Continuing Medical Education societies regarding the definition of a Intracavitary balloon (Mammosite and Clinical evidence for partial- suitable candidate. Briefly, these include Contura) or strut-based brachytherapy breast irradiation early-stage, low-risk breast cancer: T1 or (SAVI) are another modality of breast The TARGIT, a phase III non- T2 invasive ductal breast carcinoma less brachytherapy. These devices come in The Department of Radiation Oncology offers free Continuing Medical Education credit to readers who read the inferiority trial, compared single-dose than 3 cm; estrogen positive; age greater different sizes, have single or multiple designated CME article and successfully complete a follow-up test online. You can complete the steps necessary targeted intraoperative radiotherapy than 60; and node negative12 (see Table lumens (strut-based or balloon-based to receive your AMA PRA Category 1 Credit(s)™ by visiting (TARGIT) versus fractionated external cme.utsouthwestern.edu/content/target-news- 1 for ASTRO consensus guidelines). catheters), and the entire device is placed beam radiotherapy (EBRT) for breast letter-accelerated-partial-breast-irradiation-apbi-options-and-new-horizons-em150 into the lumpectomy cavity. The lumens cancer.14 From 2000-2012, a total of Treatment options are then connected to an HDR unit, and 3,451 patients were randomized between Partial-breast radiation can be deliv- treatments are given twice daily for five APBI and whole-breast radiation in 33 ered via several different modalities, days to a dose of 34 Gy in 10 fractions. centers in 11 countries. Fifteen percent including interstitial brachytherapy, This treatment is invasive, and the device of women in the APBI arm were treated Accelerated partial breast irradiation (APBI): intracavitary brachytherapy (SAVI, stays within the lumpectomy cavity for the with additional EBRT due to adverse Contura, or Mammosite), intraopera- duration of the radiation treatments (five pathological features. With a median tive radiation and 3-D external beam to seven days, typically). The ASBS regis- Options and new horizons follow-up of two years and five months Figure A Figure B for the whole After completing this activity, the fractions), has become another option tumor site is only 1.5-3.5%.10-11 These cohort, the participant should be better able to: for early-stage breast cancer, constitut- observations have led to the hypothesis five-year risk of local • Determine good candidates for hypo- ing 42.5 Gy in 16 fractions of radiation that limiting radiation therapy to the 6 recurrence fractioned whole-breast irradiation and therapy. Whelan et al., in their phase III primary tumor site—a technique called was 3.3% with accelerated partial-breast irradiation randomized trial, compared standard accelerated partial-breast irradiation fractionation to hypofractionated whole- (APBI)—rather than treating the whole TARGIT and • Differentiate between the various breast irradiation and found similar local breast may result in potentially less mor- 1.3% with modalities of partial-breast irradiation control and cosmetic results at 10 years. bidity and shorter overall treatments in the WBRT, • Describe newer modalities and technol- However, hypofractionated whole-breast early-stage breast cancer. (p=0.04). ogy currently under investigation for radiation is not an option for every Partial-breast radiation therapy The ELIOT partial-breast irradiation candidate for breast conservation therapy allows for completion of radiation in a trial using as ASTRO consensus guidelines require faster time frame, thus allowing a more megavoltage favorable dosimetric parameters that convenient treatment for women. Larger electrons has Breast cancer is the second most usually rely on breast size, T1 or T2N0 doses per fraction are used while limit- a median fol- Tangential whole-breast radiation (Fig. A) versus CyberKnife stereotactic partial-breast radiation (Fig. B). common cancer diagnosed in women. disease, age >/= 50 years old, and no ing the volume of normal breast tissue low-up of 5.8 (Skin cancer is the most common.) prior chemotherapy.7 exposed to radiation. The lumpectomy years.15 The radiation therapy. Brachytherapy try trial has reported 1,449 patients treated With better screening modalities such as Over the years, it has been dis- cavity is treated with a 1-2.5 cm mar- five-year risk of ipsilateral breast recur- and conventional 3-D external beam with balloon-based brachytherapy with annual mammography and MRI, more covered that 15-30% of women fail gin, depending on the technique of rence was 4.4% with IORT and 0.4% radiation therapy treatments are usually a median follow-up of 53.3 months. The women are diagnosed with breast cancer to complete whole-breast radiation APBI used. Even though the standard with the standard WBRT (p<0.0001). given over a five-day period twice per five-year actuarial rate of ipsilateral breast at earlier stages. Depending on the loca- therapy treatments as part of their breast of care is still whole-breast radiation, The overall mortality was not different day while intraoperative radiation is tumor recurrence is only 2.59%.13 tion of the tumor and patient breast size, conservation therapy (BCT).8-9 Contrib- the frequency of partial-breast radia- between both groups, with a five-year delivered at the time of surgery in the Intraoperative radiation (IORT) is a breast conservation therapy is usually uting factors for this high incompletion tion in breast conservation therapy has survival rate around 97%. operating room in a single fraction. single high-dose fraction of radiation an option for many women instead of percentage include inaccessibility to a increased due to promising clinical data Initial phase II trials have reported Interstitial brachytherapy is the old- delivered to the lumpectomy cavity at the mastectomy. Several randomized trials nearby radiation facility, development and perceived patient convenience. low rates of local recurrences and est technique for APBI. This technique time of surgery. This can be done with have demonstrated that breast irradia- of toxicity, and/or the inconvenience of Several consensus guidelines outline acceptable rates of cosmesis (with at uses multiple interstitial catheters that either megavoltage electrons or 50KV tion substantially reduces the risk of 6.5 weeks of daily radiation treatments. the ideal candidate for partial-breast least 80% good-to-excellent cosme- are placed in the breast with either a photons prescribed to 20-21 Gy. The local recurrence and prevents the need Common early toxicities include fatigue, radiation outside of a clinical trial sis outcomes) following APBI with template or free-hand and usually with advantage of this technique is that radia- for subsequent mastectomy in patients edema, and skin erythema or blister- setting. As more institutions have 3DCRT. Currently, the largest U.S. 1-5 some image guidance (ultrasound or CT tion treatment can be completed at the with invasive breast cancer. ing, all of which can have an impact on started implementing PBI techniques randomized control trial (RTOG 0413 scan). This technique is very operator- time of surgery, tissues can be physically Breast conservation therapy typically quality of life. in their practices, different medical / NSABP 39) comparing whole-breast dependent and requires an experienced displaced out of the radiation beam as requires lumpectomy surgery with or Clinical trials evaluating the role societies have published guidelines— radiation to partial-breast radiation has physician to produce an implant of needed, and radiation can be delivered without nodal evaluation and whole- of breast irradiation following breast- among them the American Society for finished accruing, and we are awaiting excellent quality. The catheters can be theoretically before residual tumor cells breast radiation treatments. Whole-breast conserving surgery suggest that if local Radiation Oncology (ASTRO), Groupe final results. More than 4,000 women loaded with either low dose rate (LDR) have time to proliferate postoperatively. radiation treatments have historically recurrences occur, they are most likely Européen de Curietherapie-European participated in this trial nationwide. or high dose rate (HDR) sources. One disadvantage is that some women required 6-6.5 weeks of treatment (30-33 (70-80% of cases) to develop at the site Society of Therapeutic Radiation Oncol- PBI treatments were delivered via HDR is the most common because will still require whole-breast radiation fractions). Hypofractionated whole- of the primary tumor with or without ogy (GEC-ESTRO), American Society interstitial brachytherapy, intracavitary iridium-192 sources can be used on an after IORT when unexpected findings breast radiation (involving a higher dose radiation therapy. The risk of recurrence of Breast Surgeons (ASBS), and Ameri- brachytherapy, or 3-D external beam outpatient basis. are found on the final pathology report of radiation per fraction, with fewer total in the breast away from the primary can Brachytherapy Society (ABS). There radiation at the discretion of the treating because final pathology results are not are minor variations among the different 6 available at the time of surgery. SUMMER 2015 The Target 7 radiation oncologist. The clinical target cosmetic results seem promising. Physi- References: 10. Clark RM, McCulloch PB, Levine Table 1 ASTRO Consensus Guidelines for APBI volume (CTV) and planning target vol- cians have scored cosmesis