standard Linear Accelerators for Early Breast Cancer

Abstract

Purpose. To assess feasibility, efficacy, toxicity, and cosmetic results of intraoperative radiotherapy (IORT) with electrons delivered by standard linear accelerators (Linacs) during breast conserving surgeries for early infiltrating breast cancer (BC) treatment. Materials and Methods. A total of 152 patients with invasive ductal carcinoma (T ≤ 3.0 cm) at low risk for local relapses were treated. All had unicentric lesions by imaging methods and negative sentinel node. After a wide local excision, 21 Gy were delivered on the parenchyma target volume with electron beams. Local recurrences (LR), survival, toxicity, and cosmetic outcomes were analyzed. Results. The median age was 58.3 years (range 40–85); median follow-up was 50.7 months (range 12–101.5). There were 5 cases with LR, 2 cases with distant metastases, and 2 cases with deaths related to BC. The cumulative incidence rates of LR, distant metastases, and BC death were 3.2%, 1.5%, and 1.5%, respectively. Complications were rare, and the cosmetic results were excellent or good in most of the patients. Conclusions. IORT with electrons delivered by standard Linacs is feasible, efficient, and well tolerated and seems to be beneficial for selected patients with early infiltrating BC.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy with electrons (IOERT) in breast cancer

“…For example, lead and aluminium can be used in combination, with lead facing the breast parenchyma to stop electrons, while the aluminium blocks the electrons back-scattered by the lead [37]. Alternative materials can be used [38][39][40], allowing for transmission of up to 15% of the maximum prescribed dose. Although the use of a shielding disc is recommended in case of full-dose IOERT, it is not mandatory, as the treated tissues can stop most of the electrons depending on their energy and the thickness of the tissue itself.…”

Key proteins as potential effective biomarkers under Intraoperative Radiotherapy (IORT) in tumor bed of Breast Cancer patients

“…Tumor bed has been reported as the highest risk of breast tumor recurrence [10,11]. As a result, local recurrence can be significantly reduced by using an extra dose to the tumor bed [12]. EBRT can be replaced by accelerating partial breast irradiation, including an IORT session, due to approved several advantages including; lack of gap between surgery and RT, avoidance of long treatment duration, reduced radiation-induced toxicity, tumor bed delineation under direct palpation and visual assessments and sparing non-targeted tissues surrounding the tumor bed [12,13].…”

“…As a result, local recurrence can be significantly reduced by using an extra dose to the tumor bed [12]. EBRT can be replaced by accelerating partial breast irradiation, including an IORT session, due to approved several advantages including; lack of gap between surgery and RT, avoidance of long treatment duration, reduced radiation-induced toxicity, tumor bed delineation under direct palpation and visual assessments and sparing non-targeted tissues surrounding the tumor bed [12,13]. In addition to the delayed time of RT after tumor excision, EBRT has harmful effects, including cardiac attack, appearance of second tumors, or stimulation of tumor cell growth by neo angiogenesis and hypoxia condition [14].…”

Intraoperative radiotherapy (IORT) induced key molecular pathways in tumor bed of breast cancer patients: a pilot study

“…Tumor bed has been reported as the highest risk of breast tumor recurrence (10,11) . As a result, local recurrence can be significantly reduced by using an extra dose to the tumor bed (12) .…”

“…EBRT can be replaced by accelerating partial breast irradiation, including an IORT session, due to approved several advantages including; lack of gap between surgery and RT, avoidance of long treatment duration, reduced radiation-induced toxicity, tumor bed delineation under direct palpation and visual assessments and sparing non-targeted tissues surrounding the tumor bed (12,13) . In addition to the delayed time of RT after tumor excision, EBRT has harmful effects, including cardiac attack, appearance of second tumors, or stimulation of tumor cell growth by neo angiogenesis and hypoxia condition (14) .…”