S35Abstracts / Brachytherapy 12 (2013) S11eS77

of cancer or their serum creatinine wasO1.5 mg/dL. Rectal, bladder, andprostate doses were calculated based upon treatment planning computedtomography scans. The Mann-Whitney U test with an alpha (type I)error 5 0.05 was used to compare two independent samples ofobservations.Results: The mean prostate size in the gel group was 54 cc vs. 53 cc in theno gel group. Gel increased the separation between the prostate and rectumby 5 to 19 mm. The mean rectal V75 was 0.09 cc and 0.32 cc with andwithout gel, respectively (p!0.001), and the mean rectal D2cc was 48%and 58% with and without gel, respectively (p!0.001). The mean rectalD2cc was 51% and 45% in the first 25 patients and the second 25 patientstreated with gel, respectively (p50.01). The mean bladder V75 was 0.52cc and 0.62 cc with and without gel, respectively (p50.32), and the meanbladder D2cc was 59% and 63% with and without gel, respectively(p50.09). Mean prostate D90 and V100 were 104% and 94% with gel and105% and 95% without gel (p50.20 and p50.28, respectively). Therewas no acute toxicity attributable to injection of the gel.Conclusions: Use of a gel to temporarily displace the rectum away from theprostate leads to a significant reduction in radiation dose delivered to theanterior rectal wall and no significant change in radiation dose deliveredto the bladder. There is a learning curve to gel injection, with anincreased reduction in rectal dose as one gains experience. Dosimetriccoverage of the prostate was not affected by use of the gel.

POSTER DISCUSSION: MISCELLANEOUS

Thursday, April 18, 2013

9:00 AMe10:00 AM

PD01

Advantages of Image-Guidance in Locally Advanced Anal Cancer

HDR Brachytherapy

Vladymir A. Solodky, Corresponding Member, Vera A. Titova, Professor,

Julya M. Kreynina, DS, Vladimir Y. Petrovsky, PhD, Anna N. Shipilova,

PhD. Brachytherapy, Russian Scientific Center of Roentgenoradiology,

Moscow, Russian Federation.

Purpose: Anal function preservation and no colostomy are the veryimportant issues for patients with locally advanced anal cancer (LACC).One consider chemoradiation with interstitial brachy as a boost techniquea preferable way of anal cancer conservative treatment, but theimplantation difficulties and complications limit the treatment access.We evaluated the capabilities of new advanced technique e MR-basedimageeguided brachytherapy (IGBT) with 9-channel flexible MR-comparable cylindric applicator e in multimodal treatment of LACC.Materials and Methods: Sixty-nine patients, (32 men and 37 women, 37-79 y.o.) were treated conservatively because of morphologically verifiedanal cancer T2-4No-2Mo with external sphincter involvement in 23(33.3%) pts. 60Co (48 pts.) and 192Ir (21 pts.) HDR intracavitarybrachytherapy was performed after chemoradiation (PFu, TP) and EBRTTD 46-50Gy to whole pelvis in 2Gy per fraction. In LN-positive patientsgroin lymph nodes were irradiated additionally till TD 60Gy. MRI 1,5Tl,abdominal and transrectal ultrasound were used for tumor monitoring,control of insertion and planning of brachytherapeutic applications. Weused oneechannel hard cylindrical applicator, standard planning, for60Co, and MR-comparable 9-channel flexible plastic mould (Nucletron�)with MR-based individualized 3D dose optimization, for 192Ir intra analapplications. For 192Ir IGBT group primary tumor extension with minimalsafety margins 10mm for normal mucosa and skin was defined as CTV,2.4 e 8.2cc [mean 4.6cc], with 2-5.5cm of tumor proximal extensionfrom anal margin. We prescribe 2Gy to the surface of intact anal mucosaand 3.6 - 4Gy to D90 of CTV per day. TD for brachy boost was 12-16Gyin intact anal mucosa and 21-24Gy in residual tumor or tumor bed, withTD of combined irradiation 67- 74Gy for CTV.Results: We reached complete response (CR) in 33 (47.8%) pts., partial(PR)O75% in 13 (18.8%), with significant results improvement in 192Irvs 60Co group: CR e 14 (67%) vs 19 (39.6%), PR e 5 (23,8%) vs 8(16.7%). In 36-mo overall survival (OS) was 50.7�5.1%, disease-freesurvival (DFS) 39.1�7.6%. Intergroup comparison: OS 61.9�3.8% vs

45.8�2.8% (p! 0.05), DFS 52.4�4.7% vs 33.3�2.9% (p!0.1) in 192Ir vs60Co group, respectively. No acute complications Grade IV were registered.Conclusions: MR-based 3Deoptimized 192Ir IGBT can be considereda method of choice for sphincter preserved treatment of locally advancedanal cancer.

PD02

Non-Melanoma Skin Cancer Treated with Electronic

Brachytherapy: Results at One Year

Ajay Bhatnagar, MD, MBA1,2. 1Cancer Treatment Services e Arizona,

Casa Grande, AZ; 2Radiation Oncology, University of Pittsburgh School

of Medicine, Pittsburgh, PA.

Purpose: We report clinical outcomes at one year or more following high-dose-rate (HDR) electronic brachytherapy (EBT) using surface applicatorsfor treatment of non-melanoma skin cancer (NMSC).Materials and Methods: From July 2009 to April 2012, 122 patients with171NMSC lesions were treatedwith EBT to a dose of 40.0 Gy in 8 fractions,delivered twice weekly. At followup, patients were assessed for acute andlate toxicities, cosmesis and local control.Results: Treatment of 171 lesions was completed in 122 patients witha mean age 73 years. There have been no recurrences to date with a meanfollowup of 10 months (range 1-28 months). One year or longer followupdata was available for 46 lesions in 42 patients. Hypopigmentation (allgrade1) was present in 5 (10.9%) of 46 lesions at one year. Other lateeffects at one year included dry desquamation, alopecia and rashdermatitis which occurred in 1 (2.2%), 1 (2.2%), and 3 (6.5%) of 46lesions, respectively. No grade 3 or higher adverse events were observedat any time point. Cosmesis was evaluated at one year for 42 of 46 lesionsand was excellent for 39 (92.9%) and good for 3 (7.1%) of the 42evaluable lesions.Conclusions: Treatment of NMSC with HDR EBT using surfaceapplicators was effective with no recurrences, good to excellent cosmesisand acceptable toxicities at one year or more post-treatment. HDR EBTprovides a convenient non-surgical treatment option for NMSC patients.

PD03

Risk Factors for Recurrence in Childhood and Adolescent Thyroid

Cancer

Stephanie Markovina, MD, PhD, Todd A. DeWees, PhD, Perry W. Grigsby,

MD. Radiation Oncology, Washington University School of Medicine, St.

Louis, MO.

Purpose: Appropriate management of differentiated thyroid cancer inpediatric patients is not well established. In this study we evaluated thecorrelation of clinical and treatment factors on disease control andsurvival in pediatric patients with well-differentiated thyroid cancer(DTC). We also explored patterns of recurrence and surveillanceapproaches.Materials and Methods: We reviewed a prospectively collected cohort of113 patients with DTC treated at our institution, ranging in age from 4.2 to21.9 years. One hundred two patients (90%) were treated with upfront totalthyroidectomy, while 3 patients received subtotal thyroidectomy and 9patients received lobectomy. All but 21 patients received post-operativeradioactive iodine, and all patients subsequently received hormonereplacement/suppressive therapy. Patients were followed with clinicalexams, serum thyroid stimulating hormone (TSH) levels, and whole body131I scintigraphy.Results: The cohort consisted of 24 males and 89 females, the majority ofwhich were Caucasian (101 patients). Tumor histologywas largely papillary(77%), and at the time of diagnosis, only 40 patients (35%) had diseaseconfined to the thyroid. The overall survival rate with a mean followup of18.9 years (median 17.4) in our cohort was 98%. 10-year progression-freesurvival was 72%, with 40 patients (35%) experiencing recurrence bytime of analysis. The mean time to first recurrence was 8.3 years (range0 to 36). Not receiving post-operative 131I was significantly associatedwith recurrence (p 5 0.0038). The cumulative recurrence-free survival of