OPENKidney Cancer
Carbon ion radiotherapy for kidney cancer
Indications
Carbon ion radiotherapy for kidney cancer is performed in a clinical study or the following cases.
| Disease | Indication | |
|---|---|---|
| 1 | Kidney cancer | Renal cell carcinoma diagnosed from biopsy or imaging |
Surgery is the first choice for the curative treatment of kidney cancer. Cryotherapy is also a standard treatment for tumors 4 cm or less in size. Since 1997, carbon ion radiotherapy has been used mainly in patients for whom standard treatment would be difficult due to complications and in patients who would require the introduction of dialysis immediately afterward if surgery were performed. Initially, 16 irradiations were performed (over 4 weeks), and despite the small number of patients (19 patients) as is indicated below, high levels of efficacy and safety comparable to those seen with surgery and other treatments were shown in a patient group that included those with advanced disease, even during long-term follow-up.*1
Beginning in 2013, a prospective clinical study of 12 irradiations (over 3 weeks) was conducted, and 8 patients were enrolled. The results were favorable, with no recurrence and only slight adverse reactions seen. Based on these results, and with the objective of further reducing the burden on the patient, a prospective clinical study of 4 irradiations (over 1 week) was started in 2017. For details regarding the use of 4 irradiations, which is currently ongoing, please see the study protocol. Even if the indication for the clinical study is not met, 12 irradiations are performed in cases where carbon ion radiotherapy is considered indicated.
Treatment record in QST hospital
| Disease | Period | Number of Patients | |
|---|---|---|---|
| 1 | Kidney cancer | 1997 to 2014 | 19 |
The treatment results in the 19 patients, consisting of those who received 16 irradiations and those not included in the clinical study of 12 irradiations, were as follows.*1 The median observation period was 6.6 years (range: 0.7-16.5 years), the 5-year local control rate (percentage of patients in which irradiated lesions were controlled for 5 years) was 94.1%, and the 5-year cancer-specific survival rate (percentage of patients who survived kidney cancer for 5 years) was 100%.
Treatment complications related to kidney function did not include any cases of severe renal impairment, except for patients who had diabetic nephropathy beforehand and patients with a single kidney. With regard to non-renal complications, a severe skin complication was seen in 1 patient treated in 2000, but only slight side effects were seen subsequently.
*1 Kasuya G et al. Cancer Sci. 2018;109:2873-2880.