Can We Predict Bleomycin Toxicity with PET-CT?

Pulmonary toxicity induced by the use of bleomycin in patients with germ cell testicular tumors

Introduction. Pulmonary toxicity induced by bleomycin is a dangerous complication of polychemotherapy in patients with germ cell tumors. It occurs with a frequency of up to 46%, and in 14% of cases it is fatal. Aim. To present cases of pulmonary toxicity during polychemotherapy with the inclusion of bleomycin for testicular germ cell tumors. Materials and Methods. Two patients aged 43 and 33 years old with testicular germ cell tumors were under observation after orchifuniculectomy who underwent chemotherapy according to the BER scheme (bleomycin + etoposide + cisplatin) in the steady-state mode in 4 and 6 cycles respectively. Positron emission tomography combined with computer tomography (PET/CT) with 18F-fluorodeoxyglucose was performed when clinical symptoms appeared at the end of treatment. Results. Histologically, the tumor in a 33-year-old patient was a mixed tumor seminoma, embryonal cancer with teratoid cancer elements. Abdominal spiral computed tomography revealed metastases to retroperitoneal lymph nodes. In a 43-year-old patient, the tumor had the structure of fetal cancer with multiple metastases to the lungs, mediastinal lymph nodes and retroperitoneal lymph nodes. Six and four cycles of polychemotherapy according to the BER regimen were administered, respectively. The cumulative dose of bleomycin was 540 and 360 mg in 18 and 12 injections. Treatment was accompanied by the development of febrile neutropenia with G-CSF correction. These risk factors should be considered the most significant. The appearance of respiratory symptoms during treatment should be regarded as a manifestation of pulmonary toxicity. PET/CT is the method of choice for diagnosis. The clinical picture in the observed patients, as well as changes on PET/CT, were detected 2 weeks after chemotherapy was completed. Conclusion. Pulmonary toxicity induced by the use of bleomycin in patients with germ cell testicular tumors is a very dangerous complication, sometimes with a lethal outcome. Therefore, its early diagnosis taking into account risk factors is of great importance in clinical practice. Among medical imaging methods, a special role is played by PET/CT, which allows predicting toxicity before the clinical and radiological debut.

Test-retest repeatability and interobserver variation of healthy tissue metabolism using 18F-FDG PET/CT of the thorax among lung cancer patients

OBJECTIVES

The aim of this study was to assess the test-retest repeatability and interobserver variation in healthy tissue (HT) metabolism using 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) PET/computed tomography (PET/CT) of the thorax in lung cancer patients.

METHODS

A retrospective analysis was conducted in 22 patients with non-small cell lung cancer who had two PET/CT scans of the thorax performed 3 days apart with no interval treatment. The maximum, mean and peak standardized uptake values (SUVs) in different HTs were measured by a single observer for the test-retest analysis and two observers for interobserver variation. Bland-Altman plots were used to assess the repeatability and interobserver variation. Intrasubject variability was evaluated using within-subject coefficients of variation (wCV).

RESULTS

The wCV of test-retest SUVmean measurements in mediastinal blood pool, bone marrow, skeletal muscles and lungs was less than 20%. The left ventricle (LV) showed higher wCV (>60%) in all SUV parameters with wide limits of repeatability. High interobserver agreement was found with wCV of less than 10% in SUVmean of all HT, but up to 22% was noted in the LV.

CONCLUSION

HT metabolism is stable in a test-retest scenario and has high interobserver agreement. SUVmean was the most stable metric in organs with low FDG uptake and SUVpeak in HTs with moderate uptake. Test-retest measurements in LV were highly variable irrespective of the SUV parameters used for measurements.

Bleomycin-Induced Lung Toxicity in Hodgkin's Lymphoma: Risk Factors in the Positron Emission Tomography Era

Introduction

Bleomycin is a major antimitotic agent in the first-line treatment for Hodgkin's lymphoma. The main limitation of its use is its pulmonary toxicity. The objectives of this study are to find out the risk factors for the occurrence of bleomycin-induced lung toxicity in patients with Hodgkin's lymphoma and, on the other hand, to determine if positron emission tomography scan is a reliable means of early detection of this toxicity.

Methods

This is a retrospective study conducted in the clinical Hematology Department of Mohammed V Military Instruction Hospital, Rabat, Morocco. All patients with Hodgkin's lymphoma and treated with a bleomycin-based chemotherapy were included. The impact of different clinical and biological factors on the risk of bleomycin-induced lung toxicity occurrence was assessed using univariate and multivariate logistic regression. The benefit of positron emission tomography, usually performed as part of the re-assessment of Hodgkin’s lymphoma after two and four cycles, has been evaluated in the detection of bleomycin-induced lung toxicity.

Results

Among 124 patients included in the study, 18 (14.5%) patients experienced bleomycin-induced lung toxicity. On multivariate analysis, smoking (p = 0.038) and the use of the ABVD regimen (doxorubicin, bleomycin, vinblastine, and dacarbazine) compared to the escalated BEACOPPe regimen (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) (p = 0.018) were statistically significant risk factors.

After two and four courses of therapy, the positron emission tomography was able to predict the occurrence of bleomycin-induced lung toxicity before the appearance of clinical symptoms only in 36.4 % and 12.5% of patients, respectively.

Conclusion

Studies to identify risk factors for the development of bleomycin-induced lung toxicity are crucial to reduce toxicity in the treatment of Hodgkin's lymphoma. However, two- and four-cycle positron emission tomography scans cannot be considered as a reliable means of early detection of this toxicity.