Evaluation of Second Cancer Induction Risk by CT Follow-up in Oncological Long-surviving Patients

Abstract

The goal of establishing prompt localization of the malignant spread or recurrence of a tumor has found a powerful solution in the definition of follow-up protocols, which include the indication for CT scans on an annual or semiannual basis. In the case of long-surviving patients, however, this approach will lead to a considerable integrated dose level over a period of several years after recovery from the illness. Pathologies treated primarily by surgery and/or chemotherapy have been considered, not taking into account cancers treated with adjuvant or radical radiotherapy. Given that the most likely protocols for these cancers often call for total body scans, an estimation of the consequent effective and organ doses can be performed with acceptable accuracy. The data acquired from five centers have been collected and the related effective and organ doses calculated by means of IMPACT software. Use of the effective dose concept, however, has lately become the subject of criticism, and the recently proposed Effective Risk Model has therefore also been applied. The evaluated absolute additional risk of second tumor induction ranges between 0.1% and 10%, depending primarily on age and pathology. These results depict this additional risk as an issue of significant importance for clinical practice. A revision of follow-up and scan parameter protocols, as well as the introduction of new algorithms for dose reduction, could significantly improve the risk-benefit ratio for all the pathologies studied.

Cancer Death Risk Related to Radiation Exposure from Computed Tomography Scanning Among Testicular Cancer Patients

“…As indicated in Table I, even in one hospital where multiple CT devices are used, the dose exposures of the patients can be variable as marked differences were observed related to the type of device and imaging protocols. This is in alignment with previous observation showing significant variation in average effective doses (mSv) for different cancer follow-up protocols among different treatment centers even when comparing single follow-up imaging (1). Vendor recommendations need to be adjusted to the centers protocols.…”

“…Testicular cancer patients become exposed to substantial radiation doses form CT examinations during follow-up (9). The risk of second cancers due to CT related radiation exposure has been suggested to exceed the risk for recurrences in this patient population (1). The overall relative risks of second cancer among testicular cancer survivors range from 1.4-to 2.8-fold (14), albeit the studies looking at the impact of diagnostic radiation exposure have generated inconclusive results.…”

“…Computed tomography (CT) in diagnostic imaging exposes patients for a substantial part of their lifetime exposure to cumulative medical radiation dose. With regard to the oncological population, multiple follow-up CTs are being justified by the need to promptly evaluate treatment effects or to localize cancer spread or recurrence (1). Nevertheless, with frequent CT imaging there is a concern for patients being exposed to high effective doses.…”

Role of routine computed tomography scan in the oncological follow up of patients treated by radical cystectomy for bladder cancer

“…However, because of conflicting evidence from the rare series addressing this issue, the oncological benefit of routine surveillance after RC is still controversial, which results in disparate recommended surveillance protocol, in heterogeneous recommendations regarding total duration of follow‐up and in a low rate of adherence to surveillance guidelines . Beyond their cost, the major drawback of surveillance strategies is the radiation burden that accompanies the routine use of imaging . In the past few years, several series have aimed to assess the impact of early diagnosis of asymptomatic tumor recurrence on survival after RC and have yielded contradictory findings .…”

“…9 Beyond their cost, the major drawback of surveillance strategies is the radiation burden that accompanies the routine use of imaging. 10 In the past few years, 840…”