Reduced Toxicity With Intensity Modulated Radiation Therapy (IMRT) for Desmoplastic Small Round Cell Tumor (DSRCT): An Update on the Whole Abdominopelvic Radiation Therapy (WAP-RT) Experience

Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
International journal of radiation oncology, biology, physics (Impact Factor: 4.18). 10/2012; 85(1). DOI: 10.1016/j.ijrobp.2012.09.005
Source: PubMed

ABSTRACT PURPOSE: Desmoplastic small round cell tumor (DSRCT) is a rare malignancy typically involving the peritoneum in young men. Whole abdominopelvic radiation therapy (WAP-RT) using conventional 2-dimensional (2D) radiation therapy (RT) is used to address local recurrence but has been limited by toxicity. Our objectives were to assess the benefit of intensity modulated radiation therapy (IMRT) on toxicity and to update the largest series on radiation for DSRCT. METHODS AND MATERIALS: The records of 31 patients with DSRCT treated with WAP-RT (22 with 2D-RT and 9 with IMRT) between 1992 and 2011 were retrospectively reviewed. All received multi-agent chemotherapy and maximal surgical debulking followed by 30 Gy of WAP-RT. A further focal boost of 12 to 24 Gy was used in 12 cases. Boost RT and autologous stem cell transplantation were nearly exclusive to patients treated with 2D-RT. Toxicities were assessed with the Common Terminology Criteria for Adverse Events. Dosimetric analysis compared IMRT and simulated 2D-RT dose distributions. RESULTS: Of 31 patients, 30 completed WAP-RT, with a median follow-up after RT of 19 months. Acute toxicity was reduced with IMRT versus 2D-RT: P=.04 for gastrointestinal toxicity of grade 2 or higher (33% vs 77%); P=.02 for grade 4 hematologic toxicity (33% vs 86%); P=.01 for rates of granulocyte colony-stimulating factor; and P=.04 for rates of platelet transfusion. Post treatment red blood cell and platelet transfusion rates were also reduced (P=.01). IMRT improved target homogeneity ([D05-D95]/D05 of 21% vs 46%) and resulted in a 21% mean bone dose reduction. Small bowel obstruction was the most common late toxicity (23% overall). Updated 3-year overall survival and progression-free survival rates were 50% and 24%, respectively. Overall survival was associated with distant metastasis at diagnosis on multivariate analysis. Most failures remained intraperitoneal (88%). CONCLUSIONS: IMRT for consolidative WAP-RT in DSRCT improves hematologic toxicity in particular. Although the long-term efficacy of current treatment options remains disappointing, the improved therapeutic index of IMRT may aid in generalizing its use and allowing the addition of novel approaches such as intraperitoneal immunotherapy.

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    ABSTRACT: Purpose. To study the clinical, radiological, and pathological characteristics of abdominal desmoplastic small round cell tumor (DSRCT) and investigate the optimal therapy modalities. Patients and Methods. A retrospective cohort study was performed on 12 abdominal DSRCT patients; all pathological, radiological, and prognostic data were analyzed. There were 3 patients (25%) with metastatic disease at presentation. In all 12 cases, 6 cases underwent operation and adjuvant chemotherapy (group 1, 6/12, 50%). The other 6 cases were diagnosed by fine needle aspiration or exploratory laparotomy biopsy (group 2, 6/12, 50%); all cases received four to six courses of multiple agents chemotherapy, respectively. Results. All cases were finally diagnosed as DSRCT pathologically. Among group 1, all cases underwent en bloc resection (2/6, 33%) or tumor debulking (4/6, 67%) and, following four courses of multiple agents chemotherapy, Kaplan-Meier analysis revealed that 3-year survival was 50% in group 1 versus 16.7% in group 2 (P < 0.05). Gross tumor resection was highly significant in prolonging overall survival; patients with localized solitary lesion have a better prognosis, most likely due to increased feasibility of resection. Conclusions. DSRCT is a rare malignant tumor with poor prognosis. Surgical excision with combination chemotherapy as an adjunct is mandatory for nonmetastatic cases because these modalities used in isolation may have less impact.
    01/2014; 2014:549612. DOI:10.1155/2014/549612
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    ABSTRACT: The St George Hospital specialises in peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) for treatment of intra-abdominal malignancies. Despite performing around 800 peritonectomy and HIPEC procedures, we have rarely encountered desmoplastic small round cell tumours (DSRCT). We present our experiences with DSRCT, and propose peritonectomy and HIPEC as a treatment option for DSRCT. This is a case series of 3 cases. The first case was a 26-year-old male who presented with appendicitis which we diagnosed as DSRCT and treated with peritonectomy and HIPEC. The second case was a 14-year-old male referred to our centre for peritonectomy and HIPEC after initial presentation with a pelvic mass and treatment with chemotherapy. The third case was a 21-year-old male referred to our centre for peritonectomy and HIPEC for recurrent DSRCT after previously being treated with neoadjuvant chemotherapy and surgery without HIPEC. DSRCT is a rare, almost exclusively intra-abdominal malignancy, which predominantly affects young males. Survival prognosis remains poor in DSRCT despite conventional treatment with surgery, chemotherapy and radiotherapy; however, HIPEC has offered promising survival results. Our recurrences with peritonectomy and HIPEC at 6 months and 15 months are comparable with the literature of 8.85 months. In our experience, patients with DSRCT who present with nodal involvement or recurrent disease tend to recur early despite treatment with peritonectomy and HIPEC. Longer term follow up of our patients and future studies involving HIPEC in DSRCT would be useful in assessing long-term clinical outcomes and survival. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
    12/2014; 7C:85-88. DOI:10.1016/j.ijscr.2014.09.022
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    ABSTRACT: Background With nearly 450 cases reported since 1991, desmoplastic small round cell tumor (DSRCT) is a rare abdominal tumor typically arising in adolescent and young adult white men. With no large series described, the best therapeutic strategy remains unclear. Methods All consecutive patients treated in our tertiary care center between January 1991 and December 2013 for a DSRCT were retrospectively studied. Results Thirty-eight patients with a median age of 27 years (range 13–57 years) were identified; 71 % were men. At the time of diagnosis, 47.4 % patients had extraperitoneal metastases (EPM): 78 % were located in the liver and 11 % were located in the lungs. Fourteen patients (37 %) were treated exclusively with systemic chemotherapy, with a median survival of 21.1 months. Twenty-three patients underwent surgery, 12 (52 %) experienced complete removal of all macroscopic disease, 5 (21.7 %) received additional intraperitoneal chemotherapy, and 7 (30 %) received postoperative whole abdominopelvic radiotherapy (WAP RT). With a median follow-up of 59.9 months, the median survival was 37.7 months, and the median disease-free survival was 15.5 months. The factors predictive of 3-year overall survival were the absence of EPM, complete surgical resection, postoperative WAP RT, and postoperative chemotherapy. The intraperitoneal chemotherapy had no impact on overall survival. Conclusions DSRCT is a rare and aggressive disease. In patients without EPM, a multimodal treatment combining systemic chemotherapy, complete macroscopic resection, and postoperative WAP RT could enable prolonged survival. No benefit of surgery was demonstrated for patients with EPM. The value of associated hyperthermic intraperitoneal chemotherapy remains unproven.
    Annals of Surgical Oncology 10/2014; 22(4). DOI:10.1245/s10434-014-4123-6 · 3.94 Impact Factor