50-175 mg) and Versed (3-12 mg). Local anesthetic was given with a mixture of 1% Lidocaine, 0.25% Marcaine, 1:100,000 Epinephrine, and 4% Sodium Bicarbonate neutralizing solution (20-120 cc). Local anesthesia was given to a 5 x 5 cm perineal area to a depth of 10 cm under TRUS guidance. The implants were placed under mobile multi-plane prostate template (Radiation Therapy Products Prostate Template) guidance using from 3 to 4 planes, and 12 to 22 needles. Needle spacing was 1.0 cm. The implant procedure included sigmoidoscopy and cystoscopy. Results: Between 2002 and 2009, 467 TRUS guided prostate implants were performed under local anesthesia. Median implant time was 45 minutes (range : 30 to 150 minutes). HDR treatment was given using the Nucletron afterloading system. The implant volume received 2,250 cGy in 3 fractions prescribed to the 100% Isodose line, given over 24 hours. Urethral dose points (12-16) were followed, and limited to # 105% of the prescription dose. The procedure was well tolerated, with all patients having completed the procedure. Three patients developed respiratory suppression, and required reversal with Narcan. All recovered uneventfully. Otherwise, there have been no acute complications to date. Conclusions: TRUS interstitial implant of the prostate under local anesthesia is feasible. Implant time, complications, cost, and scheduling convenience, compare favorably to general or spinal anesthetic technique.

St. Mary's Duluth Clinic Health System, Duluth, MNPurpose/Objective(s): Small vessel damage and fibrotic changes are thought to occur following radiotherapy. Decreased blood flow and decreased oxygenation may result from radiotherapy and contribute to long-term toxicity. We sought to test the hypothesis that normal tissue becomes hypoxic following radiotherapy. Materials/Methods: Transcutaneous oxygen sensing electrode probe was used to determine breast tissue oxygen levels in irradiated and non-irradiated breast tissue one year after breast conserving therapy for early stage breast cancer. Oxygenation was measured at the lumpectomy site and a distant site in the irradiated breast for each subject. Oxygenation levels were also determined at corresponding locations in the non-irradiated (control) breast. Radiation Therapy Oncology Group toxicity criteria were used to assess skin and subcutaneous tissue damage. Measurements from twenty subjects were analyzed. Oxygenation levels were compared using a t-test for equality of means. Results: Transcutaneous measures of tissue oxygenation one year following breast radiotherapy were lower in irradiated versus control tissue. Subjects without diabetes had an average oxygenation level of 64.8 +/-19.9 mmHg in the irradiated breast at the non-lumpectomy site and an average of 72.3 +/-18.1 mmHg (p=0.014) at the corresponding location in the control breast. One subject had developed clinical grade 2 cutaneous changes one year after treatment, all others showed grade one changes. The subject with grade 2 toxicity had oxygenation levels of 74.5 and 58.8 in the control and irradiated breasts, respectively. Patients with diabetes (n = 4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast.Conclusions: Radiotherapy appears to decrease breast tissue oxygenation in non-diabetic patients one year after treatment. Transcutaneous oxygenation measurements may provide a useful tool to assess and quantify normal tissue injury following radiotherapy.Purpose/Objective(s): 3D-CRT is the most widely and available form of APBI used in the United States; it provides improved dose homogeneity compared to other APBI techniques, theoretically leading to improved cosmetic outcomes. However, the target volumes in 3D-CRT are highly dependent on the volume of the seroma after surgery and the optimal timing of APBI with respect to surgery has yet to be determined. S210I.

#5141 Purpose/Objective(s): With the new ConturaTM Multi-Lumen Balloon (MLB) catheter (SenoRx, Inc, Aliso Viejo, CA), one may achieve 2 dosimetric advantages over a MammoSiteTM catheter: 1) avoidance of a radiation “hot spot” in the skin which may improve cosmetic results, and 2) reduction of the size of an air/fluid pocket in the planning target volume for plan evaluation (PTV_EVAL) which may improve local control by increasing the radiation dose delivered to breast tissue at risk. The purpose of this study was to analyze the frequency with which a Contura catheter can satisfy the above 2 dosimetric goals relative to a MammoSite catheter.
 Materials/Methods: From October 2007 to June 2008, 23 patients between the ages of 43 and 88 years (median, 57 years) with unifocal AJCC pathological T0, T1, or T2 (maximum, 3.0 cm; median, 1.0 cm), N0 ductal, papillary, or tubular carcinomas of the breast at least 1 mm from the inked edge of the lumpectomy specimen were treated with high-dose-rate iridium-192 brachytherapy using a Contura MLB catheter. Sixty-five percent of the cancers were estrogen-receptor positive. Brachytherapy was delivered to a total dose of 34 Gy in 10 fractions bid over 5-7 days. We prescribed the dose to a depth of 1.0 cm from the balloon surface. The Contura applicator allows one to load up to 5 source lumens: 4 lumens that are offset 0.5 cm circumferentially from a central lumen. The ability to choose from multiple lumens allows for greater control over where radiotherapy is delivered. The Contura catheter also has a sixth lumen through which air/fluid can be removed from around the balloon. This feature helps to improve tissue-balloon conformance. The minimum balloon-to-skin distance was 0.5 cm. In 39% of patients, the balloon-to-skin distance was 0.5-0.9 cm. The balloon volume was 30-55 cc, V150 was ≤ 33 cc, and V200 was ≤ 10 cc. Hypothetical MammoSite treatment plans were created using a CT scan of the breast prior to air/fluid removal. Only the central lumen was loaded for the hypothetical MammoSite plan. The 2 treatment planning goals were to keep the: 1) maximum skin dose ≤ 100% of the prescribed dose, and 2) volume of air/fluid around the balloon ≤ 3.0% of PTV_EVAL. A one-sided McNemar test was used to compare the % of Contura plans that satisfied both goals vs the % of MammoSite plans that satisfied both goals.
 Results: The maximum skin dose was 100% of the prescribed dose with the Contura catheter vs 145% of the prescribed dose with a MammoSite catheter. The volume of air/fluid around the balloon was 4.4% ± 1.0% (mean ± standard error) of PTV_EVAL prior to suctioning vs 1.2% ± 0.3% after suctioning. Ninety-one percent of Contura plans satisfied both treatment planning goals vs only 48% of MammoSite plans (p=0.08).
 Conclusion: A Contura applicator resulted in a trend towards dosimetric improvement over a MammoSite catheter. Patients will be followed long-term in order to determine their local control, disease-free survival, cosmetic results, and treatment-related toxicities. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5141.