- Email: [email protected]
Multiple Organ Toxicities in 1006 Prostate Brachytherapy Patients With Long-Term Followup
Abstracts / Brachytherapy 10 (2011) S14eS101 monotherapy patients, and 151.2Gy for the combination group. Our average urethral D30 was 129.5% for the monotherapy group, and 135.3% for the combination group. We have found a 1.8% incidence of urethral strictures, zero urethral ulcerations and zero incontinence. We have had 3.45% of patients that presented with urinary retention. Of these 2.4% presented within 1 month of the procedure. We had a further 0.88% of patients that developed urinary retention between 6 weeks and 3 months. Only 0.96% of patients required more than 2 weeks of intermittent selfcatheterisation. Further, we found that the average rectal V100 was 0,23cc in the monotherapy group. This group had 6.5% grade I and 0,8% grade II rectal complications. In the combination group the average rectal V100 was 0.19cc. This group had a 19.6% Grade I and 5.88% grade II rectal complications. These were all associated with the external beam radiotherapy. Zero grade III or IV complications have been noted in either group. We also found that erectile function was not significantly altered in previously potent patients. Although we cannot yet report conclusively on our control rates, our figures are currently showing a 3.2% failure rate. Conclusions: With a real-time feedback system and an accurate yet fast implant technique, we have achieved good quality implants consistently while ensuring that side-effects are kept to the minimum, especially when compared to published figures. These figures are still early and the high risk group needs to be removed from the greater cohort in order to assess the control rates within the various risk stratifications.
PD98 Chronic Toxicity of Two Fractionation Schedules of High-Dose-Rate Brachytherapy as Monotherapy in Low/Intermediate Prostate Cancer Michel I. Ghilezan, MD, PhD, Gary Gustafson, MD, Donald Brabbins, MD, Peter Chen, MD, Dan Krauss, MD, Michelle Wallace, RN, Joshua Dillworth, MD, PhD, James Fontanesi, MD, Alvaro A. Martinez, MD. Radiation Oncology, William Beaumont Hospital. Royal Oak, MI. Purpose: To compare the chronic toxicities of two different HDR regimens delivered via a single implant and 38 Gy in 4 fractions in two days (38/4) and 24 Gy in 2 fractions in one day (24/2). Materials and Methods: 386 patients with low- or intermediate-risk prostate cancer were treated with 192Ir and transrectal ultrasound-guided, percutaneous implantation with HDR afterloading catheters. 173 patients (107 patients treated with 38/4 regimen and 66 patients treated with12/2 regimen) with complete toxicity information and a minimum 1 year of followup were included in this analysis. Dosimetric planning and optimization was performed using Swift or Oncentra Prostate v3.2 software. Treatments were delivered twice daily with a minimum interfraction time of 6 hours. Chronic toxicities were graded using the Common Terminology Criteria for Adverse Events, version 3 and was expressed as the highest grade encountered at any time point during followup but at least at or beyond six months following treatment. Results: 80% of 38/4 patients and 64% of 24/2 patients were classified as having low-risk prostate cancer (p ! 0.001) with the remaining patients classified with intermediate-risk disease. Median followup for the 38/4 patients was 4.6 years and 2.1 years for the 24/2 patients. Overal, toxicities were low with majority of patients in both groups having none or mild symptoms. Most common grade 2 GU toxicity was frequency/ urgency with only 5% and 3% of patients experiencing it over 6 months, in both groups. 1 patient developed uretral stricture in the 38/4 group. Dysuria grade 2 was 3% in both groups. None of the patients experienced incontinence. GI toxicities were minimal with only 2% of the 38/4 patients complaining of tenesmus grade 1. One patient had a brief episode of rectal bleeding in the 24/2 group. Erections insufficient for intercourse were reported by 11% of 24/2 patients and 14% of 38/4 patients (difference not statistically significant). Conclusions: HDR monotherapy for prostate cancer is associated with an excellent chronic toxicity profile. The chronic toxicities associated with 38/4 and 24/2 regimens appear similar. The 2-fraction HDR regimen is appealing as being well tolerated and convenient for patients and staff, however, longer followup is needed to assess its validity in terms of clinical outcome.
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PD99 Radioactive Seed Migration After Transperineal Interstitial Prostate Brachytherapy and Associated Development of Small Cell Carcinoma of the Lung William C. Chen, MD1, Jerald Katcher, MD1, Carlos Nunez, MD2, Ali M. Tirgan, MD3, Rodney J. Ellis, MD1. 1Radiation Oncology, University Hospitals Case Medical Center, Cleveland, OH; 2Pathology, Hillcrest Hospital, Cleveland, OH; 3Medical Oncology, University Hospitals Case Medical Center, Cleveland, OH. Purpose: We are reporting, to our knowledge, the first case of prostate brachytherapy seed migration to the right lower lobe of the lung associated with development of small cell carcinoma. Materials and Methods: The patient is a 57-year-old male nonsmoker who was originally diagnosed with prostate adenocarcinoma Group IIB (cT2aN0M0; Gleason 8; PSA 2.1 ng/mL) in October 1999. Hormone suppression was initiated neoadjuvantly and continued for 1 year. Treatment was completed at an outside local hospital, and consisted of supplemental external beam radiation, followed by iodine-125 (125I) brachytherapy boost. He received 45 Gy to the pelvis in 25 fractions delivered through a fourfield approach. He then underwent percutaneous transperineal interstitial permanent prostate brachytherapy with implantation of 72 loose 125I seeds under transrectal ultrasound guidance in April 2000. The implantation was designed to deliver a minimum dose of 90 Gy. Results: The treatment was unremarkable for any complications. The immediate post-implant cystoscopy and plain film of the pelvis did not reveal any loose seeds in the bladder. The patient remained clinically without evidence of disease, and was asymptomatic until a solitary episode of hematuria in December 2009. Radiographic evaluation at that time noted an incidental 4.3 cm right lower lobe lung mass with a 4 mm hyperdensity slightly off-center. A positron emission tomographic (PET) scan showed corresponding intense radiotracer uptake, and biopsy confirmed Stage IB (cT2aN0M0) limited-stage small cell carcinoma of the lung. He was subsequently referred to our department for treatment and received a total dose of 45 Gy which was delivered to the right lower lobe at 1.5 Gy/fx BID with concurrent systemic chemotherapy. A posttreatment residual mass remained mildly PET avid, and he underwent subsequent surgical evaluation. A right lower lobecomy was completed for which final pathology demonstrated diffuse pneumonitis and treatment effect, with no identifiable residual tumor. However, transection of the treated area noted a metal rod-like implant at the center consistent with a migrated radioactive brachytherapy seed. Conclusions: To our knowledge, this is the first case of long-term adverse sequela from brachytherapy seed migration likely resulting in a second malignancy. While reported incidence of pulmonary seed emboli remains low with little measurable consequence on pulmonary function, we must appreciate that a theoretical risk for secondary malignancy remains not only locally within the periprostatic region, but also at any site of seed migration as seen in this case of a pulmonary malignancy. PD100 Multiple Organ Toxicities in 1006 Prostate Brachytherapy Patients With Long-Term Followup Mira Keyes, MD, FRCPC1, Tom Pickles, MD, FRCPC1, Ingrid Spadinger, PhD1, Juanita Crook, MD, FRCPC2, Michael McKenzie, MD, FRCPC1, W. James Morris, MD, FRCPC1. 1Radiation Oncology, BC Cancer Agency Vancouver Cancer Centre, Vancouver, BC, Canada; 2Radation Oncology, BC Cancer Agency Kelowna Cancer Centre, Kelowna, BC, Canada. Purpose: To assess the rate of late (O12 mo) multiple organ toxicities (rectal, urinary and erectile function) in 1006 uniformly treated prostate brachytherapy patients with long-term followup. Materials and Methods: 1006 consecutive patients treated with 125I monotherapy between July 1998 and October 2003 were included in this study. 58% had low risk and 42% intermediate risk disease. 65% received 3m neoadjuvant and 3m concurrent androgen deprivation therapy (ADT). With median fu of 73 mo, KM actuarial bNED at 5y was 96.5 1.2% and 94.4 1.6% at 7 years. Toxicity was prospectively collected on patients able to attend BC regional cancer centers. A composite toxicity
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Abstracts / Brachytherapy 10 (2011) S14eS101
score was used to calculate combined toxicity score using the maximum toxicity ever recorded and the toxicity score at last followup. The composite toxicity score was comprised of: GU/GI RTOG 0 or 1: add 0, GU/GI RTOG 2: add 1, GU/GI RTOG 3 or 4: add 2, IPSS failed to normalize: add 2, partially potent at baseline, impotent after PB: add 1, fully potent at baseline, impotent after PB: add 2, Catheterization (short !3 weeks) add 1, prolonged catheterization (O3 weeks): add 2, for a maximum score of 10. There are no validated and published composite toxicity scores; therefore, this scoring system will require a validation in other prostate brachytherapy cohorts. Results: 939 pts had all 3 toxicities recorded. 637 (63.3%) were fully potent pre-implant, 138 (13.7%) were partially potent pre-implant. The distribution (as % of patients) of composite toxicity scores (0e6) is given in the table below: based on maximum toxicity ever recorded and scored again at last followup. Maximum toxicity scores of 7 and 8 were seen in 0.75% and 0.2% of patients. No patients had maximum toxicity scores 9 or 10 and no patients had scores of 7e10 at last followup. Score Max toxicity Last followup
0 21 53
1 13 17
2 35 18
3 13 8
4 9 3
5 5 0.53
6 2 0.21
Out of all patients, 21% pts had no toxicity at all; 47% had one organ system toxicity contributing to the toxicity score, 27% had 2 systems and only 3.5% had all 3 organ systems contributing to the composite toxicity score. At last followup, 91% (n 5 648) of the patients have a score of 0 or 1; with 31% having score 0, 40% having score 1 in sexual function, 26% having score 1 in urinary function and 2.3% having score 1 in rectal function. The relationship between ideal implant dosimetry (D90 #180Gy and VR100 !1cc) and toxicity score will be presented at the meeting. Conclusions: 68% of the prostate brachytherapy patients have no, or only one, organ system late toxicity recorded. 3.5% have all 3 organ systems involved. Severe toxicity (score O 6) is seen in 3% of the patients. With a long followup toxicity is significantly reduced; at last followup to 90% of the patients have a score of 0 or 1. Further efforts should be directed to reducing PB toxicity.
BREAST POSTERS ThursdayeSaturday PO1 Interstitial High-Dose-Rate Brachytherapy for Breast Cancer in Women #50 Years of Age Compared to O50 Years of Age: Median 6Year Followup in 273 Cases Using Multicatheter Technique Rufus J. Mark, MD, Paul J. Anderson, MD, Robin S. Akins, MD, Murali Nair, PhD. Radiation Oncology, Joe Arrington Cancer Center, Lubbock, TX. Purpose: External beam radiation therapy (EBRT) has been the standard of care for breast conservation radiation therapy, for more than 20 years. It is well known that pre-menopausal women have a worse prognosis than postmenopausal women. However, it is also known that mastectomy does not confer a better prognosis than breast conservation in these younger women. Hence, the American College of Radiology does not have an age limit for breast conservation candidacy. Recent data indicates that interstitial implant and high-dose-rate (HDR) radiation afterloading compares very favorably to EBRT in early stage breast cancer. There is controversy regarding the use of HDR in patients #50 years of age. We present our data in patients #50 years of age compared toO50 years of age. Materials and Methods: Patients with Tis, T1, and T2 tumors measuring #4 cm, negative surgical margins, and 1e3 positive axillary lymph nodes were judged to be candidates for interstitial implant. Implants were performed under stereotactic mammographic guidance with conscious sedation and local anesthesia. The implants were placed using a custom designed template with 3 to 8 planes, and 8 to 74 needles. Catheters were subsequently threaded through the needles, and the needles removed. Catheter spacing was 1.0 to 1.5 cm. Radiation treatment planning was
performed using CT scanning and the Plato System. Treatment volumes ranged from 25 cm3 to 458 cm3. HDR treatment was given using the Nucletron afterloading system. The breast implant volume received 3400 cGy in 10 fractions prescribed to the planning target volume, given BID over 5 days. Results: Between 2000 and 2010, 273 patients underwent interstitial HDR implant. The procedure was well tolerated. No patient required hospital admission. With a median followup 72 months (range 6e132 months), local recurrence (LR) occurred in 4.0% (11/273). LR occurred in 6.5% (2/ 31) of patients #50 years of age vs. 3.7% (9/242) in patients O50 years of age (p 5 0.36). Cosmetic results were good to excellent in 89.0% (243/273) of the patients. There were no infections. Wound healing complications developed in 2.9% (8/273). Three of these patients had received anthracycline-based chemotherapy. The other five had large (O200 cm3) implant volumes. In patients with catheter spacing of 1.5 cm and V-150% O30%, 9.5% (8/84) developed wound complications vs. 0% (0/189) in patients with catheter spacing of 1.0 cm and V-150% !30% (p 5 0.0001). Two patients healed after 6 months of conservative treatment. Surgery was required in six patients who developed fat necrosis. Conclusions: With median 72-month followup, breast conservation radiation therapy utilizing interstitial multi-catheter HDR implant has yielded local recurrence rates and cosmetic results which compare favorably to EBRT in selected patients. There was no statistically significant difference in LR between patients #50 years of age vs. O50 years of age. While there was a trend towards higher LR in patients #50 years, LR appears comparable to patients treated with EBRT. Therefore, we believe that age #50 years should not be a contraindication for HDR for breast conservation. PO2 Dose Measurements to the Contralateral Breast During Accelerated Partial Breast Irradiation, Medial vs Lateral Insertion Gene A. Cardarelli, PhD, MPH, Theodore Steger, PhD, Janet Gortney, MS, Timothy Boyd, MD, Andrew Salner, MD. Radiation Oncology, Hartford Hospital, Hartford, CT. Purpose: The purpose of this investigation was to determine the dose to the contralateral breast dose during accelerated partial breast irradiation. Specifically, the differences between types of balloon applicators and the method of insertion, medial versus lateral was investigated. Materials and Methods: During patient APBI treatment, Mosfett (One Dose) dosimeters were placed at various locations on the contralateral breast for the entire treatment. Measurements were compared to the dose calculated by the treatment planning system. The treatments were performed using a Nucletron Microselectron High-dose-rate brachytherapy treatment unit using version 8.3 of Oncentra Brachy planning system. The following balloon type applicators were investigated: Single and Multilumen MammoSite, Contura, and Savi multilumen applicators. Results: The results of these measurements show a slight increase in dose due to Multilumen applicators. It did not show any significant increase in the dose due to medial applicator insertion vs lateral insertion. Conclusions: Multilument applicators show and increase dose to the contralateral breast dose. The position of the lumpectomy cavity appear to be the greatest effect on the dose to the contralateral dose.
PHYSICS POSTERS ThursdayeSaturday PO3 In-Vivo Diode Dosimetry Versus Comuterized Tomography and Digital Reconstructed Radiographs for Critical Organ Dose Calculation in HDR Brachytherapy of Cervix Cancer Ashraf H. Hassouna, MD1,2, Yasir A. Bahadur, FRCP3, Camelia Constantinescu, PhD2, Mohamed E. El Sayed, MD1,2, Hussain M. Naseem, MSc2, Adly F. Naga, MSc1,2. 1Radiation Oncology, National Cancer Institute, Cairo University, Cairo, Egypt; 2Oncology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia; 3 Radiology, King Abdul Aziz University, Jeddah, Saudi Arabia.
PD98 Chronic Toxicity of Two Fractionation Schedules of High-Dose-Rate Brachytherapy as Monotherapy in Low/Intermediate Prostate Cancer Michel I. Ghilezan, MD, PhD, Gary Gustafson, MD, Donald Brabbins, MD, Peter Chen, MD, Dan Krauss, MD, Michelle Wallace, RN, Joshua Dillworth, MD, PhD, James Fontanesi, MD, Alvaro A. Martinez, MD. Radiation Oncology, William Beaumont Hospital. Royal Oak, MI. Purpose: To compare the chronic toxicities of two different HDR regimens delivered via a single implant and 38 Gy in 4 fractions in two days (38/4) and 24 Gy in 2 fractions in one day (24/2). Materials and Methods: 386 patients with low- or intermediate-risk prostate cancer were treated with 192Ir and transrectal ultrasound-guided, percutaneous implantation with HDR afterloading catheters. 173 patients (107 patients treated with 38/4 regimen and 66 patients treated with12/2 regimen) with complete toxicity information and a minimum 1 year of followup were included in this analysis. Dosimetric planning and optimization was performed using Swift or Oncentra Prostate v3.2 software. Treatments were delivered twice daily with a minimum interfraction time of 6 hours. Chronic toxicities were graded using the Common Terminology Criteria for Adverse Events, version 3 and was expressed as the highest grade encountered at any time point during followup but at least at or beyond six months following treatment. Results: 80% of 38/4 patients and 64% of 24/2 patients were classified as having low-risk prostate cancer (p ! 0.001) with the remaining patients classified with intermediate-risk disease. Median followup for the 38/4 patients was 4.6 years and 2.1 years for the 24/2 patients. Overal, toxicities were low with majority of patients in both groups having none or mild symptoms. Most common grade 2 GU toxicity was frequency/ urgency with only 5% and 3% of patients experiencing it over 6 months, in both groups. 1 patient developed uretral stricture in the 38/4 group. Dysuria grade 2 was 3% in both groups. None of the patients experienced incontinence. GI toxicities were minimal with only 2% of the 38/4 patients complaining of tenesmus grade 1. One patient had a brief episode of rectal bleeding in the 24/2 group. Erections insufficient for intercourse were reported by 11% of 24/2 patients and 14% of 38/4 patients (difference not statistically significant). Conclusions: HDR monotherapy for prostate cancer is associated with an excellent chronic toxicity profile. The chronic toxicities associated with 38/4 and 24/2 regimens appear similar. The 2-fraction HDR regimen is appealing as being well tolerated and convenient for patients and staff, however, longer followup is needed to assess its validity in terms of clinical outcome.
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PD99 Radioactive Seed Migration After Transperineal Interstitial Prostate Brachytherapy and Associated Development of Small Cell Carcinoma of the Lung William C. Chen, MD1, Jerald Katcher, MD1, Carlos Nunez, MD2, Ali M. Tirgan, MD3, Rodney J. Ellis, MD1. 1Radiation Oncology, University Hospitals Case Medical Center, Cleveland, OH; 2Pathology, Hillcrest Hospital, Cleveland, OH; 3Medical Oncology, University Hospitals Case Medical Center, Cleveland, OH. Purpose: We are reporting, to our knowledge, the first case of prostate brachytherapy seed migration to the right lower lobe of the lung associated with development of small cell carcinoma. Materials and Methods: The patient is a 57-year-old male nonsmoker who was originally diagnosed with prostate adenocarcinoma Group IIB (cT2aN0M0; Gleason 8; PSA 2.1 ng/mL) in October 1999. Hormone suppression was initiated neoadjuvantly and continued for 1 year. Treatment was completed at an outside local hospital, and consisted of supplemental external beam radiation, followed by iodine-125 (125I) brachytherapy boost. He received 45 Gy to the pelvis in 25 fractions delivered through a fourfield approach. He then underwent percutaneous transperineal interstitial permanent prostate brachytherapy with implantation of 72 loose 125I seeds under transrectal ultrasound guidance in April 2000. The implantation was designed to deliver a minimum dose of 90 Gy. Results: The treatment was unremarkable for any complications. The immediate post-implant cystoscopy and plain film of the pelvis did not reveal any loose seeds in the bladder. The patient remained clinically without evidence of disease, and was asymptomatic until a solitary episode of hematuria in December 2009. Radiographic evaluation at that time noted an incidental 4.3 cm right lower lobe lung mass with a 4 mm hyperdensity slightly off-center. A positron emission tomographic (PET) scan showed corresponding intense radiotracer uptake, and biopsy confirmed Stage IB (cT2aN0M0) limited-stage small cell carcinoma of the lung. He was subsequently referred to our department for treatment and received a total dose of 45 Gy which was delivered to the right lower lobe at 1.5 Gy/fx BID with concurrent systemic chemotherapy. A posttreatment residual mass remained mildly PET avid, and he underwent subsequent surgical evaluation. A right lower lobecomy was completed for which final pathology demonstrated diffuse pneumonitis and treatment effect, with no identifiable residual tumor. However, transection of the treated area noted a metal rod-like implant at the center consistent with a migrated radioactive brachytherapy seed. Conclusions: To our knowledge, this is the first case of long-term adverse sequela from brachytherapy seed migration likely resulting in a second malignancy. While reported incidence of pulmonary seed emboli remains low with little measurable consequence on pulmonary function, we must appreciate that a theoretical risk for secondary malignancy remains not only locally within the periprostatic region, but also at any site of seed migration as seen in this case of a pulmonary malignancy. PD100 Multiple Organ Toxicities in 1006 Prostate Brachytherapy Patients With Long-Term Followup Mira Keyes, MD, FRCPC1, Tom Pickles, MD, FRCPC1, Ingrid Spadinger, PhD1, Juanita Crook, MD, FRCPC2, Michael McKenzie, MD, FRCPC1, W. James Morris, MD, FRCPC1. 1Radiation Oncology, BC Cancer Agency Vancouver Cancer Centre, Vancouver, BC, Canada; 2Radation Oncology, BC Cancer Agency Kelowna Cancer Centre, Kelowna, BC, Canada. Purpose: To assess the rate of late (O12 mo) multiple organ toxicities (rectal, urinary and erectile function) in 1006 uniformly treated prostate brachytherapy patients with long-term followup. Materials and Methods: 1006 consecutive patients treated with 125I monotherapy between July 1998 and October 2003 were included in this study. 58% had low risk and 42% intermediate risk disease. 65% received 3m neoadjuvant and 3m concurrent androgen deprivation therapy (ADT). With median fu of 73 mo, KM actuarial bNED at 5y was 96.5 1.2% and 94.4 1.6% at 7 years. Toxicity was prospectively collected on patients able to attend BC regional cancer centers. A composite toxicity
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Abstracts / Brachytherapy 10 (2011) S14eS101
score was used to calculate combined toxicity score using the maximum toxicity ever recorded and the toxicity score at last followup. The composite toxicity score was comprised of: GU/GI RTOG 0 or 1: add 0, GU/GI RTOG 2: add 1, GU/GI RTOG 3 or 4: add 2, IPSS failed to normalize: add 2, partially potent at baseline, impotent after PB: add 1, fully potent at baseline, impotent after PB: add 2, Catheterization (short !3 weeks) add 1, prolonged catheterization (O3 weeks): add 2, for a maximum score of 10. There are no validated and published composite toxicity scores; therefore, this scoring system will require a validation in other prostate brachytherapy cohorts. Results: 939 pts had all 3 toxicities recorded. 637 (63.3%) were fully potent pre-implant, 138 (13.7%) were partially potent pre-implant. The distribution (as % of patients) of composite toxicity scores (0e6) is given in the table below: based on maximum toxicity ever recorded and scored again at last followup. Maximum toxicity scores of 7 and 8 were seen in 0.75% and 0.2% of patients. No patients had maximum toxicity scores 9 or 10 and no patients had scores of 7e10 at last followup. Score Max toxicity Last followup
0 21 53
1 13 17
2 35 18
3 13 8
4 9 3
5 5 0.53
6 2 0.21
Out of all patients, 21% pts had no toxicity at all; 47% had one organ system toxicity contributing to the toxicity score, 27% had 2 systems and only 3.5% had all 3 organ systems contributing to the composite toxicity score. At last followup, 91% (n 5 648) of the patients have a score of 0 or 1; with 31% having score 0, 40% having score 1 in sexual function, 26% having score 1 in urinary function and 2.3% having score 1 in rectal function. The relationship between ideal implant dosimetry (D90 #180Gy and VR100 !1cc) and toxicity score will be presented at the meeting. Conclusions: 68% of the prostate brachytherapy patients have no, or only one, organ system late toxicity recorded. 3.5% have all 3 organ systems involved. Severe toxicity (score O 6) is seen in 3% of the patients. With a long followup toxicity is significantly reduced; at last followup to 90% of the patients have a score of 0 or 1. Further efforts should be directed to reducing PB toxicity.
BREAST POSTERS ThursdayeSaturday PO1 Interstitial High-Dose-Rate Brachytherapy for Breast Cancer in Women #50 Years of Age Compared to O50 Years of Age: Median 6Year Followup in 273 Cases Using Multicatheter Technique Rufus J. Mark, MD, Paul J. Anderson, MD, Robin S. Akins, MD, Murali Nair, PhD. Radiation Oncology, Joe Arrington Cancer Center, Lubbock, TX. Purpose: External beam radiation therapy (EBRT) has been the standard of care for breast conservation radiation therapy, for more than 20 years. It is well known that pre-menopausal women have a worse prognosis than postmenopausal women. However, it is also known that mastectomy does not confer a better prognosis than breast conservation in these younger women. Hence, the American College of Radiology does not have an age limit for breast conservation candidacy. Recent data indicates that interstitial implant and high-dose-rate (HDR) radiation afterloading compares very favorably to EBRT in early stage breast cancer. There is controversy regarding the use of HDR in patients #50 years of age. We present our data in patients #50 years of age compared toO50 years of age. Materials and Methods: Patients with Tis, T1, and T2 tumors measuring #4 cm, negative surgical margins, and 1e3 positive axillary lymph nodes were judged to be candidates for interstitial implant. Implants were performed under stereotactic mammographic guidance with conscious sedation and local anesthesia. The implants were placed using a custom designed template with 3 to 8 planes, and 8 to 74 needles. Catheters were subsequently threaded through the needles, and the needles removed. Catheter spacing was 1.0 to 1.5 cm. Radiation treatment planning was
performed using CT scanning and the Plato System. Treatment volumes ranged from 25 cm3 to 458 cm3. HDR treatment was given using the Nucletron afterloading system. The breast implant volume received 3400 cGy in 10 fractions prescribed to the planning target volume, given BID over 5 days. Results: Between 2000 and 2010, 273 patients underwent interstitial HDR implant. The procedure was well tolerated. No patient required hospital admission. With a median followup 72 months (range 6e132 months), local recurrence (LR) occurred in 4.0% (11/273). LR occurred in 6.5% (2/ 31) of patients #50 years of age vs. 3.7% (9/242) in patients O50 years of age (p 5 0.36). Cosmetic results were good to excellent in 89.0% (243/273) of the patients. There were no infections. Wound healing complications developed in 2.9% (8/273). Three of these patients had received anthracycline-based chemotherapy. The other five had large (O200 cm3) implant volumes. In patients with catheter spacing of 1.5 cm and V-150% O30%, 9.5% (8/84) developed wound complications vs. 0% (0/189) in patients with catheter spacing of 1.0 cm and V-150% !30% (p 5 0.0001). Two patients healed after 6 months of conservative treatment. Surgery was required in six patients who developed fat necrosis. Conclusions: With median 72-month followup, breast conservation radiation therapy utilizing interstitial multi-catheter HDR implant has yielded local recurrence rates and cosmetic results which compare favorably to EBRT in selected patients. There was no statistically significant difference in LR between patients #50 years of age vs. O50 years of age. While there was a trend towards higher LR in patients #50 years, LR appears comparable to patients treated with EBRT. Therefore, we believe that age #50 years should not be a contraindication for HDR for breast conservation. PO2 Dose Measurements to the Contralateral Breast During Accelerated Partial Breast Irradiation, Medial vs Lateral Insertion Gene A. Cardarelli, PhD, MPH, Theodore Steger, PhD, Janet Gortney, MS, Timothy Boyd, MD, Andrew Salner, MD. Radiation Oncology, Hartford Hospital, Hartford, CT. Purpose: The purpose of this investigation was to determine the dose to the contralateral breast dose during accelerated partial breast irradiation. Specifically, the differences between types of balloon applicators and the method of insertion, medial versus lateral was investigated. Materials and Methods: During patient APBI treatment, Mosfett (One Dose) dosimeters were placed at various locations on the contralateral breast for the entire treatment. Measurements were compared to the dose calculated by the treatment planning system. The treatments were performed using a Nucletron Microselectron High-dose-rate brachytherapy treatment unit using version 8.3 of Oncentra Brachy planning system. The following balloon type applicators were investigated: Single and Multilumen MammoSite, Contura, and Savi multilumen applicators. Results: The results of these measurements show a slight increase in dose due to Multilumen applicators. It did not show any significant increase in the dose due to medial applicator insertion vs lateral insertion. Conclusions: Multilument applicators show and increase dose to the contralateral breast dose. The position of the lumpectomy cavity appear to be the greatest effect on the dose to the contralateral dose.
PHYSICS POSTERS ThursdayeSaturday PO3 In-Vivo Diode Dosimetry Versus Comuterized Tomography and Digital Reconstructed Radiographs for Critical Organ Dose Calculation in HDR Brachytherapy of Cervix Cancer Ashraf H. Hassouna, MD1,2, Yasir A. Bahadur, FRCP3, Camelia Constantinescu, PhD2, Mohamed E. El Sayed, MD1,2, Hussain M. Naseem, MSc2, Adly F. Naga, MSc1,2. 1Radiation Oncology, National Cancer Institute, Cairo University, Cairo, Egypt; 2Oncology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia; 3 Radiology, King Abdul Aziz University, Jeddah, Saudi Arabia.