18F FDG PET/TC en un niño con Gliomatosis Cerebri / 18F FDG PET/CT in a child with gliomatosis cerebri

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Dosimetric comparison of ring and ovoid applicators.

PURPOSE: To compare the dosimetry of different vaginal applicators used in the postoperative vaginal cuff irradiation. MATERIALS AND METHODS: In this model dosimetric study, standard ovoid applicator sets with 3 cap sizes (small/15 mm, medium/20 mm, and large/25 mm), and ring applicator sets with 3 diameter sizes (small/26 mm, medium/30 mm, large/34 mm) each with 3 different angles (30, 45, and 60 degrees) were used. Calculations were performed in Plato TPS (Treatment Planning System) as dwell positions of 2.5 mm step and equal dwell time for the sources. For ovoid applicators, the source positions 1-5 were loaded as active on each catheter, and in ring applicators the source positions 1-12, and 18-29; 1-14, and 19-32; 1-17, and 22-37 were loaded for small, medium and large ones, respectively. In addition to ICRU rectum reference point (R(1)), 4 different rectum reference points (RP(s)) (R(2)-R(5)) were defined 1 cm apart. The vaginal cuff RP (V(c)) was defined at 5 mm depth from the vaginal surface. The reference volume dose distribution was obtained according to the V(c) (100%) reference point. The width (w), max-min length (h, h'), and max-min thickness (t, t') of the reference isodoses were measured and max-min reference volume (v, v') was calculated. RESULTS: R(1) dose was higher for ovoids (43.1%) than ring (28.6%), in all applicators. The increase of R(1) dose was parallel to the increase of ovoid/ring size (70-89%). As the applicator (ovoid-ring) size increased, max thickness of the reference isodose also increased (19-50%). For the largest size, the max increase was 62% (74.1-119.88 cm(3)) and 93% (59.15-114.24 cm(3)) for v and v', respectively. However, the magnitude of the reference volume was independent of the ring angle. CONCLUSION: In the present study it was found that when ring applicators were used according to recommended dwell positions, max rectum reference dose decreased in comparison to ovoid applicators; on the other hand, it should be noted that the size of the reference volume also decreased significantly.

Is re-irradiation effective in symptomatic local recurrence of non small cell lung cancer patients? A single institution experience and review of the literature.

PURPOSE: To determine reirradiation results of patients with recurrent non-metastatic non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: 38 NSCLC patients who showed clinical and/or radiological progression and were retreated with hypofractionated irradiation (RT) were retrospectively evaluated. Two parallel or oblique opposed fields were used for reirradiation of the recurrent tumor while excluding the spinal cord. "Improvement" and "complete or near complete response" were defined as > or = 50% and 75-100% regression of symptoms, respectively. Log-rank test, chi-square test and Cox regression analysis were used for statistical analyses. RESULTS: Median age was 58 years (range 33-80) and only 3 patients were females. Median follow-up was 13.5 months (range 4-65). In the initial and second course of RT the total dose was 30 Gy (range 28.8-67.2) and 25 Gy (range 5-30) and the number of fractions was 10 (range 9-33) and 10 (range 1-10), respectively. The median interval between the two RT courses was 35 weeks (range 4-189). After reirradiation improvement was observed in 86% of the patients assessable for hemoptysis, in 77% with cough, in 69% with dyspnea, and in 60% with thoracic pain. After reirradiation, the median survival time was 3 months (range 0-55). Two-year survival rates from diagnosis were 28.8% and from reirradiation 5.8%. An interval more than 35 weeks between the end of initial RT and the start of reirradiation was found as the only independent prognostic factor affecting survival. No grade III-IV RTOG late side effects were observed. CONCLUSION: In initially non-metastatic NSCLC patients, reirradiation can be a safe and effective treatment for palliation after recurrence. Large prospective studies are needed to confirm the safety, effectiveness and economical advantages of this modality.

Prognostic factors in limited-stage small cell lung cancer of patients treated with combined modality approach.

PURPOSE: To evaluate the combined modality treatment results of patients with limited-stage small cell lung cancer (SCLC), who were treated and followed by the DELCSG. PATIENTS AND METHODS: Sixty-three patients with limited-stage SCLC diagnosed between April 1991 and December 2002 were included. All patients were treated with combined chemotherapy and thoracic radiotherapy. Median age was 59 years (range 36-84), and all patients were male except 4. Surgery was performed for diagnosis in 3 patients. Four cycles of chemotherapy (median) were administered, composed of cisplatin-etoposide (CE) (26 patients), cyclophosphamide-vincristine-adriamycin (CAV) (10 patients) or alternated CE and CAV (18 patients). Nine patients received various chemotherapy regimes other than CE and/or CAV. A total dose of 5000 cGy with 180-200 cGy daily fractions was given to the primary tumor and mediastinum, excluding the spinal cord after 4500 cGy. Prophylactic cranial irradiation (PCI) was performed in 13 (20%) patients. Overall survival (OS) and progression-free survival (PFS) were calculated, beginning from the date of diagnosis and the end of radiotherapy, respectively. Kaplan-Meier method was used for obtaining survival rates. Log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively. RESULTS: Median follow-up time was 17 months (range 3-131). Median PFS and OS were 12 (range 1-131) and 17 (range 3-131) months, respectively. Two-years PFS and OS rates were 27 % and 38 %, respectively. During follow-up, 27 (43%) patients developed brain metastasis; among them only 3 had received PCI. Univariate analysis showed that addition of PCI significantly improved PFS (p=0.025) and advanced age was a favorable prognostic factor for OS (p=0.039). In the multivariate analysis, advanced age (p=0.034) and addition of PCI (p=0.004) were independent factors increasing PFS, however no significant prognostic factor influencing OS was found. CONCLUSION: Our treatment results are in accordance with the relevant literature. It is also concluded that PCI should be given to all patients with complete response to chemotherapy. However, analysis of prognostic factors should be cautiously evaluated because of small number and heterogeneous distribution of patients in subgroups. Prospective studies are necessary for better determination of prognostic factors.

Prognostic significance of EGF receptor expression in early glottic cancer.

OBJECTIVE: A positive relationship between epidermal growth factor receptor (EGFR) expression and radioresistance has been shown both in vitro and in vivo. In a group of 31 patients with early glottic cancer treated with definitive radiotherapy, the relationship of EGFR expression with patient and tumor related parameters were analyzed and the prognostic effect of EGFR expression on local control (LC) was assessed. MATERIAL AND METHOD: Between 1991 and 2001, 114 patients with early glottic (Tis-T2N0M0) squamous cell carcinoma were treated with radiotherapy at our institution. Among these, 31 patients whose pretreatment pathology specimens were available for immunohistochemical analysis formed the study population. Median age was 64 (46-77). Anterior commissure involvement was evident in 12 (38.7%) patients. Distribution according to T stage was as follows: Tis 6 (19.3%), T1 22 (71%), and T2 3 (9.7%). Histopathological grades of the 25 T1-2 tumors were 10/25 (40%) grade 1, 9/25 (36%) grade 2 and 6/25 (24%) grade 3. Our radiotherapy regimen was 66-70 Gy in 33-35 fractions over 6.5-7 weeks. The median follow-up period was 45 months (range, 5-116). Following immunohistochemical staining, quantitative immunohistochemistry (IHC) was performed by image analysis software and stained tumoral area percentage (STAP) was identified. The cut-off value was < or =5% versus >5%. The relationship of EGFR expression with patient (age) and tumor related (T stage, histopathological grade, and anterior commissure involvement) parameters was evaluated using chi-square test. Prognostic significance of EGFR expression, age, T stage, histopathological grade, and anterior commissure involvement on LC was assessed using log-rank test. RESULTS: No difference was found in EGFR content distribution in relation to age, T stage, histopathological grade, and anterior commissure involvement. In the univariate analysis including age (< or =60 versus >60), T stage (Tis and T1 versus T2), histopathological grade (grade 1 and 2 versus grade 3), anterior commissure involvement (present versus absent), and EGFR expression (high versus low), only T stage and EGFR expression were found to be significant prognostic factors affecting LC (P = 0.0006 and P = 0.03, respectively). CONCLUSION: The results of this series support that EGFR expression is an unfavorable prognostic factor in early glottic carcinomas. For this reason EGFR IHC may be considered for selecting patients for more aggressive therapies (radiotherapy with different fractionation schemes or surgery) or enrollment into trials targeting EGFR signaling pathways.

Primary primitive neuro-ectodermal tumor of cauda equina with intracranial seeding.

Primitive neuro-ectodermal tumor (PNET) of the cauda equina is a rare entity. 18 cases have been reported in the literature so far, including 4 cases with intracranial seeding. Moreover parenchymal involvement of brain has never been reported as a form of intracranial seeding from PNET of the cauda equina. A 31 year-old female patient, with PNET of cauda equina showing intracranial seeding 6 months after surgery, is presented in this report. To our knowledge, this is the first adult case of spinal cord PNET with parenchymal involvement of brain. The histopathological, clinical and radiological findings as well as treatment of the patient were evaluated.

The role of radiotherapy in the management of diabetes insipidus caused by Langerhans cell histiocytosis.

Diabetes insipidus (DI) occurs in 5-50% of patients with a diagnosis of Langerhans cell histiocytosis (LCH). DI is the most common manifestation of central nervous system (CNS) involvement and is due to defects in the function of the posterior pituitary. Radiotherapy is recommended as early as possible after the diagnosis of DI, because response rates increase and the need for pitressin therapy may be obviated. The optimal period for radiotherapy seems to be less than one week. Generally, a total radiotherapy dose of 15-20 Gy or less is preferred. Further prospective studies are strongly needed to compare recurrence rates, late effects, disease course, and survival in treated and untreated groups.

Prognostic factors in lung cancer with brain metastasis.

BACKGROUND AND PURPOSE: Metastasis to the brain develops in 25% of all patients with lung cancer. Although the outcome is usually poor, there seems to be a subset of patients with favorable prognostic factors who may live longer. Prognostic factors were analyzed retrospectively in 103 patients with brain metastases from lung carcinoma to identify patients who would benefit from more intensive treatment strategies. MATERIALS AND METHODS: Between October 1991 and December 1994, 103 patients with brain metastasis from lung cancer were irradiated with palliative intent. Palliation was defined as 50% or more regression of neurological signs and symptoms 2 weeks after the completion of cranial radiotherapy. Local (related to the lung tumor) symptom status at the time of brain metastasis, the presence of metastases other than brain, multiplicity of brain metastases on CT scan and time of occurrence of brain metastasis were the factors which were evaluated with multivariate analysis. RESULTS: Palliation was accomplished in 85% of cases. Palliation duration ranged from 0.5 to 54 months (median 3 months). The overall median survival was 5 months. Only one patient is under follow-up without any symptoms related to the brain metastasis. According to the multivariate analysis survival was significantly decreased in the presence of symptoms related to the primary tumor (P = 0.001). CONCLUSION: The presence of symptoms related to the primary tumor at the time of brain metastasis is one of the factors that can be used to distinguish patients with a favorable outcome. In patients with favorable prognostic factors and thus longer survival probability, the role of boost dose after whole brain radiotherapy or surgical resection in suitable cases needs to be investigated.