Intensity modulated radiotherapy in abdominal malignancies: our experience in reducing the dose to normal structures as compared to the gross tumor.

BACKGROUND AND PURPOSE: A better understanding of appropriate sequencing and use of multimodality approach in the management and subsequent improvement in overall survival mandates a vigil on quality of life issues. Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities. The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for abdominal malignancies. MATERIALS AND METHODS: During the period January 2002 to March 2004, 11 patients of various sites of malignancies in the abdominal region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms. RESULTS: An average dose reduction of the mean values by 50% to the liver, 57% to the right kidney, 56% to the left kidney, 66% to the cord and 27% to the bowel, with respect to the GTV could be achieved with IMRT. The two-year disease free survival was 79% and two-year overall survival was 88%. The average number of IMRT fields used was six. CONCLUSION: IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

Desmoplastic small round cell tumor: extra abdominal and abdominal presentations and the results of treatment.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare malignant neoplasm of adolescent males. Current multimodality treatment prolongs life and rarely achieves cure. AIM: To review the presenting features, histopathology and outcome of 18 patients with DSRCT treated at a single institution. SETTING AND DESIGN: This is a retrospective observational study of patients with DSRCT who presented at the Tata Memorial Hospital between January 1994 to January 2005. MATERIALS AND METHODS: Eighteen patients of DSRCT seen during this period were evaluated for their clinical presentation, response to chemotherapy and other multimodality treatment and overall survival. The cohort of 18 patients included 11 males (61%) and 7 females (39%) with a mean age of 16 years (Range 1(1/2)--30 years). Majority (83%) presented with abdomino-pelvic disease. The others, involving chest wall and extremities. There were 6 patients (33%) with metastatic disease at presentation. RESULTS: The treatment primarily included a multimodality approach using a combination of multiagent chemotherapy with adjuvant surgery and radiotherapy as applicable. A response rate of 39% (CR-1, PR-6), with chemotherapy was observed. The overall response rate after multimodality treatment was 39% (CR-5, PR-2). The overall survival was poor except in patients who had complete excision of the tumor. Conclusion:0 Abdomino-pelvic site was the commonest presentation, the disease can occur at other non-serosal surfaces also. Despite aggressive treatment the outcome was poor. However, complete surgical excision seems to provide a better survival.