Compensatory Enlargement of the Liver after Proton Beam Therapy for Hepatocellular Carcinoma

PURPOSE/OBJECTIVE(S)

Charged particle therapy (CPT) has been applied as a safe and effective treatment option for hepatocellular carcinoma (HCC). Although most HCC patients have cirrhosis, favorable treatment outcome has been achieved with CPT preserving liver function. After proton beam therapy (PBT) for patients with HCC, the liver volume in the non-irradiated area is often enlarged. Here, we evaluated whether enlargement of the non-irradiated liver affects preserving hepatic function and prognosis in HCC patients treated with PBT.

MATERIALS/METHODS

Among consecutive patients with HCC treated with PBT between April 2011 and July 2017, we retrospectively identified patients who fulfilled the following criteria: (i) receiving PBT to the right hepatic lobe, (ii) the left lateral segment was not irradiated, (iii) no local treatment was performed for liver within 12 months after PBT, and (iv) the albumin-bilirubin (ALBI) score was evaluable at 12 months after PBT. The left lateral segment was defined as the non-irradiated region and measured by contrast-enhanced CT just before and 3 months after PBT. ALBI scores just before and 12 months after PBT were compared to evaluate changes of hepatic function. Overall survival rate was estimated using the Kaplan-Meier method, and differences in survival between subgroups were examined using the log-rank test. The ALBI scores were compared using the Wilcoxon signed-rank test.

RESULTS

We identified 40 patients (male/female = 32/8). The median age at the start date of PBT was 72 (range, 54-87) years. The prescribed dose was 66.0-76.0 Gy (relative biological effectiveness) delivered in 10-38 fractions. The median follow-up was 61 (range, 12-126) months. The 5-year overall survival rates were 79.0% (95% CI: 60.4-100.0%) in the larger enlargement group (n = 16, enlarged volume of non-irradiated region 3 months after PBT ≥75 cm3) and 53.7% (95% CI: 36.0-79.9%) in the smaller enlargement group (n = 24, as above, <75 cm3), respectively (p = 0.21). The median ALBI scores just before and 12 months after PBT were -3.14 (95% CI: -3.22- (-2.53)) and -2.74 (95% CI: -3.07- (-2.42)) in the larger enlargement group (p = 0.09), and -2.91 (95% CI: -3.15- (-2.40)) and -2.59 (95% CI: -2.74- (-2.12)) in the smaller enlargement group (p = 0.006), respectively.

CONCLUSION

Our study suggests that larger enlargement of the non-irradiated liver after PBT is related to well-preserved liver function at 1 year and modestly associated with a favorable prognosis.

Comparison of a Hybrid IMRT/VMAT technique with non-coplanar VMAT and non-coplanar IMRT for unresectable olfactory neuroblastoma using the RayStation treatment planning system-EUD, NTCP and planning study

The purpose of this study was to compare hybrid intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (Hybrid IMRT/VMAT), with non-coplanar (nc) IMRT and nc-VMAT treatment plans for unresectable olfactory neuroblastoma (ONB). Hybrid IMRT/VMAT, nc-IMRT and nc-VMAT plans were optimized for 12 patients with modified Kadish C stage ONB. Dose prescription was 65 Gy in 26 fractions. Dose-volume histogram parameters, conformation number (CN), homogeneity index (HI), integral dose and monitor units (MUs) delivered per fraction were assessed. Equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) based on the EUD model (NTCPLogit) and the Lyman-Kutcher-Burman model (NTCPLKB) were also evaluated. We found that the Hybrid IMRT/VMAT plan significantly improved the CN for clinical target volume (CTV) and planning treatment volume (PTV) compared with the nc-VMAT plan. In general, sparing of organs at risk (OARs) is similar with the three techniques, although the Hybrid IMRT/VMAT plan resulted in a significantly reduced Dmax to contralateral (C/L) optic nerve compared with the nc-IMRT plan. The Hybrid IMRT/VMAT plan significantly reduce EUD to the ipsilateral (I/L) and C/L optic nerve in comparison with the nc-IMRT plan and nc-VMAT plan, but the difference in NTCP between the three technique was <1%. We concluded that the Hybrid IMRT/VMAT technique can offer improvement in terms of target conformity and EUD for optic nerves, while achieving equal or better OAR sparing compared with nc-IMRT and nc-VMAT, and can be a viable radiation technique for treating unresectable ONB. However, the clinical benefit of these small differences in dosimetric data, EUD and NTCP of optic nerves may be minimal.

Aggressive neoplastic plasma cell growth with MLL gene rearrangement after high-dose therapy with autologous stem cell support for multiple myeloma

We report a case of a patient with IgA kappa multiple myeloma (MM) mobilized with etoposide and subsequently receiving high-dose melphalan (HDM) with stem cell support. She relapsed rapidly post transplantation. Southern blot and fluorescent in situ hybridization analysis showed MLL gene rearrangement in the myeloma cells, which was not detected in the sample at diagnosis or in the PBSC harvested with etoposide plus G-CSF. These observations suggest that clonal rearrangement of the MLL gene is caused by etoposide. Patients with MM undergoing HDM with stem cell rescue may be at an increased risk of not only secondary leukemia, but also secondary genetic abnormalities in myeloma cells, especially those receiving priming with etoposide for peripheral blood stem cell collection.

Morphological subtyping of acute myeloid leukemia with maturation (AML-M2): homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of AML-M2 with t(8;21)

Morphologic and cytochemical features of 30 acute myeloid leukemia subtype M2 (AML-M2) patients with t(8;21) were compared with those of 50 AML-M2 patients without t(8;21). It was disclosed that irregular nuclear shape, Auer bodies, and at least 90% myeloperoxidase positivity in blast cells, and pseudo-Pelger-Huët anomaly of the nuclei and homogeneous pink-colored cytoplasm of mature neutrophils were observed in 90-100% of the t(8;21)+ patients. The percentages of patients showing these features were significantly (P < 0.01) lower in the t(8;21)- group. Among these morphological features, homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of t(8;21)+ AML-M2, because it was seen in 90% of the t(8;21)+ patients but in only 2% of the t(8;21)- patients. Conversely, pale-colored cytoplasm without any granules in mature neutrophils or dyserythropoietic features was observed in 84% of the t(8;21)- patients, but in none of the t(8;21)+ patients. These data suggest that it is possible to subtype AML-M2 patients morphologically by the recognition of homogeneous pink-colored or pale-colored cytoplasm of mature neutrophils and dyserythropoietic features. Thus, the morphologic subtyping of AML-M2 can be utilized alone or in combination with chromosomal or molecular subtyping for biological and clinical studies of AML with maturation.