Stereotactic ablative radiation therapy for spinal metastases: experience at a single Brazilian institution.

BACKGROUND: This study aims to assess the clinical outcomes of patients with spine metastases who underwent stereotactic ablative radiation therapy (SABR) as part of their treatment. SABR has arisen as a contemporary treatment option for spinal metastasis patients with good prognoses. MATERIALS AND METHODS: Between November 2010 and September 2018, Spinal SABR was performed in patients with metastatic disease in different settings: radical (SABR only), postoperative (after decompression and/or fixation surgery), and reirradiation. Local control (LC), pain control, overall survival (OS) and toxicities were reported. RESULTS: Eighty-five patients (corresponding to 96 treatments) with spine metastases were included. The median age was 59 years (range, 23-91). In most SA BR (82.3%, n = 79) was performed as the first local spine treatment, while in 12 settings (12.5%), fixation and/or decompression surgery was performed prior to SABR. Two-year overall survival rate was 74.1%, and median survival was 19 months. The LC rate at 2 years was 72.3%. With regard to pain control, among 67 patients presenting with pain before SA BR, 83.3% had a complete response, 12.1% had a partial response, and 4.6% had progression. Vertebral compression fractures occurred in 10 patients (11.7%), of which 5 cases occurred in the reirradiation setting. Radiculopathy and myelopathy were not observed. No grade III or IV toxicities were seen. CONCLUSION: This is the first study presenting a Brazilian experience with spinal SA BR, and the results confirm its feasibility and safety. SABR was shown to produce good local and pain control rates with low rates of adverse events.

Treatment of Localized and Locally Advanced, High-Risk Prostate Cancer: A Report From the First Prostate Cancer Consensus Conference for Developing Countries.

PURPOSE: To generate and present survey results on important issues relevant to treatment and follow-up of localized and locally advanced, high-risk prostate cancer (PCa) focusing on developing countries. METHODS: A panel of 99 PCa experts developed more than 300 survey questions of which 67 questions concern the main areas of interest of this article: treatment and follow-up of localized and locally advanced, high-risk PCa in developing countries. A larger panel of 99 international multidisciplinary cancer experts voted on these questions to create the recommendations for treatment and follow-up of localized and locally advanced, high-risk PCa in areas of limited resources discussed in this article. RESULTS: The panel voted publicly but anonymously on the predefined questions. Each question was deemed consensus if 75% or more of the full panel had selected a particular answer. These answers are based on panelist opinion and not on a literature review or meta-analysis. For questions that refer to an area of limited resources, the recommendations considered cost-effectiveness as well as the possible therapies with easier and greater access. Each question had five to seven relevant answers including two nonanswers. Results were tabulated in real time. CONCLUSION: The voting results and recommendations presented in this article can guide physicians managing localized and locally advanced, high-risk PCa in areas of limited resources. Individual clinical decision making should be supported by available data; however, as guidelines for treatment of localized and locally advanced, high-risk PCa in developing countries have not been defined, this article will serve as a point of reference when confronted with this disease.

Consensus on Prostate Cancer Treatment of Localized Disease With Very Low, Low, and Intermediate Risk: A Report From the First Prostate Cancer Consensus Conference for Developing Countries (PCCCDC).

PURPOSE: A group of international urology and medical oncology experts developed and completed a survey on prostate cancer (PCa) in developing countries. The results are reviewed and summarized, and recommendations on consensus statements for very low-, low-, and intermediate-risk PCa focused on developing countries were developed. METHODS: A panel of experts developed more than 300 survey questions of which 66 questions concern the principal areas of interest of this paper: very low, low, and intermediate risk of PCa in developing countries. A larger panel of 99 international multidisciplinary cancer experts voted on these questions to create the recommendations for treatment and follow-up for very low-, low-, and intermediate-risk PCa in areas of limited resources discussed in this manuscript. RESULTS: The panel voted publicly but anonymously on the predefined questions. Each question was deemed consensus if 75% or more of the full panel had selected a particular answer. These answers are based on panelist opinion not a literature review or meta-analysis. For questions that refer to an area of limited resources, the recommendations consider cost-effectiveness and the possible therapies with easier and greater access. Each question had five to seven relevant answers including two nonanswers. The results were tabulated in real time. CONCLUSION: The voting results and recommendations presented in this document can be used by physicians to support management for very low, low, and intermediate risk of PCa in areas of limited resources. Individual clinical decision making should be supported by available data; however, as guidelines for treatment for very low, low, and intermediate risk of PCa in developing countries have not been developed, this document will serve as a point of reference when confronted with this disease.

Micromorphology of the dental pulp is highly preserved in cancer patients who underwent head and neck radiotherapy.

INTRODUCTION: Teeth are often included in the radiation field during head and neck radiotherapy, and recent clinical evidence suggests that dental pulp is negatively affected by the direct effects of radiation, leading to impaired sensitivity of the dental pulp. Therefore, this study aimed to investigate the direct effects of radiation on the microvasculature, innervation, and extracellular matrix of the dental pulp of patients who have undergone head and neck radiotherapy. METHODS: Twenty-three samples of dental pulp from patients who finished head and neck radiotherapy were analyzed. Samples were histologically processed and stained with hematoxylin-eosin for morphologic evaluation of the microvasculature, innervation, and extracellular matrix. Subsequently, immunohistochemical analysis of proteins related to vascularization (CD34 and smooth muscle actin), innervation (S-100, NCAM/CD56, and neurofilament), and extracellular matrix (vimentin) of the dental pulp was performed. RESULTS: The morphologic study identified preservation of the microvasculature, nerve bundles, and components of the extracellular matrix in all studied samples. The immunohistochemical analysis confirmed the morphologic findings and showed a normal pattern of expression for the studied proteins in all samples. CONCLUSIONS: Direct effects of radiotherapy are not able to generate morphologic changes in the microvasculature, innervation, and extracellular matrix components of the dental pulp in head and neck cancer patients.

Intensity-modulated radiation therapy for head and neck cancer: systematic review and meta-analysis.

BACKGROUND AND PURPOSE: Intensity-modulated radiation therapy (IMRT) provides the possibility of dose-escalation with better normal tissue sparing. This study was performed to assess whether IMRT can improve clinical outcomes when compared with two-dimensional (2D-RT) or three-dimensional conformal radiation therapy (3D-CRT) in patients with head and neck cancer. METHODS AND MATERIALS: Only prospective phase III randomized trials comparing IMRT with 2D-RT or 3D-CRT were eligible. Combined surgery and/or chemotherapy were allowed. Two authors independently selected and assessed the studies regarding eligibility criteria and risk of bias. RESULTS: Five studies were selected. A total of 871 patients were randomly assigned for 2D-RT or 3D-CRT (437), versus IMRT (434). Most patients presented with nasopharyngeal cancers (82%), and stages III/IV (62.1%). Three studies were classified as having unclear risk and two as high risk of bias. A significant overall benefit in favor of IMRT was found (hazard ratio - HR=0.76; 95% CI: 0.66, 0.87; p<0.0001) regarding xerostomia scores grade 2-4, with similar loco-regional control and overall survival. CONCLUSIONS: IMRT reduces the incidence of grade 2-4 xerostomia in patients with head and neck cancers without compromising loco-regional control and overall survival.

Observation of interfractional variations in lung tumor position using respiratory gated and ungated megavoltage cone-beam computed tomography.

PURPOSE: To evaluate the use of megavoltage cone-beam computed tomography (MV CBCT) to measure interfractional variation in lung tumor position. METHODS AND MATERIALS: Eight non-small-cell lung cancer patients participated in the study, 4 with respiratory gating and 4 without. All patients underwent MV CBCT scanning at weekly intervals. Contoured planning CT and MV CBCT images were spatially registered based on vertebral anatomy, and displacements of the tumor centroid determined. Setup error was assessed by comparing weekly portal orthogonal radiographs with digitally reconstructed radiographs generated from planning CT images. Hypothesis testing was performed to test the statistical significance of the volume difference, centroid displacement, and setup uncertainty. RESULTS: The vertebral bodies and soft tissue portions of tumor within lung were visible on the MV CBCT scans. Statistically significant systematic volume decrease over the course of treatment was observed for 1 patient. The average centroid displacement between simulation CT and MV CBCT scans were 2.5 mm, -2.0 mm, and -1.5 mm with standard deviations of 2.7 mm, 2.7 mm, and 2.6 mm in the right-left, anterior-posterior and superior-inferior directions. The mean setup errors were smaller than the centroid shifts, while the standard deviations were comparable. In most cases, the gross tumor volume (GTV) defined on the MV CBCT was located on average at least 5 mm inside a 10 mm expansion of the GTV defined on the planning CT scan. CONCLUSIONS: The MV CBCT technique can be used to image lung tumors and may prove valuable for image-guided radiotherapy. Our conclusions must be verified in view of the small patient number.

A comparison of intensity-modulated radiation therapy and concomitant boost radiotherapy in the setting of concurrent chemotherapy for locally advanced oropharyngeal carcinoma.

PURPOSE: The aim of this study was to compare toxicity/efficacy of conventional radiotherapy using delayed accelerated concomitant boost radiotherapy (CBRT) vs. intensity-modulated radiotherapy (IMRT) in the setting of concurrent chemotherapy (CT) for locally advanced oropharyngeal carcinoma. METHODS AND MATERIALS: Between September 1998 and June 2004, a total of 293 consecutive patients were treated at our institution for cancer of the oropharynx. Of these, 112 had Stage III/IV disease and squamous cell histology. In all, 41 were treated with IMRT/CT and 71 were treated with CBRT/CT, both to a median dose of 70 Gy. Most common CT was a planned two cycles given every 3 to 4 weeks of cisplatin, 100 mg/m2 i.v., but an additional cycle was given to IMRT patients when possible. Both groups were well-matched for all prognostic factors. RESULTS: Median follow-up was 46 months (range, 3-93 months) for the CBRT patients and 31 months (range, 20-64 months) for the IMRT group. Three-year actuarial local-progression-free, regional-progression-free, locoregional progression-free, distant-metastases-free, disease-free, and overall survival rates were 85% vs. 95% (p = 0.17), 95% vs. 94% (p = 0.90), 82% vs. 92% (p = 0.18), 85% vs. 86% (p = 0.78), 76% vs. 82% (p = 0.57), and 81% vs. 91% (p = 0.10) for CBRT and IMRT patients, respectively. Three patients died of treatment-related toxicity in the CBRT group vs. none undergoing IMRT. At 2 years, 4% IMRT patients vs. 21% CBRT patients were dependent on percutaneous endoscopic gastrostomy (p = 0.02). Among those who had > or =20 months follow-up, there was a significant difference in Grade > or =2 xerostomia as defined by the criteria of the Radiation Therapy and Oncology Group, 67% vs. 12% (p = 0.02), in the CBRT vs. IMRT arm. CONCLUSION: In the setting of CT for locally advanced oropharyngeal carcinoma, IMRT results in lower toxicity and similar treatment outcomes when compared with CBRT.

Low-dose megavoltage cone-beam computed tomography for lung tumors using a high-efficiency image receptor.

We report on the capabilities of a low-dose megavoltage cone-beam computed tomography (MV CBCT) system. The high-efficiency image receptor consists of a photodiode array coupled to a scintillator composed of individual CsI crystals. The CBCT system uses the 6 MV beam from a linear accelerator. A synchronization circuit allows us to limit the exposure to one beam pulse [0.028 monitor units (MU)] per projection image. 150-500 images (4.2-13.9 MU total) are collected during a one-minute scan and reconstructed using a filtered backprojection algorithm. Anthropomorphic and contrast phantoms are imaged and the contrast-to-noise ratio of the reconstruction is studied as a function of the number of projections and the error in the projection angles. The detector dose response is linear (R2 value 0.9989). A 2% electron density difference is discernible using 460 projection images and a total exposure of 13 MU (corresponding to a maximum absorbed dose of about 12 cGy in a patient). We present first patient images acquired with this system. Tumors in lung are clearly visible and skeletal anatomy is observed in sufficient detail to allow reproducible registration with the planning kV CT images. The MV CBCT system is shown to be capable of obtaining good quality three-dimensional reconstructions at relatively low dose and to be clinically usable for improving the accuracy of radiotherapy patient positioning.

Intensity-modulated radiation therapy for the treatment of oropharyngeal carcinoma: the Memorial Sloan-Kettering Cancer Center experience.

PURPOSE: To review the Memorial Sloan-Kettering Cancer Center's experience in using intensity-modulated radiation therapy (IMRT) for the treatment of oropharyngeal cancer. METHODS AND MATERIALS: Between September 1998 and June 2004, 50 patients with histologically confirmed cancer of the oropharynx underwent IMRT at our institution. There were 40 men and 10 women with a median age of 56 years (range, 28-78 years). The disease was Stage I in 1 patient (2%), Stage II in 3 patients (6%), Stage III in 7 (14%), and Stage IV in 39 (78%). Forty-eight patients (96%) received definitive treatment, and 2 (4%) were treated in the postoperative adjuvant setting. Concurrent chemotherapy was used in 43 patients (86%). Patients were treated using three different IMRT approaches: 76% dose painting, 18% concomitant boost with IMRT in both am and pm deliveries, and 6% concomitant boost with IMRT only in pm delivery. Regardless of the approach, the average prescription dose to the gross tumor planning target volume was 70 Gy, while the average dose delivered to the subclinical volume was 59.4 Gy in the dose painting group and 54 Gy in the concomitant boost group. Percutaneous endoscopic gastrostomy feeding tubes (PEGs) were placed before the beginning of treatment in 84% of the patients. Acute and late toxicity were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Toxicity was also evaluated using subjective criteria such as the presence of esophageal stricture, and the need for PEG usage. The local progression-free, regional progression-free, and distant metastases-free rates, and overall survival were calculated using the Kaplan-Meier method. RESULTS: Three patients had persistent locoregional disease after treatment. The 2-year estimates of local progression-free, regional progression-free, distant metastases-free, and overall survival were 98%, 88%, 84%, and 98%, respectively. The worst acute mucositis experienced was Grade 1 in 4 patients (8%), Grade 2 in 27 (54%), and Grade 3 in 19 (38%). Xerostomia decreased with increasing time interval from the end of radiotherapy, and among the patients with at least 9 months of follow-up there was 67% Grade 0-1 and 33% Grade 2 toxicity. Of the 42 patients who required upfront PEG placement, 6 were still using PEG for nutrition at the time of this analysis. Three patients had cervical esophageal strictures, and of these, 1 was still PEG dependent 1 year after treatment. Two of these patients were treated with the IMRT concomitant boost am and pm approach, whereas the other was treated with the dose painting technique. CONCLUSIONS: Intensity-modulated radiotherapy achieved encouraging local control rates in patients with oropharyngeal carcinoma. Treatment toxicity was acceptable even in the setting of concurrent chemotherapy. Long-term follow-up is needed to confirm these preliminary findings.