Nuclear Medicine & Radiation Therapy

The adaptation and integration of imaging into the process of cancer detection, diagnosis, and intervention is an area of medicine that is undergoing extremely rapid development. Radiation therapy is a prime example of this change. While the objectives of these developments are clear, they raise numerous issues regarding the skills and resources that assure these technologies are appropriately integrated and applied. We will explore the basic concepts related to image guidance in various radiotherapy-related procedures with special emphasis on the clinical potentials of this impressive technology.

Purpose: The present work deals with pre-treatment dosimetric verification of 10 prostate intensity-modulated radiotherapy (IMRT) plans obtained by Gafchromic EBT3 film and 2D-Array seven29 to establish quality control protocol for the delivery of prostate IMRT in our clinic.
Methods: 10 prostate patients were irradiated according to IMRT techniques with 6 MV photon beams produced by a Varian DHX linear accelerator. Dose plans were computed using Eclipse 8.9 (version8.9, Varian, Palo Alto, CA, United States) treatment planning system (TPS). Pre-treatment dosimetric verification was carried out on field-perfield and total IMRT plan basis measuring 2D dose distributions in RW3 solid water phantom (PTW-Freiburg, Germany). For 10 patient plans, the dose distribution was re-calculated with the phantom CT scan and delivered to the phantom with the original and 0 degrees gantry, collimator and table angles. Thus IMRT quality control (QC) plans were generated. Dose distribution measurements were measured with Gafchromic EBT3 film and 2D-Array seven29 (PTW-Freiburg, Germany) two dimensional ionization chamber system. Verification measurements of total IMRT plans and each individual beams were compared with expected dose maps, and differences were evaluated by Verisoft program (PTW-Freiburg, Germany). To provide comparisons of multidimensional dose distributions, dose comparison tools such as gamma dose distribution, distance- to- agreement (DTA) and dose difference (DD) have been developed. The gamma dose distribution tool was used in our study. Three different gamma criteria of dose difference (DD) and distance to agreement (DTA) (3%/3 mm, 4%/4 mm and 5%/5 mm DD / DTA) are selected. These criteria are evaluated while suppressing the dose of 5% from dose distribution. Criterion validity accepted as section with gamma value less than or equal to 1 (γ ≤ 1) to be 90%.
Results: In the comparison of dose distributions obtained from TPS and the results of PTW 2D-Array seven29 and Gafchromic EBT3 film dosimetry systems, it was showed that the compatibility of both methods were above 90% with respect to 3% DD and 3mm DTA criteria. PTW 2D-Array seven29 results compared to the results of the film was closer to the TPS data and this difference was statistically meaningful (p<0.05). If the range of criteria is increased, the compatibility increases and it reaches to 100%. It was observed that analyzing by measuring all fields which are composing IMRT plans and analyzing by measuring each individual fields at the same time, made no statistically meaningful difference (p>0.05).
Conclusions: The measurements performed with PTW 2D-Array seven29 were closer to the TPS data than film measurements and it takes less time during clinical use, so it could be preferred for routine use. The present results suggest the gamma criteria of 3%/3 mm as the most suitable criteria for prostate IMRT quality assurance.

Objective: Primary intracranial or spinal hemangiopericytoma (HPC) represents a rare tumour that is more difficult to distinguish from other CNS tumours based on clinical symptoms and imaging findings. In this article, here we present 5 cases with HPC (3 intracranial and 2 spinal) with histologically confirmed were treated at our hospital between June 2009 to January 2010, and a review of the literature pertaining to the diagnosis, clinical management, and so on. Methods: Clinical data of the 5 patients with HPCs from cerebra and spinal cord including the manifestations of imaging, pathology, treatment and prognosis factors were investigated, and relevant literatures were reviewed. Of which, 3 males, 2 females, age ranged from 6-35 years old, median age at primary diagnosis was 29 years. Results: 3 patients underwent craniotomy and the other 2 patients underwent spinal surgery. Total mass removal was achieved in 1 case and subtotal removal in 4 cases. All 5 patients received radiotherapy after resection, A total dose of 59.4 Gy/33f was delivered in a fractionation of 5 x1.8 Gy per week for the 3 patients with cerebral lesions using three dimensional conformal radiation therapy (3D-CRT) or intensive modulated radiation therapy (IMRT) technique, and 45Gy in 25 fractions for the 2 patients with spinal lesions. The patients were followed up varied from 6 to 27 months, and none of the patients was found with evidence of radiation complications. Acute toxicity was mild including skin erythema and alopecia. Follow-up of the patients has not yet discovered that a tumour recurrence and extra-cranial metastasis all remain alive up to date. Conclusions: Multidisciplinary care should be highly advocated in the management of intracranial or spinal HPC. Surgical resection, either complete or subtotal excision, followed by postoperative radiotherapy, will provide the patients with higher probability for disease-free survival.

Endometrial cancer is the most commonly diagnosed malignancy of the female genital tract in the United States. The role of adjuvant radiation for the treatment of patients with early stage disease is still heavily debated, as no overall survival benefit has been demonstrated in large prospective trials. There is, however, evidence to suggest a decrease in recurrence risk with administration of adjuvant radiotherapy, especially in patients with high-risk features. In this review, we describe the relevant literature to date, define how we determine which patients are considered high or intermediate risk, and describe the findings related to the addition of chemotherapy to adjuvant brachytherapy.

Objective: To evaluate biochemical recurrence-free survival (b-RFS) in patients with Gleason score 7 prostate cancers treated with external beam radiotherapy at Ehime University Hospital. Materials and Methods: Between January 2003 and October 2009, 63 patients with Gleason score 7 prostate cancers were treated with three-dimensional conformal radiotherapy (3D-CRT) at our institute. Of the 63 patients analyzed, 41 and 22 had a primary Gleason pattern of 3 and 4 carcinoma, respectively. Neoadjuvant hormonal therapy had been given to 37 patients (59%) for 6 months prior to radiotherapy. The American Society for Therapeutic Radiology and Oncology Phoenix consensus definition was used to determine the b-RFS after treatment. Results: The overall b-RFS rate at 5 year was 71% and 77% for Gleason score 3+4 and 4+3 prostate cancer, respectively. The overall b-RFS at 5 year was 59% and 86% in Gleason score 3+4 patients with and without neoadjuvant hormonal therapy for 6 months, respectively. Conclusions: Our results indicate that the 5 year b-RFS outcome with 3D-CRT is not dependent on Gleason score 3+4 versus 4+3 histological features, or on neoadjuvant hormonal therapy for 6 months in patients with a Gleason score of 3+4.

Trans hepatic arterial radioembolotherapy using yttrium-90 microspheres represents in situ therapy in hepatocellular cancer, which is the third leading cause of cancer-related deaths in the world. This therapy shows interesting results in the treatment of these patients. This review focuses on clinical application, advantages, sideeffects and toxicity, and contradictions of the radioembolization treatment program.