In unresectable hepatocellular carcinoma several local ablative treatments are available. Among others, radiation based treatments such as stereotactic body radiotherapy (SBRT) and high-dose rate ...interstitial brachytherapy (HDR BT) have shown good local control rates.
We conducted a dose comparison between actually performed HDR BT versus virtually planned SBRT to evaluate the respective clinically relevant radiation exposure to uninvolved liver tissue. Moreover, dose coverage and conformity indices were assessed.
Overall, 46 treatment sessions (71 lesions, 38 patients) were evaluated. HDR BT was applied in a single fraction with a dose prescription of 1 × 15 Gy. D98 was 17.9 ± 1.3 Gy, D50 was 41.8 ± 8.1 Gy. The SBRT was planned with a prescribed dose of 3 × 12.5 Gy (65%-Isodose), D98 was 50.7 ± 3.1 Gy, D2 was 57.0 ± 2.3 Gy, and D50 was 55.2 ± 2.3 Gy. Regarding liver exposure Vliver10Gy
was compared to Vliver15.9Gy
, Vliver16.2Gy
(EQD2 equivalent doses), and Vliver20Gy
(clinically relevant dose), all results showed significant differences (p < .001). In a case by case analysis Vliver10Gy
was smaller than Vliver20Gy
in 38/46 cases (83%). Dmean of the liver was significantly smaller in BT compared to SBRT (p < .001). GTV volume was correlated to the liver exposure and showed an advantage of HDR BT over SBRT in comparison of clinically relevant doses, and for EQD2 equivalent doses. The advantage was more pronounced for greater liver lesions The Conformity Index (CI) was significantly better for BT, while Healthy Tissue Conformity Index (HTCI) and Conformation Number (CN) showed an advantage for SBRT (p < .001).
HDR BT can be advantageous in respect of sparing of normal liver tissue as compared to SBRT, while providing excellent target conformity.
The impact of multileaf collimator (MLC) design and IMRT technique on plan quality and delivery improvements for head-and-neck and meningioma patients is compared in a planning study.
Ten previously ...treated patients (5 head-and-neck, 5 meningioma) were re-planned for step-and-shoot IMRT (ssIMRT), sliding window IMRT (dMLC) and VMAT using the MLCi2 without (-) and with (+) interdigitation and the Agility-MLC attached to an Elekta 6MV linac. This results in nine plans per patient. Consistent patient individual optimization parameters are used. Plans are generated using the research tool Hyperion V2.4 (equivalent to Elekta Monaco 3.2) with hard constraints for critical structures and objectives for target structures. For VMAT plans, the improved segment shape optimization is used. Critical structures are evaluated based on QUANTEC criteria. PTV coverage is compared by EUD, Dmean, homogeneity and conformity. Additionally, MU/plan, treatment times and number of segments are evaluated.
As constrained optimization is used, all plans fulfill the hard constraints. Doses to critical structures do not differ more than 1 Gy between the nine generated plans for each patient. Only larynx, parotids and eyes differ up to 1.5 Gy (Dmean or Dmax) or 7% (volume-constraint) due to (1) increased scatter, (2) not avoiding structures when using the full range of gantry rotation and (3) improved leaf sequencing with advanced segment shape optimization for VMAT plans. EUD, Dmean, homogeneity and conformity are improved using the Agility-MLC. However, PTV coverage is more affected by technique. MU increase with the use of dMLC and VMAT, while the MU are reduced by using the Agility-MLC. Fastest treatments are always achieved using Agility-MLC, especially in combination with VMAT.
Fastest treatments with the best PTV coverage are found for VMAT plans with Agility-MLC, achieving the same sparing of healthy tissue compared to the other combinations of ssIMRT, dMLC and VMAT with either MLCi2(-/+) or Agility.
Purpose
Modern breast cancer radiotherapy techniques, such as respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) or volumetric-modulated arc radiotherapy (VMAT) have been shown to ...reduce the high dose exposure of the heart in left-sided breast cancer. The aim of the present study was to comparatively estimate the excess relative and absolute risks of radiation-induced secondary lung cancer and ischemic heart disease for different modern radiotherapy techniques.
Methods
Four different treatment plans were generated for ten computed tomography data sets of patients with left-sided breast cancer, using either three-dimensional conformal radiotherapy (3D-CRT) or VMAT, in free-breathing (FB) or DIBH. Dose–volume histograms were used for organ equivalent dose (OED) calculations using linear, linear–exponential, and plateau models for the lung. A linear model was applied to estimate the long-term risk of ischemic heart disease as motivated by epidemiologic data. Excess relative risk (ERR) and 10-year excess absolute risk (EAR) for radiation-induced secondary lung cancer and ischemic heart disease were estimated for different representative baseline risks.
Results
The DIBH maneuver resulted in a significant reduction of the ERR and estimated 10-year excess absolute risk for major coronary events compared to FB in 3D-CRT plans (
p
= 0.04). In VMAT plans, the mean predicted risk reduction through DIBH was less pronounced and not statistically significant (
p
= 0.44). The risk of radiation-induced secondary lung cancer was mainly influenced by the radiotherapy technique, with no beneficial effect through DIBH. VMAT plans correlated with an increase in 10-year EAR for radiation-induced lung cancer as compared to 3D-CRT plans (DIBH
p
= 0.007; FB
p
= 0.005, respectively). However, the EARs were affected more strongly by nonradiation-associated risk factors, such as smoking, as compared to the choice of treatment technique.
Conclusion
The results indicate that 3D-CRT plans in DIBH pose the lowest risk for both major coronary events and secondary lung cancer.
PurposeModern breast cancer radiotherapy techniques, such as respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) or volumetric-modulated arc radiotherapy (VMAT) have been shown to ...reduce the high dose exposure of the heart in left-sided breast cancer. The aim of the present study was to comparatively estimate the excess relative and absolute risks of radiation-induced secondary lung cancer and ischemic heart disease for different modern radiotherapy techniques.MethodsFour different treatment plans were generated for ten computed tomography data sets of patients with left-sided breast cancer, using either three-dimensional conformal radiotherapy (3D-CRT) or VMAT, in free-breathing (FB) or DIBH. Dose–volume histograms were used for organ equivalent dose (OED) calculations using linear, linear–exponential, and plateau models for the lung. A linear model was applied to estimate the long-term risk of ischemic heart disease as motivated by epidemiologic data. Excess relative risk (ERR) and 10-year excess absolute risk (EAR) for radiation-induced secondary lung cancer and ischemic heart disease were estimated for different representative baseline risks.ResultsThe DIBH maneuver resulted in a significant reduction of the ERR and estimated 10-year excess absolute risk for major coronary events compared to FB in 3D-CRT plans (p = 0.04). In VMAT plans, the mean predicted risk reduction through DIBH was less pronounced and not statistically significant (p = 0.44). The risk of radiation-induced secondary lung cancer was mainly influenced by the radiotherapy technique, with no beneficial effect through DIBH. VMAT plans correlated with an increase in 10-year EAR for radiation-induced lung cancer as compared to 3D-CRT plans (DIBH p = 0.007; FB p = 0.005, respectively). However, the EARs were affected more strongly by nonradiation-associated risk factors, such as smoking, as compared to the choice of treatment technique.ConclusionThe results indicate that 3D-CRT plans in DIBH pose the lowest risk for both major coronary events and secondary lung cancer.
Correction to:
Strahlenther Onkol 2017
https://doi.org/10.1007/s00066-017-1213-y
Unfortunately, during copy editing, the titles of Fig. 2a and 2b were removed.
The correct Fig. 2a and 2b are shown ...below. The original article has been corrected …
Objective
To assess the feasibility of autofluorescence spectroscopy in the diagnosis of cervical intraepithelial neoplasia (CIN) using broadband light excitation.
Design
Feasibility study.
Setting
...Colposcopy clinic of an university hospital.
Population
Sixty‐eight patients at risk for CIN.
Methods
After excitation with a broadband light between 375 and 440 nm, spectral distribution of native tissue fluorescence (autofluorescence) was acquired from 685 cervical sites for the localisation and differentiation of CIN, and compared with colposcopically directed biopsy and human papillomavirus (HPV) DNA testing.
Main outcome measure
Detection of CIN.
Results
The evaluation of spectral measurements revealed significantly lower autofluorescence values for CIN 3 lesions compared with normal tissue (P < 0.001), and compared with CIN 1 or CIN 2 (P < 0.002). High grade CIN lesions (CIN 2/3) presented with a significant reduced autofluorescence compared with CIN 1 (P < 0.002). Patients with a positive HPV DNA testing showed a significantly lower autofluorescence than patients tested negative for HPV DNA (P < 0.05). Severe inflammation such as chronic cervicitis may lead to false positive results.
Conclusions
Autofluorescence spectroscopy represents an interesting approach for the detection of cervical neoplasia. Using an excitation wavelength band between 375 and 440 nm, significant differences between normal and precancerous lesions of the cervix can be seen.
To assess the feasibility of autofluorescence spectroscopy in the diagnosis of cervical intraepithelial neoplasia (CIN) using broadband light excitation.
Feasibility study.
Colposcopy clinic of an ...university hospital.
Sixty-eight patients at risk for CIN.
After excitation with a broadband light between 375 and 440 nm, spectral distribution of native tissue fluorescence (autofluorescence) was acquired from 685 cervical sites for the localisation and differentiation of CIN, and compared with colposcopically directed biopsy and human papillomavirus (HPV) DNA testing.
Detection of CIN.
The evaluation of spectral measurements revealed significantly lower autofluorescence values for CIN 3 lesions compared with normal tissue (
P < 0.001), and compared with CIN 1 or CIN 2 (
P < 0.002). High grade CIN lesions (CIN 2/3) presented with a significant reduced autofluorescence compared with CIN 1 (
P < 0.002). Patients with a positive HPV DNA testing showed a significantly lower autofluorescence than patients tested negative for HPV DNA (
P < 0.05). Severe inflammation such as chronic cervicitis may lead to false positive results.
Autofluorescence spectroscopy represents an interesting approach for the detection of cervical neoplasia. Using an excitation wavelength band between 375 and 440 nm, significant differences between normal and precancerous lesions of the cervix can be seen.
Objective: The purpose of this study was to examine the diagnostic potential for patients with endometriosis of porphyrin fluorescence after oral administration of 5-aminolevulinic acid. Study ...Design: Fifteen women referred for laparoscopy because of suspected endometriosis received 1 or 10 mg/kg 5-aminolevulinic acid orally. After 1.5 to 6 hours endoscopic fluorescence spectral analysis and video inspection were performed. Results: With 10 mg/kg 5-aminolevulinic acid and application intervals of >3 hours we observed a significantly higher porphyrin fluorescence in active peritoneal endometriosis than in adjacent normal peritoneum. Pigmented and nodular endometriosis showed weak to negative fluorescence. A strong fluorescence of the fimbrial mucosa was seen. A 1-mg/kg dose of 5-aminolevulinic acid was insufficient for fluorescence diagnosis. No side effects were recorded. Conclusion: Porphyrin fluorescence after oral administration of 5-aminolevulinic acid may be beneficial in diagnosis of peritoneal endometriosis. The strong fluorescence of fimbrial mucosa may limit the applicability of this technique in young women, however, because phototoxic damage cannot be excluded at present. (Am J Obstet Gynecol 2000;183:52-7.)
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