Amifostine-induced back pain: a case report.
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Amifostine↗
Biomedical subjects
Amr Aref
Publications and source records attributed to Amr Aref.
Bilateral risk for subsequent breast cancer after lobular carcinoma-in-situ: analysis of surveillance, epidemiology, and end results data.
PURPOSE: Noninvasive lesions involving the lobules of the breast are increasingly diagnosed as incidental microscopic findings at the time of lumpectomy or core-needle biopsy. We investigated the incidence rates of invasive breast cancer (IBC) after a diagnosis of lobular carcinoma-in-situ (LCIS) by using Surveillance, Epidemiology, and End Results (SEER) data. PATIENTS AND METHODS: Patients (N = 4,853) having a diagnosis of primary LCIS in the time period of 1973 to 1998 were identified using the SEER Public Use CD-ROM data. The database was then searched for patients with subsequent primary IBC occurrences (n = 350). The clinical and pathologic characteristics of patients with subsequent primary IBCs were compared with the characteristics of patients with primary IBCs attained during the same time period (N = 255,114). RESULTS: The incidence of IBC increased over time from diagnosis of LCIS, with 7.1% +/- 0.5% incidence of IBC at 10 years. IBCs detected after partial mastectomy occurred in either breast (46% ipsilateral and 54% contralateral); however, after mastectomy, most IBCs were contralateral (94.7%). IBCs occurring after LCIS more often represented invasive lobular histology (23.1%) compared with primary IBCs (6.5%). The standardized incidence ratio (the ratio of observed to expected cases) for developing IBC was 2.4 (95% CI, 2.1 to 2.6) adjusted for age and year of diagnosis. CONCLUSION: LCIS is associated with increased risk of subsequent invasive disease, with equal predisposition in either breast. The minimum risk of developing IBC after LCIS is 7.1% at 10 years.
Breast Neoplasms↗
Sarcoma as a second malignancy after treatment for breast cancer.
BACKGROUND: Second malignant neoplasms may be a consequence of radiotherapy for the treatment of breast cancer. Prior studies evaluating sarcomas as second malignant neoplasms in breast cancer patients have been limited by the numbers of patients and relatively low incidence of sarcoma. Using data from the Surveillance, Epidemiology and End Results registries, we evaluated the influence of radiation therapy on the development of subsequent sarcomas in cases with primary breast cancer. METHODS: Cases with primary invasive breast cancer (n = 274,572) were identified in the Surveillance, Epidemiology and End Results Cancer Incidence Public-Use Database (1973-1997). The database was then queried to determine the cases developing subsequent sarcomas (n = 263). Eighty-seven of these cases received radiation therapy, and 176 had no radiation therapy. The cumulative incidence of developing secondary sarcoma and the survival post developing secondary sarcoma were determined by the Kaplan-Meier method. RESULTS: The occurrence of sarcoma was low, regardless of whether cases received or did not receive radiation therapy: 3.2 per 1,000 (SE [standard error] = 0.4) and 2.3 per 1,000 (SE = 0.2) cumulative incidence at 15 years post diagnosis, respectively (p = 0.001). Of the sarcomas occurring within the field of radiation, angiosarcoma accounted for 56.8%, compared to only 5.7% of angiosarcomas occurring in cases not receiving radiotherapy. The cumulative incidence of angiosarcoma at 15 years post diagnosis was 0.9 per 1,000 for cases receiving radiation (SE = 0.2) and 0.1 per 1,000 for cases not receiving radiation (SE < 0.1). Overall survival was poor for cases of sarcoma after breast cancer (27-35% at 5 years), but not significantly different between patients receiving or not receiving radiation therapy for their primary breast cancer. CONCLUSIONS: Radiotherapy in the treatment of breast cancer is associated with an increased risk of subsequent sarcoma, but the magnitude of this risk is small. Angiosarcoma is significantly more prevalent in cases treated with radiotherapy, occurring especially in or adjacent to the radiation field. The small difference in risk of subsequent sarcoma for breast cancer patients receiving radiotherapy does not supersede the benefit of radiotherapy.
Adult↗
Design considerations for a computer controlled multileaf collimator for the Harper Hospital fast neutron therapy facility.
The d(48.5) + Be neutron beam from the Harper Hospital superconducting cyclotron is collimated using a unique multirod collimator (MRC). A computer controlled multileaf collimator (MLC) is being designed to improve efficiency and allow for the future development of intensity modulated radiation therapy with neutrons. For the current study the use of focused or unfocused collimator leaves has been studied. Since the engineering effort associated with the leaf design and materials choice impacts significantly on cost, it was desirable to determine the clinical impact of using unfocused leaves in the MLC design. The MRC is a useful tool for studying the effects of using focused versus unfocused beams on beam penumbra. The effects of the penumbra for the different leaf designs on tumor and normal tissue DVHs in two selected sites (prostate and head and neck) was investigated. The increase in the penumbra resulting from using unfocused beams was small (approximately 1.5 mm for a 5 x 5 cm2 field and approximately 7.6 mm for a 25 x 25 cm2 field at 10 cm depth) compared to the contribution of phantom scatter to the penumbra width (5.4 and 20 mm for the small and large fields at 10 cm depth, respectively). Comparison of DVHs for tumor and critical normal tissue in a prostate and head and neck case showed that the dosimetric disadvantages of using an unfocused rather than focused beam were minimal and only significant at shallow depths. For the rare cases, where optimum penumbra conditions are required, a MLC incorporating tapered leaves and, thus, providing focused collimation in one plane is necessary.
Adenocarcinoma↗
Pathological distribution of positive lymph nodes in patients with clinically and radiologically N0 oropharyngeal carcinoma: implications for IMRT treatment planning.
BACKGROUND: We identified involved lymph node groups in patients with oropharyngeal carcinoma and radiologically N0 disease, aiming to define the clinical target volume, and to assess the negative predictive value of CT neck and correlate it to the tumor site, stage, and grade. METHODS AND MATERIALS: Between 1988 and 2000, we evaluated 53 patients who satisfied all of the following criteria: 1) oropharyngeal carcinoma diagnosis; 2) NO stage based on CT; 3) no prior treatment; and 4) primary surgical resection including ipsi-lateral neck dissection. The pathology reports were reviewed to identify the exact site of lymph node involvement. RESULTS: Twenty patients (37.7%) were found to have pathologically positive lymph nodes, yielding a negative predictive value of 62.3% for CT neck. Node levels II, III, and IV were the most commonly involved (26%, 17%, and 11% of all patients, respectively). Fifty percent of patients with T3 and T4 tumors had positive lymph nodes versus 20% of patients with T1 and T2 (P = 0.036). Tumor grade and site were insignificant (P > 0.05). DISCUSSION: Ipsilateral neck levels II-IV should be included during elective nodal irradiation in patients with N0-stage oropharyngeal carcinoma, regardless of the primary tumor site, stage, and grade.
False Negative Reactions↗