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EP-1895: Treated volumes comparison for different fractionation regimens of cervical cancer HDR brachytherapy
ESTRO 33, 2014 The total number of late toxicity among patients First group treated with HDR brachytherapy substantially (p< 0.05) was 6% more in comparison with Second group, due to a reliable (p< 0.05) increase in to 3% the quantity of late urinary bladder toxicity. Conclusions: Quantity early and late toxicity substantially depend from method dose treatment planning brachytherapy for combine radiotherapy carcinoma of the uterine cervix. EP-1895 Treated volumes comparison for different fractionation regimens of cervical cancer HDR brachytherapy K. Akbarov1, I. Isayev1, E. Guliyev1, R. Huseynov1, T. Muravyov1 1 National Oncological Centre, Radiotherapy, Baku, Azerbaijan Purpose/Objective: HDR brachytherapy boost is the important tool which allows us to escalate dose to the HRCTV of cervical carcinoma. But it could be done by different fractions and regimens. In this research we compared dose distribution for two HDR brachytherapy regimens: four times 7 Gy (group A) and two times 9 Gy (group B). Materials and Methods: We analyzed treatment plans of 29 patients. 18 of them had IIB stage and 11 – IIIB stage cervical carcinoma. All patients received concurrent chemoradiotherapy: EBRT (3D conformal or IMRT in case of metastatic pelvic lymph nodes) by 2 Gy daily fraction to 50 Gy and cisplatin 40 mg/m2. At the last week of EBRT we started HDRBt by CT-based 3D image guiding. We contoured HRCTV (relevant to pretreatment MRI) and organs at risk (rectum, sigmoid, intestine, bladder) according to GEC-ESTRO recommendations. Patients in group A received two 7 Gy fractions with one applicator insertion in two consecutive days (leaved wit applicator in place) with one week interval, totally 4 fractions; patients in group B received two 9 Gy fractions with one week interval, totally 2 fractions. For all 29 patients we did both plans (2 plans by 7Gy and 2 plans by 9 Gy prescription dose for each patient, at the same contoured study sets, totally 116 plans). Dose constraints for 2 cc of bladder was ≤ 90 Gy and for rectum, sigmoid and bowel ≤ 70 Gy using α/β 3 in all cases. Results: EQD2 (α/β10) for 4x7Gy is 39.7 Gy, also we calculated the same isodose from 2x9 Gy – 11.2 Gy (EQD2 for 2x11.2 Gy is 39.7Gy). Afterwards we calculated volumes of 7 Gy isodose levels on 4x7 Gy plans (group A) and 11.2 Gy isodose levels on 2x9 Gy plans (group B). The mean volumes received 39.7 Gy HDR brachytherapy boost were 67.1cc and 62.7cc in groups A and B respectively without statistically significant difference. Conclusions: Inspite of different fractionation regimens (4x7 Gy and 2x9 Gy) and moreover - different total doses (28 and 18 Gy) of HDR brachytherapy, there is no significant advantage between these regimens according to the treated volume due to the organs at risk dose constraints limiting factor. EP-1896 Brachytherapy BT in locally advanced cervical cancer after two different schedules of external radiotherapy. T. Leroy1, A. Cordoba1, S. Palumbo1, E. Tresch2, A. Wagner3, P. Nickers1, T. Lacornerie3, E. Lartigau1 1 Centre Oscar Lambret, Radiation Oncology, Lille, France 2 Centre Oscar Lambret, Statistic, Lille, France 3 Centre Oscar Lambret, Radiation physics, Lille, France Purpose/Objective: Evaluate High Risk Clinical Target Volume (HRCTV) shrinkage in in Locally Advanced Cervical Cancer (LACC) treated with two different external therapy schedule treatments and its influence in organ at risk (OR) irradiated volume. Materials and Methods: From 09/2012 to 06/2012, thirty-six patients with LACC (FIGO Ib-IVa) received BT boost at our institution. In all patients three IRM were realized: at diagnosis time, after concomitant radio-chemotherapy (RTCT) and at BT application time. Histology: 25 patients (69.4%) squamous cell (SC) histology and 11 (30.6%) Adenocarcinoma (AC) histology. Group A patients: 22 (61.11%) received 60Gy (50.4Gy to pelvic and para aortic, if indicated, volume and 59.96Gy to Intermediated Risk CTV) with Tomotherapy and two BT fractions of 6.5Gy each one. Group B: 14 (38.88%) received 45-50.4Gy to pelvic and para aortic, if indicated, volume and four BT fractions of 6.5Gy each one. HRCTV and OAR contouring volumes were done according GECESTRO recommendations. D90 and D100 referring HRCTV coverage and D0.1, D1, D2, D5 and D10 referring OAR received dose were noted. Results: Group A patients had an average decrease in tumor size of 61% at BT application time and 45% for group B patients (p:0.074). SC histology patients presented an average decrease in tumor size of 59% at
S321 BT application time and AC patients of 45% (p:0.083). Median D90 HRCTV of group A patients were 80.8 Gy (74-88 Gy) and 89.6 Gy (82.6-104 Gy) for group B patients (p≤ 0.001). No differences in terms of OR irradiated volume were seen comparing both groups of patients, neither in terms of acute toxicity nor local recurrence (9.1% in group A and 7.1% in group B patients respectively) at 6 months. Conclusions: Delivery of 60 Gy to IRCTV with Tomotherapy is feasible and provides a great HRCTV volume reduction at BT application time without more acute toxicity or local recurrences rates. EP-1897 Clinical outcomes and toxicity in MRI based cervical brachytherapy F. Celada1, E. Cuervo1, O. Pons1, S. Roldán1, A. Soler1, R. Chicas1, S. Rodríguez2, A. Tormo1 1 Hospital La Fe, Radiotherapy, Valencia, Spain 2 Clinica Benidorm, Radiotherapy, Benidorm, Spain Purpose/Objective: The GEC-ESTRO recommendations for IGRT in brachytherapy (BT-IGRT), the incorporation of magnetic resonance imaging (MRI) in the planning and new MRI-compatible applicators have changed the specification of the dose to the tumor and organs at risk. The new volumes: GTVB (gross tumor at the time of BT), HR-CTV (GTVB + all areas suspicious + cervix), IR-CTV (GTVD-macroscopic tumor at the start of radiotherapy-+ HR-CTV with range of 5 to 10 mm), 2cc maximum dose of bladder, rectum and sigmoid appear to correlate best with the responses and risk of complications that ICRU points (A / H, bladder / rectal). To review clinical outcomes, toxicity and dosimetry in patients with tumors of the cervix, in whom BT has been performed as recommended by GEC-ESTRO with exclusive MRI planning. Materials and Methods: 59 patients were retrospectively reviewed with squamous cell carcinoma of cervix treated with BT-IGRT between September 2007 and June 2012. After a standard weekly QT (cisplatin 40 mg/m2) concomitant with RTE (minimum 45 Gy over pelvis, the BT-IGRT was performed with the MRI compatible applicator of Nucletron ® . With two separate applications 1 week, 2 fractions in each application, 24 hours apart, reaching 28Gy to D90 (HR-CTV). In no case, limits established for bladder, rectal and sigmoid have been exceeded. The technique included in all cases, MRI exclusive planning. Patients were classified according to the FIGO 2009 classification, AJCC TNM 2006 and toxicities according to CTCAE v4.0. The response was assessed with brachytherapy gynecological examination and MRI at 3 months. Results: 59 patients were treated and staged as follows: 3% Ib, IIa 8%, IIb 58%, IIIb 24% and IVA 7% and 75% negative nodes and 25% positive nodes. The final average doses in EQD2 (HR-CTV D90, D90 IR-CTV, max dose 2cc bladder, rectum and sigmoid) were respectively (85.5 Gy, 65.2 Gy, 79.3 Gy, 61.2 Gy and 58.2 Gy). Mean follow-up was 18 months. High toxicities have been genitourinary ( G0 90%, G1-G2 8% and G3-4 2%) and gastrointestinal (GO 88%, G1-2 9% and G3-4 3%). Local failure / regional was 4/59 patients (7%) and only has been associated with large tumors (>4 cm) with poor response to RTE 3 relapses (75%.) Conclusions: Our results suggest that BT-IGRT as recommended by the GEC-ESTRO, is safe in terms of local control and acute morbidity. These clinical and dosimetric results compare favorably with the traditional technique. EP-1898 Quantification of dwell position inaccuracy and dose heterogeneity in ring & tandem applicator using OSL-nano dots A.Q. Jangda1, A. Sharib1, R. Latif1, N. Mansoor1, A. Nasir1 1 Aga Khan University Hospital, Oncology, Karachi, Pakistan Purpose/Objective: Ring applicators have got an inherent dwell position inaccuracy due to the flexible nature of the wire and the tight curvature of the ring applicator. Varian has issued two CTBs and one Medical Device Recall to inform the users about this discrepancy and emphasized to characterize each individual applicator to avoid the unintended dose delivery. The aim of this study is to present a method to determine the optimal universal distal dwell offset on the basis of the relative dose heterogeneity.The method was established using Varian 60o ring applicator (GM11000760)and OSL-Nano Dots. Materials and Methods: The study based on the characterization of Varian 60oring applicator with Varian GammaMed Plus after loader. 12 OSL-Nano Dots positioned on the surface of the ring applicator and irradiated for a universal dwell offset of 0, 1, 2, 3, and 4 mm. The irradiation carried out for a total of 20 dwell positions at a step size of 5 mm and for dwell time of 2 Sec(reference to 10 Ci Ir-192 source).
S321 BT application time and AC patients of 45% (p:0.083). Median D90 HRCTV of group A patients were 80.8 Gy (74-88 Gy) and 89.6 Gy (82.6-104 Gy) for group B patients (p≤ 0.001). No differences in terms of OR irradiated volume were seen comparing both groups of patients, neither in terms of acute toxicity nor local recurrence (9.1% in group A and 7.1% in group B patients respectively) at 6 months. Conclusions: Delivery of 60 Gy to IRCTV with Tomotherapy is feasible and provides a great HRCTV volume reduction at BT application time without more acute toxicity or local recurrences rates. EP-1897 Clinical outcomes and toxicity in MRI based cervical brachytherapy F. Celada1, E. Cuervo1, O. Pons1, S. Roldán1, A. Soler1, R. Chicas1, S. Rodríguez2, A. Tormo1 1 Hospital La Fe, Radiotherapy, Valencia, Spain 2 Clinica Benidorm, Radiotherapy, Benidorm, Spain Purpose/Objective: The GEC-ESTRO recommendations for IGRT in brachytherapy (BT-IGRT), the incorporation of magnetic resonance imaging (MRI) in the planning and new MRI-compatible applicators have changed the specification of the dose to the tumor and organs at risk. The new volumes: GTVB (gross tumor at the time of BT), HR-CTV (GTVB + all areas suspicious + cervix), IR-CTV (GTVD-macroscopic tumor at the start of radiotherapy-+ HR-CTV with range of 5 to 10 mm), 2cc maximum dose of bladder, rectum and sigmoid appear to correlate best with the responses and risk of complications that ICRU points (A / H, bladder / rectal). To review clinical outcomes, toxicity and dosimetry in patients with tumors of the cervix, in whom BT has been performed as recommended by GEC-ESTRO with exclusive MRI planning. Materials and Methods: 59 patients were retrospectively reviewed with squamous cell carcinoma of cervix treated with BT-IGRT between September 2007 and June 2012. After a standard weekly QT (cisplatin 40 mg/m2) concomitant with RTE (minimum 45 Gy over pelvis, the BT-IGRT was performed with the MRI compatible applicator of Nucletron ® . With two separate applications 1 week, 2 fractions in each application, 24 hours apart, reaching 28Gy to D90 (HR-CTV). In no case, limits established for bladder, rectal and sigmoid have been exceeded. The technique included in all cases, MRI exclusive planning. Patients were classified according to the FIGO 2009 classification, AJCC TNM 2006 and toxicities according to CTCAE v4.0. The response was assessed with brachytherapy gynecological examination and MRI at 3 months. Results: 59 patients were treated and staged as follows: 3% Ib, IIa 8%, IIb 58%, IIIb 24% and IVA 7% and 75% negative nodes and 25% positive nodes. The final average doses in EQD2 (HR-CTV D90, D90 IR-CTV, max dose 2cc bladder, rectum and sigmoid) were respectively (85.5 Gy, 65.2 Gy, 79.3 Gy, 61.2 Gy and 58.2 Gy). Mean follow-up was 18 months. High toxicities have been genitourinary ( G0 90%, G1-G2 8% and G3-4 2%) and gastrointestinal (GO 88%, G1-2 9% and G3-4 3%). Local failure / regional was 4/59 patients (7%) and only has been associated with large tumors (>4 cm) with poor response to RTE 3 relapses (75%.) Conclusions: Our results suggest that BT-IGRT as recommended by the GEC-ESTRO, is safe in terms of local control and acute morbidity. These clinical and dosimetric results compare favorably with the traditional technique. EP-1898 Quantification of dwell position inaccuracy and dose heterogeneity in ring & tandem applicator using OSL-nano dots A.Q. Jangda1, A. Sharib1, R. Latif1, N. Mansoor1, A. Nasir1 1 Aga Khan University Hospital, Oncology, Karachi, Pakistan Purpose/Objective: Ring applicators have got an inherent dwell position inaccuracy due to the flexible nature of the wire and the tight curvature of the ring applicator. Varian has issued two CTBs and one Medical Device Recall to inform the users about this discrepancy and emphasized to characterize each individual applicator to avoid the unintended dose delivery. The aim of this study is to present a method to determine the optimal universal distal dwell offset on the basis of the relative dose heterogeneity.The method was established using Varian 60o ring applicator (GM11000760)and OSL-Nano Dots. Materials and Methods: The study based on the characterization of Varian 60oring applicator with Varian GammaMed Plus after loader. 12 OSL-Nano Dots positioned on the surface of the ring applicator and irradiated for a universal dwell offset of 0, 1, 2, 3, and 4 mm. The irradiation carried out for a total of 20 dwell positions at a step size of 5 mm and for dwell time of 2 Sec(reference to 10 Ci Ir-192 source).