Feasibility of Monte-Carlo algorithm in comparison with collapse-cone dose calculation algorithm of a commercial treatment planning system in the presence of high-density metallic implant: a dosimetric study.

BACKGROUND: The number of people with implanted hip prosthesis has grown worldwide. For radiotherapy planning of patients with hip implants, few main challenges are encountered. The aim of the present study was to evaluate the feasibility of different planning algorithms in the presence of high-density metallic implant in the treatment of patients with carcinoma cervix. RESULTS: It was found that D98% were 44.49 ± 0.11, 44.51 ± 0.13, 44.39 ± 0.22, and 44.45 ± 0.16 Gy for 4FMC6MV (4-field technique calculated with Monte-Carlo algorithm and 6 MV photon energy), 4FMC6MV_WP (4-field technique calculated with Monte-Carlo algorithm and 6 MV photon energy without prosthesis), 4FCC6MV (4-field technique calculated with collapse-cone-convolution algorithm and 6 MV photon energy), and 4FCC6MV_WP (4-field technique calculated with collapse-cone-convolution algorithm and 6 MV photon energy without prosthesis) respectively. Similarly, D2% were 49.40 ± 0.84, 49.05 ± 0.76, 48.97 ± 0.91, and 48.57 ± 0.85 Gray (Gy) for 4FMC6MV, 4FMC6MV_WP, 4FCC6MV, and 4FCC6MV_WP respectively. The present study has not suggested any major difference between the Monte-Carlo (MC) and collapse-cone-convolution (CCC) calculation algorithm in the presence of high-Z metallic implants. Volume of bowel receiving 15 Gy dose has shown a significant difference with prosthesis cases. This study investigates that hip prosthesis creates considerable changes in the treatment planning of cervical malignancies. CONCLUSION: CCC algorithm is in good agreement with MC calculation algorithm in the presence of high-density metallic implants in terms of target coverage and avoidance organ sparing except few parameters.

Primary angiosarcoma of the breast: a radiation oncologist's perspective with a concise review of the literature.

A 28-year-old premenopausal woman presented with a painful rapidly growing mass in her right breast and was evaluated with a core needle biopsy, which was suggestive of poorly differentiated carcinoma. Immunohistochemical evaluation revealed primary angiosarcoma of breast. Whole body 18flouro-deoxyglucose positron emission tomography CT showed few metabolically active soft tissue lesions in upper inner quadrant of right breast. The patient underwent breast conservation surgery and in view of positive surgical margins, received adjuvant radiation therapy. Post-treatment completion, the patient has been disease free for 6 months. Primary angiosarcoma of the breast is a rare malignancy which is best managed with a surgery as first approach, with due importance being given to the patient's perspective on their disease and choices for adjuvant treatment. Decisions in addition to adjuvant radiotherapy need to be made in the multidisciplinary clinic, due to paucity of data.