Management algorithm for HIV-associated parotid lymphoepithelial cysts

We report an evidence-based management algorithm for benign lymphoepithelial cysts (BLEC) of the parotid glands in HIV patients based on long-term outcomes after radiation therapy. From 1987 to 2013, 72 HIV-positive patients with BLEC of the parotid glands treated at our institutions were identified and their medical records were reviewed and analyzed. The primary endpoint of our study was to determine a dose response in HIV patients with BLEC. In group A (≤18 Gy), which received a median dose of 10 Gy (8-18), overall response (OvR), complete response (CR), partial response (PR), and local failure (LF) was experienced by 7, 7, 0, and 93 %, respectively. In group B (≥22.5 Gy), which received a median dose of 24 Gy (22.5-30), OvR, CR, PR, and LF was experienced by 88, 65, 23, and 12 %. Logistic regression revealed that higher dose (≥22.5 Gy) predicted for cosmetic control (p = 0.0003). Multiple regression analysis revealed higher dose predicted for cosmetic control (p = 0.0001) after adjusting for confounding variables (age, gender, race, HAART use, BLEC duration, and fractionation size). No patients in either group experienced RTOG grade ≥3 toxicities. A radiation dose of 24 Gy delivered in 12-16 fractions of 1.5-2 Gy per fraction provides long-term cosmetic control in HIV-positive patients with BLEC of the parotid glands.

Osteosarcoma following single fraction radiation prophylaxis for heterotopic ossification

Radiotherapy for prophylaxis of heterotopic ossification (HO) is commonly used in high risk patients following orthopedic surgery. While treatment is effective and can prevent morbidity associated with HO, with any dose of radiation there is a concern of a radiation induced malignancy. Here we a report a case of radiation induced osteosarcoma which developed 11 years after a single fraction of 700 cGy. We performed dosimetric analysis by superimposing the patient’s original treatment field on a CT scan performed after the diagnosis. The radiotherapy dose for this patient is lower than classically reported for radiation induced sarcomas. We identified greatest bony destruction that was thought to be the epicenter of the tumor, and this was specially contoured on the diagnostic CT scan. This volume appears to be located at the edge of the radiotherapy field. Fifty percent of the treated volume received 240 cGy, the mean dose was 333 cGy. There was a variation across the treatment volume, between 21.8 cGy and 717 cGy. While a rare complication, we stress the importance of informing regarding the risk of a radiation induced malignancy following HO prophylaxis.