Radiation Therapy of Spinal Metastases: Results with Different Fractionations

Aims and background

Local radiotherapy plays an important role in the palliative treatment of all skeletal metastases, particularly those of the spine, with the purpose to obtain pain relief and prevent pathologic fractures or vertebral collapse.

Methods

From June 1991 to October 1993, 95 patients with a total of 103 sites of spinal metastases were treated at the Institute of Radiology of the University of Rome “La Sapienza”. Fractionations and total doses were divided as single fractions of 800 cGy, hypofractionated multiple fractions for a total dose of 20 Gy administered in 4-5 days, and conventional multiple fractions for a total dose of 30-40 Gy in 2-4 weeks. An evaluation of the efficacy of the different radiation treatments was performed with the use of a simplified descriptive pain scale.

Results

Seventy-three (70.9%) of 103 treatments were evaluables. An overall response rate of 82.2% was obtained: complete in 38.3% and partial in 43.8%, irrespective of total dose, fractionation and location of irradiated spinal metameres. The analysis of results did not show significant differences between the treatment courses.

Conclusions

We confirm that radiation therapy has a major role in the management of pain control and prevention of fractures in patients with spinal metastases. Hypofractionated and single fraction treatments showed equal efficacy compared to more prolonged therapy, with an advantage for the patient and the radiation therapy institution.

[The role of MRI in the diagnosis and evaluation of extension of the disease and condition of patients with neurofibromatosis]

Neurofibromatosis 1 (NF 1) and Neurofibromatosis 2 (NF 2) have been recently recognized to be distinct disorders through genetic linkages. MR imaging can be used to identify abnormalities of the head and spine in patients with these disorders. This review highlights some important but lesser known aspects of the two more common phakomatoses. The role of newer imaging technique such as contrast-enhanced MR imaging in the evaluation of these disorders also are discussed.

[Diagnostic imaging in the detection of parotid adenoma. Review of the literature and personal experience with the combined use of computerized tomography and MRI]

In this report we reviewed the role of Ultrasonography, Computed Tomography, Magnetic Resonance and 99Tc-Sestamibi Scintigraphy for the detection of abnormal parathyroid glands in patients with biochemical evidence of hyperparathyroidism. We also report our personal experience with CT and RM.

[Anatomic changes after radical surgery and reconstruction with pedunculated or revascularized flaps in advanced head and neck tumors: computerized tomography and magnetic resonance findings]

January, 1992, to October, 1995, sixty-four patients with advanced head and neck cancer underwent head and neck reconstructive surgery using myocutaneous or revascularized flaps; in the same period, all patients were consecutively examined with CT and MRI. Myocutaneous flaps wer used in 26 patients: 12 flaps were tubular and 14 linear. Revascularized flaps were used in 38 patients: to repair a large defect in 26 patients (14 latissimus dorsi flaps and 12 temporal muscle flaps) and to repair an oral damage in 12 patients (5 revascularized radial and 7 jejunal flaps). CT and MR images of myocutaneous flaps showed the flaps as fatty areas, repairing large surgical defects, hypodense at CT and hyperintense at MRI, with no post-contrast enhancement. The postoperative scar around the flap exhibited soft-tissue density with slight post-contrast enhancement at CT and slightly hypodense on T2-weighted MR images. Post-contrast CT and MRI showed slight scar enhancement with no signal changes in the fatty component. The appearance of revascularized flaps at CT and MRI depends on the characteristics of the structure used to repair the surgical defect: jejunal and radial flaps appeared as mostly fatty thickened layers with both imaging methods. Temporal and latissimus dorsi flaps are made basically of muscular tissue, fatty tissue and occasionally skin (used to repair a mucosal defect): consequently, CT showed a structure with mostly parenchymal density in all cases and MRI depicted intermediate signal intensity. MRI was useful to detect 12 revascularized jejunal or radial flaps thanks to its higher contrast resolution and multiplanar capabilities showing even such thin structures as these flaps. Moreover, MRI permitted to study skull base reconstruction with revascularized (latissimus dorsi) flaps in 5 of our patients.

Comparison between transrectal ultrasonography and computed tomography with rectal inflation of gas in preoperative staging of lower rectal cancer

Computed tomography with rectal air insufflation was compared with transrectal ultrasonography (TRUS) in 63 patients. The CT protocol involved pre- and postcontrast scans with 5 mm slice thickness following air insufflation in IV antiperistaltic agent. Of the patients, 79 % were scanned in the prone position. Results of the preoperative examinations were compared with the histological findings. The CT examination had an accuracy rate of 74 %, predicting perirectal spread with a sensitivity of 83 % and a specificity of 62 %, whereas the corresponding figures for TRUS were 83, 91 and 67 %. The accuracy, sensitivity and specificity of CT and TRUS for nodal involvement were 57, 56, 57, 66, 68 and 64 %-respectively. These findings confirm that TRUS is more accurate than CT in local tumour (T) staging and in detecting nodal (N) spread. However, the appropriate CT technique shows spread of tumour outside the rectal wall and locoregional lymph nodes with reasonable accuracy. Lymphatic spread correlated with nodal size. TRUS and CT correctly staged only 57 and 43 %, respectively, of cases with nodal metastases with maximum diameter of 5 mm. TRUS sometimes overstaged perirectal growth of tumour in 7 patients, due to inflammation (5 patients) or incorrect positioning of the balloon in relation to the tumour surface (2 patients).

[Role of computerized tomography following transrectal air insufflation and hypotonization and transrectal ultrasonography in the staging of rectal tumors]

Computed Tomography (CT) with rectal air inflation was compared with transrectal ultrasound (TRUS) in the preoperative staging of lower rectal cancer in 126 patients. Precontrast and postcontrast CT scans were performed with 5 mm thick slices; the rectum was previously inflated with air and antiperistaltic agents were administered. Preoperative results were compared with histologic findings. The accuracy, sensitivity and specificity of CT in predicting perirectal spread were 76%, 62% and 83%, whereas the corresponding figures for TRUS were 84%, 69% and 92%. The accuracy, sensitivity and specificity of CT and TRUS for nodal involvement were 58%, 60%, 57% and 72%, 68% and 66%, respectively. These results show that TRUS predicts perirectal spread and detects nodal metastases better than CT. However CT, when performed appropriately, shows tumor spread into perirectal fat and locoregional lymph nodes with high accuracy. Lymphatic involvement is strictly correlated with tumor size: TRUS and CT correctly staged only 57% and 43%, respectively, of the cases with nodal metastases and max. diameter of 5 mm. TRUS sometimes overstaged perirectal tumor growth (13 patients in our series) due to perirectal inflammation (9 cases) or artifacts caused by the presence of air bubbles between the probe and the tumor surface (4 patients). TRUS is a very useful tool for detecting tumor distance from the anal opening; in our series, the distance was incorrectly calculated only in one case (3 cm with TRUS versus 4 cm at surgery).

[The basic concepts of the use of magnetic resonance in neuropediatrics]

Before the development of X-ray computed tomography (CT) and magnetic resonance imaging (MRI), it was not possible to analyze normal brain maturation in vivo. Only autopsy studies were really able to show changes in the maturing brain, nevertheless these studies did not represent an homogeneous and correct appearance of the sample population by the various causes of infant death. MR shows gross morphologic changes in the maturing brain, and the high contrast resolution of MR scans permits highly sensitive assessment of white matter changes. Changes of white matter maturation are seen best on T1 weighted images (TR = 600 msec., TE = 15 msec., SL = 4, AL = 2, FOV = 200 mm, 1 acquisition), specially on sagittal scans, during the first 6 months of life and the second echo of T2 images (TR = 2500 msec., TE = 40-50 msec., FOV = 200 mm, 1 acquisition), between the ages of 6 and 18 months. The most important factor in obtaining high quality MR images in children is adequate sedation. In this report the authors explain MR imaging of white matter changes in a period from birth to 18 months of age of normal postnatal brain development.

[Comparison of computerized tomography and magnetic resonance in staging of T and N parameters in head and neck neoplasms]

January 1990, through January 1994, eighty untreated patients with head and neck cancer were consecutively submitted to CT and MRI of the head and neck before surgery. CT and MR findings were then compared to operative histologic findings. Forty-eight of 52 T4 cases at CT were confirmed at surgery (89%), 7 of 13 T3 cases at CT were also confirmed (54%), as well as 8 of 15 T2 cases (53%). CT understaged 13 cases (6 T3 and 7 T2), which surgery staged as T4, CT overstaged 4 cases as T4, which were 2 pT2 and 2 pT3 at histology. All the 54 cases MRI staged as T4 were confirmed at surgery (100%), 3 of 12 MRI staged as T3 were pT4 at surgery (25%) and, finally, 4 of 14 cases MRI staged as T2 were pT4 at histology (28%). Only one case staged as pT4 at surgery and CT had been staged as T3 by MRI because the latter method had failed to depict hyoid involvement. On the other hand, in 6 cases MRI correctly modified CT staging. Overall CT accuracy was 79% and MR accuracy 91%. CT sensitivity was 70% versus 75% with MRI, specificity was 80% versus 78%, respectively, and overall accuracy 75% versus 76%. Only in two patients MRI correctly modified CT staging (N1 at surgery). Our results confirm various advantages of MRI over CT in the assessment of tumor mass ("T" parameter), mainly in T2 and T3 cases, because MRI yields higher soft tissue contrast resolution and has multiplanar capabilities. CT was superior to MRI only in the assessment of bone involvement. This study also confirmed similar CT and MR capabilities in detecting lymph node tumor spread. Finally, MRI did not allow earlier detection of micrometastases than CT.