Solitary Hot Spots Research Articles

Transrectal Ultrasound-Guided Robotic Excision of Perirectal Lymph Node Metastasis After Primary Radical Prostatectomy

Clinical History: A 60-year-old man with prostate specific antigen (PSA) of 10.8 ng/mL underwent a biopsy that showed grade group (GG) 5 adenocarcinoma of the prostate. The MRI showed organ-confined disease although there was an indeterminate 1 cm node in the left anterolateral perirectal fat. During the robotic radical prostatectomy, bilateral extended node dissection was performed, but the perirectal lymph node was not identifiable. Final pathology report confirmed adenocarcinoma GG5, pT2pN0MxR0, 22 lymph nodes were examined. At 3 months follow-up, PSA was 7.5 ng/mL. Diagnosis: Axumin positron emission tomography and computed tomography showed a solitary hot spot at the location of the perirectal node. We discussed treatment options androgen deprivation therapy, radiotherapy, and surgery. The patient elected for perirectal lymph node dissection (LND). In office contrast-enhanced transrectal ultrasound (TRUS) was performed. This confirmed location and visibility for planned intraoperative TRUS-guided excision. Intervention: Robotic LND started between the rectovesical pouch and the anterolateral aspect of the distal rectum. The node was identified with intraoperative TRUS and then a 17F Chiba needle was placed transrectally through the node into the surgical field. Transfixing the node gave direct vision and guided the robotic LND off the rectal wall and surrounding fat. There were no intraoperative complications, operative time was 214 minutes, estimated blood loss minimum, and length of stay 1 day. Follow-Up: Pathology report confirmed two distinct lymph nodes with metastatic prostatic carcinoma with 14- and 3-mm tumor deposit, respectively. PSA has remained undetectable at last follow-up, 40 weeks after LND. Authors do not have any commercial associations during the past 3 years that might create a conflict of interest in connection with the video. Authors have received and archived patient consent for video recording and publication in advance of video recording of procedure. Runtime of video: 5 mins

Retinoblastoma with Isolated Parotid Gland Metastasis: A Report of 2 Cases with Review of Literature.

Retinoblastoma, the most common primary intraocular malignant neoplasm in young children, show frequent metastasis to lymph nodes, central nervous system and bones. However, retinoblastoma metastasizing to parotid gland is very rare. We here present 2 cases of isolated parotid gland metastasis in two children with unilateral retinoblastoma. Case 1 was a one-year-old child presenting with left globe lesion which was diagnosed as Retinoblastoma. Post chemotherapy, enucleation was done which on histopathology examination showed retinoblastoma with scleral invasion and anterior chamber seeding. On 3 month follow up, patient presented with left parotid swelling. He underwent Fine needle aspiration cytology (FNAC) and Core needle biopsy which confirmed retinoblastoma metastasizing to parotid following which superficial parotidectomy was done as it was a solitary hotspot on PET-CT followed by localized radiotherapy and chemotherapy. While case 2, a 6-year-old child presented with left parotid swelling with a history of undergoing enucleation 3 months earlier in an outside hospital; Enucleation slides were reviewed in addition to patient undergoing FNAC and Biopsy from parotid swelling, all of which were consistent with Retinoblastoma metastasizing to parotid; This patient was lost to follow up; Although rare with only a few case reports in literature, both the pathologist and the clinician should be aware of retinoblastoma metastasizing to parotid, which when diagnosed and treated promptly has overall better prognosis in the cases reported so far.

Reliability of different radioisotopic techniques in diagnosing solitary hot spots in the spine of patients with malignant neoplasm

Early diagnosis of spinal metastases is of key importance in further therapeutic management. The aim of the study was to assess the reliability of single-photon emission computed tomography (SPECT) or SPECT and computed tomography (SPECT/CT) in the diagnosis of solitary hot nodules in the spine identified by scintigraphy. In this retrospective study, 70 patients with neoplastic disease and a solitary nodule detected in the spine were analyzed. Using a SPECT/CT γ-camera, the type and site of the foci in the vertebra were analyzed. Bone scintigraphy, SPECT, and CT were performed. Reliability of the results was assessed depending on the applied technique. In malignant lesions, increased isotope uptake was observed in the vertebral body with the posterior arch (89%), the body and both arches (67%), and the body alone (14%). In benign lesions, increased uptake was observed in the body area or in the joint area. Using SPECT, 25 of 27 cases (93%) of foci were properly classified as malignant. Using SPECT/CT, malignant lesions were observed in 26 of 27 cases (96%). Using SPECT, 19 of 43 cases were identified as benign (44%), and using SPECT/CT, 31 of 43 were identified as benign (72%). The agreement between SPECT and SPECT/CT was higher for malignant lesions (89%) than for benign lesions (67%). The use of CT in SPECT/CT examinations allowed to change the SPECT diagnosis of malignant lesions to that of benign lesions in 50% of the cases. The criteria used in the diagnosis of solitary nodules in the spine direct the diagnosis largely towards noncancerous lesions. Reliability of positive assessment was significantly lower than that of negative one - 51% in SPECT and 68% in SPECT/CT. A hybrid SPECT/CT camera is more reliable than SPECT alone in the assessment of spinal lesions.

Single bony lesions on 99mTc-MDP bone scintigrams of children with known malignancy

Introduction: 99mTc-MDP bone scintigraphy is employed to investigate children with known or suspected malignancy. While the presence of multiple lesions on bone scans of children in the context of known malignancy is generally considered to be due to metastases, the exact significance of solitary hot spots remains unknown. An accurate diagnosis is critical in order to determine the optimal management and eventual outcome. This study was undertaken to evaluate the significance of solitary abnormalities on bone scintigrams of children with known or suspected malignancy.

WHAT IS THE SIGNIFICANCE OF SOLITARY BONY ABNORMALITIES ON BONE SCINTIGRAMS OF CHILDREN WITH MALIGNANCY?

This investigation was undertaken to evaluate the significance of solitary bony abnormalities on bone scintigrams of children with known or suspected malignancy. A total of 215 bone scans were performed in 183 children in order to look for possible metastasis over a 10-year period. Forty-nine scans (22.8%) were found to have single lesions, of which 18 were due to uptake at the primary site and were excluded from further consideration. Of the remaining 31 lesions, 13 (41.9%) were confirmed as metastases, 17 lesions were proved to be benign, and 1 indeterminate. Solitary hot spots in children with known or suspected malignancy are common and therefore have to be taken seriously due to their higher malignant potential.

Frequency and etiology of solitary hot spots in the pelvis at whole-body positron emission tomography/computed tomography imaging

Purpose To determine the frequency and etiology of a single hypermetabolic focus within the pelvis with no other areas of increased 18-fluorodeoxyglucose (FDG) uptake in the reminder of the whole body in an oncological population. Method and Materials We retrospectively examined the first 700 whole-body PET/CT scans performed at our institution for baseline staging or follow-up of cancer and identified all patients with a solitary focus of increased FDG uptake in the pelvis. All available medical records and imaging findings in these patients were reviewed in order to determine the etiology of increased FDG uptake. Results Eight (1.1%) of the 700 patients had a solitary hot spot in the pelvis at positron emission tomography (PET)/computed tomography (CT) imaging, consisting of seven of 380 women and one of 320 men. In the seven women, increased FDG uptake was due to physiological endometrial uptake ( n=2), leiomyoma ( n=1), corpus luteum cyst ( n=1), physiological ovarian uptake ( n=1), urinary leak ( n=1), and nonspecific colitis ( n=1). In the man, uptake was due to recurrent rectosigmoid adenocarcinoma. None of the 700 patients was found to have metastatic disease in the pelvis. Conclusion Isolated pelvic hot spots at PET/CT imaging in an oncological population are not common and usually benign; physiological endometrial or ovarian uptake is the single commonest cause.

Do short-time SPECT images of bone scintigraphy improve the diagnostic value in the evaluation of solitary lesions in the thoracic spine in patients with extraskeletal malignancies?

Single photon emission computed tomography (SPECT) images provide many details of the anatomical structure. Also about bone scintigraphy, there are many reports of the improvement of diagnosis by SPECT images. Although SPECT is useful, it requires much time. So to perform SPECT for all cases is difficult in the clinical situation. Recently, due to technical improvements in gamma cameras, we can get SPECT images in a short time. We examined diagnosis of solitary hot spots of thoracic spine in cancer patients using short-time SPECT. And we considered whether short-time SPECT contributes to the precise diagnosis of the lesion. We performed bone scintigraphy image acquisition and both planar and short-time SPECT of the chest. Short-time SPECT was acquired in 6 minutes. We selected 36 cases with malignancy, whose bone scintigraphy demonstrated a solitary accumulation hot spot in the thoracic spine. Three experienced radiologists in nuclear medicine and 4 beginners diagnosed the images. They interpreted planar, short-time SPECT and maximum intensity projection (MIP) view of the chest of each case. The observers' response data were analyzed with receiver operating characteristic (ROC) curve analysis. Of the three types of images, the Az (the area under ROC curve) values of short-time SPECT were the highest in all the observers except for only one beginner. Compared with experienced observers, beginners scored lower Az values of short-time SPECT. MIP images were constructed using SPECT data, but the Az values of MIP images were not higher than those of planar images. As to diagnosis, beginners tended to interprete most of the accumulations as metastatic lesions. Short-time SPECT can be helpful to some degree, but to provide greater benefit, the observers require considerable exercise and experience.

Clinical Significance of Solitary Rib Hot Spots on Bone Scans in Patients with Extraskeletal Cancer

Bone scans showing solitary hot spots in the ribs pose diagnostic problems in patients with proved extraskeletal cancers. The authors wanted to determine the importance of solitary rib lesions and their correlation with other clinical manifestations. The study included 199 patients with solitary rib hot spots on their bone scans. The follow-up radiographic and scintigraphic images were reviewed to determine their origin. The correlation between the occurrence of a malignant rib lesion and clinical data were determined using Pearson chi-square tests. Ninety-three patients had an established cause of the rib hot spot. Eleven (11.8%) had a solitary malignant rib hot spot and 82 (88.2%) had a solitary benign rib hot spot. None of the hot spots at costochondral junctions were malignant. Of the 11 patients with proved metastatic rib hot spots, 1 of 11 (9.1%) had localized bone pain, 5 of 6 (83.3%) were concordant with primary tumors, 4 of 7 (57.1%) had elevated tumor markers, and 5 of 11 (45.5%) had concurrent extraskeletal metastases. For the 82 patients with benign rib hot spots, the figures were 2 of 82 (2.4%), 43 of 57 (75.4%), 26 of 69 (37.7%), and 19 of 82 (23.2%), respectively. Statistical analysis did not show a significant correlation between the incidence of metastases in solitary rib hot spots and clinical manifestations. Most solitary rib hot spots on bone scans were benign. The interpretation of a solitary hot spot in the ribs is difficult even with the help of these clinical manifestations. Follow-up bone scintigrams or radiographs are needed for further investigation of solitary rib hot spots.

Parathyroid Surgery: Separating Promise from Reality

We set out to determine the accuracy in predicting the success of biochemical and localizing studies for use in a minimally invasive parathyroidectomy. Preoperative sestamibi scans, intraoperative gamma-probe examinations, and intraoperative PTH (IOPTH) monitoring were performed on a prospective cohort of patients. Seventy-one patients were included in the study. Of the 59 patients (83%) with primary HPT, adenoma localization by sestamibi scanning was correct in 95% with solitary adenomas, but was correct in only 25% of the 14 patients with multiple adenomas. In patients with secondary and tertiary disease, sestamibi scanning incorrectly identified a single hot spot in 64% of cases. In no case of hyperplasia was the probe useful in locating other glands after a single gland was removed. IOPTH was accurate in 78% of patients with primary disease and in only 45% of patients with nonprimary disease. A minimal approach can be considered in a select group of patients that does not have familial primary HPT, secondary or tertiary disease, coexisting thyroid pathology, or an equivocal sestamibi scan. Only patients with a positive single hot spot on sestamibi scan can be considered candidates. Using this criteria only 64% of all patients with hyperparathyroidism are candidates for a minimally invasive approach. The combination of a solitary hot spot on sestamibi scan and a fall in IOPTH allows the surgeon to make the correct decision regarding the need to convert to a bilateral approach in 93% of these selected patients.

Clinical significance of a solitary hot spot in the skull.

Retrospective evaluation of bone scintigrams over the last 10 years was performed to determine the incidence of a solitary hot spot in the skull, examine its significance in patients with and without extra-skeletal malignancy, and determine if location along the suture lines is clinically significant or not. Review of the reports of bone scintigrams in 9968 patients yielded 37 (0.37%) patients with a solitary hot spot in the skull. In the group of 27 patients with extra-skeletal malignancy, the hot spot was secondary to metastasis in four patients and of a non-metastatic origin in 15. In the remaining eight patients, the cause was indeterminate. Two of the four metastatic foci were located along the suture lines. In another group of 10 patients without extra-skeletal malignancy, the cause was non-metastatic in eight patients and indeterminate in two. No significant differences between the scintigraphic features (intensity of uptake, location and relationship with sutures) of metastatic and non-metastatic foci were noted. We conclude that a solitary hot spot in the skull is rare and is predominantly benign in nature. However, in patients with known extra-skeletal malignancy, approximately 21% are secondary to a solitary bone metastasis of the skull. Location of a hot spot along the suture lines may not always be a normal variation and can represent a solitary bone metastasis.

The aetiology of solitary hot spots in the ribs on planar bone scans

The aetiology of solitary hot spots in the ribs on planar bone scans

The aetiology of solitary hot spots in the ribs on planar bone scans

The aim of this study was to determine the aetiology of solitary hot spots in the ribs found at bone scintigraphy in patients with known extraskeletal malignancy. A group of 34 patients whose bone scans showed a solitary hot spot in a rib were identified retrospectively over a 4-year period. They all had a known extraskeletal malignancy. Aetiology of the rib hot spot was established in 26 patients based on a review of clinical features, radiographic findings and clinical follow-up. In eight cases it remained indeterminate. In 14 (41%) cases, the rib lesion was malignant in origin, 9 were due to metastasis and 5 due to direct spread from intrapulmonary malignancy. In 12 (35%) cases, it was benign. In the remaining 8 (24%) cases, the aetiology was indeterminate. In the subgroup of 14 hot spots confined to the anterior rib end, 5 (36%) were due to malignancy, 4 (28%) were benign and 5 (36%) were indeterminate. We conclude that solitary hot spots in the ribs of patients with known extraskeletal malignancy undergoing bone scintigraphy are frequently (41%) malignant in origin. This also applies when the hot spot is in the anterior rib end (36% malignant). Thus, such hot spots are far more sinister than previously reported and require careful clinical and radiographic evaluation.

The aetiology and distinguishing features of solitary spinal hot spots on planar bone scans

To determine the aetiology of solitary spinal hot spots on planar bone scans and to determine which radiographic and scintigraphic features aid in distinguishing benign from malignant lesions. 81 bone scans showing a solitary hot spot in the spine were identified. Aetiology was determined in 73 based on imaging and clinical findings, including clinical follow-up. The location of the hot spot was classified as paravertebral (related to the lateral spinal margin), panvertebral (diffuse uptake confined within a vertebra), hemivertebral (uptake confined between the midline and lateral spinal margin) or complex (all others). The aetiology of the spinal hot spot was benign in 55 patients and malignant in 18. The latter all belonged to the subgroup of 42 patients with a known malignancy. Only eight of the 18 malignant cases had suggestive plain radiographic findings. There was no significant relationship between aetiology and age. The spinal level of the hot spot was cervical in three (all benign), thoracic in 16 (eight benign) and lumbar in 54 (44 benign). The hot spot was paravertebral in 21 (all benign), panvertebral in 24 (20 benign), hemivertebral in 13 (10 benign) and complex in 15 (only four benign). Most (75%) solitary spinal hot spots are benign, and even in patients with known malignancy just over half (57%) are benign. Malignant lesions are often (56%) radiographically occult. Thoracic or complex hot spots are more likely to be malignant while paravertebral hot spots are characteristically benign. These features may be helpful in distinguishing benign and malignant lesions in patients with a known malignancy and unremarkable radiographs. Other scintigraphic features are unhelpful in distinguishing benign from malignant lesions.

89. The aetiology and distinguishing features of solitary spinal hot spots on planar bone scans

89. The aetiology and distinguishing features of solitary spinal hot spots on planar bone scans

The possible nature of hot spots on tokamak walls

The authors consider the mechanism of the contraction of the thermal contact area between the plasma and the wall in a tokamak. This mechanism is attributed to the strong dependence of the thermionic emission of electrons on the temperature of the wall surface. A simple, largely analytical model for the description of the heat balances of the plasma and the wall is developed. An instability of small perturbations of homogeneous stationary states is investigated. The possibility of the existence of 'autosolitons', i.e. long living solitary hot spots with a surface temperature of 3000 degrees C, being an intensive source of impurities in a discharge, is shown. The theoretical results are compared with experimental data from TFTR and JET

Kernspintomographie des Knochenmarks bei Karzinompatienten mit einer solitären Mehranreieherung im Skelettszintigramm

Solitary abnormalities in bone scintigrams of cancer patients are a finding causing special diagnostic problems. In a prospective study the value of MRI imaging of the bone marrow was to be ascertained when compared to recognized X-ray studies, as a method of clarifying suspect bone scintigraphy findings. 25 cancer patients presenting with a solitary suspect abnormality in bone scintigrams were examined by X-rays and MRI. In 15 patients, MRI showed that metatases were the probable cause of the hot spot. In 7 patients, radiography, the routinely used method to confirm or exclude the presence of metastases, failed to detect these metastases. In the remaining 10 patients other causes of increased activity in the bone scintigrams could be demonstrated, e.g. fracture, degenerative disease, benign tumour. The results were confirmed by biopsy, operation, autopsy or follow-up. Considering the clinical consequences of the diagnosis of bone metastases, we suggest that a bone marrow MRI of the affected region should be performed to clarify the cause of a solitary hot spot in bone scintigrams of cancer patients, especially if X-ray studies are inconclusive.

Painless fibro-osseous lesion of the rib resembling osteoid osteoma: a report of six cases.

Six cases of an unusual fibro-osseous rib lesion are presented. These six lesions were asymptomatic, and five were found incidentally as solitary hot spots on bone scans which had been performed to rule out metastatic carcinoma. One was found incidentally in a rib resected for another reason. Histologically, these painless lesions most closely resemble osteoid osteomas. This study also documents that solitary rib hot spots are almost always benign even if the patient has a primary carcinoma.