A comparative study in left-sided breast cancer treated with moderate deep inspiratory breath hold versus free breathing

BACKGROUND

The moderate deep inspiratory breath hold (mDIBH) is a modality famed for cardiac sparing. Prospective studies based on this are few from the eastern part of the world and India. We intend to compare the dosimetry between mDIBH and free-breathing (FB) plans.

METHODS

Thirty-two locally advanced left breast cancer patients were taken up for the study. All patients received a dose of 50 Gy in 25 fractions to the chest wall/intact breast, followed by a 10-Gy boost to the lumpectomy cavity in the case of breast conservation surgery. All the patients were treated in mDIBH using active breath coordinator (ABC). The data from the two dose volume histograms were compared regarding plan quality and the doses received by the organs at risk. Paired t-test was used for data analysis.

RESULTS

The dose received by the heart in terms of V5, V10, and V30 (4.55% vs 8.39%) and mean dose (4.73 Gy vs 6.74 Gy) were statistically significant in the ABC group than that in the FB group (all p-values < 0.001). Also, the dose received by the LADA in terms of V30 (19.32% vs 24.87%) and mean dose (32.99 Gy vs 46.65 Gy) were significantly less in the ABC group. The mean treatment time for the ABC group was 20 min, while that for the free-breathing group was 10 min.

CONCLUSIONS

Incorporating ABC-mDIBH for left-sided breast cancer radiotherapy significantly reduces the doses received by the heart, LADA, and left and right lung, with no compromise in plan quality but with an increase in treatment time.

Laser induced fluorescence spectroscopy analysis of kidney tissues: A pilot study for the identification of renal cell carcinoma

The 325 nm-excited autofluorescence spectra from cancerous and normal renal tissues were collected ex vivo biopsy tissue samples, through an optical fiber probe-based system. Noticeable changes in intensity/wavelength were observed in the fluorescence emissions from endogenous fluorophores such as collagen, Nicotinamide adenine dinucleotide (NADH), Vitamin A (retinol), and flavin adenine dinucleotide, in pathological conditions with respect to the normal state. The energy metabolism involved in clear cell renal cell carcinoma (ccRCC) and chromophobe renal cell carcinoma (chRCC) are reflected in the fluorescence emission band at 445 nm due to bound NADH attributed to enhanced oxidative phosphorylation in chRCC and emission at 465 nm contributed by free NADH showing higher glycolytic action in ccRCC. The principal component analysis and one-way ANOVA effectively discriminate ccRCC from chRCC. It is shown that laser induced fluorescence technique with 325 nm excitation can be a suitable technique for optical pathology and in vivo surgical boundary demarcation in renal cell carcinoma.

Mono iso-centric VMAT planning for SBRT of multiple liver metastasis- A case report

INTRODUCTION

Hepatocellular carcinoma (HCC) is the second most common cause of cancer mortality worldwide. The risk factors associated with the development of HCC are chronic Hepatitis B, Hepatitis C, and alcoholic cirrhosis. The standard care for HCC is surgical resection but the scope is limited for some patients. Continuous advancement of radiation therapy enabled the technique of stereotactic body radiotherapy (SBRT) as an option for the treatment of those cases for which surgery cannot be done. According to recent literature and meta-analysis, SBRT is an optimum treatment method with high local control with low toxicity. In SBRT, radiation is delivered with a smaller number of fractions than conventional radiation and employs high-precision delivery and accuracy with the help of image guidance. From a series of retrospective and prospective studies, it has been confirmed that SBRT achieves excellent local control in patients with early-stage inoperable, intermediate-stage, and advanced diseases.

BACKGROUND

A 42-year-old male patient related to HBeAg infection and high AFP levels developed HCC BCLC Stage A was admitted to our department. There were two lesions with PTV volumes of 41.07 cc and 9.573 cc with a distance between them of 3.51 cm. These two lesions were treated with a mono-isocentric VMAT planning with SBRT technique. In this case, we present an unusual clinical practice of mono-isocentric treatment planning for treating multiple liver lesions. Since radiation therapy was viewed as the primary form of treatment because the patient wasn't an ideal candidate for surgery, SBRT was selected as the patient's primary modality of treatment because of the tiny volume of the two lesions and the normal liver volume (>700cc). Triple-phase 4DCT was performed for simulation to account for the motion of target volume and normal structures. After delineating the target volume and other normal structures, treatment planning was done with a dose of 45 Gray which was to be delivered in 5 fractions. Two PTVs were created with a margin of 3.0 mm to IGTV. Considering the positions of the lesions, a single isocentre plan was created using a 6MV FFF photon beam for both the PTVs with the VMAT technique. The treatment was carried through with 3 arcs, one coplanar, and the other 2 non-coplanar. At the time of treatment, after the proper positioning of the patient, one CBCT image was taken to match with the planned CT image acquired at the time of the simulation. After applying the translational and rotational errors, the patient was treated.

RESULTS

The patient was treated successfully. After treatment, the condition of the patient was normal, and no toxicities have been observed in follow-up.

CONCLUSION

Mono isocentric VMAT planning can be used for closely spaced lesions considering the position of lesions and other normal structures in the vicinity.

Dose optimization comparison study of inverse planning simulated annealing [IPSA] and hybrid inverse planning optimization [HIPO] in interstitial brachytherapy of head and neck cancer

PURPOSE

This study was a retrospective dose optimization comparison of two commercially available inverse planning algorithms, the inverse planning simulated annealing (IPSA) and hybrid inverse planning optimization (HIPO) for head and neck cancer interstitial brachytherapy.

MATERIALS AND METHODS

Seven patients with head and neck cancer were selected (4 with tongue cancer, 2 with buccal mucosa cancer and 1 with carcinoma lip) who were previously treated with interstitial brachytherapy using a flexible nylon tube catheter and graphical optimization/geometric optimization technique. All seven patients were retrospectively re-planned using both IPSA as well as HIPO algorithms available in the Oncentra Brachytherapy Treatment Planning System (TPS) version V4.5.3.30. The dosimetric parameters [PTV-V₁₀₀, V₁₅₀, V₂₀₀, D₉₀; mandible-D2cc, parotid-D2cc, conformity index (CI), dose homogeneity index (HI), overdose volume index (ODI)] were chosen for evaluation in compliance with the objective function and organ at risk dose constraints.

RESULTS

Using the paired sample T test in chosen parameters (PTV-V₁₀₀, V₁₅₀, V₂₀₀, D₉₀; mandible-D2cc, CI, HI, ODI both the inverse planning algorithms), it was found that IPSA and HIPO were comparable.

CONCLUSIONS

Even though both IPSA and HIPO are largely comparable in most of the dosimetric parameters for inverse planning in brachytherapy of head and neck cancers, differences in the algorithms can be exploited to improve certain parameters in specific situations such as D2cc parotid.

Laser-induced breakdown spectroscopy-Raman: An effective complementary approach to analyze renal-calculi

Presence of renal-calculi (kidney stones) in human urethra is being increasingly diagnosed over the last decade and is considered as one of the most painful urological disorders. Accurate analysis of such stones plays a vital role in the evaluation of urolithiasis patients and in turn helps the clinicians toward exact etiologies. Two highly complementary laser-based analytical techniques; laser-induced breakdown spectroscopy (LIBS) and micro-Raman spectroscopy have been used to identify the chemical composition of different types of renal-calculi. LIBS explores elemental characteristics while Raman spectroscopy provides molecular details of the sample. This complete information on the sample composition might help clinicians to identify the key aspects of the formation of kidney stones, hence assist in therapeutic management and to prevent recurrence. The complementarity of both techniques has been emphasized and discussed. LIBS spectra of different types of stones suggest the probable composition of it by virtue of the major, minor and trace elements detected from the sample. However, it failed to differentiate the crystalline form of different hydrates of calcium oxalate stone. This lacuna was overcome by the use of Raman spectroscopy and these results are compared with conventional chemical analysis.

Determination of urinary peptides in patients with proteinuria

Although considered useful in the diagnosis and prognosis of renal diseases, proteinuria can only be detected after significant renal paranchymal changes. There is considerable interest in the estimation of urinary peptides as an early marker of renal disease. In the current study, we have estimated urinary peptides in patients with different grades of proteinuria. Twenty-four hour urine samples were collected from 138 subjects and classified into three groups based on the urine protein excreted: group I (normoproteinuria, 0–150 mg/day, n = 37), group II (microproteinuria, 150–300 mg/day, n = 31), and group III (macroproteinuria, > 300 mg/day, n = 70). Urine proteins were determined using Bradford's method and urinary peptide levels were determined by subtracting Bradford's value from the Lowry value of the same sample. There was a significant decrease in the levels of urinary peptides in group III compared to group I (P < 0.01), however, there was no difference in peptides between groups I and II. The percentage of urinary peptides was decreased in both groups II and III compared to group I (P < 0.01), and there was a significant difference in % urinary peptide content in group II compared to group III (P < 0.01). On correlation, % urinary peptides correlated negatively with urinary proteins/g creatinine (r = - 0.782, P < 0.01) and positively with urinary peptides/g creatinine (r = 0.238, P < 0.01). Our data suggest that there is a marked decrease in urinary peptide levels with an increase in proteinuria. This may suggest impaired tubular protein reabsorption and degradation capacity of renal tubules.