Limits...
Post-radioembolization yttrium-90 PET/CT - part 2: dose-response and tumor predictive dosimetry for resin microspheres.

Kao YH, Steinberg JD, Tay YS, Lim GK, Yan J, Townsend DW, Budgeon CA, Boucek JA, Francis RJ, Cheo TS, Burgmans MC, Irani FG, Lo RH, Tay KH, Tan BS, Chow PKh, Satchithanantham S, Tan AE, Ng DC, Goh AS - EJNMMI Res (2013)

Bottom Line: There was complete response in a cholangiocarcinoma at D70 90 Gy and partial response in an adrenal gastrointestinal stromal tumor metastasis at D70 53 Gy.In two patients, a mean dose of 18 Gy to the stomach was asymptomatic, 49 Gy caused gastritis, 65 Gy caused ulceration, and 53 Gy caused duodenitis.In one patient, a bilateral kidney mean dose of 9 Gy (V20 8%) did not cause clinically relevant nephrotoxicity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore 169608, Singapore. yung.h.kao@gmail.com.

ABSTRACT

Background: Coincidence imaging of low-abundance yttrium-90 (90Y) internal pair production by positron emission tomography with integrated computed tomography (PET/CT) achieves high-resolution imaging of post-radioembolization microsphere biodistribution. Part 2 analyzes tumor and non-target tissue dose-response by 90Y PET quantification and evaluates the accuracy of tumor 99mTc macroaggregated albumin (MAA) single-photon emission computed tomography with integrated CT (SPECT/CT) predictive dosimetry.

Methods: Retrospective dose quantification of 90Y resin microspheres was performed on the same 23-patient data set in part 1. Phantom studies were performed to assure quantitative accuracy of our time-of-flight lutetium-yttrium-oxyorthosilicate system. Dose-responses were analyzed using 90Y dose-volume histograms (DVHs) by PET voxel dosimetry or mean absorbed doses by Medical Internal Radiation Dose macrodosimetry, correlated to follow-up imaging or clinical findings. Intended tumor mean doses by predictive dosimetry were compared to doses by 90Y PET.

Results: Phantom studies demonstrated near-perfect detector linearity and high tumor quantitative accuracy. For hepatocellular carcinomas, complete responses were generally achieved at D70 > 100 Gy (D70, minimum dose to 70% tumor volume), whereas incomplete responses were generally at D70 < 100 Gy; smaller tumors (<80 cm3) achieved D70 > 100 Gy more easily than larger tumors. There was complete response in a cholangiocarcinoma at D70 90 Gy and partial response in an adrenal gastrointestinal stromal tumor metastasis at D70 53 Gy. In two patients, a mean dose of 18 Gy to the stomach was asymptomatic, 49 Gy caused gastritis, 65 Gy caused ulceration, and 53 Gy caused duodenitis. In one patient, a bilateral kidney mean dose of 9 Gy (V20 8%) did not cause clinically relevant nephrotoxicity. Under near-ideal dosimetric conditions, there was excellent correlation between intended tumor mean doses by predictive dosimetry and those by 90Y PET, with a low median relative error of +3.8% (95% confidence interval, -1.2% to +13.2%).

Conclusions: Tumor and non-target tissue absorbed dose quantification by 90Y PET is accurate and yields radiobiologically meaningful dose-response information to guide adjuvant or mitigative action. Tumor 99mTc MAA SPECT/CT predictive dosimetry is feasible. 90Y DVHs may guide future techniques in predictive dosimetry.

No MeSH data available.


Related in: MedlinePlus

Patient 17. Non-target 90Y activity along the gastric greater curve causing CTCAE grade 3 toxicity [1]. A 90Y PET VOI of the activity along the gastric greater curve was defined by volumetric isocontour thresholding, visually constrained to its CT anatomical margins, shown here in (a) trans-axial, (b) coronal, and (c) sagittal planes. Within this VOI, the mean 90Y radioconcentration at the time of scan (813.1k Bq/ml) was decay-corrected back to the time of 90Y radioembolization (1,021.5 kBq/ml). By 90Y MIRD macrodosimetry, the non-target mean absorbed dose to the gastric greater curve was approximately 49 Gy within the VOI. Gastroscopy and biopsy findings were reported in part 1 [1].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3733999&req=5

Figure 7: Patient 17. Non-target 90Y activity along the gastric greater curve causing CTCAE grade 3 toxicity [1]. A 90Y PET VOI of the activity along the gastric greater curve was defined by volumetric isocontour thresholding, visually constrained to its CT anatomical margins, shown here in (a) trans-axial, (b) coronal, and (c) sagittal planes. Within this VOI, the mean 90Y radioconcentration at the time of scan (813.1k Bq/ml) was decay-corrected back to the time of 90Y radioembolization (1,021.5 kBq/ml). By 90Y MIRD macrodosimetry, the non-target mean absorbed dose to the gastric greater curve was approximately 49 Gy within the VOI. Gastroscopy and biopsy findings were reported in part 1 [1].

Mentions: All dose-response results of non-target tissue were serendipitously obtained in cases of unintended non-target shunting of 90Y resin microspheres due to unexpected vascular stasis and microsphere reflux during 90Y radioembolization. The dose-response of the stomach (Figure 7) and proximal duodenum by 90Y MIRD macrodosimetry are presented in Table 3. 90Y DVH dose-response of the right kidney is presented in Table 4. All results were in keeping with published experiences of external beam radiotherapy [29,30].


Post-radioembolization yttrium-90 PET/CT - part 2: dose-response and tumor predictive dosimetry for resin microspheres.

Kao YH, Steinberg JD, Tay YS, Lim GK, Yan J, Townsend DW, Budgeon CA, Boucek JA, Francis RJ, Cheo TS, Burgmans MC, Irani FG, Lo RH, Tay KH, Tan BS, Chow PKh, Satchithanantham S, Tan AE, Ng DC, Goh AS - EJNMMI Res (2013)

Patient 17. Non-target 90Y activity along the gastric greater curve causing CTCAE grade 3 toxicity [1]. A 90Y PET VOI of the activity along the gastric greater curve was defined by volumetric isocontour thresholding, visually constrained to its CT anatomical margins, shown here in (a) trans-axial, (b) coronal, and (c) sagittal planes. Within this VOI, the mean 90Y radioconcentration at the time of scan (813.1k Bq/ml) was decay-corrected back to the time of 90Y radioembolization (1,021.5 kBq/ml). By 90Y MIRD macrodosimetry, the non-target mean absorbed dose to the gastric greater curve was approximately 49 Gy within the VOI. Gastroscopy and biopsy findings were reported in part 1 [1].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3733999&req=5

Figure 7: Patient 17. Non-target 90Y activity along the gastric greater curve causing CTCAE grade 3 toxicity [1]. A 90Y PET VOI of the activity along the gastric greater curve was defined by volumetric isocontour thresholding, visually constrained to its CT anatomical margins, shown here in (a) trans-axial, (b) coronal, and (c) sagittal planes. Within this VOI, the mean 90Y radioconcentration at the time of scan (813.1k Bq/ml) was decay-corrected back to the time of 90Y radioembolization (1,021.5 kBq/ml). By 90Y MIRD macrodosimetry, the non-target mean absorbed dose to the gastric greater curve was approximately 49 Gy within the VOI. Gastroscopy and biopsy findings were reported in part 1 [1].
Mentions: All dose-response results of non-target tissue were serendipitously obtained in cases of unintended non-target shunting of 90Y resin microspheres due to unexpected vascular stasis and microsphere reflux during 90Y radioembolization. The dose-response of the stomach (Figure 7) and proximal duodenum by 90Y MIRD macrodosimetry are presented in Table 3. 90Y DVH dose-response of the right kidney is presented in Table 4. All results were in keeping with published experiences of external beam radiotherapy [29,30].

Bottom Line: There was complete response in a cholangiocarcinoma at D70 90 Gy and partial response in an adrenal gastrointestinal stromal tumor metastasis at D70 53 Gy.In two patients, a mean dose of 18 Gy to the stomach was asymptomatic, 49 Gy caused gastritis, 65 Gy caused ulceration, and 53 Gy caused duodenitis.In one patient, a bilateral kidney mean dose of 9 Gy (V20 8%) did not cause clinically relevant nephrotoxicity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore 169608, Singapore. yung.h.kao@gmail.com.

ABSTRACT

Background: Coincidence imaging of low-abundance yttrium-90 (90Y) internal pair production by positron emission tomography with integrated computed tomography (PET/CT) achieves high-resolution imaging of post-radioembolization microsphere biodistribution. Part 2 analyzes tumor and non-target tissue dose-response by 90Y PET quantification and evaluates the accuracy of tumor 99mTc macroaggregated albumin (MAA) single-photon emission computed tomography with integrated CT (SPECT/CT) predictive dosimetry.

Methods: Retrospective dose quantification of 90Y resin microspheres was performed on the same 23-patient data set in part 1. Phantom studies were performed to assure quantitative accuracy of our time-of-flight lutetium-yttrium-oxyorthosilicate system. Dose-responses were analyzed using 90Y dose-volume histograms (DVHs) by PET voxel dosimetry or mean absorbed doses by Medical Internal Radiation Dose macrodosimetry, correlated to follow-up imaging or clinical findings. Intended tumor mean doses by predictive dosimetry were compared to doses by 90Y PET.

Results: Phantom studies demonstrated near-perfect detector linearity and high tumor quantitative accuracy. For hepatocellular carcinomas, complete responses were generally achieved at D70 > 100 Gy (D70, minimum dose to 70% tumor volume), whereas incomplete responses were generally at D70 < 100 Gy; smaller tumors (<80 cm3) achieved D70 > 100 Gy more easily than larger tumors. There was complete response in a cholangiocarcinoma at D70 90 Gy and partial response in an adrenal gastrointestinal stromal tumor metastasis at D70 53 Gy. In two patients, a mean dose of 18 Gy to the stomach was asymptomatic, 49 Gy caused gastritis, 65 Gy caused ulceration, and 53 Gy caused duodenitis. In one patient, a bilateral kidney mean dose of 9 Gy (V20 8%) did not cause clinically relevant nephrotoxicity. Under near-ideal dosimetric conditions, there was excellent correlation between intended tumor mean doses by predictive dosimetry and those by 90Y PET, with a low median relative error of +3.8% (95% confidence interval, -1.2% to +13.2%).

Conclusions: Tumor and non-target tissue absorbed dose quantification by 90Y PET is accurate and yields radiobiologically meaningful dose-response information to guide adjuvant or mitigative action. Tumor 99mTc MAA SPECT/CT predictive dosimetry is feasible. 90Y DVHs may guide future techniques in predictive dosimetry.

No MeSH data available.


Related in: MedlinePlus