New era of radiotherapy: an update in radiation-induced lung disease

Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans.

Respiratory-driven lung tumor motion is independent of tumor size, tumor location, and pulmonary function

PURPOSE

To determine whether superior-inferior lung tumor motion is predictable by tumor size or location, or pulmonary function test results.

METHODS AND MATERIALS

Superior-inferior tumor motion was measured on orthogonal radiographs taken during simulation of 22 patients with inoperable lung cancer diagnosed by orthogonal radiographs.

RESULTS

The tumor size averaged 5.5 +/- 3.1 cm (range 1.5-12 cm). Seven of 11 central tumors demonstrated some motion compared with 5 of 11 peripheral tumors. Four of 5 upper lobe tumors moved compared with 8 of 17 tumors that were either middle or lower lobe lesions. The mean fourth rib motion was 7.3 +/- 3.2 mm (range 2-15). The mean FeV(1) was 1.8 +/- 1.2 (range 0.55-5.33. The mean diffusing capacity of the lung for carbon monoxide was 14.0 +/- 6.5 (range 7.8-21.9). The mean total lung capacity was 6.5 +/- 1.2 (range 3.3-8.4). None of these parameters correlated with tumor motion. Although lateral tumor motion could not be consistently determined, 1 tumor moved 10 mm anterior-posteriorly.

CONCLUSIONS

Lung tumors often move significantly during respiration. Tumor motion is not predictable by tumor size or location, or pulmonary function test results. Therefore, tumor motion must be measured in all patients. Measurement in three dimensions will likely be necessary to maximize the irradiated lung volumes or choose beam arrangements parallel to the major axis of motion.

“Ditzels” on Chest CT

OBJECTIVE

We surveyed the members of the Society of Thoracic Radiology regarding their interpretation of and management decisions for very small (3-5 mm) pulmonary nodules-"ditzels"-noted on CT.

SUBJECTS AND METHODS

A survey consisting of 13 case scenarios in which ditzels were encountered on CT examinations was mailed to the 406 members of the Society of Thoracic Radiology. Statistical analysis was performed to determine associations between responses, years of experience, location in an endemic region of granulomatous disease, and location at a lung or a general cancer center.

RESULTS

One hundred fifty-one surveys (37%) could be included in the analysis. The most common response was "short-term follow-up." As the likelihood of malignancy increased, the response of "recommend biopsy" or "considered malignant or metastatic" increased. Those radiologists located in an area considered endemic for granulomatous disease were more likely to consider an incidental ditzel benign and to recommend follow-up, whereas those in a nonendemic area were more likely to recommend biopsy. In the cases in which years of experience had an influence, the less experienced respondents were more likely to choose "nothing, considered benign" or short-term follow-up than biopsy.

CONCLUSION

The most common response was short-term follow-up, with less aggressive recommendations in cases with a lower likelihood of malignancy and more aggressive recommendations in cases with a higher likelihood of malignancy. Location in an area considered endemic for granulomatous disease and years of experience influenced decisions.

Kaposi sarcoma in a renal transplant patient

The radiographic abnormalities of primary Kaposi's sarcoma of the lung in a patient with a renal transplant are reported. The findings are similar to other malignancies and infections that are well recognized in the renal transplant population. In the appropriate clinical setting, the radiologist should consider the diagnosis of Kaposi's sarcoma even in the absence of cutaneous lesions as reducing immunosuppression can be curative therapy.

A multidisciplinary surgical approach to superior sulcus tumors with vertebral invasion

BACKGROUND

Vertebral body invasion by superior sulcus tumor has traditionally been considered a contraindication to surgical resection. Attempts at definitive radiation or chemoradiation have not been successful. Recent advances in spinal instrumentation have allowed more complete resection of vertebral body tumors. We, therefore, reviewed our recent experience with vertebral resection of superior sulcus tumors.

METHODS

All patients (n = 17) undergoing resection of superior sulcus tumors with T4 involvement of the vertebrae from October 18, 1990 to September 21, 1998 at the University of Texas M.D. Anderson Cancer Center (MDACC) were evaluated. Their clinical and pathologic data were reviewed and analyzed for short- and long-term outcomes.

RESULTS

Total vertebrectomy was performed in 7 patients (42%), partial vertebrectomy in 7 (42%), and 3 (18%) underwent neural foramina or transverse process resection. The median hospital stay was 11 days. Postoperative complications occurred in 7 patients (42%) and included pneumonia (6, 36%), arrhythmia (2, 12%), cerebrospinal fluid leak (2, 12%), wound breakdown (1, 6%), and reoperation for bleeding (1, 6%). Sixteen out of 17 patients received preoperative or postoperative radiation therapy. No perioperative mortality occurred. All patients remained ambulatory after spinal reconstruction. Overall actuarial survival at 2 years was 54%, with 11 patients still alive 2 to 50 months after resection. Locoregional tumor recurrence was noted in all 6 patients who had positive surgical margins, as opposed to 1 out of 11 patients (9%) with negative margins (p < 0.006). Additionally, the 2-year actuarial survival of patients with negative microscopic margins was 80% versus 0% for positive margins (p < 0.0006).

CONCLUSIONS

An aggressive multidisciplinary approach to superior sulcus tumors with vertebral invasion can lead to long-term survival with acceptable morbidity if negative margins can be obtained. Vertebral body invasion should no longer be considered a contraindication for resection of superior sulcus tumors.

Malignant pleural mesothelioma: the spectrum of manifestations on CT in 70 cases

AIM

The aim of this pictorial review is to illustrate the spectrum of manifestations on computed tomography (CT) of malignant pleural mesothelioma. Malignant pleural mesothelioma is the most common primary neoplasm of the pleura, but nevertheless is a rare tumour. It has a strong association with previous occupational exposure to asbestos and has a bleak prognosis.

MATERIALS AND METHODS

The pre-treatment CT findings of 70 patients at our institution, and the subsequent findings of the 35 patients who had follow-up CT, have been reviewed by three observers by consensus. 16 patients had surgical resections.

RESULTS

The most common pre-treatment findings were pleural thickening (94%) and pleural effusions (76%). Both contraction (27%) and enlargement (10%) of the ipsilateral hemithorax were identified. Extension of disease to the chest wall, mediastinum, thoracic lymph nodes, and below the diaphragm were identified. Concurrent bilateral pleural calcification and plaques indicative of previous asbestos exposure were identified in 16% of patients. CT failed to identify chest wall and mediastinal invasion in a number of patients who underwent surgical resections.

CONCLUSION

CT plays an important role in the diagnosis, assessment, and evaluation of treatment response of this tumour, although it has some limitations in specific areas in evaluating patients for surgical resection.

Value of spiral CT in hemodynamically stable patients following blunt chest trauma

INTRODUCTION

Features of spiral CT (SCT)-fast scanning, dynamic injection of contrast allowing optimal vessel opacification, and supplemental multiplanar imaging-promises to provide increased accuracy in the diagnosis of acute and non acute thoracic vascular disease. Recent work demonstrating the cost effective triage of hemodynamically stable patients after blunt chest trauma for angiography based on dynamic CT findings has prompted an investigation into the accuracy of SCT in this clinical setting.

METHODS

A retrospective review of all patients seen in the emergency department over the period of one year for aortic, thoracic, or blunt chest trauma evaluation was performed (74 patients) and all SCT scans available were reviewed and data reformatted for optimal delineation of pathology using maximum intensity projection and multiplanar reformation. The accuracy and predictive positive and negative values of SCT were calculated with respect to angiography, surgical, and/or clinical follow up evaluation.

RESULTS

Twenty three (31%) patients went directly to angiography owing to mediastinal widening on chest film and hemodynamic instability, of which four were positive and required emergent surgery. Seven hemodynamically stable patients (9%) had noncontrast SCT owing to mediastinal widening on chest film, all of which had angiography with none having great vessel trauma. Fourty four hemodynamically stable patients (60%) had contrast enhanced SCT (ceSCT), of which five (11%) were abnormal and underwent angiography, four of these were positive for aortic damage, one for a subclavian artery laceration. Of the remaining 39 patients who had normal ceSCT; five had angiography, all of which were normal. Of the remaining 34 patients that had normal ceSCT none had adverse outcome on clinical follow-up, minimum of 12 months.

CONCLUSION

The predictive positive value for aortic trauma of ceSCT in blunt trauma is 80%, with a predictive negative value of 100%, indicating that it is feasible for SCT to be a first line exam in blunt chest trauma in the future.

The radiology of the thoracic manifestations of AIDS

The thoracic manifestations of AIDS have undergone a gradual metamorphosis, partly due to more awareness about the disease leading to earlier diagnoses and partly due to the fact that research has produced more effective prophylaxis as well as treatment for these patients. Many patients now demonstrate partial or complete clinical response which prolongs the length and quality of life of individuals positive for the Human Immunodeficiency Virus (HIV+). Also, with the large number of infected individuals coming to medical attention, and the years of experience in diagnosing and treating these AIDS patients, we now recognize not only the usual but also less usual manifestations of thoracic illnesses in AIDS, including infections, non-infectious diseases such as HIV associated Lymphocytic Interstitial Pneumonia and the neoplasms associated with AIDS. A section will be devoted to HIV infection in children. We will finish the article with a discussion of the current role of Nuclear Medicine in the diagnosis of HIV associated thoracic diseases. These topics are the subject of this article.

Rounded atelectasis and mesothelioma

OBJECTIVE

The purpose of this article is to report the coexistence of rounded atelectasis with malignant pleural mesothelioma as revealed by radiography and CT.

CONCLUSION

Our five cases show the coexistence of rounded atelectasis and malignant mesothelioma. If rounded atelectasis is associated with a pleural effusion, a pleural mass with or without chest-wall invasion, or thickened pleura not adjacent to the rounded atelectasis, malignant mesothelioma should be strongly considered.

Small pulmonary lesions detected at CT: clinical importance

PURPOSE

To evaluate the histopathologic findings of pulmonary nodules 1 cm or smaller detected at computed tomography (CT) that were removed at video-assisted thorascopic surgery.

MATERIALS AND METHODS

Clinical, radiologic, and histopathologic findings were retrospectively reviewed in 64 patients (48 women, 16 men; aged 22-85 years) who underwent video-assisted thorascopic surgical resection of small pulmonary lesions present on CT scans.

RESULTS

Sixty-four patients had a total of 65 lesions resected. Of the 64 patients, 37 (58%) patients had no known previous malignancy and 27 (42%) had previous malignancy. Overall, 58% (38 of 65 [95% confidence interval = 0.45, 0.73]) of these lesions were malignant. Among the patients without previous malignancy, 14 (38%) had lung carcinoma (10 [27%], primary bronchogenic carcinoma; four [11%], carcinoid). In patients with a previous malignancy, malignant lesions were diagnosed in 81% (22 of 27). This included seven (26%) patients with bronchogenic carcinoma as a second primary carcinoma. In patients without previous malignancy, benign lesions were diagnosed in 59% (22 of 37); in patients with previous malignancy, benign lesions were diagnosed in 18% (five of 27).

CONCLUSION

A considerable number of the malignant lesions were primary bronchogenic carcinoma. In addition, diagnosis in patients with a previous malignancy other than suspected metastatic disease can substantially alter treatment. For these reasons, early biopsy with an acceptable technique for diagnosis of these lesions is recommended.

Sarcoidlike reaction in patients with malignancy

PURPOSE

To determine the radiologic features, pathogenesis, and prognostic importance of sarcoidlike reaction in patients with malignancy.

MATERIALS AND METHODS

Radiographs and computed tomographic (CT) scans of the chests of 10 patients with known malignancy and either concurrent or subsequent development of noncaseating granulomas (NCG) were reviewed and correlated with histopathologic reports and pertinent clinical data.

RESULTS

Ten patients with malignancy were found to have either mediastinal or hilar lymph node enlargement (n = 4) or parenchymal lung disease (n = 6). The presumptive diagnosis was metastatic disease. In eight of 10 histopathologic specimens, no tumor was found, but innumerable NCGs were present. They were thought to be consistent with sarcoidlike reaction. In the other two specimens, only a small focus of tumor cells was found amidst innumerable NCGs. On CT scans of the chests, parenchymal lung disease took the form of either ground-glass attenuation (n = 1) or nodules following perivascular and peribronchial distributions (n = 5).

CONCLUSION

Lymph node enlargement and parenchymal lung nodules may not indicate metastatic disease. Sampling of all abnormal areas may be helpful in staging the disease and in treating and determining the prognosis of patients. Likewise, the discovery of NCG does not necessarily indicate sarcoidosis and may represent sarcoidlike reaction.

Acquired microileum: a companion to microcolon?

Acquired microcolon results from a lack of distension by the fecal stream because of a proximal obstruction or diversion. We report a case of acquired microileum, which we believe resulted from a similar mechanism, that is, lack of distension by the intestinal fluid column after a proximal ileal diversion.