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topicact TRANSVERSAL THEMES
SOCIÉTÉ INTERNATIONALE D'ONCOLOGIE PÉHATRIQUE
SIOP ASIA CONGRESS
RADIATION ONCOLOGY
ABSTRACT NO.: OP-139
The first Russian experience of TomoTherapy application for total body irradiation in children
D.A. Kobyzeva
Federal Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitriy Rogachev, Moscow, Russia Key words: tomotherapy, total body irradiation, bone marrow transplantation
Introduction. Total Body Irradiation (TBI) combined with chemotherapy is widely used all over the world as a conditioning regimen before hematopoietic stem cell transplantation in patients with hematological malignancies. The main effects of TBI are elimination of tumour cells, as well as immunosuppression. The combination of TBI with chemotherapy showed the best results of survival of patients compared to the conditioning regimen including only chemotherapy (Rinden et al., 1996; Kroger et al., 2001). The main issue of this type of radiation therapy is a maximal homogeneous irradiation of the whole human body in an adequate dose. However, the irradiation of healthy organs and tissues that are highly sensitive to ionizing radiation (such as lungs, kidneys, anterior eye) may lead to the development of serious and most often fatal complications (Cheng et al. 2008; Esiashvili et al., 2009; Gerstein et al., 2009; Kal et al., 2009).
Aim. The development of TBI technique in children as a conditioning stage before allogenic bone marrow transplantation on TomoTherapy unit in order to maximal homogeneous radiation of the target (Planning Target Volume, PTV) and reducing the dose on critical organs without worsening of the therapy results.
Materials and methods. Over the period from July, 2014 to February, 2016 radiation therapy was performed for 39 patients. Gender ratio: boys - 25 (64 %), girls - 14 (36 %). The age of patients was from 3.2 to 20.3 years. Age median - 6.5 years. In the group there were patients with malignant hematological diseases: acute lymphoblastic leukemia ^ (n = 30), acute myeloid leukemia (n = 7), juvenile myelomonocytic leukemia (n = 1), myeloid sarcoma (n = 1). All patients were included in the group of high risk on the main disease.
O The therapy was performed every day, 2 times a day in a single boost dose (SBD) on PTV 2.0 Gy to total boost dose (TBD) 12.0 Gy. Considering a potential sensitivity of healthy
O organs and having based on a literature data the following organs of risk were chosen: lungs, kidneys and lens. The prescribed dose on PTV - 12.0 Gy. Prescribed dose on lungs:
^ Dmin (minimal dose) - 6.0 Gy.
O Results. After design of treatment plan on the TomoTherapy system the following result were received: the mean dose for PTV (Dmean) was from 11.95 to 12.7 Gy,
Z (12.39 Gy is mean dose for all patients). The dose on critical organs were following: lungs - Dmin from 5.7 to 7.1 Gy; V8 was from 5.5 to 40 % (mean for all patients - 25 %); kidneys - from
Q 8.39 to 10.71 Gy (mean for all patients - 9.17 Gy); lens - from 1.43 to 7.71 Gy (mean for all patients - 5.13 Gy). ALL patients ended the planning therapy program. Radiation therapy
< was performed in the course of the scheduled appointment of antiemetic therapy (5-HT3-receptor antagonists). Acute toxicity was observed in 38 (97 %) patients in the form O of nausea, vomiting (in 17 (55 %) patients - I degree, in 20 (51 %) - II degree, in 2 (5 %) - III degree on RTOG scale). Also during the treatment the acute parotiditis was observed oc in 17 (44%) of39 patients.
Conclusion. The performance of TBI on TomoTherapy unit gives an opportunity to provide a maximal control over irradiation dose distribution in PTV with a simultaneous reduction ofdose on critical organs. It allowsto decrease the probability of development of complications and to achieve high efficiency ofthe treatment.
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May 2016, Moscow, Russia
OF PEDIATRIC HEMATOLOGY and ONCOLOGY
ABSTRACT NO.: Q-310
Helical tomotherapy for Askin's tumor of chest wall: clinical outcomes
Siddhartha Laskar, Nikhil Kalyani, Nehal Khanna, Tushar Vora, Sajid Qureshi, Girish Chinnaswamy, Seema Medhi, Mukta Ramadwar, Sneha Shah, Rituraj Upreti, Purna Kurkure
Tata Memorial Hospital, Mumbai, India
Key words: Askin's tumor, chest wall, helical tomotherapy, outcomes
Introduction. Askin's tumor of the chest wall is a challenging tumor to treat in view of the large volume of disease at presentation & the proximity to critical structures like the lungs, heart, & spinal cord.
Aim. To evaluate the clinical outcomes of patients with Askin's tumor of the chest wall treated using helical tomotherapy.
Materials and methods. The treatment comprised multiagent chemotherapy (CTh) and local therapy in the form of surgery (Sx) & radiation therapy (RT) or definitive RT alone. Results. Sixty-four pts. between 7-21 yrs (Median: 17Yrs) treated with radical intent between January 2008 - December 2013 were included. Most (63 %) were males. Fifty-three (83 %) pts. had non-metastatic disease. Ipsilateral pleural effusion (IPE) was present in 21 (33 %). Median tumor volume was 840cc. Forty-one (64 %) underwent Sx + RT while 23 (36 %) received definitive RT. The Sx margins were close/positive in 24 (59 %) with residual viable tumor in 32 (78 %) of the resected specimen. Median percentage necrosis in the resected specimen was 85 % (Range 45-99). After a median follow-up of 24 mths the actuarial local control (LC), disease free survival (DFS), & overall survival (OS) were 74 %, 54 %, & 81 % respectively. Pts. with IPE had poorer LC (50 % vs. 84 %, P = 0.07) & DFS (42 % vs. 71 %, P = 0.02). Tumors with median volume more than 850 cc had inferior LC (67 % vs. 80 %, P = 0.74) & DFS (58 % vs. 61 %, P = 0.89) compared to smaller volumes. Post-op RT resulted in superior LC (90 % vs. 32 %, P = 0.001), DFS (69 % vs. 33 %, P = 0.003), & OS (84 % vs. 75 %, P = 0.35) compared to definitive RT. RT related late toxicities included Grade 2 pulmonary fibrosis in 1 (1.5 %) & Grade 2/3 pneumonitis in 4 (6 %). In pts. undergoing Sx, percentage necrosis in the specimen of more than 85 % resulted in superior DFS (73 % vs. 66 %, P=0.43).
Conclusion. Primary tumor volume, surgical resection, surgical margins, percentage necrosis & presence of pleural effusion influenced disease outcomes. RT related toxicities with the use of Helical Tomotherapy were not significant. The combination of CTh, Sx, & RT resulted in superior outcomes for non-metastatic Askin's Tumor.
ABSTRACT NO.: OP-367
Intensity-modulated radiation therapy in multimodality therapy for head-and-neck soft-tissue sarcomas in children
A. Usychkina, D. Kobyzeva, D. Kachanov, A. Loginova, N. Loginova, K. Fateev, M. Teleshova, S. Varfolomeeva, A. Nechesnyuk
Federal Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitriy Rogachev, Moscow, Russia
Key words: IMRT, soft-tissue sarcomas, head and neck
Introduction. Head and neck soft-tissue sarcomas in children are difficult to treat with radiation therapy due to their proximity to the critical organs and normal tissues. Aim. To report the preliminary results of Intensity-Modulated Radiation Therapy (IMRT) for head-and-neck soft-tissue sarcomas (STS) in children.
Materials and methods. From 02.2012 to 12.2015 sixty-seven patiens with STS received external-beam radiation therapy as a part of multimodality therapy programme. IMRT treatment was performed in 20 patients (29.8 %) with head-and-neck STS. The choice of treatment technique was based on the proximity of target volume to the critical organs and normal tissues. The median patient age was 46.8 months (range, 6.7-155 months). Six patients (30 %) were younger than 3 years. Male to female ratio was 1.8 to 1. The IRS clinical grouping was as follows: IRS II 2 patients (10 %), IRS III 13 patients (65 %), IRS IV 5 patients (25 %). STS histologic types were as follows: rhabdomyosarcoma in 14 patients (70 %), non-rhabdomyosarcoma in 5 patients (25 %), rhabdomyosarcoma-like in 1 patient (5 %). The tumors were located in parameningeal, head and neck sites in 12 (60 %), 7 (35 %) and 1 (5 %) patients, respectively. The surgical treatment consisting of R1, R2 resection and biopsy only was initial treatment in 2 (10 %), 2 (10 %) and 16 (80 %) patients, respectively. All patients with histologic confirmation of diagnosis received treatment according to the CWS-2009 guidelines. The time from the beginning of chemotherapy to the beginning of radiotherapy was on average 8.73 weeks (range, 1.5-37.14). The planned total dose was from 41.4 to 54 Gy with normal fractionation of 1.8 Gy 5 times per week according to the CWS-2009 guidelines. Two (10 %), 12 (60 %) and 3 (15 %) patients were treated to the total dose of 41.4 Gy, 50.4 Gy and 54 Gy, respectively. In two patients the fraction dose was reduced to 1.6 Gy due to young age (1 year and 2 years). The total dose was 51.2 Gy and 49.6 Gy in these 2 cases.
Results. Nineteen patients (95 %) received the full planned total dose. One patient was treated to the reduced total dose of 46.8 Gy due to the high-grade acute hematological and non-hematological toxicity (Grade 4) associated with acute systemic infection. In eight patients (40 %) treated with concomitant chemoradiotherapy the preventive tracheostomy tube and/or gastrostomy tube was inserted based on the preliminary analysis of the acute toxicty risks. All patients had acute hematological toxicity Grade 1-4, acute skin toxicity Grade 1 and 2 inside the irradiated area. Nineteen patients (95 %) had acute mucositis Grade 1-3. Five patients had acute esophagitis Grade 1-2. At the time of last follow-up 15 patients are alive (75 %), 4 patients (20 %) are lost to follow-up, 1 patient (5 %) died. One patient had the local tumor relapse in the regional lymphatic nodes outside of radiation field at 4.5 months follow-up. Another patient had treatment-resistant disease and clinical disease progression during the course of chemoradiotherapy. The patient died 5 months after the start of treatment. In all other patients the irradiated tumors are controlled locally. The median follow-up time was 12.2 months (range, 1.27-35.7 months). Conclusion. IMRT technique creates the homogenous dose distribution in the target volume and leads to the significant dose-sparing of critical organs and normal tissues. IMRT allows achieving the high local tumor control and low rate of Grade 3-4 acute treatment-associated toxicity in children with head-and-neck STS.
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