Rtog 0319
Building on the initial William Beaumont experience of Vicini and colleagues, a multiinstitution phase I II study, RTOG 0319, examined the feasibility of 3D conformal external beam partial breast irradiation. Selection criteria were similar to those for the previous RTOG 95-17 APBI trial of interstitial brachytherapy and included patients with unifocal, invasive non-lobular histology, size lt 3 cm, negative margins gt 2 mm, up to three positive nodes with no extracapsular spread. Patients were...
Technique and Dosimetry
The largest distinction between the NSABP B39 RTOG 0413 and the GEC-ESTRO multicenter phase III trial is the technique of delivering partial breast irradiation and the dose delivery schemes used. Intraoperative dose delivery techniques are not included in either study, reflecting the investigators desire for complete pathologic evaluation to assure eligibility prior to protocol enrollment and the need for clear target delineation and confirmation of dose delivery to the target. Interstitial...
Mastectomy Studies
The classic pathologic evaluation of mastectomy specimens performed by Holland et al. suggested that microscopic disease was present in a multicentric pattern with relatively high frequency. Breast cancer multifocality was studied in mastectomy specimens by correlated specimen radiography and histologic techniques. It was found that up to 40 of patients undergoing breast conservation therapy BCT might have residual tumor within the breast. This analysis justified the concept that whole-breast...
References Sey
1. American Society of Breast Surgeons 2005 Consensus statement for accelerated partial breast irradiation. American Society of Breast Surgeons, Columbia, MD. http www.breastsurgeons. org apbi.shtml 2. Arthur D 2003 Accelerated partial breast irradiation a change in treatment paradigm for early stage breast cancer. J Surg Oncol 84 185-191 3. Arthur DW, Vicini FA, Kuske RR, et al 2002 Accelerated partial breast irradiation an updated report from the American Brachytherapy Society. Brachytherapy...
Dose Prescription and Delivery 1
Dose prescription is 385 cGy per fraction, ten fractions, twice daily. The minimum time between fractions is 6 hours, and duration of treatment is 5-10 days. The dose in this case is prescribed to a reference point, usually the isocenter. Ipsilateral breast constraints are defined at the 50 and 100 dose levels V50 and V100 . In addition to the V50 constraint defined for brachytherapy, no more than 35 of the breast reference volume is allowed to receive the prescription dose 385 cGy per fraction...
The Novac7 System
The Milan group is also testing the same approach Intra et al. 2002 Veronesi et al. 2001 using a mobile linear accelerator Novac7 see Fig. 12.3 in a randomized trial ELIOT . Novac7 Hitesys, Italy is a mobile dedicated linear accelerator. Its radiating head can be moved by an articulated arm which can work in an existing operating room. It delivers electron beams at four different nominal energies 3, 5, 7, 9 MeV radiation. The beams are collimated by means of a hard-docking system, consisting of...
Ptveval
For dosimetric evaluation of coverage, a new ROI is defined specifically for the study the planning target volume PTV for evaluation PTV_EVAL . Based upon the International Commission on Radiation Units and Measurements ICRU target definitions ICRU 1993 , it is defined for interstitial irradiation to be identical to the clinical target volume CTV and PTV. It is formed by placing a uniform 15 mm expansion around the excision cavity, with the exceptions that chest wall and pectoralis muscles are...
MammoSite Brachytherapy
The first and perhaps most critical factor to consider in assessing risk of normal tissue effects with MammoSite brachytherapy is that, from the perspective of both dosimetry and radiobiology, it is a distinctly different implant from interstitial brachytherapy. As such, one must be cautious in transferring the lessons learned from interstitial brachy-therapy APBI as they likely have limited relevance to this applicator system. As an example of these inherent differences, Shah et al. 2004...
Beaumont Hospital APBI Fat Necrosis
Fig. 17.2 The incidence of fat necrosis as a function of time after interstitial brachytherapy APBI at the William Beaumont Hospital data plotted from Benitez et al. 2004 Fig. 17.2 The incidence of fat necrosis as a function of time after interstitial brachytherapy APBI at the William Beaumont Hospital data plotted from Benitez et al. 2004 can be for both the better and the worse. Some end-point measures significantly improved with time. For example, the cosmetic rating was scored as excellent...
Phase III Trial of Prone 3D Conformal APBI New York University
On the basis of the results of the pilot study, Formenti et al. conducted a study of 47 postmenopausal women with stage I T1N0 breast cancer, who refused to undergo 6 weeks of WBI, treated to 30 Gy in five 6-Gy fractions over 10 days Monday, Wednesday, Friday, Monday, and Wednesday Formenti et al. 2004 . Other eligibility criteria included Fig. 11.2 A PTV and isodose distributions left-right . B PTV and isodose distributions cranial-caudal . New York University Formenti et al. 2002 Fig. 11.2 A...
The William Beaumont Hospital Experience 3D Conformal APBI in Supine Position
Initial clinical experience at William Beaumont Hospital in utilizing 3D conformal radiation therapy to deliver PBI in patients with early-stage breast cancer treated with breast-conserving therapy supported the technical feasibility of such treatment delivery Baglan et al. 2003 Vicini et al. 2003a, 2003b . In this phase I II study, 23 patients were prospectively enrolled between August 2000 and December 2002. An additional 5 patients were treated according to the guidelines of the protocol for...
Challenges and Limiting Factors in the Application of 3D Conformal APBI
A primary potential disadvantage of 3D conformal APBI relates to organ motion effects and patient set-up, which can necessitate a larger target volume in order to avoid a geographic miss. Based on previously published data Frazier et al. 2004 , a 5 mm CTV to PTV expansion should account for normal breathing Baglan et al. 2003 and the use of 10 mm CTV-PTV margin also allows for random and systematic components of set-up error. The final component of geometric uncertainty is the potential for the...
Judgment Selecting the Optimal Technique for a Particular Patient
1. When to offer external beam PBI techniques or breast brachytherapy. 2. If you have decided that breast brachytherapy is preferable, do you select balloon intracavitary or interstitial breast brachytherapy techniques For issues and concerns highlighted in the summary section of this chapter, most of the author's patients will receive brachytherapy over external beam PBI. Note that these are theoretical concerns, and more data will be required before one can apply these selection criteria...
European GECESTRO Multicentric Randomized APBI Trial
Based on the success of the Hungarian and German-Austrian studies of APBI, a phase III multicentric APBI protocol has been developed by the Breast Cancer Working Group of the GEC-ESTRO Polgar et al. 2005 . As long-term results beyond 5 years are available only with interstitial implants, proving that multicatheter BT can be used with adequate reproducibility, low toxicity, and appropriate local control, it has been decided that only interstitial HDR PDR BT will be allowed for the APBI arm of...
Results of Clinical Trials with the Intrabeam System
Based on the hypothesis that index quadrant irradiation is sufficient, in July 1998 we introduced the technique of TARGIT Vaidya 2002 Vaidya et al. 2001, 2002b, 2004b radiotherapy delivered as a single dose using low-energy x-rays targeted to the peritu-moral tissues from within the breast using the Intrabeam device. In patients with small well-differentiated breast cancers, which are now the majority, this could be the sole radiotherapy treatment. In those with a high risk of local recurrence...
The Intrabeam Machine and Surgical Technique
The Intrabeam machine contains a miniature electron gun and electron accelerator contained in an x-ray tube which are powered by a 12V power supply. Soft x-rays 50 kVp are emitted from the point source. Tissue is kept at a distance from the source by spheri- Fig. 12.1 Top The Intrabeam system - with the x-ray source in the breast wound - and the electron generator and accelerator held by the articulated arm. Bottom The target breast tissue wraps around the applicator giving true conformal...
Intraoperative Radiation Therapy
Treatment with a single dose of radiation at the time of surgery is an extremely attractive alternative for patients undergoing lumpectomy for breast cancer. In fact, this one-stop-shopping approach to local control of breast cancer would be the preferred form of APBI for most clinicians and patients if intraoperative radiation therapy IORT proves to be efficacious with minimal short- and long-term complications. However, many questions remain among clinicians in the United States concerning...
Open Freehand Interstitial Catheter Insertion
Open freehand technique depends upon the skill of the brachytherapist to insert catheters or needles in an array that both covers the target volume, and provides a spacing that will insure a homogeneous dose distribution. It was the original method of breast brachytherapy, used by Geoffrey Keynes in England in the 1920s as the original breast conservation therapy Keynes 1937 , Samuel Hellman from the Joint Center for Radiotherapy in the late 1970s and early 1980s as a boost, and myself in the...
References Yxo
1. Clark RM, McCulloch PB, Levine MN, et al 1992 Randomized clinical trial to assess the effectiveness of breast irradiation following lumpectomy and axillary dissection for node-negative breast cancer. J Natl Cancer Inst 84 9 683-689 2. Clark RM, Whelan T, Levine M, et al 1996 Randomized clinical trial of breast irradiation following lumpectomy and axillary dissection for node-negative breast cancer an update. Ontario Clinical Oncology Group. J Natl Cancer Inst 88 22 1659-1664 3. Faverly D,...
Radiobiology of Intraoperative Radiotherapy
The main basis of IORT is that a single dose of IORT could have a biological effect on tissue that is equivalent to a full course of fractionated external beam radiotherapy EBRT . This is therefore being tested in randomized trials. There is already some evidence suggesting the safety and effectiveness of a single dose of radiotherapy in achieving tumor cell kill Vaidya et al. 2004b, 2005b . The theoretical basis for calculation of the biological effects of a given dose of radiation is the...
Elliptical MammoSite
The elliptical balloon measures 4x6 cm and requires multiple dwell positions for appropriate dosimetry. It was designed to improve the filling of the sometimes irregularly shaped lumpectomy cavity. The standard weighting of five dwell positions loaded 50 66 100 66 50 matches the 200 isodose to the balloon surface. Depending on the angle of balloon entry the weightings can be optimized to potentially spare superficial or deep structures such as the skin or chest wall, while still providing good...
Target Delineation
As the post-lumpectomy radiation target decreases from the whole breast to partial breast, the precision of target delineation becomes increasingly important. A universally accepted target definition has not been established and the present definitions used vary depending on physician preferences and biases, specific pathologic findings and the treatment technique used. The partial breast target has most often been defined as a 12 cm margin of normal breast tissue beyond the lumpectomy cavity,...
Patient SelectionStudy Eligibility
Proper conservative patient selection appears to be crucial to the success of APBI, yet clear boundaries of inclusion and exclusion criteria have yet to be fully tested. The goal of patient selection is to identify those patients without a significant risk of harboring microscopic disease outside the immediate vicinity of the lumpectomy cavity. To provide guidance for those practitioners offering APBI, selection criteria have been endorsed and published by the American Brachytherapy Society ABS...
History of APBI
Over the past 5 years, APBI has generated a great degree of enthusiasm among both cancer care providers and breast cancer patients. However, the first investigations of APBI as an alternative to conventional whole-breast irradiation began some time ago and were abandoned because of lack of efficacy. The first two trials investigating APBI were conducted in the United Kingdom in the early 1990s. Investigators at Guy's Hospital, London, conducted a relatively small phase I II trial in which a...