增强CT冠状扫描在诊断鼻咽癌颅底侵犯中的意义

目的：探讨鼻咽部增强CT冠状位扫描对诊断鼻咽癌侵犯颅底的价值。方法：将经病理学检验证实的193例鼻咽癌的CT增强轴位扫描与冠状位扫描颅底情况进行回顾性对照分析。结果：193例鼻咽癌中，120例(占62．2％)经两种扫描均未见颅底侵犯；10例(5．2％)轴位扫描未见颅底异常而经冠状扫描发现其受侵犯；15例(7．8％)轴位可疑颅底受侵犯而经冠状扫描肯定侵犯11例．排除4例；轴位扫描显示海绵受窦侵有26例。增强CT冠状扫描则为3例。结论：增强CT冠状扫描对确定鼻咽癌有无颅底骨质侵犯及其侵犯部位、范围与程度均有重要价值，在显示海绵窦受侵犯，肿瘤组织沿脑池或／和脑沟等蛛网膜下腔生长，侵犯周围组织的征像方面，明显优于轴位扫描。     

The impact of postimplant edema on the urethral dose in prostate brachytherapy

PURPOSE: The objective of this work is to determine the effect of timing of the postimplant CT scan on the assessment of the urethral dose. METHODS AND MATERIALS: A preimplant CT scan and two postimplant CT scans were obtained on 50 patients who received I-125 prostate seed implants. The first postimplant CT scan was obtained on the day of the implant; the second usually 4 to 9 weeks later (mean: 46 +/- 23 days; range: 27-135 days). The urethra was localized in each postimplant CT scan and a dose-volume histogram (DVH) of the urethral dose was compiled from each CT study. The relative decrease in the prostate volume between the first and second postimplant CT scans was determined by contouring the prostate in each CT scan. RESULTS: The prostate volume decreased by 27 +/- 9% (mean +/- SD) between the first and second postimplant CT scans. As a result, the averaged urethral dose derived from the second CT scan was about 30% higher. In terms of dose, the D(10), D(25), D(50), D(75), and D(90) urethral doses derived from the second CT scan were 90 +/- 56 Gy, 81 +/- 49 Gy, 67 +/- 42 Gy, 49 +/- 44 Gy, and 40 +/- 46 Gy higher, respectively. The increase in the urethral dose is correlated with the decrease in the prostate volume (R = 0.57, rho < 0.01). CONCLUSION: The assessment of the urethral dose depends upon the timing of the postimplant CT scan. The mean D(10) dose derived from the CT scans obtained at 46 +/- 23 days postimplant was 90 +/- 56 Gy higher than that derived from the CT scans obtained on the day of the implant. Because of this large difference, the timing of the postimplant CT scan needs to be specified when specifying dose thresholds for urethral morbidity.     

PET scans for decision-making in metastatic renal cell carcinoma: a single-institution evaluation

OBJECTIVE: Therapeutic decision-making in metastatic renal cell carcinoma (MRCC) is based on conventional radiological evaluation. Fluorodeoxyglucose positron emission tomography (FDG-PET) scans may modify this strategy. METHODS: Patients with MRCC for whom a therapeutic decision had been made underwent an FDG-PET scan in order to complete the standard radiological evaluation. RESULTS: Twenty-four patients and 26 FDG-PET scans were eligible. In 18 patients, metastatic disease was evaluable on the computed tomography (CT) scan; the FDG-PET scan was positive in 16 patients and negative in 10. In 2 patients, the FDG-PET scan was positive while they were considered disease free on radiological evaluation. In 5 patients (20.8%), the previous therapeutic decision was changed. Thirteen patients had a pathological evaluation for 19 sites. One patient out of 13 had a false-positive FDG-PET scan, while 4 sites out of 6 were false-negative. The sensitivity was 75% (95% CI: 47.6-92.7) and the predictive positive value was 92.3% (95% CI: 64-99.8). With a median follow-up of 24 months, 3 patients developed new metastatic sites. CONCLUSION: Our data suggest that, when positive, an FDG-PET scan may modify the decision made; when negative, it should not modify decision-making especially for surgery, owing to its sensitivity.     

Unsuspected abnormalities noted on CT treatment-planning scans obtained for breast and chest wall irradiation

PURPOSE: Three-dimensional treatment planning and CT simulation is widely used for the treatment of a variety of cancers. At the Stanford University Medical Center, a treatment-planning CT scan is obtained before breast irradiation to optimize the dose distribution to the treated breast and to limit radiation to the opposite breast, heart, and lung. In this paper, we review the incidental findings discovered on a careful review of these scans. METHODS AND MATERIALS: Between 1997 and 1999, 153 patients referred for breast or chest wall radiation therapy underwent a treatment-planning CT scan in our department. The planning scans were extended to include not only the breast, but also the neck, thorax, and liver. A resident and attending radiation oncologist carefully reviewed each scan before approving the treatment plan. Any abnormal findings were reviewed by an attending in the department of radiology, and additional diagnostic imaging or other evaluation was obtained as necessary. RESULTS: One hundred and fifty-three sequential scans were reviewed, and 17 unsuspected abnormalities were noted (11%). The abnormalities involved the lung (n = 4), the liver (n = 3), the gallbladder (n = 4), the esophagus (n = 2), lymph nodes (n = 3), and the breast. All abnormalities were evaluated with additional imaging studies and/or appropriate consultations. Four of these abnormalities represented additional cancer foci (3%) and altered the treatment plan. CONCLUSIONS: Three-dimensional treatment-planning CT scans for breast cancer should be carefully reviewed. In our institution, 11% of these planning studies contained abnormalities, and 3% demonstrated additional unanticipated sites of involvement by breast cancer.     

Abdominal computed tomography scans in the selection of patients with malignant peritoneal mesothelioma for comprehensive treatment with cytoreductive surgery and perioperative intraperitoneal chemotherapy

BACKGROUND: Malignant peritoneal mesothelioma is a rare and fatal disease. Until recently, the treatment options were very limited and ineffective. The new comprehensive approach of cytoreductive surgery with perioperative intraperitoneal chemotherapy offers improved survival rates at a cost of considerable morbidity and mortality as in other peritoneal surface malignancies. The outcome after these treatments is predominantly dependent on adequate cytoreduction. The aim of the current study was to identify computed tomography (CT) scan images that are useful in patient selection for this comprehensive approach. METHODS: An analysis of the preoperative CT scans of 30 patients with peritoneal mesothelioma treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy at a single institution was performed. Based on the size of residual tumor nodules after cytoreductive surgery, patients were divided into 2 groups: those with residual lesions2.5 cm (suboptimal cytoreduction). The CT scans for each patient were evaluated by a standardized scoring system with the reader blinded to the operative findings. Thirty-nine CT scan parameters were obtained and statistically analyzed to determine their association with the study outcome variables, namely, adequacy of cytoreduction. RESULTS: Seven patients (64%) in the suboptimal cytoreduction group and 2 patients (11%) in the adequate cytoreduction group had a >5-cm tumor mass in the epigastric region (P=0.004). Nine patients (82%) in the suboptimal group and 2 patients (11%) in the adequate cytoreduction group had CT scans that showed loss of normal architecture of the small bowel and its mesentery (P<0.001). In a composite analysis of these 2 radiologic features, none of the patients with a >5-cm tumor mass in the epigastric region and loss of normal architecture of the small bowel and its mesentery had an adequate cytoreduction. Patients who lacked these two preoperative CT scan findings had a 94% probability of an adequate cytoreduction. CONCLUSIONS: CT scans effectively identified large peritoneal mesothelioma tumors at crucial anatomic sites. Because adequate cytoreduction is necessary to achieve prolonged survival, CT scans became an accurate prognostic radiologic test for patient selection for comprehensive treatment.     

Are positron emission tomography-computed tomography (PET-CT) scans useful in preoperative assessment of patients with peritoneal disease before cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC)?

Introduction: CRS and HIPEC confer survival benefit in selected patients with peritoneal metatases (PM). Accurate preoperative assessment of disease burden and exclusion of distant metastases are crucial in selecting the appropriate patient. We evaluate the utility of PET-CT scans in comparison with CT and MRI scans in patients considered for CRS and HIPEC.

Methods: Data were retrospectively collected from patients who had been discussed for CRS and HIPEC between January 2011 and December 2015, at our institutional multidisciplinary tumour board. Patients who underwent PET-CT scan were included. Results of PET-CT were compared against traditional imaging. Patient and tumour factors were analysed to identify those who were most likely to benefit from PET imaging.

Results: Four hundred and seven patients were considered for CRS and HIPEC. PET-CT was performed for 128(31.4%) patients: being the only imaging modality in 37 and used as an adjunct in 91. In the latter group, it was not beneficial in 58 patients as it provided no additional information (n?=?33) or showed lesions of minimal FDG uptake (n?=?25). In 33 patients, PET-CT provided definitive answers for indeterminate lesions seen on CT and MRI, confirmed the diagnosis of peritoneal disease in 10 patients (30.3%), identified extra-peritoneal disease and/or nodal metastases in 15 (45.5%) and excluded peritoneal disease in 8 (24.2%). The usefulness of PET-CT was predicted by tumour histology (p?=?.009), with non-mucinous tumours benefitting the most.

Conclusion: Our results suggest that PET-CT can be used as an adjunct to CT and/or MRI scans, when lesions on the CT/MRI scans are indeterminate, and that it is most useful in patients with non-mucinous tumours.     

Value of computed tomography in staging the primary lesion (T-staging) of nasopharyngeal carcinoma (NPC): an analysis of 54 patients with special reference to the parapharyngeal space

CT scans of the nasopharynx and the base of skull were performed in 54 patients with histologically proven NPC. The CT findings are compared to those obtained by routine clinical examination. In this series, involvement of the parapharyngeal spaces was found by CT scan in 61% (33/54) of patients, which is impossible to assess by clinical means. Intracranial invasion was demonstrated by CT scan with intravenous contrast enhancement in five patients. CT is more sensitive in showing the erosion of skull base than X ray film. CT scans demonstrated 17% (5/30) of bony invasion in X ray negative patients. Clinical examination showed one involved wall in nine patients; CT scan discovered involvement of two or more walls in five (55%) of these nine. Routine clinical examination discovered extra-nasopharyngeal extensions in 34 locations, whereas CT scans discovered 106, a ratio of 1:3.1. The common sites of extra-nasopharyngeal extension detected by CT scan are: parapharyngeal space, intracranial invasion, sphenoidal sinus, orbit, ethmoidal sinus, maxillary antrum, oropharynx and the nasal cavity. In T-staging of NPC, 55% (6/11) of clinical T2 lesions are up-staged by CT. Thirty-six percent (4/11) of clinical T3 lesions were also up-staged. However, 94% (17/18) of clinical T4 lesions remained unchanged. Only 6% (1/18) of clinical T4 lesions were down-staged.     

Multiple "slow" CT scans for incorporating lung tumor mobility in radiotherapy planning.

PURPOSE: The high local recurrence rates after radiotherapy in early-stage lung cancer may be due to geometric errors that arise when target volumes are generated using fast spiral CT scanners. A "slow" CT technique that generates more representative target volumes was evaluated. METHODS AND MATERIALS: Planning CT scans (slice thickness 3 mm, reconstruction index 2.5 mm) were performed during quiet respiration in 10 patients with peripheral lung lesions. Planning CT scans were repeated twice, followed by three slow CT scans (slice thickness 4 mm, index 3 mm, revolution time 4 s/slice). All, except the first scan, were limited to the tumor region. Three-dimensional registration of all scans was performed. The reproducibility of the imaged volumes was evaluated with each technique using (1) the common overlapping volume (COM), the component of the clinical target volume (CTV) covered by all three CT scans, and (2) the encompassing volume (SUM), which is the volume enveloped by all CTVs. RESULTS: In all patients, the target volumes generated using slow CT scans were larger than those derived using planning scans (mean ratio of planning-CTV:slow-CTV of 88.8% +/- 5.6%), and also more reproducible. The mean ratio of the respective COM:SUM volumes was 62.6% +/- 10.8% and 54.9% +/- 12.9%. CONCLUSIONS: Larger, and more reproducible, target volumes are generated for peripheral lung tumors with the use of slow CT scans, thereby indicating that slow scans can better capture tumor movement.     

肺原发恶性纤维组织细胞瘤的影像表现

探讨肺原发恶性纤维组织细胞瘤（ＭＦＨ）的影像特点,提高术前确诊率。方法对本院７例及文献中４４例共５１例影像资料进行分析。包括胸片５１例,ＣＴ９例及ＭＲＩ１例。结果本院肺原发ＭＦＨ占同期肺癌０．０１％。全组发病中位年龄５５岁。主要症状为咳嗽、血痰及胸痛。随诊４０例中,死因不明５例,复发和（或）转移１５例,复发率为４２．８％（１５／３５）,发生在一年内占８０．０％。肿瘤位于右叶３４例,左叶１７例。周围型４９例,占９６．１％;中心型２例,占３．９％。影像表现：肿瘤呈软组织肿块,瘤体较大,≥５ｃｍ者３５例,占６８．６％。形态呈规则或不规则形。边缘光整或界限清者２９例,占５６．９％;伴有分叶者２２例,占４３．１％;密度均匀者３３例,占６４．７％。少数病灶边缘有毛刺、囊性变及空洞形成。ＣＴ显示病变密度低且有坏死区,周围组织器官受侵。结论肺原发ＭＦＨ的影像表现虽无特征,但瘤体大,边界清,少分叶,少毛刺,密度低,可有别于常见的肺癌和良性肿瘤。ＣＴ及ＭＲＩ检查有助于显示病变内部密度、侵犯范围和转移情况,可提高诊断率。本病变恶性度高,复发转移快,根治切除可有长期生存的可能     

Radioimmunoguided imaging of prostate cancer foci with histopathological correlation

Purpose: We have previously presented a technique that fuses ProstaScint and pelvic CT images for the purpose of designing brachytherapy that targets areas at high risk for treatment failure. We now correlate areas of increased intensity seen on ProstaScint-CT fusion images to biopsy results in a series of 7 patients to evaluate the accuracy of this technique in localizing intraprostatic disease.

Methods and Materials: The 7 patients included in this study were evaluated between June 1998 and March 29, 1999 at Metrohealth Medical Center and University Hospitals of Cleveland in Cleveland, Ohio. ProstaScint and CT scans of each patient were obtained before transperineal biopsy and seed implantation. Each patient’s prostate gland was biopsied at 12 separate sites determined independently of Prostascint-CT scan results.

Results: When correlated with biopsy results, our method yielded an overall accuracy of 80%: with a sensitivity of 79%, a specificity of 80%, a positive predictive value of 68%, and a negative predictive value of 88%.

Conclusion: The image fusion of the pelvic CT scan and ProstaScint scan helped identify foci of adenocarcinoma within the prostate that correlated well with biopsy results. These data may be useful to escalate doses in regions containing tumor by either high-dose rate or low-dose rate brachytherapy, as well as by external beam techniques such as intensity modulated radiotherapy (IMRT).     

Positron emission tomography/computed tomography in the management of recurrent/metastatic breast cancer: a large retrospective study from the Royal Marsden Hospital

BackgroundDespite the increasing use of positron emission tomography/computed tomography (PET/CT) in the management of patients with breast cancer, its role is yet to be defined.Patients and methodsWe reviewed PET/CT scans carried out in breast cancer patients, the indication, concordance/discordance with other imaging and whether their use had altered patient management.ResultsPET/CT scans (233) were carried out in 122 patients between July 2004 and October 2008. Indications were as follows: staging (S) (91), response assessment (RA) (87), clarification (C) of findings on other imaging (32) and reassurance (ASS) (23). In the S group, positive scans were helpful in accurately defining the extent of disease and guided localised or systemic treatment. PET/CT was particularly useful for detecting lytic bone metastases. One-third of the scans was carried out for RA. PET/CT allowed early RA and in some cases appropriate discontinuation of ineffective treatment. PET/CT was used effectively for the clarification of indeterminate lesions on CT (18), magnetic resonance imaging (15) and bone scan (13). In the ASS group, all scans were negative.ConclusionsPET/CT is useful in accurately staging metastatic disease, assessing response to systemic treatment and clarifying equivocation on other imaging. Incorporation of PET/CT in these areas contributes to breast cancer management optimisation.     

The integration of 18-fluoro-deoxy-glucose positron emission tomography and endoscopic ultrasound in the treatment-planning process for esophageal carcinoma

PURPOSE: Accurate delineation of the gross tumor volume (GTV) is important in radiation therapy treatment planning. We evaluated the impact of PET and endoscopic ultrasound (EUS) compared with CT simulation in the planning of radiation fields for patients with esophageal carcinoma. MATERIAL AND METHODS: Twenty-five patients presenting with esophageal carcinoma for radiation therapy underwent PET scans in the treatment position after conventional CT simulation. Patients underwent PET/CT scanning after being injected with 10 to 20 mCi of [F-18]-2-deoxy-2-fluro-D-glucose. The length of the abnormality seen on the CT portion of the PET/CT scan vs. the PET scan alone was determined independently by 2 separate investigators. The length of the GTV and detection of regional adenopathy by PET was also correlated with EUS in 18 patients. Of the 18 patients who had EUS, 2 had T2 tumors and 16 had T3 tumors. Eighteen patients had adenocarcinoma and 7 had squamous cell carcinoma. Nine tumors were located at the gastroesophageal junction, 8 at the lower esophagus, 7 in the middle esophagus, and 1 in the cervical esophagus. The PET scans were reviewed to determine the length of the abnormality by use of a standard uptake value (SUV) of 2.5 to delineate the tumor extent. RESULTS: The mean length of the cancer was 5.4 cm (95% CI 4.4-6.4 cm) as determined by PET scan, 6.77 cm (95% CI, 5.6-7.9 cm) as determined by CT scan, and 5.1 cm (95% CI, 4.0-6.1 cm) for the 22 patients who had endoscopy. The length of the tumors was significantly longer as measured by CT scans compared with PET scans (p = 0.0063). EUS detected significantly more patients with periesophageal and celiac lymphadenopathy compared to PET and CT. The SUV of the esophageal tumors was higher in patients with peri-esophageal lymphadenopathy identified on PET scans. CONCLUSION: Endoscopic ultrasound and PET scans can add additional information to aid the radiation oncologist's ability to precisely identify the GTV in patients with esophageal carcinoma.     

Correlation among [18F]fluorodeoxyglucose positron emission tomography/computed tomography, cancer antigen 27.29, and circulating tumor cell testing in metastatic breast cancer

Background: Tumor marker cancer antigen (CA) 27.29 and combined [18F]-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) scans are used to follow up response to treatment and disease progression in patients with metastatic breast cancer (MBC). Recently, circulating tumor cell testing (CTC) has been used in this context. It is not known if 1 of the 3 tests can be a surrogate for another. Patients and Methods: We analyzed a database of 35 patients with MBC. There were 173 time points (>/= 6 weeks apart) when >/= 2 of these tests were performed. Correlation among all the 3 tests was statistically analyzed. Results: Results of PET/CT scans were compared with CA 27.29 at 163 time points. There was a statistically significant correlation between both groups (P = .02); however, sensitivity of CA 27.29 to detect metastatic disease observed on PET/CT scan was 59%. The results of PET/CT scans were compared with CTC at 93 events, where there was a statistically significant correlation between both groups (P = .0002); however, sensitivity of CTC to detect metastatic disease shown on PET/CT scans was 55%. Cancer antigen 27.29 results were also compared to CTC at 100 events, where there was a statistically significant correlation between both groups (P = .0002). However, only 64% of patients with high CA 27.29 had abnormal CTC. Conclusion: Our data shows correlation among PET/CT scan, CA 27.29, and CTC. However, both CA 27.29 and CTC had poor sensitivity and negative predictive value to detect metastatic disease observed on PET/CT scan. Normal CA 27.29 testing or CTC has to be interpreted cautiously in patients with MBC.     

A feasibility study for image guided radiotherapy using low dose, high speed, cone beam X-ray volumetric imaging.

BACKGROUND AND PURPOSE: Image Guidance of patient set-up for radiotherapy can be achieved by acquiring X-ray volumetric images (XVI) with Elekta Synergy and registering these to the planning CT scan. This enables full 3D registration of structures from similar 3D imaging modalities and offers superior image quality, rotational set-up information and a large field of view. This study uses the head section of the Rando phantom to demonstrate a new paradigm of faster, lower dose XVI that still allows registration to high precision. MATERIALS AND METHODS: One high exposure XVI scan and one low exposure XVI scan were performed with a Rando Head Phantom. The second scan was used to simulate ultra low dose, fast acquisition, full and half scans by discarding a large number of projections before reconstruction. Dose measurements were performed using Thermo Luminescent Dosimeters (TLD) and an ion chamber. The reconstructed XVI scans were automatically registered with a helical CT scan of the Rando Head using the volumetric, grey-level, cross-correlation algorithm implemented in the Syntegra software package (Philips Medical Systems). Reproducibility of the registration process was investigated. RESULTS: In both XVI scans the body surface, bone-tissue and tissue air interfaces were clearly visible. Although the subjective image quality of the low dose cone beam scan was reduced, registration of both cone beam scans with the planning CT scan agreed within 0.1 mm and 0.1 degrees . Dose to the patient was reduced from 28mGy to less than 1mGy and the equivalent scan speed reduced to one minute or less. CONCLUSIONS: Automatic 3D registration of high speed, ultra low dose XVI scans with the planning CT scan can be used for precision 3D patient set-up verification/image guidance on a daily basis with out loss of accuracy when compared to higher dose XVI scans.     

The influence of small bowel motion on both a conventional three-field and intensity modulated radiation therapy (IMRT) for rectal cancer.

PURPOSE: To investigate the reduction of irradiated small bowel volume with intensity modulated radiation therapy (IMRT) planning in rectal cancer and to asses the variability of the irradiated small bowel in the conventional planning as in the IMRT planning (IMPlan) by obtaining weekly CT scans. PATIENTS AND MATERIALS: Twelve patients with rectal cancer had treatment planning CT scans of the pelvis with small bowel contrast obtained for planning and once a week during treatment (65 CT scans total). The scans were registered using the bony structures. The clinical target volume (CTV), small bowel, large bowel and bladder were outlined on each slice. The first CT scan was used for IMPlan and conventional three-field planning (ConPlan), which were then applied to the CT scans obtained during therapy. RESULTS: The median value among patients of the mean volume over a patient's scan of small bowel irradiated > or =95% was 112 cm3 (standard deviation (SD): 31 cm3) for the ConPlan and 42 cm3 (SD: 17 cm3) for the IMPlan. The median total bladder volume was 148 cm3 (SD: 130 cm3). There was a good correlation between the volume of irradiated small bowel and the bladder volume for IMPlan with <50 cm3 irradiated small bowel and ConPlan with <150 cm3 (p = 0.002). CONCLUSION: The use of IMRT led to a potentially clinically meaningful reduction in the volume of small bowel irradiated, even when accounting for small bowel motion. A full bladder was of greatest benefit in individuals with the smallest volume of small bowel in the treatment field.     

Adaptive radiotherapy for invasive bladder cancer: a feasibility study

PURPOSE: To evaluate the feasibility of adaptive radiotherapy (ART) in combination with a partial bladder irradiation. METHODS AND MATERIALS: Twenty-one patients with solitary T1-T4 N0M0 bladder cancer were treated to the bladder tumor + 2 cm margin planning target volume (PTV(CONV)). During the first treatment week, five daily computed tomography (CT) scans were made immediately before or after treatment. In the second week, a volume was constructed encompassing the gross tumor volumes (GTVs) on the planning scan and the five CT scans (GTV(ART)). The GTV(ART) was expanded with a 1 cm margin for the construction of a PTV(ART). Starting in the third week, patients were treated to PTV(ART). Repeat CT scans were used to evaluate treatment accuracy. RESULTS: On 5 of 91 repeat CT scans (5%), the GTV was not adequately covered by the PTV(ART). On treatment planning, there was only one scan in which the GTV was not adequately covered by the 95% isodose. On average, the treatment volumes were reduced by 40% when comparing PTV(ART) with PTV(CONV) (p < 0.0001). CONCLUSION: The adaptive strategy for bladder cancer is an effective way to deal with treatment errors caused by variations in bladder tumor position and leads to a substantial reduction in treatment volumes.     

Retroperitoneal sarcomas

Opinion statement The approach to the management of retroperitoneal tumors begins with a complete history and physical examination. Imaging of the abdomen and pelvis by computed tomography (CT) provides both an imaging modality and a method by which to obtain tissue for diagnosis. Because a histologic diagnosis is essential in treatment planning, adequate tissue can usually be obtained by a CT-guided core biopsy. If the diagnosis is sarcoma, additional tests necessary for staging include plain chest radiography and evaluation of the liver by either CT scan or magnetic resonance imaging (MRI). The treatment options for primary retroperitoneal sarcomas include chemotherapy, radiation therapy, surgery, or a combination of these modalities; therefore, a multidisciplinary group best manages treatment planning. Primary radiation therapy for cure is seldom effective for retroperitoneal sarcomas but can provide palliation in select cases. Systemic chemotherapy for chemosensitive lesions, such as poorly differentiated liposarcoma, malignant fibrous histiocytoma (MFH), synovial cell sarcoma, and primitive neuroectodermal tumors (PNET), can be useful when used in a neoadjuvant manner. Consequently, surgical resection continues to be the mainstay of treatment for retroperitoneal sarcomas and requires en bloc resection of the primary tumor. Frequently this includes adjacent organs such as colon, small bowel, kidney, adrenal, and pancreas. Postoperative adjuvant therapy with chemotherapy or radiation has not been proven to be of any additional benefit. Overall treatment results are predominantly influenced by tumor stage, grade, size, and margins of surgical resection. Follow-up CT scans at 6-month intervals and surgical resection of recurrences can be valuable.     

FDG-PET scanning for detection and staging of extranodal marginal zone lymphomas of the MALT type: a report of 42 cases.

BACKGROUND: Although reports have suggested that FDG-PET scans were not useful for staging of extranodal marginal zone lymphomas (MZL), experience at our center suggests otherwise. Thus we reviewed the findings of FDG-PET scans in patients with extranodal MZL seen at our center. PATIENTS AND METHODS: A database of 175 patients with histologically-confirmed diagnoses of extranodal MZL was reviewed. Forty-two patients who had had FDG-PET scans for initial staging were identified. All information was obtained by retrospective review of medical records and PET scans. RESULTS: Thirty-four (81%) patients had focal tracer uptake within verified tumor sites, six (14%) patients did not, and two (5%) patients had indeterminate uptake. Seven of the 34 (21%) patients with uptake within verified tumor sites had uptake in regional lymph nodes and four patients were upstaged due to FDG-PET findings. Eight patients also obtained post-treatment FDG-PET scans. In five of those eight, the repeated FDG-PET scan indicated a complete response, and in three there was an indeterminate or mixed response. CONCLUSION: FDG-PET scans carried out for initial staging of extranodal MZL detected disease in a high proportion of patients. This study suggests that imaging with FDG-PET scans is useful for both initial staging and follow-up of patients with extranodal MZL.     

Are multiple CT scans required for planning curative radiotherapy in lung tumors of the lower lobe?

PURPOSE: Lung tumors located in the lower lobe are the most mobile. Multiple computed tomographic (CT) scans, which had been performed for radiotherapy planning, were analyzed to determine the minimal number of required scans. METHODS AND MATERIALS: Six spiral CT scans (3 rapid and 3 slow) from 7 such patients were coregistered. Reproducibility of target volumes was defined as the ratio between the overlapping and encompassing volume (COM/SUM) from scans derived using one technique. Volumetric and dosimetric analyses were performed. RESULTS: Slow CT scans generated larger and more reproducible target volumes than rapid planning scans, with a mean COM/SUM ratio of 71.9 +/- 8.7% and 58.0 +/- 12.7%, respectively. When only a single slow CT scan was used for planning, the addition of a symmetrical 3D margin of 5 mm ensured 99% coverage of the "optimal" target volume, which was derived from summation of target volumes from all six scans. CONCLUSION: Planning target volumes (PTVs) derived from a single slow CT scan plus a 5-mm margin covered the "optimal" PTVs generated from six scans. Although these "slow PTVs" were larger, the increase in V(20) (the volume of lung tissue receiving a dose > or = 20 Gy) was limited. This indicates that only two CT scans, i.e., a full rapid scan of the entire thorax and a limited slow scan, are necessary for treatment planning in peripheral lung cancers.     

The use of computerized tomography scanning in treatment planning for bladder carcinoma

Computerized tomography (CT) scans of the pelvis were performed in 50 patients with and without known pelvic malignancies at the Albert Einstein Medical Center, Northern Division, between September 1976 and September 1977. Each scan was reviewed systematically to determine size, location and interrelationship of pelvic structures as well as to evaluate the possible extent of tumor. For the 21 patients who were to receive radiation therapy for carcinoma of the bladder, the treatment plans, which were based on the patient contour and diagnostic studies, were compared to the information gained from the CT scan. Twenty nine per cent of the original treatment plans were altered after reviewing the CT scans. Ten patients with a diagnosis of bladder carcinoma underwent pre- and post-voiding scans. The area of the bladder at the level of the femoral heads which remained after voiding was on the average 69% of the original (range, 54–81%). The CT scan provided information which permitted better understanding of the dynamics of physiologic anatomy. It could replace the more invasive techniques presently used for localization in carcinoma of the urinary bladder.