|ORIGINAL RESEARCH REPORT
|Year : 2019 | Volume
| Issue : 1 | Page : 33-36
Use of imaging modalities and the effectiveness of radiation therapy on brain tumors in a tertiary hospital in Nigeria
Sandra C Nkamigbo1, Omodele Abosede Olowoyeye2, Muhammad Y. M. Habeebu2, Anunobi Charles Chidozie3, Oselumenosen David Omiyi1, Omolola Salako4, Victor I Edeh1
1 Department of Radiography, College of Medicine, University of Lagos, Lagos, Nigeria
2 Department of Radiation Biology, Radiotherapy and Radiodiagnosis, College of Medicine, University of Lagos, Lagos, Nigeria
3 Anatomic and Molecular Pathology, College of Medicine, University of Lagos, Lagos, Nigeria
4 Department of Radiotherapy, Lagos University Teaching Hospital, Lagos, Nigeria
|Date of Web Publication||14-Feb-2019|
Dr. Omodele Abosede Olowoyeye
Department of Radiation Biology, Radiotherapy and Radiodiagnosis College of Medicine, University of Lagos, Lagos
Source of Support: None, Conflict of Interest: None
Background: Brain neoplasia is of concern in our environment because there are no preventive measures or sufficient availability of definite treatment. With imaging, the disease can be detected and the treatment evaluated. Materials and Methods: In this retrospective study carried out at a tertiary hospital in Nigeria, diagnostic imaging modalities used for imaging brain tumors, the pattern of tumors identified at histology, and the response of brain neoplasia to radiation therapy were analyzed. Results: Out of the 147 patients included in the study, the mean age was 44.5 ± 2.3 years of age. For diagnostic imaging, 60% used only computed tomography (CT) scan, 24% used magnetic resonance imaging (MRI), while 16% used both CT scan and MRI. Histologically, primary tumors (54%) occurred more than metastasis (46%). Breast metastasis (33.3%) was the singular most common tumor, followed by astrocytoma (19%). For definitive management, almost half of the cases (49%) had radiotherapy alone. 25% had radiotherapy with surgery, 10% had both radiotherapy and chemotherapy while 16% had all three. Four weeks posttreatment, there was 78% positive response to therapy. Conclusion: In our environment, the radiological evaluation of brain tumors is often by CT scan, even though MRI offers better soft-tissue contrast. This may be ascribed to the relative affordability and availability of CT scan. Radiation therapy is effective in the treatment of brain tumors.
Keywords: Brain tumor, computed tomography scan, magnetic resonance imaging, radiation therapy, response evaluation criteria in solid tumors
|How to cite this article:|
Nkamigbo SC, Olowoyeye OA, Habeebu MY, Chidozie AC, Omiyi OD, Salako O, Edeh VI. Use of imaging modalities and the effectiveness of radiation therapy on brain tumors in a tertiary hospital in Nigeria. J Clin Sci 2019;16:33-6
|How to cite this URL:|
Nkamigbo SC, Olowoyeye OA, Habeebu MY, Chidozie AC, Omiyi OD, Salako O, Edeh VI. Use of imaging modalities and the effectiveness of radiation therapy on brain tumors in a tertiary hospital in Nigeria. J Clin Sci [serial online] 2019 [cited 2020 Jul 9];16:33-6. Available from: http://www.jcsjournal.org/text.asp?2019/16/1/33/252271
| Introduction|| |
Brain tumors account for 85%–90% of all the primary central nervous system (CNS) tumors. Primary brain tumors rarely metastasize outside the CNS; hence, there is no standard staging method, they are not as common as the secondary metastatic lesions., The majority of adult tumors are supratentorial, arising in the frontal, temporal, and parietal lobes. Secondary brain tumor is usually as a result of metastasis from carcinoma of the breast, lungs, kidneys, colorectum, or melanoma. In children, the most common sources of brain metastasis are sarcomas, neuroblastoma, and germ cell tumors. Secondary brain tumors are rarely due to metastasis from carcinoma of the prostate, esophagus, oropharynx, and nonmelanoma skin cancers.
In general, brain tumor affects patients of all ages and sexes, though they become more common with old age. Except in the case of meningioma, males have a higher occurrence incidence than females with a lifetime relative risk of 0.65% as opposed to 0.5% for women., Regardless of its rareness, primary brain tumors have a relatively high mortality rate, being the leading cause of death among pediatric cancer and the third leading cause in young adults between the ages of 15 and 34. Appropriate management of patients with suspected brain tumor requires a well-detailed history, physical examination, standard neurological investigation, and diagnostic neuroimaging studies.
Diagnostic imaging is necessary to confirm the presence of an intracranial tumor, to determine its specific location, and to highlight its unique radiological features. The definitive diagnosis is usually through histopathology. Magnetic resonance imaging (MRI) scan is the primary imaging modality for diagnosing brain tumors, and intravenous gadolinium contrast is normally administered to enhance the appearance of lesions. Computed tomography (CT) may also be used as an alternative imaging modality, but compared to MRI, it has poorer soft-tissue contrast and involves exposing patients to ionizing radiation.
The common brain tumors are gliomas, meningiomas, schwannomas, and pituitary tumors. In those with malignancy, a histological diagnosis is required before radiation therapy can be commenced. All brain tumors pose a threat to patients, benign tumors can be dangerous due to their situation in the brain, their ability to infiltrate locally, and their ability to undergo malignant transformation. Brain tumors may be treated with surgery, radiation therapy, and chemotherapy. Currently, the clinical standard which is used in evaluating the response of tumor to radiation treatment is by comparing the tumor size before and after treatment on CT and MRI. This standard is termed response evaluation criteria in solid tumors (RECIST). The RECIST standard focuses on reduction in tumor size, which is not necessarily a criterion for checking survival rate. “RECIST is a set of published rules that define when cancer patients improve (respond), stay the same (stable), or worsen (progression) during treatments.”
This research paper is aimed at assessing the utility of imaging modalities such as CT and MRI for brain tumors and the effect of radiotherapy on the tumors.
| Materials and Methods|| |
The research was carried out at the Radiotherapy and Oncology Department, of a tertiary hospital in Nigeria using a convenient, nonprobability sampling technique. All brain tumor cases, both primary and metastatic, presenting at the department from 2012 to 2016 were included, irrespective of age or gender. Ethical clearance was also obtained from the Research Ethics Committee of the hospital.
The demographical data of each patient, the type of imaging modality used, and histological diagnosis were obtained from the patients' case notes. In analyzing the effectiveness of radiation therapy on brain tumors, RECIST standard, which accesses the response of brain tumor, in respect to size was used. The tumor had to be at least 10 mm in its longest diameter, which is the diameter (size) used in the criterion. In multiple tumors, the sum of the longest diameters of all the tumors was regarded as the size. The four response categories were; “complete response” (CR) meaning total disappearance of the tumor, “partial response” (PR) meaning at least a 30% decrease in size, “stable disease” meaning the tumor size had not reduced so much as to be considered PR or increased so much as to be considered a progressive disease, and “progressive disease” meaning at least a 20% increase in the size of the tumor. Postimaging results were checked after 4 weeks of treatment and tumor sizes were compared with preimaging results.
All data were analyzed using the Statistical Package for the Social Sciences version 22.0 (SPSS Inc., Chicago, IL, USA).
| Results|| |
Three hundred and eighty-four new cases presented at the hospital over 5 years. However, only 147 people who had complete data were included in the study.
Patients between the ages of 41 and 50 had the largest frequency of 49 (34%), followed by those aged 61 years and above (22%). There was a female predominance of 1.6:1 to male, which was not statistically significant (P < 0.05). CT scan was the most commonly used imaging modality. More than half (60%) of the case participants used only CT scan for diagnostic imaging, 24% used just MRI while 16% used both CT and MRI [Figure 1].
|Figure 1: Pie chart showing the percentage usage of each diagnostic imaging modality for brain tumors|
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Brain tumors were located most commonly in parietal lobe of the cerebrum, followed by the ventricles [Figure 2]. [Figure 3] shows a tumor in the cerebrum with accompanying hydrocephalus. Primary tumors (54%) occurred more than metastasis (46%), breast metastasis (33.3%) was the singular most common tumor, followed by astrocytoma (19%) [Figure 4]. Primary tumors occurred significantly more in males (47%) than females (33%) while metastasis occurred significantly more in females (60%) than males (7%) (P < 0.05).
|Figure 2: Pie chart showing the radiological anatomic site of tumors in percentages|
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|Figure 3: Pre- and post-treatment T1-weighted magnetic resonance imaging slices of the brain. (a) Shows a rim-enhancing mass measuring 4.0 cm present in the right cerebrum. There is a visible mass effect on the right lateral ventricle and causing midline shift. There is also obstructive hydrocephalus. (b) Shows a decrease in tumor size to 3.2 cm with reduction in the degree of hydrocephalus. A decrease in the tumor size signifies treatment progression, according to the WHO and response evaluation criteria in solid tumors standards|
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|Figure 4: Bar chart showing the histological diagnosis of the various brain tumors in percentages|
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For definitive management, almost half of the cases (49%) had radiotherapy alone, while 25% had radiotherapy with surgery, 10% had both radiotherapy and chemotherapy while 16% had all three [Figure 5]. Four weeks posttreatment, there was 78% positive response to therapy [Figure 6].
|Figure 5: Venn diagram showing the different management options in combinations with radiotherapy, with almost half of the patients sampled having radiotherapy alone|
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|Figure 6: Bar chart showing the response of tumor to radiation therapy using the response evaluation criteria in solid tumors classification. 24% of cases had complete response to radiotherapy, 54% had partial response, 12% had a stable disease following treatment, and 10% had a progressive disease|
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| Discussion|| |
Treatment options for brain tumors such as with surgery, radiation therapy, or chemotherapy may be applied solitarily or in combination with one or both of the other options [Figure 5]. The treatment option chosen depends on whether the tumor is radiosensitive, chemosensitive, or both. In some cases, chemotherapy and/or radiotherapy may be applied before the surgery to debulk the tumor. In other cases in which complete surgical resection cannot be achieved, chemotherapy and/or radiotherapy may be applied postsurgery to treat the residual tumor. This study was to highlight the relevance of imaging in the management of patients who had radiation therapy as part of their management.
We found that CT scan was used more often than MRI for diagnosing brain tumors [Figure 1], even though MRI is usually the preferred imaging modalities for brain tumors due to its superior soft-tissue contrast. The greater percentage of CT scan usage may be due to the relative availability and affordability of CT scan compared with MRI. In our environment, the price of a brain CT scan may be between N35,000 and N40,000 while that of MRI may be in the range of N70,000–N80,000, making the cost for MRI twice as much as that for CT scan.
The finding that the cerebrum was the most common site of tumor with parietal lobe as the most occurring lobe agreed with that observed by other researchers., Histopathologically, astrocytoma was the most commonly occurring primary tumor. This is similar to other studies that reported astrocytoma as the most occurring brain tumor.,, Astrocytoma Grade IV (glioblastoma multiforme) was the most frequent occurring astrocytoma. This finding is in agreement with the research carried out by Mwang'ombe and Ombachi in Nairobi, Kenya and also closely compatible with a research carried out in 2015 in Lagos, Nigeria. The occurrence of breast metastatic lesion to the brain as the most common site, with lungs, cervix, and rectum following disagrees with the research carried out in India by Saha et al. It also disagrees with the study by Wen and Loeffler which had lungs as the most common site of origin for metastatic brain tumor. These discrepancies may be due to the incident rise of breast cancer in Nigeria.
Imaging conducted 4-week postintervention showed PR in about half of the cases, CR in about a quarter of cases and stable disease in 12% based on the RECIST criteria. 10% showed regression and there was a 78% positive response of brain tumors to radiation therapy. The research results were close to that carried out by Wong et al. in which they reported that 9% had complete or PR whereas 21% were alive and disease-free progression-free at 6 months.
| Conclusion|| |
CT scan is often used in the evaluation of brain tumors in our environment, even though MRI offers better soft-tissue contrast. This may be ascribed to the relative affordability and availability of CT scan. We found that radiation therapy is an effective mode of treatment.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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