Evaluation of post-chemotherapy residual seminomatous masses by 18F-fluorodeoxyglucose PET/CT using tumor-to-liver ratio - conundrum or solution?

OBJECTIVE

Assessment of diagnostic accuracy of FDG-PET/CT in the detection of viable disease in post-chemotherapy seminomatous residual masses using visual interpretation, SUVmax, and T/L ratio.

METHODS

This is a retrospective study assessing the post-chemotherapy seminomatous residual masses of size >3 cm. The PET/CT scan findings were interpreted visually for presence of residual disease which were validated from histopathology reports or imaging follow-up for a maximum of 3 years. SUVmax and T/L ratios were also determined for all the residual lesions. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value NPV were calculated and compared for all three parameters along with ROC analysis to obtain an optimal cutoff value for SUVmax and T/L ratio, respectively.

RESULTS

Sample size was 49. Out of these 49 patients, 8 had validation of PET results with histopathology. Rest was validated with imaging follow-up. FDG-PET was positive in 30 patients and negative in 19 patients by visual interpretation. The sensitivity, specificity, PPV, and NPV by this method were 100%, 62.5%, 73%, and 100%, respectively. The SUVmax and T/L ratios were also calculated for these lesions. The cutoff for these two variables was 4.56 and 1.21, respectively. The sensitivity, specificity, PPV, and NPV at these cutoffs were 76%, 87.5%, 86%, 77.7%, and 92%, 87.5%, 88%, 91%, respectively.

CONCLUSION

FDG-PET has a favorable diagnostic value in predicting viable disease in post-chemotherapy seminomatous residual masses and using T/L ratio cutoff of 1.21 will increase the specificity of the test.

Role of neoadjuvant chemotherapy in advanced carcinoma of the hypopharynx and larynx

BACKGROUND

To assess the response rate and impact of neoadjuvant chemotherapy (NACT) in advanced carcinoma of the hypopharynx and larynx.

MATERIALS AND METHODS

This is a retrospective case series of 80 patients with locally advanced laryngopharynx carcinoma who received NACT from April 2010 to October 2011 at our tertiary care center. The patients received NACT either for achieving resectability or for organ preservation.

RESULTS

Majority of the patients (60%) had T4 a disease. Grade 3 and 4 neutropenia was seen in 18%, febrile neutropenia in 4%, mucositis in 4%, diarrhea in 5%, and vomiting in 3% patients. Resectability could be achieved in 34%, and larynx was preserved in 51% patients at a mean follow-up of 13 months.

CONCLUSIONS

NACT was safe with acceptable toxicity. Majority of the patients who achieved resectability had oropharyngeal involvement. NACT followed by concurrent chemoradiotherapy could provide a high rate of organ preservation.

Sebaceous carcinoma and systemic chemotherapy

Sebaceous gland carcinoma is a rare malignant tumor, which arises from the adnexal epithelium of sebaceous glands. Sebaceous glands are present all over the body and hence have variable sites of origin, histological growth patterns, and clinical presentations. Here, we report a case of recurrent extraocular sebaceous carcinoma of left occipital region with lung metastases who went into complete remission with chemotherapy for lung metastasis. Role of chemotherapy in the management ofmetastatic sebaceous carcinoma is evolving. Combination chemotherapy can result in long term remission as described in this case report.