ESTRO 36 Abstract Book

S962 ESTRO 36 2017 _______________________________________________________________________________________________

1 CHU de Québec- L'Hôtel Dieu de Québec, Radiation Oncology and Research Centre, Quebec, Canada 2 Odette Cancer Centre, Radiation Oncology, Toronto, Canada 3 Canadian Cancer Trials Group, Queen 's University, Kingston, Canada 4 Mc Gill Jewish General Hospital, Department of Radiation Oncology, Montreal, Canada 5 Windsor Regional Hospital, Radiation Oncology, Windsor, Canada 6 CHUM Hôpital Notre Dame, Radiation Oncology, Montreal, Canada 7 University Health Network Princess Margaret Cancer Centre, Radiation Oncology, Toronto, Canada 8 Lakeridge Hospital, Radiation Oncology, Oshawa, Canada 9 Dr H Bliss Murphy Cancer Centre, Radiation Oncology, St-John's, Canada Purpose or Objective The purpose of this phase II randomized feasibility study was to assess the ability of Canadian investigators from multiple institutions to randomize patients to IGRT (Image Guided Radiotherapy) or IGRT with HDR (High Dose Rate) brachytherapy boost and to deliver the treatment according to the highest radiation oncology quality assurance benchmarks and standards. Material and Methods The primary endpoint was to determine the ability to randomize 60 patients over an 18 months period. Arm 1 (IGRT) patients received 78 Gy in 39 fractions or 60 Gy in 20 fractions (physician’s preference) while Arm 2 (IGRT + HDR) received 37.5 Gy in 15 fractions with HDR boost of 15Gy. IGRT options were daily imaging with prostate fiducial markers, cone/fan beam CT images, or ultrasound localization system. The secondary endpoints included: acute genitourinary (GU) and gastrointestinal (GI) toxicity, using NCI Common Terminology Criteria for Adverse Events (CTCAE V 3.0) at 3 months, validation of a prospectively defined radiation oncology quality assurance process including real time peer review and treatment compliance. All analyses were descriptive; no formal comparisons between treatment arms were performed. Results Between April 2014 and September 2015, 57 NCCN defined intermediate risk prostate cancer patients were randomized between IGRT alone (Arm 1) N=29, vs. IGRT plus HDR brachytherapy boost (Arm 2) N= 28. Overall, 93.0% received the treatment as randomized. There were 4 patients (1 on IGRT arm 1 and 3 patients on the IGRT+HDR arm 2) who were treated differently from randomization assignment. For the 29 patients receiving IGRT (arm 1), there were 14 cases reported with minor deviations and 3 with major deviations. For patients on IGRT+HDR (arm 2), there were 18 cases reported with minor deviations and 2 with major deviations. At 3 months in the IGRT group (Arm 1), one patient reported grade 3 diarrhea while in the IGRT+HDR group (Arm 2), two patients reported grade 3 hematuria. No other GI and GU toxicities were reported. Conclusion The pilot study demonstrated the feasibility of randomization between treatment with IGRT alone vs IGRT + HDR boost. Treatment compliance was good including adherence quality assurance. EP-1775 Acute toxicity in early cancer prostate patients: low dose rate vs high dose rate monotherapy. S. Rodríguez Villalba 1 , A. Otal Palacín 1 , J. Richart Sanchez 1 , J. Pérez-Calatayud 2,3 , M. Santos Ortega 1 1 Clinica Benidorm, Radiotherapy Department, Benidorm, Spain 2 Clinica Benidorm and Hospital La Fe, Radiotherapy Department, Benidorm, Spain

3 Hospital La Fe, Radiothetherapy Department, Valencia, Spain Purpose or Objective Brachytherapy (BT) in their two modalities, Low dose rate (LDR) and High Dose Rate (HDR) are used in prostate cancer. At present, all available clinical data regarding these two techniques suggests that they are equally effective, providing high tumor control rates. We compare our experience considering acute toxicity in patients with low or intermediate stages treated with LDR BT or HDR BT in monotherapy. Material and Methods Between January 2004 and June 2016 we have treated 113 patients with BT as an exclusively treatment, 85 patients with permanent LDR with Iodine-125 seeds and 28 with HDR Ir-192. Both modalities were performed using ultrasound based intraoperative techniques. Results LDR BT PATIENTS: Median age 68 years (48-81 y), median Gleason 5 (2-7), median value of PSA at diagnosis 7,3 ng/ml (2,5-16,3). 70 patients (82%) low risk (DÁmico classification) and 15 (18%) intermediate risk. In 25 cases (29%) the prescription dose was 145 Gy and in 60 (71%) 160 Gy. Thirty-three (39%) received hormonal treatment. HDR BT PATIENTS: Median age 70,5 years (55-80 y), median Gleason 6 (3-8), median value of PSA at diagnosis 9,08 ng/ml (3-19,75). 12 patients (42%) low risk (DÁmico classification) and 16 (58%) intermediate risk. All patients were treated with 2 applications of 13,5 Gy in monotherapy. Twenty (71%) received hormonal treatment. We analyze the acute toxicity of both treatments following criteria CTCEV.3 and the results are presented on the table. There are not Grade 3 o 4 acute toxicity.

GRADE 1 LDR/HD R

GRADE 2 LDR/HD R

GRADE

0

LDR/HDR

HAEMATURIA

100%/ 100% 0%/ 0% 0%/ 0%

CYSTITIS

35%/ 100%

3%/ 0% 21%/ 0%

INCONTINENCY URYNARY OBSTRUCCION URYNARY

97%/ 87%

0%/ 8% 3%/ 4%

60%/ 100% 15%/ 0% 30%/0%

URINARY FRECUENCY/URGEN CY

41%/ 96%

9%/ 0% 47%/ 4%

URINARY RETENTION 94%/ 100%

3%/ 0% 3%/ 0%

DIARRHEA

94%/ 100% 3%/ 0% 3%/ 0%

RECTAL INCONTINENCY

100%/ 100% 0%/ 0% 0%/ 0%

RECTITIS

94%/ 96% 6%/ 4% 0%/ 0%

Conclusion In this analyses the acute genitourinary toxicity was higher when the patient were treated with LDR BT including 2 patients (3%) who needed urinary catheter after the implant. We did not find any differences in gastrointestinal toxicity with and excellent tolerance in both groups.

Electronic Poster: Brachytherapy: Gynaecolgy

EP-1776 Is a single CT plan for vaginal cylinder brachytherapy adequate? M. Zahra 1 , M. Doak 1 , W. Keough 2 1 Western General Hospital- Edinburgh Cancer Centre,