Feasibility of biology-guided radiotherapy for metastatic renal cell carcinoma driven by PSMA PET imaging.
Clin Transl Radiat Oncol
; 40: 100608, 2023 May.
Article
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| MEDLINE
| ID: mdl-36942088
ABSTRACT
Background:
Biology-guided radiotherapy (BgRT) is a novel treatment where the detection of positron emission originating from a volume called the biological tracking zone (BTZ) initiates dose delivery. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is a novel imaging technique that may improve patient selection for metastasis-directed therapy in renal cell carcinoma (RCC). This study aims to determine the feasibility of BgRT treatment for RCC. Material andmethods:
All consecutive patients that underwent PSMA PET/CT scan for RCC staging at our institution between 2014 and 2020 were retrospectively considered for inclusion. GTVs were contoured on the CT component of the PET/CT scan. The tumor-to-background ratio was quantified from the normalized standardized uptake value (nSUV), defined as the ratio between SUVmax inside the GTV and SUVmean inside the margin expansion. Tumors were classified suitable for BgRT if (1) nSUV was greater or equal to an nSUV threshold and (2) if the BTZ was free of any PET-avid region other than the tumor.Results:
Out of this cohort of 83 patients, 47 had metastatic RCC and were included in this study. In total, 136 tumors were delineated, 1 to 22 tumors per patient, mostly in lung (40%). Using a margin expansion of 5 mm/10 mm/20 mm and nSUV threshold = 3, 66%/63%/41% of tumors were suitable for BgRT treatment. Uptake originating from another tumor, the kidney, or the liver was typically inside the BTZ in tumors judged unsuitable for BgRT.Conclusions:
More than 60% of tumors were found to be suitable for BgRT in this cohort of patients with RCC. However, the proximity of PET-avid organs such as the liver or the kidney may affect BgRT delivery.
Abdo, abdomen; BTZ; BTZ, biological tracking zone; BgRT; BgRT, biology-guided radiotherapy; GTV, gross tumor volume; LN&ST, lymph node and soft tissue; MIP, maximum intensity projection; PET, positron emission tomography; PSMA; PSMA, prostate specific membrane antigen; RCC; RCC, renal cell carcinoma; SUV, standardized uptake value; TPS, treatment planning system; nSUV, normalized SUV
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Bases de datos:
MEDLINE
Idioma:
En
Revista:
Clin Transl Radiat Oncol
Año:
2023
Tipo del documento:
Article
País de afiliación:
Australia