The Existence of Symptomatic Localized Lesion(s) and ≤4 Lesions Are Indications for Radiotherapy: Screening Computed Tomography Images of Patients with Metastatic/Recurrent/Inoperable Cancer in a Single Japanese Institution Observational Study

Background: To investigate the prevalence of indications for radiotherapy (RT) in patients with metastatic/recurrent/inoperable cancer. We also sought to analyze such patients’ clinical and radiological characteristics for indications of radiotherapy in those patients who had either surveillance or an initial assessment done by computed tomography (CT). Methods: Two diagnostic radiologists and a radiation oncologist evaluated a total of 13,225 consecutive patients from January 2012 to December 2012 at a single Japanese institution. Patients with metastatic/recurrent/ inoperable cancer were selected for further study. After two diagnostic radiologists identified patients with a detectable cancerous lesion, a radiation oncologist subsequently investigated whether there was any indication for RT. The oncologist also evaluated the relationship between patients’ clinical/radiological factors, and patients with or without indications for RT. Results: Two diagnostic radiologists selected 329 patients showing a detectable gross cancerous lesion. In this patient group, a radiation oncologist identified 196 patients with metastatic/recurrent/inoperable cancer, of which 96 patients (49%) showed an indication for RT. According to both univariate and multivariate analyses, ≤4 lesions were significantly associated with patients who showed an indication for RT (P = 0.0002 and P 0.001, respectively). Conclusions: In screening CT images, approximately half of all patients with metastatic/recurrent/inoperable cancer showed an indication for RT. Moreover, ≤4 lesions and/or the existence of a symptomatic, localized lesion were highly suggestive of an indication for RT. These findings would be of considerable interest to radiation oncologists planning appropriate treatments for cancer patients.