IORT with Electrons as Boost Strategy during Breast Conserving Therapy in Limited Stage Breast Cancer: Results of an ISIORT Pooled Analysis (original) (raw)

Full-Dose Intraoperative Radiotherapy with Electrons in Breast Cancer

Strahlentherapie und Onkologie, 2006

Purpose: To investigate the feasibility of applying exclusive intraoperative radiation therapy (IORT) after conservative surgery in limited-stage breast carcinoma and to evaluate late effects and cosmetic results after this new conservative treatment. Patients and Methods: From October 2000 to November 2002, 47 consecutive patients with unifocal breast carcinoma up to a diameter of 2 cm received conservative surgery followed by IORT with electrons as the sole adjuvant local therapy. Three different dose levels were used: 20 Gy (seven patients), 22 Gy (20 patients), and 24 Gy (20 patients). Patients were evaluated using RTOG/ EORTC scale to assess the incidence of late complications. During follow-up, a radiologic assessment with mammography and sonography was periodically performed and any breast-imaging alterations were reported. Results: After a follow-up ranging from 36 to 63 months (median, 48 months), 15 patients developed breast fibrosis (grade 2 in 14 patients, grade 3 in one patient), two patients presented with grade 3 skin changes, one patient developed a clinically relevant fat necrosis, and one patient showed breast edema and pain. Two patients developed contralateral breast cancer and one distant metastases; no local relapses occurred. Asymptomatic findings of fat necrosis were observed at mammography in twelve patients (25.5%), while an hypoechoic area was revealed by sonography in ten patients (21.5%). In four patients (8%), mammographic and sonographic findings suggested malignant lesions and required a rebiopsy to confirm the benign nature of the lesion. Conclusion: IORT in breast carcinoma is still an experimental treatment option for select patients with breast cancer and its application should be restricted to prospective trials. Although preliminary data on local control are encouraging, a longer follow-up is needed to confirm the efficacy of IORT in breast cancer and to exclude that severe late complications compromise the cosmetic results or modify the radiologic breast appearance during follow-up increasing the need for additional investigations.

IOERT versus external beam electrons for boost radiotherapy in stage I/II breast cancer: 10-year results of a phase III randomized study

Breast Cancer Research

Background Intraoperative radiotherapy with electrons (IOERT) boost could be not inferior to external beam radiotherapy (EBRT) boost in terms of local control and tissue tolerance. The aim of the study is to present the long-term follow-up results on local control, esthetic evaluation, and toxicity of a prospective study on early-stage breast cancer patients treated with breast-conserving surgery with an IOERT boost of 10 Gy (experimental group) versus 5 × 2 Gy EBRT boost (standard arm). Both arms received whole-breast irradiation (WBI) with 50 Gy (2 Gy single dose). Methods A single-institution phase III randomized study to compare IOERT versus EBRT boost in early-stage breast cancer was conducted as a non-inferiority trial. Primary endpoints were the evaluation of in-breast true recurrences (IBTR) and out-field local recurrences (LR) as well as toxicity and cosmetic results. Secondary endpoints were overall survival (OS), disease-free survival (DFS), and patient’s grade of satisfa...

A preliminary report of intraoperative radiotherapy (IORT) in limited-stage breast cancers that are conservatively treated

European Journal of Cancer, 2001

Local recurrences after breast conserving surgery occur mostly in the quadrant harbouring the primary carcinoma. The main objective of postoperative radiotherapy should be the sterilisation of residual cancer cells in the operative area, while irradiation of the whole breast may be avoided. We have developed a new technique of intra-operative radiotherapy (IORT) of a breast quadrant after the removal of the primary carcinoma. A mobile linear accelerator (linac) with a robotic arm is utilised delivering electron beams able to produce energies from 3 to 9 MeV. Through a perspex applicator, the radiation is delivered directly to the mammary gland and to spare the skin from the radiation, the skin margins are stretched out of the radiation field. To protect the thoracic wall, an aluminium-lead disc is placed between the gland and the pectoralis muscle. Different dose levels were tested from 10 to 21 Gy without important side-effects. We estimated that a single fraction of 21 Gy is equivalent to 60 Gy delivered in 30 fractions at 2 Gy/ fraction. Seventeen patients received a dose of IORT of 10 to 15 Gy as an anticipated boost to external radiotherapy, while 86 patients received a dose of 17-19-21 Gy intra-operatively as their whole treatment. The follow-up time of the 101 patients varied from 1 to 17 months (mean follow-up time was 8 months). The IORT treatment was very well accepted by all of our patients, either due to the rapidity of the radiation course in cases where IORT was given as the whole treatment or to the shortening of the subsequent external radiotherapy in cases where IORT was given as an anticipated boost. We believe that single dose IORT after breast resection for small mammary carcinomas may be an excellent alternative to the traditional postoperative radiotherapy. However, a longer follow-up is needed for a better evaluation of the possible late side-effects. #

Intraoperative radiotherapy (IORT) as boost in breast cancer

Radiation Oncology, 2017

The term IORT (intraoperative radiotherapy) is currently used for various techniques that show huge differences in dose delivery and coverage of the tissue at risk. The largest evidence for boost IORT preceding whole breast irradiation (WBI) originates from intraoperative electron treatments (IOERT) with single doses around 10 Gy. At median follow-up periods at 6 years, outstandingly low local recurrence rates of less than 1% are observed. Higher local relapse rates were described for G3 tumors and triple negative breast cancers as well as for IORT following primary systemic treatment for locally advanced tumors. Even there, long term (>5y) local tumor control rates mostly beyond 95% were maintained. Compared to other boost methods, an intraoperative treatment has evident advantages in terms of precision (by avoiding a "spatial and/or temporal miss"), cosmetic outcome and patient comfort. Direct visualisation of a tumor bed during surgery guarantees for an accurate dose delivery, which has additionally gained importance in times of primary reconstruction techniques after lumpectomy, since IORT is performed before breast tissue including parts of the tumor bed is mobilized for plastic purposes. As a consequence of direct tissue exposure without distension by hematoma/seroma, IORT allows for small treatment volumes and complete skin sparing, both having a positive effect on late tissue tolerance and, hence, cosmetic appearance. Boost IORT marginally prolongs the surgical procedure, while significantly shortening postoperative radiotherapy. Its combination with external beam radiotherapy to the whole breast (WBI) is currently tested in two multicentric prospective trials: as kV-IORT in the multicentric TARGIT-B (oost) study, and as IOERT in the HIOB trial (3 weeks hypofractionated WBI preceded by IORT electron boost).

IORT with Electrons in Limited-stage Breast Cancer -A Novel Boost Strategy During Breast Conserving Therapy

Local recurrences after breast conserving therapy (BCT) mostly occur in the vicinity of the primary tumor site. This risk is reduced by an additional boost to the tumor bed, demanding for high quality boost techniques. From 10/98 until 12/00, 170 patients with early stage breast cancer were operated in a dedicated IORT facility. After tumorectomy, the tissue surrounding the excision hole was treated by IORT with electron energies ranging from 4-18 MeV. Intraoperative sonography of the tumor bed preceded depth dose prescription, a single fractional dose of 9 Gy was applied to the 90% reference isodose. Whole-breast irradiation with 51 Gy to 56 Gy was performed after wound healing. There were no complications associated with the use of IORT. Five patients underwent secondary mastectomies due to massive positive margins or multicentrictiy. IORT allows for small treatment volumes and complete skin sparing. Direct visualization of the tumor bed guarantees an accurate dose delivery. With ...

Concepts and techniques of intraoperative radiotherapy (IORT) for breast cancer

Breast Cancer, 2008

The standard treatment for early breast cancer comprises wide local excision, sentinel lymph node biopsy or axillary lymph node dissection, adjuvant medical treatment and radiotherapy to the whole breast. Many studies suggest that local control plays a crucial role in overall survival. The local recurrence rate is estimated to be 1% per year and varies between 4 and 7% after 5 years and up to 10-20% in the long-term follow up. On the basis of low local recurrence rates the concept of whole breast irradiation comes up for discussion, and partial breast irradiation (PBI) is increasingly under consideration. Intraoperative radiotherapy (IORT) is referred to as the delivery of a single high dose of irradiation directly to the tumor bed (confined target) during surgery. PBI (limited field radiation therapy, accelerated partial breast irradiation APBI) is the irradiation exclusively confined to a breast volume, the tumor surrounding tissue (tumor bed) either during surgery or after surgery without whole breast irradiation. Various methods and techniques for IORT or PBI are under investigation. The advantage of a very short radiation time or the integration of the complete radiation treatment into the surgical procedure convinces at a first glance. The promising short-term results of those studies must not fail to mention that local recurrence rates could probably increase and furthermore give rise to distant metastases and a reduction in overall survival. The combination of IORT in boost modality and whole breast irradiation has the ability to reduce local recurrence rates. The EBCTCG overview approves that differences in local treatment that substantially affect local recurrence rates would avoid about one breast cancer death over the next 15 years for every four local recurrences avoided, and should reduce 15-year overall mortality.

The POLO (Partially Omitted Lobe) approach to safely treat in-breast recurrence after intraoperative radiotherapy with electrons

The British Journal of Radiology, 2021

Objectives: The aim of this study is to evaluate feasibility of salvage 4-week hypofractionated whole breast radiotherapy (WBRT) in patients with in-breast recurrence after receiving intraoperative radiotherapy with electrons (IOERT) for primary breast cancer (BC). Methods: BC patients who had repeated quadrantectomy underwent modified WBRT with intensity-modulated radiotherapy using Helical Tomotherapy to underdose the IOERT region. This approach, called POLO (Partially Omitted Lobe), excluded the IOERT volume from receiving the full prescription dose. Results: Nine patients were treated with this approach, receiving 45 Gy in 20 fractions. A simultaneous integrated boost of 2.5 Gy in 20 fractions was delivered in 6/9 patients. Dose constraints and planning objectives were reported. No severe toxicity was reported while local control and overall survival were 100%. Conclusion: The POLO approach is technically feasible and capable to achieve a significant reduction of radiation dose ...

IOERT in Breast Cancer: Results of Ten-Year Follow-Up in an Italian Experience Confirm High Local Recurrence Rate

2022

Purpose: Accelerated Partial Breast Irradiation (APBI) using Electron-Beam Intraoperative Radiation Therapy (IOERT) in carefully selected breast cancer patients is usually performed as single dose after conserving surgery. IOERT has demonstrated a low incidence of complications without compromising oncological outcomes. In our study we evaluated the rate of LR and progression free survival in a long-term follow-up. Patients and Methods: We performed IOERT with a 21 Gy single total dose referred to iso dose 90% in 322 selected patients for a total of 332 irradiated tumor lesions at the Breast Center of Pisa between January 2004 and May 2015. A close multidisciplinary follow-up was regularly conducted every 6 months. We evaluated the data at the end of 2020. Results: At a median follow-up of 10 years, 27 patients had in-field breast recurrence (8.1%) while considering a 5-year follow-up, we observed 16 LR (4.8%). According to our data, although a 5-year follow-up demonstrates an accep...