Stereotactic body radiotherapy of primary and metastatic renal lesions for patients with only one functioning kidney

Figures & data

Table I.  Clinical summary of renal cell carcinomas.

Patient no	Type of Lesion	Fuhrman Grade*	Time to first Metastasis (months)	Treatment prior to SBRT	Post SBRT treatment^#	Follow-Up (months)	Status
1	Metastatic	GI	108	No	No	14	DoD
2	Metastatic	GII	31	No	IFN	10	DoD
3	Metastatic	GI	50	No	DC	49	DoD
4	Metastatic	GI	9	Met surgery	No	52	Alive
5	Primary	NA	NA	No	No	66	Alive
6	Metastatic	GIV	at diagnose	No	No	14	Alive
7	Metastatic	NA	72	IFN	Pall RT	70	DoD

*All patients were nefrectomized. Patient 5 lost the right kidney during childhood due to infections and malformation, #None of the post SBRT treatments had any antitumoral effect. DoD= Dead of distant disease.

Figure 1.  Approximate size and location in the kidneys of all tumors treated. Note that all patients had only one kidney at SBRT. This summation pictures what a projection of the treated tumor looks like in a normal individual.

Table II.  Data for patients treated for metastases of an initial renal cancer to a second kidney.

Patient no	Fractio-nation	Prescribed BED (Gy3)	Tumor diameter (cm)	CTV Volume (cm^3)	PTV volume (cm^3)	Volume of OAR-kidney** (cm^3)	Mean dose to OAR-kidney (% of prescribed dose)	Effective volume	V15 (%)
1	10 Gy×3	130	4.1	29	70	145	29.4	0.27	23.4
2	10 Gy×3	130	4.7	32	71	280	27.9	0.22	20.6
3	10 Gy×3	130	5.5	39	82	177	35.8	0.28	24.7
4	10 Gy×3	130	6.4	63	115	155	42.0	0.28	31.3
5	10 Gy×3	130	6.0	36	95	220	31.6	0.24	24.1
5*	10 Gy×4	173	6.5	47	107	189	31.9	0.24	33.7
6	10 Gy×4	173	6.8	42	122	312	40.8	0.39	37.3
7	10 Gy×3	130	2.3	3.8	19	254	10.8	0.07	5.2

* This patient was retreated after local progression 4 years after the first SBRT treatment. The treated lesion in this case was a primary renal cell carcinoma to the remaining kidney.

** Remaining healthy kidney minus CTV.

Figure 2.  Upper figure (a) shows the CTV and PTV of patient 5 at first treatment. Lower figures (b) shows the relative dose distribution, with the prescription isodose (100% in blue), at the periphery of the PTV.c) Relative dose distribution to the target in sagittal view. The color codes of the isodoses are also shown.

Figure 3.  Serum creatinine levels in all seven patients during follow-up. (.-◊-.) patient 1, (- -▴ - -) patient 2, (….∇….) patient 3, (- -▪- -) patient 4, (–•–) patient 5, (–○–) patient 6, (-.-•-.-) patient 7.

Figure 4.  Cumulative dose-volume histogram for OAR-kidneys in all seven patients. Dose on the x-axis is expressed as equivalent dose in 2 Gy/ fraction (EQD2), and volume on the y-axis as relative volume (percent of remaining normal kidney parenchyma minus CTV). Patients no. 4 and 7 are marked with filled boxes.