Department of Radiation Oncology, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India.
Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India.
Radiother Oncol. 2022 Apr;169:71-76. doi: 10.1016/j.radonc.2022.02.014. Epub 2022 Feb 18.
To study patterns of recurrence in Ga68-PSMA PETCT at rising serum PSA after radical radiotherapy for non-metastatic prostate cancer.
Among patients with non-metastatic prostate cancer treated with radical external beam radiotherapy and androgen deprivation therapy, those who underwent Ga68-PSMA PETCT for rising PSA during follow up were analysed. Patterns of recurrence in Ga68-PSMA PETCT were studied. Extra-prostatic recurrences ≤5 were considered oligometastases. Local and oligometastatic recurrences were deemed suitable for focal salvage therapy. Probabilities of identifying recurrent lesion and potentially salvageable recurrences in Ga68-PSMA PETCT in relation to PSA were calculated.
Total 114 patients were included (69% high-risk). Radiotherapy was hypofractionated in 57% (moderate 40%, extreme 17%), with median prostate EQD2 78.5 Gy. Median time from radiotherapy to Ga68-PSMA PETCT was 4.3 years (IQR 2.4-6.4), with median PSA 4.7 ng/mL (IQR 2.6-10.7) at scan. Uptake suggesting recurrence was observed in 91.2% patients, with positivity of 75%, 87%, 89%, and 100% at PSA thresholds ≤2, ≤5, ≤10, and >10 ng/mL respectively. Probability of detecting recurrence in Ga68-PSMA PETCT increased with higher PSA at scan (AUC = 0.82). Uptake was local in 20 (17.5%), oligometastatic in 39 (34.2%), and polymetastatic in 45 (39.5%) patients. Recurrence was potentially salvageable in 59/104 (56.7%) patients, being 67% at PSA ≤2 ng/mL but only 38% at PSA >10 ng/mL. Probability of recurrence being potentially salvageable declined with increasing PSA at scan (AUC = 0.68).
Early Ga68-PSMA PETCT for rising PSA after definitive prostate radiotherapy detected majority of recurrent lesions and identified oligorecurrences amenable to focal salvage therapy.
研究非转移性前列腺癌根治性放疗后 PSA 升高时 Ga68-PSMA PETCT 中的复发模式。
对接受根治性外照射放疗和雄激素剥夺治疗的非转移性前列腺癌患者，分析了在随访期间因 PSA 升高而进行 Ga68-PSMA PETCT 的患者。研究了 Ga68-PSMA PETCT 中的复发模式。将外扩散性复发<5 定义为寡转移。局部和寡转移复发被认为适合进行局部挽救性治疗。计算了 Ga68-PSMA PETCT 在 PSA 相关时识别复发性病变和潜在可挽救性复发的概率。
共纳入 114 例患者（69%为高危）。57%的患者接受了低分割放疗（中度 40%，重度 17%），前列腺 EQD2 中位数为 78.5Gy。从放疗到 Ga68-PSMA PETCT 的中位时间为 4.3 年（IQR 2.4-6.4），扫描时 PSA 中位数为 4.7ng/ml（IQR 2.6-10.7）。91.2%的患者出现提示复发的摄取，PSA 阈值分别为≤2、≤5、≤10 和>10ng/ml 时，阳性率分别为 75%、87%、89%和 100%。Ga68-PSMA PETCT 检测复发的概率随扫描时 PSA 水平的升高而增加（AUC=0.82）。摄取局部的患者为 20 例（17.5%），寡转移的患者为 39 例（34.2%），多转移的患者为 45 例（39.5%）。104 例患者中有 59 例（56.7%）的复发灶有潜在的挽救机会，PSA≤2ng/ml 时为 67%，但 PSA>10ng/ml 时仅为 38%。随着扫描时 PSA 的增加，复发灶有潜在挽救机会的概率下降（AUC=0.68）。
早期 Ga68-PSMA PETCT 在根治性前列腺放疗后 PSA 升高时，可检测出大多数复发性病变，并识别出适合局部挽救性治疗的寡发性复发。
