A Prospective Study of {sup 18}FDG-PET With CT Coregistration for Radiation Treatment Planning of Lymphomas and Other Hematologic Malignancies

Journal Article · Sun Jun 01 04:00:00 EDT 2014 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2014.02.006· OSTI ID:22416585

Terezakis, Stephanie A. ^[1]; Schöder, Heiko ^[2]; Kowalski, Alexander; McCann, Patrick ^[1]; Lim, Remy; Turlakov, Alla ^[2]; Gonen, Mithat ^[3]; Barker, Chris; Goenka, Anuj; Lovie, Shona ^[1]; Yahalom, Joachim ^[1]

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1. Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)
2. Department of Nuclear Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)
3. Department of Statistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

Purpose: This prospective single-institution study examined the impact of positron emission tomography (PET) with the use of 2-[{sup 18}F] fluoro-2-deoxyglucose and computed tomography (CT) scan radiation treatment planning (TP) on target volume definition in lymphoma. Methods and Materials: 118 patients underwent PET/CT TP during June 2007 to May 2009. Gross tumor volume (GTV) was contoured on CT-only and PET/CT studies by radiation oncologists (ROs) and nuclear medicine physicians (NMPs) for 95 patients with positive PET scans. Treatment plans and dose-volume histograms were generated for CT-only and PET/CT for 95 evaluable sites. Paired t test statistics and Pearson correlation coefficients were used for analysis. Results: 70 (74%) patients had non-Hodgkin lymphoma, 10 (11%) had Hodgkin lymphoma, 12 (10%) had plasma-cell neoplasm, and 3 (3%) had other hematologic malignancies. Forty-three (45%) presented with relapsed/refractory disease. Forty-five (47%) received no prior chemotherapy. The addition of PET increased GTV as defined by ROs in 38 patients (median, 27%; range, 5%-70%) and decreased GTV in 41 (median, 39.5%; range, 5%-80%). The addition of PET increased GTV as defined by NMPs in 27 patients (median, 26.5%; range, 5%-95%) and decreased GTV in 52 (median, 70%; range, 5%-99%). The intraobserver correlation between CT-GTV and PET-GTV was higher for ROs than for NMPs (0.94, P<.01 vs 0.89, P<.01). On the basis of Bland-Altman plots, the PET-GTVs defined by ROs were larger than those defined by NMPs. On evaluation of clinical TPs, only 4 (4%) patients had inadequate target coverage (D95 <95%) of the PET-GTV defined by NMPs. Conclusions: Significant differences between the RO and NMP volumes were identified when PET was coregistered to CT for radiation planning. Despite this, the PET-GTV defined by ROs and NMPs received acceptable prescription dose in nearly all patients. However, given the potential for a marginal miss, consultation with an experienced PET reader is highly encouraged when PET/CT volumes are delineated, particularly for questionable lesions and to assure complete and accurate target volume coverage.

• OSTI ID: 22416585
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 89; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

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