Advantages of additional PET vs. MRI in the clinical diagnosis of anterior mediastinal tumors.

The present study retrospectively examined the diagnostic utility of adding positron emission tomography (PET) or magnetic resonance imaging (MRI) to computed tomography (CT) alone for preoperative diagnosis of anterior mediastinal tumors. A total of 104 consecutive patients who had undergone surgical resection of anterior mediastinal tumors were divided into two groups: Additional PET to another modality and no additional PET to another modality, and further subdivided into three groups: CT alone, additional MRI to CT and additional PET to CT. The sensitivity, specificity, and accuracy for diagnosing malignant tumors in each subgroup was calculated. Comparing the two groups, the diagnostic sensitivity was similar for additional PET (98.0%) and no additional PET (95.2%) groups; however, the specificity and accuracy for additional PET (75.0 and 92.2%, respectively) were significantly improved compared with no additional PET (31.6 and 65.0%, respectively). In the subgroup analysis, adding PET to CT showed an improvement in specificity and positive predictive value for detecting malignant tumors, compared with either additional MRI to CT or CT alone. Additional PET, but not MRI, has advantages over CT alone in clinically distinguishing benign from malignant tumors of the mediastinum.

Proton magnetic resonance spectroscopy of lung cancer in vivo.

Proton magnetic resonance spectroscopy (1H-MRS) has demonstrated that in vitro, lung cancer has higher lactate and choline signals than those of normal tissues. The detection of these metabolites in lung cancer in vivo by 1H-MRS would be useful for clinical diagnoses of lung cancer. We report the in vivo detection of lactate and choline in lung cancer by 1H-MRS in a 41-year-old Asian man who was diagnosed with pT4N0M0 ⅢA stage, right upper lobe lung adenocarcinoma. A lactate-lipid peak was observed near 1.33 ppm in the spectrum of lung cancer in vivo at TE  =  30 ms, and it was inverted at TE  =  135 ms, indicating that a lactate signal is contained in the lactate-lipid peak. A choline peak was also observed near 3.2 ppm in the spectrum with fat suppression at TE  =  135 ms. An accumulation of similar cases will help determine the appropriate applications of 1H-MRS for lung cancer.

Optimal timing for the resection of pulmonary metastases in patients with colorectal cancer.

This study aims to clarify the surgical treatment time of pulmonary metastasis in patients with colorectal cancer.Early relapse after resection of pulmonary metastasis is often encountered when the interval from the detection of pulmonary metastasis to pulmonary metastasectomy was short.In this retrospective analysis, data of patients with colorectal cancer who underwent surgical treatment of pulmonary metastasis at the Gunma Prefectural Cancer Center, Gunma, from April 2001 through September 2018 were evaluated. The patients were divided into 2 groups. We examined the interval period from the diagnosis of pulmonary metastasis to pulmonary metastasectomy. This period was divided into every 3 months, and the prognosis of each group was compared with clarify the appropriate timing of pulmonary metastasectomy.The primary endpoints were 5-year overall survival and recurrence-free survival rates.The most significant difference was observed when the cutoff value was 9 months (5-year recurrence-free survival 45.8% vs 85.6%, P < .01). No significant difference was found in any background factors between the 2 groups. Twenty-five patients (34.7%) experienced recurrence after pulmonary metastasectomy. The most common site of recurrence was the lung (48%). Among the 12 cases of recurrence of pulmonary metastasis, 11 cases belonged to the <9 months group. A multivariable survival analysis found that the interval period of <9 months was a significant predictor of recurrence.Our study suggests that clinical follow-up for 9 months prior pulmonary metastasectomy in colorectal patients would improve the prognosis.