Summary
Positron Emission Tomography (PET) is a functional imaging technique that, combined with computerized tomography (PET‐CT), is increasingly used in lymphoma. Most subtypes accumulate ...fluorodeoxyglucose (FDG) and the increased sensitivity of PET‐CT, especially for extranodal disease, compared to CT, makes PET‐CT an attractive staging tool. The availability of a staging PET‐CT scan also improves the accuracy of subsequent response assessment. ‘Interim’ PET‐CT can be used to assess early response and end‐of‐treatment PET‐CT assesses remission. Clinical trials are currently seeking to establish whether the predictive value of PET‐CT can be successfully used to guide individual treatment to reduce toxicity and/or to improve outcomes. Standardized methods for performing and reporting PET have been developed in the context of trials. The role of PET in transplantation selection is currently evolving, as it appears to be more accurate and prognostic than CT. The role of FDG PET‐CT throughout the management course in patients with lymphoma is explored in this review, with areas discussed that may limit the use of PET‐CT imaging which clinicians should be familiar with to inform practice.
We investigated whether positron emission tomography combined with computed tomography (PET-CT) identifies clinically important bone marrow involvement by diffuse large B-cell lymphoma (DLBCL) with ...sufficient accuracy to replace routine staging bone marrow biopsy. All patients from a single centre diagnosed as DLBCL since 2005 had data extracted from staging PET-CT, marrow biopsy, and treatment records. Of 130 patients, 35 (27%) were judged to have marrow involvement; 33 were identified by PET-CT compared with 14 by marrow histology. PET identified all clinically important marrow lymphoma, while biopsy did not upstage any patient. Sensitivity and specificity were 94% and 100% for PET-CT and 40% and 100% for marrow biopsy. As a secondary aim, we compared the prognosis of marrow involvement, as detected by PET-CT or biopsy. Cases with marrow deposits identified by PET-CT but not biopsy had progression-free survival (PFS) and overall survival similar to stage IV disease without involved marrow. Positive biopsy conferred significantly inferior PFS (P = .003); these cases frequently had other markers of poor-risk disease. These data confirm that in experienced hands PET-CT has a high level of accuracy for identifying marrow disease in DLBCL, and provide new insight into the nature and clinical significance of marrow involvement.
• Routine staging by PET-CT identifies all clinically relevant marrow involvement by DLBCL.• Cases with marrow involvement identified by PET-CT have PFS and overall survival similar to stage IV cases without marrow involvement.
•Lowering the dose to organs at risk is a primary goal in mediastinal lymphoma radiotherapy.•We compared full arc and limited arc plans, with and without the use of breath-hold.•The effect of ...combining limited arc and DIBH is additive or complementary.
Radiotherapy is an effective treatment for mediastinal lymphoma but induces late effects including cardiac toxicity and secondary breast and lung cancer. Therefore reducing the dose to these organs is vital. We compared full arc volumetric modulated arc therapy (F-VMAT) against limited angle ‘Butterfly’ VMAT (B-VMAT) on free breathing (FB) and deep inspiration breath-hold (DIBH) computed tomography scans. The aim was to assess the benefits of B-VMAT over F-VMAT and to establish if the addition of DIBH results is a cumulative benefit.
F-VMAT and B-VMAT plans were calculated for 20 consecutive patients (15 females) with mediastinal lymphoma on both FB and DIBH scans. The planning target volume V95% was kept comparable between all plans while reducing organ doses as much as possible.
B-VMAT significantly reduced low lung doses (V5–10), while F-VMAT was better for higher lung doses (V20–30). DIBH further improved lung doses for both types of plans. DIBH B-VMAT produced the lowest mean lung dose. With FB, heart doses were slightly higher for B-VMAT but the maximum difference was small (0.8% for V20) and only statistically significant for V10-20. The mean heart dose increased by only 0.1 Gy. The addition of DIBH however significantly reduced heart doses. While DIBH F-VMAT had the lowest heart doses, the difference was small compared with DIBH B-VMAT. B-VMAT significantly reduced breast V4 while DIBH reduced the V10.
B-VMAT and DIBH are both effective in reducing organ doses and the dosimetric benefit is additive for some parameters and complementary for others.
Abstract Purpose Development of secondary central nervous system involvement (SCNS) in patients with diffuse large B-cell lymphoma is associated with poor outcomes. The CNS International Prognostic ...Index (CNS-IPI) has been proposed for identifying patients at greatest risk, but the optimal model is unknown. Methods We retrospectively analysed patients with diffuse large B-cell lymphoma diagnosed between 2001 and 2013, staged with PET/CT and treated with R-CHOP(-like) regimens. Baseline clinicopathologic characteristics, treatments, and outcome data were collected from clinical databases and medical files. We evaluated the association between candidate prognostic factors and modelled different risk models for predicting SCNS. Results Of 1532 patients, 62 (4%) subsequently developed SCNS. By multivariate analysis, disease stage III/IV, elevated serum LDH, kidney/adrenal and uterine/testicular involvement were independently associated with SCNS. There was a strong correlation between absolute number of extranodal sites and risk of SCNS; the 144 patients (9%) with >2 extranodal sites had a 3-year cumulative incidence of SCNS of 15.2% (95% confidence interval CI 9.2–21.2%) compared with 2.6% (95% CI 1.7–3.5) among those with ≤2 sites ( P < 0.001). The 3-year cumulative risks of SCNS for CNS-IPI defined risk groups were 11.2%, 3.1% and 0.4% for high-, intermediate- and low-risk patients, respectively. All risk models analysed had high negative predictive values, but only modest positive predictive values. Conclusions Patients with >2 extranodal sites or high-risk disease according to the CNS-IPI should be considered for baseline CNS staging. Clinical risk prediction models suffer from limited positive predictive ability, highlighting the need for more sensitive biomarkers to identify patients at highest risk of this devastating complication.
Summary
Involvement of the internal female reproductive organs by diffuse large B‐cell lymphoma (DLBCL) is uncommon, and there are sparse data describing the outcomes of such cases. In total, 678 ...female patients with DLBCL staged with positron emission tomography/computed tomography and treated with rituximab‐containing chemotherapy were identified from databases in Denmark, Great Britain, Australia, and Canada. Overall, 27/678 (4%) had internal reproductive organ involvement: uterus (n = 14), ovaries (n = 10) or both (n = 3). In multivariate analysis, women with uterine DLBCL experienced inferior progression‐free survival and overall survival compared to those without reproductive organ involvement, whereas ovarian DLBCL was not predictive of outcome. Secondary central nervous system (CNS) involvement (SCNS) occurred in 7/17 (41%) women with uterine DLBCL (two patients with concomitant ovarian DLBCL) and 0/10 women with ovarian DLBCL without concomitant uterine involvement. In multivariate analysis adjusted for other risk factors for SCNS, uterine involvement by DLBCL remained strongly associated with SCNS (Hazard ratio 14·13, 95% confidence interval 5·09–39·25, P < 0·001). Because involvement of the uterus by DLBCL appears to be associated with a high risk of SCNS, those patients should be considered for CNS staging and prophylaxis. However, more studies are needed to determine whether the increased risk of secondary CNS involvement also applies to women with localized reproductive organ DLBCL.
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