ABSTRACT
Substantial technologic advances in radiation treatment planning and delivery have made possible exquisite tailoring of three-dimensional radiation dose distributions that conform to the tumor treatment volume while avoiding adjacent normal tissues. Although such highly precise treatment can increase the therapeutic ratio, it also introduces the potential that tumor extension outside the target is missed because it is unrecognized at the time of radiation treatment planning. As a result, accurate targeting of the tumor with radiation is of utmost importance to the radiation oncologist. Communication between diagnostic radiologists and radiation oncologists is essential, particularly given the subtleties that accompany image interpretation, to optimize the care of the cancer patient.
Subject(s)
Neoplasms/diagnostic imaging , Neoplasms/radiotherapy , Radiation Oncology , Radiology , Humans , RadiographyABSTRACT
Identification of nodal involvement is important for treatment planning in patients with rhabdomyosarcoma, and is facilitated by sentinel node biopsy. Although it is employed primarily for extremity tumors, we report using sentinel node biopsy in a patient with parameningeal rhabdomyosarcoma arising in the ethmoid sinus. Lymphoscintigraphy with single photon emission computed tomography following injection of tracer at the tumor site helped identify contralateral cervical node involvement not previously recognized by physical exam, cross sectional imaging, or other functional imaging. This case demonstrates how information from sentinel node identification and biopsy can change therapy recommendations in patients with parameningeal rhabdomyosarcoma.
Subject(s)
Meningeal Neoplasms/pathology , Rhabdomyosarcoma/pathology , Sentinel Lymph Node Biopsy , Child, Preschool , Combined Modality Therapy , Diagnostic Imaging/methods , Female , Humans , Lymph Nodes/pathology , Meningeal Neoplasms/diagnosis , Neoplasm Staging , Rhabdomyosarcoma/diagnosis , Sentinel Lymph Node Biopsy/methods , Treatment OutcomeABSTRACT
PURPOSE: To determine whether the volume of a patient's breast is correlated with reliable daily setup in treatment of breast cancer with a helical tomotherapy treatment unit. METHODS AND MATERIALS: Thirty-six consecutive patients with breast cancer were treated on a helical tomotherapy unit. During simulation, kilovoltage CT images were obtained for treatment planning. These were fused with daily megavoltage CT scans, and after setup based on skin marks and laser alignment the necessary shifts were carried out. The magnitude of daily shifts (in millimeters) was retrospectively obtained from the daily image fusions, and the breast volume was obtained from the treatment plan. A total of 873 fusion scans were reviewed. Random error for absolute and directional daily shifts was evaluated for correlation to volume. Variation over time was also evaluated. RESULTS: Mean (SD) random shift for all patients in the lateral, longitudinal, and vertical directions was 2.7 (2.0), 3.1 (1.5), and 3.2 (2.6) mm, respectively. Mean (SD) absolute distance shifted was 6.0 (3.5) mm. There was no significant correlation between mean absolute or mean directional daily shift and breast volume (0.08, 0.08, 0.22, and 0.07, respectively). There was no correlation between setup variation and time. CONCLUSIONS: In this cohort, there was no correlation between breast volume and degree of daily shift. There was no correlation between time course and setup variation. Therefore, setup variation does not improve or degrade with repeated treatment setups.
