Clinical manifestations and diagnostic approach to metastatic cancer of the mandible

Surface-enhanced Raman spectroscopy for the characterization of different anatomical subtypes of oral cavity cancer

BACKGROUND

The prognosis for oral cancer patients is still very poor worldwide. Early detection and treatment therapy remain the key issue to be addressed for improved patient survival. The characteristic Raman spectral features associated with the biochemical changes in the blood serum samples can be used for the diagnosis of diseases, particularly for oral cancer. Surface-enhanced Raman spectroscopy (SERS) is a promising technique for non-invasive and early detection of oral cancer by analyzing molecular changes in body fluids.

OBJECTIVES

To detect oral cavity anatomical subsites (buccal mucosa, cheek, hard palate, lips, mandible, maxilla, tongue and tonsillar region) cancers by using blood serum samples, SERS with principal component analysis is used.

MATERIAL AND METHOD

SERS is employed with silver nanoparticles for the analysis and detection of oral cancer serum samples by comparing with healthy serum samples. SERS spectra are recorded by Raman instrument and preprocessed using the statistical tool. Principal component analysis (PCA) and Partial least square discriminant analysis (PLS-DA) are used to discriminate between oral cancer serum samples and control serum samples.

RESULTS

Some major SERS peaks are observed at 1136 cm^-1 (Phospholipids) and 1006 cm^-1 (Phenylalanine) remain higher in intensities for oral cancer spectra as compared to healthy spectra. The peak at 1241 cm^-1 (amide III) is observed only in oral cancer serum samples while absent in healthy serum samples. Higher protein and DNA contents were detected in SERS mean spectra of oral cancer. Moreover, PCA is used to identify the biochemical differences in the form of SERS features which is used to differentiate between oral cancer and healthy blood serum samples, while PLS-DA is used to build differentiation model of oral cancer serum samples and healthy control serum samples. PLS-DA provides successful differentiation with 94% specificity and 95.5% sensitivity.

CONCLUSIONS

SERS can be used for the diagnosis of oral cancer and to identify metabolic changes that occur during disease development.

Occult prostate carcinoma with metastasis to the mandible presenting as numb chin syndrome

Prostate cancer is one of the leading causes of death due to malignancy in men. Occult malignancy presenting with no primary symptoms could be a challenge to the diagnostician. Metastasis of prostate carcinoma to the mandible is rare and usually presents with non-specific symptoms. Only 1% of oral cancers account for lesions which present as metastasis of other primary malignancies. We report a rare case of prostate carcinoma being diagnosed as metastasis to the mandible with the patient presenting with numb chin syndrome.

Metastatic Prostate Adenocarcinoma of the Mandible Diagnosed With Oral Manifestations

Metastasis from the prostate gland to the mandible is rarely encountered and commonly present with non-specific features like unexplained pain, swelling, and numb chin syndrome. Here we present a case with metastatic prostate adenocarcinoma detected secondary to oral manifestations. Patients present with unexplained facial pain and numbness should alert clinicians to the presence of malignant disease, and appropriate hematological, radiological and or histological investigations should be performed. Thereby, clinicians can prevent the overlook of the first signs of metastasis, accelerate the early diagnosis and positively orientate the prognosis of the disease, especially in a patient without known malignancy.

Two case reports on Mandibular metastases

Metastatic tumours of the oral cavity are not common. The most common site for bone metastases in the head and neck region is the mandible. Metastatic lesion of the mandible most commonly originate from the lungs in men and breast in women, and these lesions (or tumours) usually are carcinomas rather than sarcomas. We report two cases of metastatic lesions in the mandible: (1) A 19year old male with right mandibular swelling and a nodular swelling in the distal two-third of the right tibia. Radiograghs revealed sclerotic lesion with a sunburst appearance in both the jaw and tibia. Histology of the jaw lesion confirmed a metastatic osteosarcoma of the mandible. (2) A 51year old female with a right mandibular swelling with associated swelling in the anterior neck, right shoulder and right parietal region of the skull. Computerised tomography scan (CT) of the jaws showed an osteolytic lesion of the right mandible. CT scan of the brain also showed a large lytic lesion seen in the posterior aspect of the right parietal bone. Histology of the jaw mass confirmed a metastatic follicular carcinoma from the thyroid. Mandibular metastasis may be the first presenting feature of underlying occult malignancy of another primary site. Therefore, clinicians should maintain a high level of suspicion while evaluating patients with a history of cancer presenting with oral lesions.

Metastatic clear cell variant of renal cell carcinoma of the mandible: Review and case report

A case of metastatic renal cell carcinoma (RCC) to the mandible is reported. A 22-year-old man consulted us for hypoesthesia of the right lower lip. Panorama X-ray film showed a radiolucent lesion in the right mandibular body. A diagnosis of a metastatic tumor to the mandible from the right kidney was made after evaluation by computed tomography and bone scan with Tc99 methyl diphosphonate which also revealed multiple bone metastases. Histologically diagnosis was clear cell variant of RCC. Patient has been put on radiotherapy for symptomatic treatment and a molecularly targeted drug. The therapy effectively stopped the progressive growth of oral and other metastatic lesions. The quality of life is relatively well maintained with tolerable adverse effects. The patient is still on our follow-up with an improved quality of life.

Metastatic follicular thyroid carcinoma: a case report

OBJECTIVE

A case of oral metastatic follicular thyroid carcinoma is presented.

BACKGROUND

Metastatic tumours are more frequent in older individuals and can be the only sign/symptom of an undiagnosed primary malignancy.

CASE REPORT

A 69-year-old lady presented with an enlarging mandibular swelling. Incisional biopsy and imaging studies were suggestive of metastatic follicular thyroid carcinoma.

CONCLUSION

Metastatic tumours should be considered in the differential diagnosis of mandibular swellings especially in older individuals.

Prostatic adenocarcinoma with initial metastatic spread to the mandible

Prostate cancer is one of the commonest types of malignancy in males. Although prostate cancer has a propensity to metastasize to the bone, metastasis to the mandible is rare. Because of their uncommon incidence, the diagnosis of mandibular metastasis, especially those originating from the prostate, may represent a challenge both for urologists and dentists. Here we present a case of prostatic adenocarcinoma with initial metastatic spread to the mandible.

Mental nerve neuropathy: case report and review

Mental nerve neuropathy (MNN) or “numb chin syndrome” is a rare neurologic symptom most often associated with malignancy. Patients typically develop paresthesia or numbness localized to the chin and lower lip and will often seek care at their local emergency department. Pain and expansion of the lower jaw may also be present. We report a case of MNN associated with a metastatic lesion in the mandible. The purpose of this article is to highlight the importance of recognizing MNN, a potentially life-threatening symptom of metastatic carcinoma, and enable clinicians to properly diagnose MNN, which may mimic other conditions that affect the mandible.

Metastasis of prostate carcinoma in the mandible manifesting as numb chin syndrome

BACKGROUND

Numb chin syndrome is an uncommon but well-recognized symptom in medical oncology. This condition can be related to metastatic neurological manifestation of malignancy, often with no clinically visible pathology. About 1% of oral cancers, which are located in the soft tissues and jaws, are metastases of primary tumors located elsewhere in the body. The posterior mandible is the most common site of metastasis of the oral region because of its rich blood supply in active areas of hematopoiesis. This article describes prostate carcinoma metastasis located in the mandible and temporomandibular joint of a 78-year-old male.

CASE PRESENTATION

A 78-year-old male patient presented to our outpatient clinic with a complaint of numbness and pain on the left site of the mandible. The patient stated that he had been suffering from this numbness for 1 to 2 months. In the medical anamnesis, it was discovered that patient had prostate carcinoma (CA) 5 years previous, and since then, he had visited his doctor periodically for an annual examination. In these examinations and on the basis of tests carried out at the hospital 1 year previous, it was stated that no CA relapse traces were detected. The patient had visited his dentist 2 months previous for pain and numbness of the left molar region.

CONCLUSIONS

We report numb chin syndrome, which is an uncommon neurological manifestation of metastatic malignancy. The clinical course and rapid deterioration after the initial presentation of this syndrome is discussed. This clinical situation illustrates the importance of good medical history review prior to all procedures by the medical professions dealing with oncology patients. An awareness of this condition is crucial, especially in symptoms with unexplained facial pain and numbness.

Metastasis of lung adenocarcinoma to the mandible: Report of a case

Adenocarcinoma of the lung that metastasizes to the mandible is uncommon. There are only a few cases described in the English-language literature regarding metastasis to mandible from adenocarcinoma of the lung. This article shows a metastasis from adenocarcinoma of the lung affecting the mandible of a 55-year-old male patient where the metastatic lesion was detected before primary tumor. This article emphasizes the importance of detailed dentoalveolar examination and early diagnosis for finding the primary focus of metastatic lesions.

Metastatic pancreatic adenocarcinoma to the mandibular condyle: a rare clinical presentation

Metastatic disease to the oral cavity is rare, representing only 1-8% of oral malignancies, and involvement of the mandibular condyle is even less prevalent. In a recent literature review of 796 cases of metastatic disease to the oral cavity, only 39 (13.8%) involved the condyle. This report is a unique case of metastatic pancreatic adenocarcinoma to the condyle. There are only 5 documented cases of metastatic pancreatic adenocarcinoma to the oral cavity, one of which metastasized to the condyle. This is an important case because metastatic lesions to the condyle may mimic temporomandibular joint disorders making clinical diagnosis and decision-making extremely challenging for the oral and maxillofacial surgeon. The requirement for arrival at an appropriate and prompt diagnosis is crucial for determining the most appropriate treatment regimens and improved outcomes. Additionally, in approximately 33% of cases, the oral metastatic lesion may be the first indication of an undiscovered distant primary tumor, making timely evaluation and treatment critical from an oncologic perspective.

Mandibular metastasis in a patient with follicular carcinoma of thyroid

Mandibular metastasis due to thyroid carcinoma is not very frequent and the cases described in the literature are few. Due to its bloodstream dissemination, most of them are a consequence of the follicular variant of thyroid carcinomas. We are presenting a case in which the metastatic lesion of mandible was detected before diagnosis of primary malignancy.

Condylar metastasis from prostatic carcinoma mimicking temporomandibular disorder: a case report

BACKGROUND

Although metastatic carcinoma is the most common malignant tumor of the bone, less than 1% of all metastatic bone lesions are presented in the maxillofacial area. As the mandibular body is the most frequent localization, metastasis to the mandibular condyle is extremely rare.

CASE REPORT

This report describes a rare case of prostate carcinoma metastatic to the mandibular condyle in a 75-year old man, who was referred because of persistent pain in the temporomandibular joint (TMJ) region and a limitation of opening, initially misdiagnosed and treated as temporomandibular disorder (TMD). Histopathological examination confirmed the suspected metastasis of prostate carcinoma and local radiation therapy was performed.

DISCUSSION

TMD represent a diagnostic challenge and sometimes an interdisciplinary approach is required to prevent a delay of the correct treatment. Metastatic cancer should be included in the differential diagnosis of TMD, especially in patients with a malignant disease.

Head and neck manifestations of distant carcinomas

Metastatic tumors to the head and neck from distant carcinomas are rare lesions that epitomize the "zebras." They represent a diagnostic and therapeutic challenge for clinicians and health providers. These lesions usually rank low in the differential diagnosis list, but a history of cancer should prompt clinicians about the possibility of a metastatic lesion from a distant carcinoma. The presence of these lesions usually represents a poor prognosis. The surgeon's role in treating these lesions is to improve or maintain the patient's quality of life, taking into consideration the overall prognosis.

An atypical presentation of breast cancer metastasis

A 78-year-old woman heard a crack in her left mandible while eating a biscuit and reported to her dentist, who urgently referred her to the oral and maxillofacial surgery department. On examination she had a lesion in the body of her left mandible, which had eroded through the lower border and caused a pathological fracture. Her past medical history included a left mastectomy and level II axillary lymph node dissection for a 27 mm grade III invasive ductal carcinoma of the left breast 9 months prior to her mandibular fracture. A transoral incisional biopsy was performed which confirmed the mandibular lesion to be an osteolytic metastasis from the breast. The metastasis was subsequently surgically removed and the remaining mandible repaired with a reconstruction plate followed by postoperative radiotherapy. The patient regained full function of her mandible and is now eating normally. She is being closely followed-up in the oncology outpatient department.

Management of facial asymmetry

Asymmetries of the craniofacial region encompass a multitude of diverse and potentially complex abnormalities that may be the result of numerous causes. The expression and degree of asymmetry for a given condition, although a highly variable process, is the ultimate determinant of the nature of its treatment. This article highlights some of the key features and treatment strategies for various common facial asymmetries.

Numb chin syndrome as initial manifestation in a child with acute lymphoblastic leukemia

Numb chin syndrome (NCS) describes the affection of the inferior alveolar nerve and is a purely sensory neuropathy. Its symptoms include numbness of the skin of the chin, the lip and the gingival mucosa. Mostly seen in adults, it has rarely been described in children. We report on an 11-year-old male who presented with NCS as initial manifestation of acute lymphoblastic leukemia of B-cell type.

Breast metastasis around dental implants: a case report

BACKGROUND

Metastases to the oral cavity and to the jaws are rare; hence, the clinical manifestations of the oral metastasis lesion could frequently be simulating general pathologic entities, making the diagnosis a challenging process to the dental team. Local factors, such as trauma, have been observed to facilitate the growth of blood-borne tumors. To this end, surgical procedures such as fixture placement might cause cancer cells to spread.

PURPOSE

Careful clinical examination is a valuable help in diagnosing oral lesions, which can improve the quality of life of patients and reduce the risks of oral complications.

MATERIALS AND METHODS

A female patient was referred to the clinic with symptoms of irritation, swelling, and pain associated with implants in the mandible and the maxilla.

RESULTS

Clinical examination, x-ray, and histopathology revealed that the patients suffered from a metastatic lesion, primary tumor being an adenocarcinoma of the breast diagnosed at the same time.

CONCLUSION

Optimal clinical examination in conjunction with radiography and histopathology is a necessity in order to discover malignant lesions in time. Routine dental check-ups must comprise more thorough soft-tissue examination.

Mandibular metastasis in a patient with pulmonary adenocarcinoma

Metastatic tumour spread to the mandible is quite rare. We report a case of distant metastasis of pulmonary adenocarcinoma in the mandibular bone. The patient had pain in his left mandibular premolar-molar area caused by a mandibular metastasis from a previously undiagnosed pulmonary adenocarcinoma.

Metastatic lesion of the anterior mandible with an occult primary: a case report

Metastatic tumors to the oral cavity are relatively uncommon and account for about 1% of all oral cancers. Distant metastases to the jawbone are associated with a poor prognosis and a survival rate that is usually less than one year. The leading common primary sites for these lesions are the breast in females and the lung in males followed by the adrenals, kidneys, prostate, thyroid and colon. In 30% of all cancers, a metastatic lesion could be the first sign of a primary tumor elsewhere in the body. Metastatic lesions to the jaws are known to simulate periodontal and pulpal disease and other radiolucent lesions that can occur in the jaws. Microscopic evaluation with concurrent radiographic skeletal survey is warranted in patients where a metastatic lesion is suspected.

Focal osteoporotic marrow defect: report of 100 new cases with ultrasonography scans

Focal osteoporotic marrow defect (FOMD) may be the earliest detectable form of the ischemic marrow disorders. The exact cause is unknown, but three theories have been proposed in the literature. A fourth is presented in this paper. In this study, 100 biopsies were examined histologically and were diagnosed as FOMD, based upon consistent histological characteristics. Until recently, the only diagnostic criteria were radiographic evaluation and incisional biopsy. In February 2002, a through-transmission alveolar ultrasonic test (Cavitat 4000, Cavitat Medical Technologies, Inc., Aurora, CO) was approved by the US Food and Drug Administration and by Health Canada for detection of low bone density and bone desiccation, both features of FOMD and chronic ischemic bone disease. Within this article, the diagnostic criteria and pathological findings of FOMD will be presented. The three current theories concerning its etiology will be briefly presented and a fourth theory will be proposed.

[Metastatic prostate carcinoma mimicking a parotid tumor: a case report]

We report a case of prostate carcinoma metastatic to the mandible that had been initially suspected as being a primary tumor of the parotid. The initial symptom was hard swelling in the left parotid region. No pathologic fracture was diagnosed. The metastatic lesion was diagnosed 4 years after diagnosis of the carcinoma of the prostate. This is a very interesting event because of its unusual localization.

Cranial nerve deficits in patients with metastatic prostate carcinoma

BACKGROUND

Cranial nerve lesions due to metastases from prostate carcinoma to the skull base are an uncommon yet clinically significant finding.

METHODS

The authors report the clinical features, treatment, and outcomes for 15 patients who presented with cranial nerve palsies complicating metastatic prostate carcinoma. Patient charts identified from a Fox Chase Cancer Center treatment data base were reviewed.

RESULTS

All patients had hormone-refractory disease at the time of symptom onset. Twelve of 15 patients had received prior chemotherapy, and 13 of 15 patients had received prior radiation therapy to areas of bony pain. Symptoms varied from recognized clinical syndromes involving multiple cranial nerves to isolated cranial nerve lesions. All patients had lesions at the skull base that were visualized on computed tomography scans or magnetic resonance images. All patients were treated with palliative radiation therapy to either the whole brain or the skull base. Fourteen of 15 patients had a clinical (either partial or complete) response to radiation therapy. All responding patients subsequently died of prostate carcinoma without worsening of residual or development of new cranial nerve symptoms. Ten of 15 patients (67%) died within 3 months of developing symptoms, and the remaining 5 patients lived between 9 months and 31 months from onset of symptoms.

CONCLUSIONS

The authors concluded that palliative radiation therapy should be considered in this heterogeneous group of patients given the potential for significant symptom improvement.

Evaluation of the pathophysiology of odontogenic maxillary sinusitis using bone scintigraphy

The inflammatory changes in the maxillary sinus mucosa and wall (mucosal and bony lesions) were evaluated to identify the pathophysiology of odontogenic maxillary sinusitis. Out of 80 patients who underwent CT, 32 patients were examined using single photon emission computerized tomography (SPECT) bone scintigraphy (bone SPECT) with 99mTc-hydroxymethylene-diphosphonate. Mucosal and bony lesions were evaluated morphologically on both images. SPECT data were used to assess the bone activity by calculating the count ratios of the causative alveolar process over the cervical vertebrae. The relationships with clinical symptoms, mucosal changes around the maxillary ostium (ostial lesions), and radiolucencies around the causal teeth (periapical lesions) were assessed. Bone SPECT showing the causal site was valuable for aiding a definitive diagnosis. Mucosal lesions tended to exceed bony lesions horizontally and vertically. Bony lesions tended to extend posteriorly and then anteriorly. The vertical extent of mucosal lesions and the horizontal and vertical extent of bony lesions were correlated with the presence of facial symptoms, ostial lesions, and periapical lesions. Bone activity was significantly correlated with the horizontal and vertical extent of mucosal lesions, horizontal extent of bony lesions, and presence of infraorbital symptoms, ostial lesions, and periapical lesions. Bone activity caused by alveolitis affects the pathophysiology of this disease.

Metastatic breast carcinoma mimicking periodontal disease on radiographs

BACKGROUND

Tumors can metastasize to the jaws, oral soft tissues, or salivary glands. Metastasis from distant organs and tissues to the jaws or oral cavity is considered rare.

RESULTS

The mandible is the most common site of metastasis of the oral and maxillofacial region. Radiographically, there is usually an area of radiolucency with hazy outline. Such lesions are manifested as radiopaque or sclerotic areas.

CONCLUSIONS

Radiographic view of a tumor in the present case mimicked a periodontal lesion with an osteolytic area around the roots.

The use of bone scintigraphy in temporomandibular joint disorders

INTRODUCTION

The use of bone scintigraphy (bone scan) in the diagnosis of temporomandibular joint (TMJ) disease has been infrequent, as compared with traditional radiographic techniques. Bone scans have the potential to detect active bone remodeling whereas corresponding radiographs may be normal or document past structural change in the joint. Traditional radiographic findings and relevant clinical signs and symptoms correlated with bone scans may aid in the diagnosis of TMJ disease and possibly affect treatment and prognosis of individual cases. The use of bone scans as an additional tool in diagnosing TMJ disease was assessed in this series of patients.

METHODS

Thirty consecutive subjects with TMJ tenderness were selected for bone scintigraphy using technetium diphosphonate 99 mTc and single photon emission computerized tomography. These subjects received bone scans as well as other selected imaging modalities for diagnostic purposes.

RESULTS AND DISCUSSION

The findings on bone scan were evaluated and a change in preliminary clinical diagnosis or treatment was made in 60% of cases because of the findings on bone scintigraphy. Bone scintigraphy may be valuable to assess progress of TMJ inflammation or remodeling, and may affect diagnosis and treatment of patients with TMJ tenderness.

Prostate carcinoma metastatic to the cervical lymph nodes: report of two cases and review of the literature

The cervical lymph nodes are a common site of metastasis for cancers originating in the upper aerodigestive tract. Rarely, cancers originating from sites other than the head and neck can metastasize to the cervical lymph node chain. We report on 2 recent patients with metastatic prostate cancer to the cervical lymph nodes.

Diagnostic value of spect bone scintigraphy for odontogenic maxillary sinusitis

PURPOSE

The aim of this study was to assess the diagnostic value of bone SPECT for odontogenic maxillary sinusitis and bone activity in the alveolar process to clarify the pathophysiologic nature of the disease.

MATERIALS AND METHODS

Computed tomography and bone SPECT with Tc-99m HMDP were performed in 28 patients with odontogenic maxillary sinusitis. Based on the findings of the computed tomographic images, the inflammatory changes in the maxillary sinus mucosa (mucosal lesions) were evaluated horizontally and vertically. For the initial diagnosis, visualization of the causative site by bone SPECT was compared with conventional radiographic and planar findings. SPECT data were used to assess bone activity by calculating the mean count ratios of the alveolar process over the cervical vertebrae. The relation of bone activity to the structure of the mucosal lesions, the presence of clinical symptoms, mucosal changes around the maxillary ostium (ostial lesions), and conventional radiolucent images around the causative teeth (periapical lesions) were assessed.

RESULTS

Identification of the causative site was sufficiently specific in bone SPECT images. Bone activity was significantly correlated with the structure of the mucosal lesions, both horizontally and vertically, and with the presence of infraorbital symptoms, ostial lesions, and periapical lesions.

CONCLUSIONS

It is important to view odontogenic maxillary sinusitis as a bone disease in which the bone activity associated with alveolar osteitis affects the pathophysiologic nature of the disease. Bone SPECT is valuable to make a more precise diagnosis, thereby allowing more appropriate treatment of the disease.

Technetium 99m single positron emission computed tomography scanning for assessing mandible invasion in oral cavity cancer

OBJECTIVES

To study the accuracy of single positron emission computed tomography (SPECT) scanning and compare its results to clinical examination, Panorex, and computed tomography (CT) scanning with respect to determining mandibular invasion by oral cavity and oropharyngeal cancer, and to define the role of SPECT scanning in the preoperative assessment of oromandibular cancer.

STUDY DESIGN

Prospective study of 38 patients who underwent technetium 99m SPECT scanning as part of their preoperative clinical assessment for cancer at risk of invading the mandible. All patients underwent partial or segmental mandibulectomy as part of their surgical management.

METHODS

A data protocol was used to tabulate patient demographics, tumor characteristics and results of preoperative tests as patients were enrolled into the study. Following surgical treatment, these data were correlated with histopathological findings. Detailed analysis was performed to assess the tabulated data.

RESULTS

The SPECT scanning demonstrated an 87% overall accuracy in predicting bone invasion compared with 71% for clinical examination, CT scanning, and Panorex x-rays. The SPECT scanning was significantly more sensitive (95%) than either CT scans (55%) or Panorex x-rays (50%). Notably SPECT scanning demonstrated a considerable improvement in specificity (72%) compared with conventional radionuclide scanning. Although not as specific as CT scanning or plain films, SPECT scanning was significantly more effective in ruling out disease than was clinical examination.

CONCLUSIONS

Preoperative SPECT scanning used in combination with clinical examination, CT scanning, and Panorex x-rays to assess patients at risk for mandible involvement by oral cavity cancer can improve the accuracy of predicting bone invasion and help in appropriate treatment planning so as to safely reduce the proportion of disease-free jaws resected.

The role of single photon emission computed tomography in bone imaging

Single photon emission computed tomography (SPECT) of the bone is the second most frequently performed SPECT examination in routine nuclear medicine practice, with cardiac SPECT being the most frequent. Compared with planar scintigraphy, SPECT increases image contrast and improves lesion detection and localization. Studies have documented the unique diagnostic information provided by SPECT, particularly for avascular necrosis of the femoral head, in patients with back pain, for the differential diagnosis between malignant and benign spinal lesions, in the detection of metastatic cancer in the spine, for the diagnosis of temporomandibular joint internal derangement, and for the evaluation of acute and chronic knee pain. Although less rigorously documented, SPECT is being increasingly used in all types of situations that demand more precise anatomic localization of abnormal tracer uptake. The effectiveness of bone SPECT increases with the selection of the proper collimator, which allows one to acquire adequate counts and minimize the patient-to-detector distance. Low-energy, ultrahigh-resolution or high-resolution collimation is preferred over all-purpose collimators. Multihead gamma cameras can increase the counts obtained or shorten acquisition time, making SPECT acquisitions more practical in busy departments and also increasing image quality compared with single-head cameras. Iterative reconstruction, with the use of ordered subsets estimation maximization, provides better quality images than classical filtered back projection algorithms. Three-dimensional image analysis often aids lesion localization.