Presentation on theme: "Morbidity / Complications"— Presentation transcript:
1 Morbidity / Complications Patients experienced only expected post-implant reactionsTwo patients with self-limited superficial necrosis of vaginal mucosaNo hospitalizations, fistulas or other severe side effectsWooten CE, Randall ME, … Feddock J. Implementation and Early Clinical Results utilizing Cs-131 permanent interstitial implants for gynecologic malignancies. Gyn Oncol 2014.
2 WHAT IF THERE WERE A TREATMENT FOR RECURRENT GYNECOLOGIC CANCERS WITH: A SIGNIFICANT SALVAGE RATE (CURE), andLIMITED MORBIDITY, andAT A REASONABLY LOW COST?THERE IS SUCH A TREATMENT FOR SELECTEDPATIENTS: INTERSTITIAL RE-IRRADIATION.DON’T FORGET ABOUT IT!
3 Use of Cesium-131 in Definitive Therapy for Gynecologic Malignancies Primarily used as a boost:Adjuvantly for a positive margin (vaginal cuff post hysterectomy)Definitively to treat gross diseaseUnresectable diseaseSmall volume residual following standard therapyIdeally reserved for patients considered unsuitable for treatment using Syed-Neblett either for medical or logistical reasons
4 UK Experience using Cs-131 as a component of primary therapy Median age: 66 (37-87)Type of CancerN=Recurrent Endometrioid AdenoCa5Post-operative Endometrioid AdenoCa4Post-operative Cervical SCCa2Primary Vaginal AdenoCa3Vaginal MelanomaVulvar SCCa
5 Characteristics of Cs-131 Implants used for Primary Therapy Total implants performed: 18Median dose = 22 Gy (15-50 Gy)Median seed count = 13 (9-30)Median source strength = 0.76 u/seed ( )Median area treated = 6 cm2 ( cm2)Indication for Cesium-131 BoostN=Microscopic positive margin4Gross disease post-operatively2Gross disease at end of primary radiation10Gross disease before primary radiation (melanoma)
6 Results incorporating Cesium-131 into Initial Therapy Median Follow-up 6.7 months ( months)Disease control:There have been no local failures – LC = 100%Only one patient has developed regional and/or metastatic diseasePatient with vaginal melanoma developed a confirmed inguinal lymph node recurrence at 8.2 months post treatmentToxicity:Very low – nearly all develop acute grade 1-2 mucosal reactions that quickly resolveTwo patients have developed grade 3 mucosal reactionsOne with persistent changes beyond 6 monthsOne patient has identified persistent grade 2 GU toxicity beyond 6 months
7 A Case of Vulvovaginal Melanoma 40 Gy to 5mm using Cs-1312 weeks laterAdditional 30 Gy using EBRT
8 What can be gained by adding Interstitial Brachytherapy? 45 Gy PRT followed by ICB 7 Gy to 5mm depth x345 Gy PRT followed by ICB 7 Gy to surface x2 then 20 Gy Cs-131Dose to 5mm DepthBED = 88.8 GyEQD23 = 74.0 GyDose to Vaginal SurfaceBED = GyEQD23 = 87.0 GyDose to the Rectum (approx 5mm deep)EQD210 = 85.2 Gy7 Gy per implant delivered to the entire active length treatedDose to 5mm DepthBED = 88.8 GyEQD23 = 73.0 GyDose to Vaginal SurfaceBED = 97.4 GyEQD23 = 81.1 GyDose to the Rectum (approx 5mm deep)EQD210 = 70.2 GyGy per implant times active lengthReceives prescription dose of Cs-131 implant, but to length of 1-1.5cmAll calculations performed using GEC-ESTRO LQ Worksheet.
9 Patient Selection How do we decide which type of implant to use? Depth of the tumor< 5mm: vaginal cylinder will do fine5mm – 1cm: permanent implant using Cesium-131 or Gold-198≥ 1cm: Syed-Neblett or other catheter based treatmentVaginal CylinderPermanent SeedsSyed-Neblett
10 ConclusionsUK first to utilize/investigate Cs131 permanent interstitial implants for recurrent or new primary gynecologic malignancies.Actuarial local control rate at time of analysis was 84.4%, exceeding other published rates with minimal toxicity.Interstitial implants with Cs-131 should be more frequently and widely incorporated into management of gynecologic malignancies, including accessible recurrences following previous RT.
11 So How Do I Perform One?42 year old female diagnosed with Stage II clear cell uterine cancer after TAH/BSO/LNSReceives adjuvant therapy:45 Gy to the Pelvis followed by 6 cycles of Carbo/TaxolWithin first month off therapy develops vaginal bleedingBiopsy proven recurrence at vaginal apexTreated with Vaginal brachytherapy 30Gy/10 fractions BID to the surface3 weeks post brachytherapy, exam demonstrates progressive tumor at the vaginal apexMRI confirms this is only site of diseaseScheduled for Exenteration with Gyn OncologistTreated instead with Interstitial Re-irradiation using Cesium-131
13 Description of Procedure Gross tumor volume to be implanted determined based on three-dimensional tumor measurements based on pelvic exam and imagingTotal activity, seed strength, and geometry calculated using Paterson-Parker rulesOutpatient procedure in the Radiation Oncology DepartmentPremedication: 5-10 mg po DiazepamLocal anesthesia: 2% lidocaine ± epinephrineIndividual seed applicators to insert each seed
14 Plan to deliver 55 Gy to 3 x 4.5cm ellipse 3cm B4.5cm1. Determine the Area: π * A * B = π * 1.5 * 2.25 = 10.6 cm2. Determine the necessary activity to deliver 10 Gy in Radium equivalent
15 3. Convert the activity in Radium equivalent to activity in Au-198: 8.25 R-cm2/mg-hr * 250 mg-hrs * 55 Gy = mCi of Au-1982.38 R-cm2/mg-hr mg-hrs Gy4. Convert the activity in Au-198 into activity in Cs-131 using conversion factor of 1.1:51.09 mCi of Au-198 * 1.1 = mCi of Cs-1315. Determine the number of seeds necessary to perform the implant:Using Paterson-Parker RulesArea <25 cm2 2/3 in the peripheral, 1/3 centralCircumference = cmSpacing seeds evenly at 1cm increments – 12 seeds will be neededIf 2/3 = 12, then 1/3 will equal 6So total number of seeds = 18
16 6. Determine the activity needed per seed: Total activity = mCi of Cs-131 = 3.12 mCi/seedSeed count 18 seedsConvert to Air-Kerma Strength using factor of 0.638:Air-Kerma Strength = 3.12 mCi/seed * u/mCi = 1.99 u/seedSo, we need to order 18 seeds at 1.99 u/seed to deliver 55 Gy to 5mm depthI usually order 10% extra in order to account for tumor growth between calculation and implant dateSo we ordered #21 seeds