Electron intraoperative treatment in patients with early-stage breast cancer: data update

Partial–breast irradiation: towards a replacement for whole–breast irradiation?

Largely thanks to all of the investigators and patients who have participated in randomized breast-conservation trials, many women facing a diagnosis of breast cancer today can conserve their breast with the help of adjuvant radiation therapy. A standard course of radiation consists of 5-7 weeks of daily radiation treatments delivered to the whole breast. The success of this treatment has led investigators to attempt to determine whether the same control can be achieved while decreasing the volume of breast tissue irradiated, thus allowing treatment to be delivered in a shorter period of time. This approach could alleviate time and logistical problems faced by patients during their course of treatment as well as improving overall cost-effectiveness. It can also allow complete avoidance of the adjacent heart and lung tissue in the radiation treatment portal. Partial-breast irradiation (the delivery of radiation to the resection cavity, plus a safety margin) delivered in just hours or days, is currently under investigation. Although relatively new, its use is growing rapidly and many institutional and cooperative group trials are quickly enlisting patients, while physicians are gaining experience in a variety of partial-breast irradiation techniques.

Dosimetric characteristics of electron beams produced by two mobile accelerators, Novac7 and Liac, for intraoperative radiation therapy through Monte Carlo simulation

The Novac7 and Liac are linear accelerators (linacs) dedicated to intraoperative radiation therapy (IORT), which produce high energy, very high dose-per-pulse electron beams. The characteristics of the accelerators heads of the Novac7 and Liac are different compared to conventional electron accelerators. The aim of this work was to investigate the specific characteristics of the Novac7 and Liac electron beams using the Monte Carlo method. The Monte Carlo code BEAMnrc has been employed to model the head and simulate the electron beams. The Monte Carlo simulation was preliminarily validated by comparing the simulated dose distributions with those measured by means of EBT radiochromic film. Then, the energy spectra, mean energy profiles, fluence profiles, photon contamination, and angular distributions were obtained from the Monte Carlo simulation. The Spencer-Attix water-to-air mass restricted collision stopping power ratios (sw,air) were also calculated. Moreover, the modifications of the percentage depth dose in water (backscatter effect) due to the presence of an attenuator plate composed of a sandwich of a 2 mm aluminum foil and a 4 mm lead foil, commonly used for breast treatments, were evaluated. The calculated sw,air values are in agreement with those tabulated in the IAEA TRS-398 dosimetric code of practice within 0.2% and 0.4% at zref (reference depth in water) for the Novac7 and Liac, respectively. These differences are negligible for practical dosimetry. The attenuator plate is sufficient to completely absorb the electron beam for each energy of the Novac7 and Liac; moreover, the shape of the dose distribution in water strongly changes with the introduction of the attenuator plate. This variation depends on the energy of the beam, and it can give rise to an increase in the maximum dose in the range of 3%-9%.

Accelerated partial breast irradiation in early breast cancer: focus on intraoperative treatment with electrons (ELIOT)

Wide tumor resection plus postoperative whole breast irradiation is standard treatment for early breast cancer. Irradiation decreases recurrence rates, but may cause poor cosmesis, breast pain, and cardiac and lung toxicity. Accelerated partial breast irradiation is increasingly used in the hope of increasing convenience, decreasing sequelae and maintaining cure rates. Intraoperative radiotherapy with electrons is an attractive accelerated partial breast irradiation technique because collimator placement is under the direct control of the surgeon who removes the tumor, the skin is spared, shielding protects the chest wall and complete irradiation can be given in a single intraoperative session (avoiding 5-7 weeks of whole breast irradiation). Intraoperative radiotherapy with electrons seems as safe as whole breast irradiation; however, long-term results on local control and survival are not available yet.

Accelerated Partial Breast Irradiation (APBI): A review of available techniques

Breast conservation therapy (BCT) is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified.

Feasibility trial of partial breast irradiation with concurrent dose-dense doxorubicin and cyclophosphamide in early-stage breast cancer

PURPOSE

Anthracyclines and concurrent whole-breast irradiation result in prohibitive cutaneous toxicity. We hypothesized that anthracycline-based chemotherapy and concurrent partial breast irradiation (PBI) is safe and conducted a single-arm feasibility trial testing this hypothesis with dose-dense doxorubicin and cyclophosphamide (ddAC).

PATIENTS AND METHODS

Women with T1-2, N0-1 breast cancer with > or = 3 mm lumpectomy margins received PBI (40.5 Gy, 15 daily 2.7-Gy fractions) concurrently with the first two of four cycles of ddAC (60 and 600 mg/m2 of doxorubicin and cyclophosphamide, respectively, every 14 days with colony-stimulating support). Primary end points were local and systemic toxicity. Additional systemic therapy was given at the physician's discretion.

RESULTS

Twenty-seven patients enrolled between November 2004 and January 2007, but two patients did not receive protocol therapy (one found with additional local disease and one withdrew consent). Twenty-five women completed all planned PBI. Four (16%) of 25 did not complete all ddAC (febrile neutropenia [FN], n = 2; diverticulitis and neutropenia, n = 1; and social/economic reasons, n = 1). Four among the remaining 21 who completed all ddAC had a cycle delayed (FN, n = 1; acute respiratory illness, n = 1; foot blisters, n = 1; perianal dermatitis, n = 1). There was no grade 3 to 4 anemia or thrombocytopenia. Grade 3 nonhematologic toxicities (none grade 4) occurred in 28% (seven of 25) of patients (nausea/vomiting, n = 3; stomatitis, n = 2; contralateral breast abscess, n = 1; fatigue, n = 1; and cough/bronchospasms, n = 1). The observed rate of > or = grade 2 skin toxicity was 0% (0 of 25; one-sided 95% CI, 0% to 11%).

CONCLUSION

PBI with concurrent ddAC is feasible, and local/systemic toxicity is acceptable. Larger studies are warranted to assess long-term locoregional control and late toxicities.

Video-assisted axillary surgery for cancer: Non-randomized comparison with conventional techniques

Endoscopic techniques have been introduced in most of surgical disciplines including surgery for breast cancer. However, there is shortage of evidence-based guidelines and oncological outcome data. We present a controlled trial of endoscopic axillary surgery for breast cancer with mid-term oncologic results. Fifty cases of axilloscopy for sentinel node biopsy, axillary sampling or full axillary dissection were included. Sentinel node biopsy was accomplished with the blue dye technique. Full axillary dissection was performed with a three-port approach with gas insufflation without liposuction. Endoscopic axillary dissection significantly lowered duration of drainage and operative blood loss. Lymph node harvest with endoscopic approach was significantly lower than with open procedure. One case developed axillary recurrence. Endoscopic sentinel node biopsy yielded identification rate of 80%. Current data do not justify the oncological safety of resectional endoscopic procedures. Endoscopically assisted axillary cancer surgery is technically feasible. The technique is valuable to maximize utility of blue dye method for sentinel lymphadenectomy in areas with no access to radio-guided surgery.