Early Biochemical Relapse After Radical Prostatectomy: Which Prostate Cancer Patients May Benefit from a Restaging¹¹C-Choline PET/CT Scan Before Salvage Radiation Therapy?

Abstract

The aim of the study was to assess which factors may influence 11 C-choline PET/CT detection rate in a population of recurrent prostate cancer (PCa) patients listed for salvage radiation therapy (S-RT) in an early phase of biochemical relapse, to select which patients could obtain the most benefit by performing restaging 11 C-choline PET/CT before S-RT. Methods: The study comprised 605 patients, treated with radical prostatectomy (RP) with curative intent for PCa who showed rising PSA levels after primary therapy and listed for S-RT. Prostate-specific antigen (PSA) values were .0.2 ng/mL and ,2 ng/mL (mean, 1.05 ng/mL; median, 1.07 ng/mL; range, 0.2-2 ng/m; SD, ±0.59). All patients were classified as N0 after RP. Seventeen of 605 patients received adjuvant RT together with RP, whereas 148 of 605 patients received androgen-deprivation therapy (ADT) at the time of PET/CT. PSA, PSA kinetics, Gleason score, age, time to biochemical relapse, ADT, and initial tumor stage were statistically analyzed to assess which factor could influence PET/CT positivity and the detection of local versus distant relapse. Results: 11 C-choline PET/CT was positive in 28.4% of patients (172/605). Eighty-three of 605 patients were positive in the pelvis (group A), distant metastasis (group B) were detected in 72 of 605 patients, and local and distant sites of relapse were detected in 17 of 605 patients (group C). At multivariate analysis, PSA, PSA doubling time (PSAdt), and ongoing ADT were significant predictors for positive scan results, whereas PSA and PSAdt were significantly related to distant relapse detection (P , 0.05). At the receiver-operatingcharacteristic analysis, a PSA value of 1.05 ng/mL and PSAdt of 5.95 mo were determined to be the optimal cutoff values in the prediction of a positive 11 C-choline PET/CT scan, with an area under the curve (AUC) of 0.625 for PSA and 0.677 for PSAdt. Conclusion: 11 Ccholine PET/CT may be suggested before S-RT during the early phase of biochemical relapse, to select patients who may benefit from this aggressive treatment. Particularly, patients showing fast PSA kinetics or PSA increasing levels despite ongoing ADT should be studied with 11 C-choline PET/CT before S-RT, considering the higher probability to detect positive findings outside the pelvis.

18F-choline PET/CT for early detection of metastases in biochemical recurrence following radical prostatectomy

“…Castelluci et al reported 11C--choline PET/CT scans indicating metastases in 23% of 605 patients with PSA < 2 ng/mL, and in 18% of 291 patients with PSA < 1.0 ng/mL [15]. This is slightly less than in our study, but almost 25% of the patients in their study received HT at the time of the PET/CT investigation, which is known to affect the sensitivity of choline PET/CT [22].…”

“…Few previous studies have reported specifically on patients with low PSA values, i.e. when the choice of secondary treatment usually has to be made [13][14][15][16][17][18]. Most of the studies included a large proportion of patients on HT, for whom the association between PSA values and tumour burden is different than for hormone--naïve patients, and for whom treatment with additional RT is not evidence based.…”

PET/CT com Fluorocolina-F18 em Doentes com Carcinoma da Próstata em Recidiva Bioquímica

“…38 Embora também pareça ter utilidade clínica no estadiamento inicial, apresenta-se como particularmente útil no restadiamento de doentes com recidiva bioquímica. 39 Revela-se principalmente vantajosa numa fase precoce da recidiva bioquímica, permitindo seleccionar os doentes que podem beneficiar de terapêutica de salvação. Revela-se, ainda, particularmente vantajosa na avaliação de doentes em recidiva bioquímica sob TSH, devido à elevada probabilidade de apresentarem doença extra pélvica.…”

“…Revela-se, ainda, particularmente vantajosa na avaliação de doentes em recidiva bioquímica sob TSH, devido à elevada probabilidade de apresentarem doença extra pélvica. 39 Vários estudos têm avaliado a acuidade diagnóstica desta técnica no contexto de recidiva bioquímica de CaP, apresentando valores de sensibilidade muito variáveis, entre 43 e 95%. 5,7,10,12,14,24,[40][41][42][43] Um estudo recente demonstrou a elevada sensibilidade e o elevado valor preditivo negativo da PET/CT com FCH-18.…”

68Ga-PSMA PET/CT for the detection of bone metastasis in recurrent prostate cancer and a PSA level <2 ng/ml: Two case reports and a literature review

“…However, the majority of large series have included patients with a PSA level >2 ng/ml (6,7). Most studies that included patients with low PSA levels have shown infrequent bone metastases, and little information is provided concerning tumor characteristics in individual patients (8)(9)(10)(11). Generally, choline PET is only indicated in biochemical failure if the PSA level is >2 ng/ml or the PSA level is rising rapidly (12).…”