Three-year clinical outcome using the Contura multilumen balloon breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI): improving radiation standards for the optimal application of APBI

PurposeWe reviewed our institution’s 3-year clinical experience in treating patients with the Contura multilumen balloon (SenoRx, Inc., Aliso Viejo, CA) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI).Methods and MaterialsForty-six patients treated with breast-conserving therapy received adjuvant radiation using the Contura catheter (34 Gy in 3.4 Gy fractions). Fourteen patients had Stage 0, 24 had Stage I, and 8 had Stage II breast cancer. Median follow-up was 36 months (range, 1–44 months).ResultsOnly one local recurrence developed (2%). The rate of persistent seroma formation at latest reported follow-up was 4.3% (2 patients) and the incidence of any clinically detectable telengiectasias was 2.2%. No major toxicities (0% Grade III) have occurred. The median skin dose (% of the prescribed dose) was 99.7. The median dose to 95% of the planning target volume for evaluation was 98.8%. The percentage of patients with excellent/good cosmetic results at 24 (n = 23) and 36 (n = 22) months was 100% and 97%, respectively.ConclusionAdjuvant APBI using the Contura multilumen balloon catheter exhibited similar locoregional control, cosmesis, and toxicities to other forms of APBI with similar lengths of follow-up. In addition, improved radiation standards for the delivery of APBI were demonstrated.     

A comparison of the biological effective dose of 50-kV electronic brachytherapy with (192)Ir high-dose-rate brachytherapy for vaginal cuff irradiation

PurposeAdvantages for electronic brachytherapy (EBT) of the vaginal cuff include decreased physical dose to the bladder and rectum. Here we compare ¹⁹²Ir with EBT using biological effective dose (BED) to account for the different radiobiological effectiveness (RBE) predicted for low-energy x-rays.Methods and MaterialsFifteen data sets from five consecutive postoperative endometrial cancer patients treated with EBT were analyzed. Treatment planning was performed using PLATO software. The dose was prescribed as 21 Gy in three fractions to a depth of 0.5 cm. Physical dose, BED₃, and BED₁₀ were evaluated for the mucosa, bladder, and rectum. An RBE value of 1.5 was used for BED calculations.ResultsMucosal physical dose is 28.4% greater with EBT (36.6 vs. 28.5 Gy, p < 0.05). However, the BED₁₀ is increased by 79.1% (55.6 vs. 99.6 Gy, p < 0.05) and the BED₃ by 71.5% (118.8 vs. 203.7 Gy, p < 0.05). The physical dose (dose to 50% volume of the organ) to the bladder (9.3 vs. 6.6 Gy, p < 0.05) and rectum (7.2 vs. 4.2 Gy, p < 0.05) are reduced with EBT. BED₃ to the rectum and bladder are also reduced but to a lesser extent (13 vs. 8.3 Gy, p < 0.05; 18.9 vs. 14.7 Gy, p = 0.06, respectively).ConclusionsBED takes into account the higher RBE of low-energy photons generated with EBT and provides a more accurate estimate of the biological effect. When using EBT, physical dose may underestimate the biological effect on the vaginal mucosa and overestimate the benefit for the bladder and rectum. Dose adjustment for EBT based on BED should be considered.     

Multicatheter hybrid breast brachytherapy: a potential alternative for patients with inadequate skin distance

PurposeThe purpose of this study was to determine whether the ClearPath (CP) multicatheter hybrid device was able to achieve acceptable dosimetry in patients in whom the proximity of the breast surgical cavity to the skin precluded treatment with intracavitary MammoSite (MS) brachytherapy.Methods and materialsThe study consisted of 11 patients who had the MS catheter placed and who were subsequently not treated due to inadequate skin distance. A phantom scan of the CP multicatheter hybrid device was superimposed on the MS CT scan and a dosimetric comparison was performed.ResultsThe median MS balloon size, diameter, and minimum skin distance were 40 cc, 4.1 cm, and 5 mm, respectively. The D₉₀, V₁₀₀, V₁₅₀, and V₂₀₀ with MS vs. CP were 95.29% vs. 97.06%, 88.8% vs. 91.3%, 35.7% vs. 38.0%, and 9.4% vs. 9.6%, respectively. The median maximum skin dose was 5.5 Gy vs. 3.9 Gy (p <.0001). The median dose homogeneity index (DHI) was 0.60 vs. 0.59 (p = .09). The median maximum rib, heart, and lung dose were 2.17 Gy vs. 2.18 Gy, 2.17 Gy vs. 2.18 Gy, and 0.50 Gy vs. 0.56 Gy, respectively.ConclusionThe hybrid CP catheter reduced the skin dose significantly without compromising the planning target volume coverage, DHI, or dose to other critical organs. The use of this device has the potential to increase the applicability of accelerated partial breast brachytherapy (APBI) in patients with a surgical cavity close to skin compared with balloon brachytherapy.     

Comparison of high-dose-rate 192Ir source strength measurements using equipment with traceability to different standards

PurposeAccording to the American Association of Physicists in Medicine Task Group No. 43 (TG-43) formalism used for dose calculation in brachytherapy treatment planning systems, the absolute level of absorbed dose is determined through coupling with the measurable quantity air-kerma strength or the numerically equal reference air-kerma rate (RAKR). Traceability to established standards is important for accurate dosimetry in laying the ground for reliable comparisons of results and safety in adoption of new treatment protocols. The purpose of this work was to compare the source strength for a high-dose rate (HDR) ¹⁹²Ir source as measured using equipment traceable to different standard laboratories in Europe and the United States.Methods and MaterialsSource strength was determined for one HDR ¹⁹²Ir source using four independent systems, all with traceability to different primary or interim standards in the United States and Europe.ResultsThe measured HDR ¹⁹²Ir source strengths varied by 0.8% and differed on average from the vendor value by 0.3%. Measurements with the well chambers were 0.5% ± 0.1% higher than the vendor-provided source strength. Measurements with the Farmer chamber were 0.7% lower than the average well chamber results and 0.2% lower than the vendor-provided source strength. All of these results were less than the reported source calibration uncertainties (k = 2) of each measurement system.ConclusionsIn view of the uncertainties in ion chamber calibration factors, the maximum difference in source strength found in this study is small and confirms the consistency between calibration standards in use for HDR ¹⁹²Ir brachytherapy.     

Early breast cancer treated with conservative surgery, adjuvant chemotherapy, and delayed accelerated partial breast irradiation with high-dose-rate brachytherapy

PurposeTo evaluate the feasibility and intermediate-term results of conservative surgery, adjuvant chemotherapy, and delayed accelerated partial breast irradiation (APBI) with high-dose-rate brachytherapy.Methods and MaterialsBetween 2000 and 2007, a total of 26 patients with a median age of 54 years were treated with conservative surgery followed by adjuvant chemotherapy and exclusive high-dose-rate brachytherapy. Inclusion criteria followed the Radiation Therapy Oncology Group 95-17 trial guidelines. The tumor bed was marked at the time of surgery (n = 2) or before brachytherapy (n = 24). The brachytherapy procedure was performed at a median of 22 weeks after surgery. A median of 14 brachytherapy catheters were placed in three to four parallel planes. A dose of 34.0 Gy in 10 b.i.d. fractions given over 5 consecutive days was prescribed to the clinical target volume (CTV₉₀).ResultsAfter a median followup of 53 months (range, 6.8–81), Radiation Therapy Oncology Group Grade 1–2 events and Grade 3 events were observed in 10 (38.4%) patients and 3 (11.5%) patients, respectively. No Grade 4–5 events were observed. Patients rated their cosmetic result as excellent (37.5%), good (50.0%), fair (8%), or poor (4%) based on the Wazer's Criteria. The 6-year actuarial local, elsewhere in the breast, and distant control rates were 100%, 96.2%, and 96.2%, respectively. Six-year disease-free survival and overall survival were 92.3% and 96.2%, respectively.ConclusionsPatients undergoing surgery and adjuvant chemotherapy can still be candidates for APBI. Optimal visualization of the internal lumpectomy scar before implantation is mandatory. Cosmetic results may be slightly worse due to the interaction between chemotherapy and APBI, and technical refinements may be needed in this group of patients.     

The use of the MammoSite balloon applicator in re-irradiation of the breast

PurposeTo examine the feasibility of using the MammoSite brachytherapy applicator in the retreatment of the previously irradiated breast.Methods and materialsBetween March 2004 and March 2007, three patients previously treated with external beam radiotherapy were retreated using the MammoSite brachytherapy device. Two patients were treated for an ipsilateral breast tumor recurrence after breast conservation surgery and postoperative irradiation, whereas the third patient developed an in-field breast cancer likely associated with Hodgkin's disease mantle irradiation 27 years before. The recurrent histology of two was ductal carcinoma in situ ([DCIS] one originally presenting as infiltrating ductal carcinoma [IDC] and the other as DCIS), whereas the Hodgkin's disease patient presented with IDC. All patients received a twice-daily tumor dose of 3400 cGy at 340 cGy/fraction. The mean maximum skin dose was 53.4% (range, 49.5–60.3%) of the prescribed dose.ResultsWith a mean followup of 32 months, no patient developed a local recurrence. Cosmesis in all three cases as graded by the National Surgical Adjuvant Breast and Bowel Project, cosmesis criteria was excellent (Grade I) in all cases. Dosimetric calculations demonstrated that the device allows for appropriate local irradiation while sparing the previously irradiated skin of the involved breast as defined by the protocol standard.ConclusionsUse of the MammoSite device in the treatment of the previously irradiated breast is feasible and may provide adequate local control as well as acceptable cosmesis in carefully selected patients.     

Initial clinical experience with the Strut-Adjusted Volume Implant brachytherapy applicator for accelerated partial breast irradiation

PurposeAccelerated partial breast irradiation is becoming increasingly popular. The Cianna single-entry high-dose-rate applicator, Strut-Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA), contains peripheral struts allowing greater planning flexibility for small-breasted women, technically easier insertion, and normal tissue exposure minimization. This study evaluates early clinical experience.Methods and MaterialsThirty patients treated with the SAVI with a median followup of 12 months were evaluated. The median age was 59.5. Tumor size averaged 0.9 cm. Fifteen cancers were ductal carcinoma in situ (50%), 1 was invasive lobular (3.3%), 4 were tubular (6.7%), and the rest infiltrating ductal (40%). Most of them were estrogen receptor (ER) positive (90%). Nine women (30%) were premenopausal.ResultsDosimetry was outstanding with median V90, V150, and V200 of 96.2%, 24.8, and 12.8 cc. There were no symptomatic seromas, and one report of asymptomatic fat necrosis seen on mammogram at 1 year. In patients who had skin spacing of less than 1 cm, the median skin dose was 245 cGy/fraction. The median rib and lung dose per fraction for those patients with either structure less than 1 cm was 340 and 255 cGy (75% of prescribed dose), respectively. There have been no local recurrences to date.ConclusionsEarly clinical experience with the SAVI demonstrates the ease of placement of a single-entry brachytherapy device combined with the increased dose modulation of interstitial brachytherapy. Dose to normal structures has remained exceedingly low. Almost half of evaluated patients were not candidates for other single-entry brachytherapy devices because of skin spacing or breast size, demonstrating an expansion of candidates for single-entry partial breast brachytherapy.     

Late chest wall toxicity after MammoSite breast brachytherapy

PurposeAccelerated partial breast irradiation (APBI) with the MammoSite^® breast brachytherapy (MBB) system is being investigated as an alternative to whole breast radiation in breast conservation therapy (BCT) at multiple centers worldwide. The newness of MBB means a complete understanding of long-term toxicity, particularly involving the chest wall, has yet to be completely articulated. We report the first pathologic rib fractures associated with MBB and dosimetric analysis of the original treatment plans.Methods and MaterialsAs part of ongoing quality assurance, we reviewed the records of 129 sequential patients who underwent MBB for breast cancer and identified those who subsequently had clinically significant and radiographically documented rib fracture(s) involving the ipsilateral chest wall. Equivalent tolerance doses yielding a 5% and 50% risk of rib toxicity within 5 years from treatment with 10 fractions (as with MBB) were previously calculated using the linear quadratic equation based on 2 Gy per fraction treatments delivered to one-third of the rib volume (TD5/5 = 37 Gy; TD50/5 = 44 Gy). The original radiation therapy plans were evaluated vis-à-vis the plane films or PET/CT images documenting the osseous abnormalities and presenting complaints to find the specific fractured ribs. The specific effected ribs were contoured on the planning CT in “bone windows” using the Nucletron MicroSelectron-classic V2 (Nucletron B.V., Veenendaal, The Netherlands) for this analysis and the original patient treatments. With these datasets, we determined the dose–volume characteristics of the effected ribs including maximal dose encompassing the entire rib on one CT slice, V_20Gy, V_30Gy, V_37Gy, V_44Gy , D₅₀, D₂₅, and D₅ (the mean dose to 50%, 25%, and 5% of the rib).ResultsBetween May 2002 and August 2007, three of 105 patients with a minimum of 6-months follow-up who underwent adjuvant APBI by MBB were found to have a total of five treatment-related rib fractures. The average dose–volume characteristics from the original plans were as follows: D₅₀ = 22.1 Gy, D₂₅ = 32.2 Gy, D₅ = 41.6 Gy, max dose to 1 cc = 34.8, D_max (to 0.1 cc) = 45.6 Gy, V₂₀ Gy = 57.4%, V₃₀ Gy = 30.8%, V₃₇ Gy = 15.9%, V₄₄ Gy = 6.6%, and max dose through rib = 35.8 Gy. Two patients sustained two rib fractures and 1 patient had a single rib fracture. Four of five fractures occurred in postmenopausal patients and two of five fractures occurred in a patient with a history of osteoporosis and exposure to adjuvant chemotherapy.ConclusionsFractures occurred in ribs with V₃₇ Gy and V₄₄ Gy each well below 33%. As long-term toxicity data accrue from APBI series, the traditional models for estimating the biologic equivalent dose may benefit from refinements that specifically address the unique radiobiologic and physical properties intrinsic to high-dose-rate brachytherapy for breast conservation therapy.     

Predicting biochemical tumor control after brachytherapy for clinically localized prostate cancer: The Memorial Sloan-Kettering Cancer Center experience

PurposeTo identify predictors of biochemical tumor control and present an updated prognostic nomogram for patients with clinically localized prostate cancer treated with brachytherapy.Methods and MaterialsOne thousand four hundred sixty-six patients with clinically localized prostate cancer were treated with brachytherapy alone or along with supplemental conformal radiotherapy. Nine hundred one patients (61%) were treated with Iodine-125 (¹²⁵I) monotherapy to a prescribed dose of 144 Gy, and 41 (4.5%) were treated with Palladium-103 (¹⁰³Pd) monotherapy to a prescribed dose of 125 Gy. In patients with higher risk features (n = 715), a combined modality approach was used, which comprised ¹²⁵I or ¹⁰³Pd seed implantation or Iridium-192 high–dose rate brachytherapy followed 1–2 months later by supplemental intensity-modulated image-guided radiotherapy to the prostate.ResultsThe 5-year prostate-specific antigen relapse-free survival (PSA-RFS) outcomes for favorable-, intermediate-, and high-risk patients were 98%, 95%, and 80%, respectively (p < 0.001). Multivariate Cox regression analysis identified Gleason score (p < 0.001) and pretreatment PSA (p = 0.04) as predictors for PSA tumor control. In this cohort of patients, the use of neoadjuvant and concurrent androgen deprivation therapy did not influence biochemical tumor control outcomes. In the subset of patients treated with ¹²⁵I monotherapy, D₉₀ > 140 Gy compared with lower doses was associated with improved PSA-RFS. A nomogram predicting PSA-RFS was developed based on these predictors and had a concordance index of 0.70.ConclusionsResults with brachytherapy for all treatment groups were excellent. D₉₀ higher than 140 Gy was associated with improved biochemical tumor control compared with lower doses. Androgen deprivation therapy use did not impact on tumor control outcomes in these patients.     

Four-year results using balloon-based brachytherapy to deliver accelerated partial breast irradiation with a 2-day dose fractionation schedule

PurposeWe present 4-year results from a Phase I/II trial using balloon-based brachytherapy to deliver accelerated partial breast irradiation in 2 days.Materials/MethodsForty-five patients received breast-conserving surgery followed by adjuvant radiation therapy using a balloon-based brachytherapy applicator delivering 2800 cGy in four fractions over 2 days. Outcomes analyzed include toxicities scored using the NCI Common Toxicity Criteria v3.0 scale, ipsilateral breast tumor recurrence, regional nodal failure, distant metastasis, disease-free survival, cause-specific survival, and overall survival.ResultsMedian age was 66 years (range, 48–83 years) and median tumor size was 0.6 cm (range, 0.2–2.3 cm). Five percent of patients were node positive (n = 2), whereas 73% was estrogen receptor positive (n = 33). Median followup was 3.7 years (2.4–7.0 years) with greater than 2 years of followup for all patients. Only Grades 1 and 2 chronic toxicities were noted with fat necrosis (18%) and asymptomatic seromas (42%) being the most common toxicities. Seven percent of patients developed ipsilateral rib fractures (n = 3), although this was not statistically associated with maximum rib dose (p = 0.31). Ninety-eight percent of patients had a good or excellent radiation-related cosmetic outcome at the time of last followup. There were no ipsilateral breast tumor recurrences or regional nodal failures; however, 2 patients developed distant metastases. Four-year actuarial disease-free survival, cause-specific survival, and overall survival were 96%, 100%, and 93%, respectively.ConclusionsTreatment of early-stage breast cancer patients with breast-conserving therapy using a 2-day radiation dose schedule resulted in acceptable chronic toxicity and similar clinical outcomes as standard 5-day fractionation.     

Comparison of 3D dose distributions for HDR 192Ir brachytherapy sources with normoxic polymer gel dosimetry and treatment planning system

Radiation fluence changes caused by the dosimeter itself and poor spatial resolution may lead to lack of 3-dimensional (3D) information depending on the features of the dosimeter and quality assurance of dose distributions for high–dose rate (HDR) iridium-192 (¹⁹²Ir) brachytherapy sources is challenging and experimental dosimetry methods used for brachytherapy sources are limited. In this study, we investigated 3D dose distributions of ¹⁹²Ir brachytherapy sources for irradiation with single and multiple dwell positions using a normoxic gel dosimeter and compared them with treatment planning system (TPS) calculations. For dose calibration purposes, 100-mL gel-containing vials were irradiated at predefined doses and then scanned in an magnetic resonance (MR) imaging unit. Gel phantoms prepared in 2 spherical glasses were irradiated with ¹⁹²Ir for the calculated dwell positions, and MR scans of the phantoms were obtained. The images were analyzed with MATLAB software. Dose distributions and profiles derived with 1-mm resolution were compared with TPS calculations. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. The x-, y-, and z-axes were defined as the sagittal, coronal, and axial planes, respectively, the sagittal and axial planes were defined parallel to the long axis of the source while the coronal plane was defined horizontally to the long axis of the source. The differences between measured and calculated profile widths of 3-cm source length and point source for 70%, 50%, and 30% isodose lines were evaluated at 3 dose levels using 18 profiles of comparison. The calculations for 3-cm source length revealed a difference of > 3 mm in 1 coordinate at 50% profile width on the sagittal plane and 3 coordinates at 70% profile width and 2 coordinates at 50% and 30% profile widths on the axial plane. Calculations on the coronal plane for 3-cm source length showed > 3-mm difference in 1 coordinate at 50% and 70% and 2 coordinates at 30% profile widths. The point source measurements and calculations for 50% profile widths revealed a difference > 3 mm in 1 coordinate on the sagittal plane and 2 coordinates on the axial plane. The doses of 3 coordinates on the sagittal plane and 4 coordinates on the axial plane could not be evaluated in 30% profile width because of low doses. There was good agreement between the gel dosimetry and TPS results. Gel dosimetry provides dose distributions in all 3 planes at the same time, which enables us to define the dose distributions in any plane with high resolution. It can be used to obtain 3D dose distributions for HDR ¹⁹²Ir brachytherapy sources and 3D dose verification of TPS.     

Complete response of endemic Kaposi sarcoma lesions with high-dose-rate brachytherapy: Treatment method,results, and toxicity using skin surface applicators

PurposeTo analyze the clinical outcome of Kaposi sarcoma skin lesions treated with high-dose-rate (HDR) brachytherapy in patients with a minimum of 2 years of followup.Methods and MaterialsBetween February 2006 and July 2008, all patients with Kaposi sarcoma who received ¹⁹²Ir HDR brachytherapy using a skin surface applicator were evaluated for clinical response. Responses to treatment and toxicity were scored using standard criteria.ResultsSixteen cases were collected. Treatment was delivered in four to six fractions, over a period of approximately 12 days. The specified dose ranged from 24 to 35 Gy. Median followup the lesion was 41.4 months. No lesion was greater than 2 cm. All patients had a complete response to treatment, with no evidence of local recurrence or tumor progression. Thirteen lesions developed Grade 1 and two lesions had Grade 2 acute skin reactions. One patient developed late skin changes with telangiectasias and hypopigmentation.ConclusionsHDR brachytherapy treatment seems to be an effective noninvasive option for patients with small cutaneous Kaposi sarcoma lesions, delivering excellent cosmesis and local control in our small series. Fewer fractions over a shorter period used in our group offer patients more convenience compared with other common regimens. Although HDR is being used more frequently for many surface applications, additional clinical studies with larger numbers of patients and longer followup are needed to confirm the general impression that it is an excellent option for many patients.     

Endobronchial brachytherapy provides excellent long-term control of recurrent granulation tissue after tracheal stenosis

PurposeTo review the experience of using endobronchial brachytherapy (EBB) as a treatment for recurrent tracheal granulation tissue.Methods and MaterialsPatients referred for EBB at the Rabin Medical Center for benign stenosis were reviewed with institutional review board approval. Patients underwent bronchoscopic resection of granulation tissue followed by insertion of self-expanding metallic stents. After stenting, repeat laser resection was done at least 1 week before brachytherapy. After CT simulation, patients had three-dimensional brachytherapy treatment planning. A single 10-Gy dose was prescribed to 1.0 cm from the source and treatment was delivered using high-dose-rate afterloader with ¹⁹²Ir source. Patients were followedup with bronchoscopy every 3 months after the completion of therapy.ResultsFrom November 2001 to January 2009, 29 patients were treated with EBB to prevent granulation tissue reformation. Median age was 70 years and 55% of patients were male. Ninety percent of patients were treated to the trachea and the remaining patients had stenoses in the main stem bronchi. The primary cause of stenosis was prolonged mechanical ventilation (76%). The median time from stent placement to brachytherapy was 69 days. Median active length of treatment was 7 cm. With a median followup of 36 months, 66% (19 of 29) of patients remained free of granulation tissue. Forty-eight percent of patients have died, with all except 1 patient dying of their underlying condition. A single patient experienced death from tracheoesophageal fistula.ConclusionEBB is an effective and safe treatment to prevent recurrent granulation tissue formation after endobronchial resection and should be considered in patients who are unable to undergo surgical resection.     

Experimental characterization of the dosimetric properties of a newly designed I-Seed model AgX100 (125)I interstitial brachytherapy source

PurposeTo measure the dosimetric properties of the Model AgX100 ¹²⁵I source for interstitial brachytherapy.Methods and MaterialsThe photon energy spectrum emitted by the AgX100 source was measured using a high-resolution germanium spectrometer customized for low-energy brachytherapy source spectrometry. The dose distribution around the source was measured using the 1 × 1 × 1 mm³ lithium fluoride thermoluminescent dosimeters in water-equivalent solid phantoms. The dosimetric parameters needed for dose calculation using the American Association of Physicists in Medicine Task Group No. 43 (TG-43) formalism were determined and compared with the results of a Monte Carlo simulation by an independent research group and with the TG-43 consensus values of the well-established model 6711 source.ResultsIt was found that (1) the photon energy spectrum emitted by the AgX100 source was nearly identical to that emitted by the model 6711, (2) the dose-rate constant determined by the photon spectrometry technique (0.957 ± 0.037 cGy·h^?1·U^?1) and by the thermoluminescent dosimeter technique (0.995 ± 0.066 cGy·h^?1·U^?1) was within 1.5% of the corresponding values determined for the model 6711 source, and (3) the radial dose function and the anisotropy function of the AgX100 source were also found to be similar to the consensus data established for the model 6711 source in the TG-43 update report.ConclusionsA comprehensive dosimetric characterization has been carried out for the model AgX100 ¹²⁵I source. The American Association of Physicists in Medicine TG-43 dosimetry parameters for this source has been determined from the experimental data.     

High-dose-rate brachytherapy boost for carcinoma of external auditory canal

PurposeTo report dosimetry and outcome in a case of early stage carcinoma of external ear (T1N0M0) treated with radical radiotherapy alone using a combination of external beam radiotherapy (EBRT) and intracavitary irradiation with a high-dose-rate (HDR) ¹⁹²Ir remote afterloading system.Methods and MethodsA 64-year-old gentleman who was diagnosed as T1N0M0 carcinoma of external ear was treated with combination of external beam radiation therapy followed by brachytherapy (BRT). A total dose of 40 Gy was delivered by EBRT, following which a 6-Fr catheter for the HDR ¹⁹²Ir remote afterloader, fixed by a customized acrylic mold, was inserted into the external auditory canal (EAC) and a total intracavitary radiation dose of 22.5 Gy (4.5 Gy/F) was given.ResultsEvaluation at the completion of treatment and at the end of 4-year followup revealed no evidence of the disease.ConclusionsIn the radical treatment of early stage EAC carcinoma, combination of external beam radiation therapy and BRT may be a modality of choice for its efficacy, less severe side effects, and better cosmetic results.     

Brachytherapy-based partial breast irradiation is associated with low rates of complications and excellent cosmesis

BackgroundRecent retrospective, claims-based analyses have suggested a potential increased rate of toxicities associated with brachytherapy-based accelerated partial breast irradiation (APBI). The purpose of this analysis was to examine cosmesis and toxicity data from the prospective American Society of Breast Surgeons (ASBS) breast brachytherapy registry trial to compare to the findings from the claims analyses.MethodsThe ASBS breast brachytherapy registry is a prospective nonblinded multi-institutional registry trial. Patients with Stage 0–II breast cancer undergoing breast conserving therapy were eligible. A total of 1665 patients were enrolled and 1449 treated between 2002 and 2004 with a median followup of 63 months. All patients were treated with the MammoSite (Hologic, Inc.) single-lumen device to deliver adjuvant APBI (34 Gy in 3.4 Gy fractions).ResultsThe rate of excellent/good cosmesis was 90.6% at 84 months. The rate of a complication (symptomatic seroma, infection, fat necrosis, telangiectasias) at 1 year/any time point was 24.2%/38.5%, whereas the rate of noninfectious complications at 1 year/any time point was 14.8%/28.9%. The rate of symptomatic seroma, fat necrosis, infection, and telangiectasia at any time was 13.4%, 2.5%, 9.6%, and 13.0%, respectively.ConclusionsThe final toxicity analysis from ASBS breast brachytherapy registry trial confirms the previously noted excellent cosmesis and toxicity profiles and fails to confirm retrospective claims analyses that have suggested higher rates of toxicity for brachytherapy-based APBI.     

Interfraction accumulation of seroma during accelerated partial breast irradiation: preliminary results of a prospective study

PurposeTo quantify and characterize the process of seroma accumulation during accelerated partial breast irradiation using multicatheter balloon brachytherapy.Materials and MethodsTwenty-two patients were treated using the Contura Multilumen brachytherapy catheter to a dose of 34 Gy in 10 fractions over 5 treatment days. Serial aspirations of the vacuum port of the catheter were performed at the time of CT simulation and before each treatment. Volume and characteristics of fluid drawn were recorded. Univariate analysis was performed to evaluate various factors predictive of seroma formation.ResultsMedian patient age was 59.5 years, body mass index was 31, and volume of surgical specimen was 62.4 cm³. Median time from breast conservation surgery to placement of Contura catheter was 18.5 days. Pericatheter seroma, typically scant with a median volume of 0.75 mL, was noted in 91% of patients at CT simulation. A total of 203 aspirations were performed with a median-aspirated seroma volume of 4.05 mL. There was no significant correlation between the volume of seroma and histology (invasive vs. in situ), quadrant of location, body mass index, reexcision or reoperation, days from breast conservation surgery to balloon placement, or the volume of specimen removed. Radiation treatment factors, including balloon volume, balloon to skin distance, and planning target volume evaluation, also did not correlate with aspirated seroma.ConclusionsInterfraction seroma accumulation has a variable pattern of development with no discernible predictors of occurrence. Routine pretreatment aspirations via vacuum port may potentially improve dosimetric reproducibility for a minority of patients.