Dosimetric analysis of cervical cancer stage IIB patients treated with volumetric modulated arc therapy using plan uncertainty parameters module of Varian Eclipse treatment planning system.

Introduction. The present study aims to investigate the dosimetric and radiobiological impact of patient setup errors (PSE) on the target and organs at risk (OAR) of the cervix carcinoma stage IIB patients treated with volumetric-modulated arc therapy (VMAT) delivery technique using plan uncertainty parameters module of Varian Eclipse treatment planning system and in-house developed DVH Analyzer program.Materials and Methods. A total of 976 VMAT plans were generated to simulate the PSE in the base plan that varies from -10 mm to 10 mm in a step size of 1 mm in x- (lateral), y- (craniocaudal), and z- (anteroposterior) directions. The different OAR and tumor (PTV) volumes were delineated in each case. Various plan quality metrics, such as conformity index (CI) and homogeneity index (HI), as well as radiobiological quantities, such as tumor control probability (TCP) and normal tissue control probability (NTCP), were calculated from the DVH bands generated from the cohort of treatment plans associated with each patient case, using an in-house developed 'DVH Analyzer' program. The extracted parameters were statistically analyzed and compared with the base plan's dosimetric parameters having no PSE.Results. The maximum variation of (i) 2.4%, 21.5%, 0.8%, 2.5% in D2ccof bladder, rectum, small bowel and sigmoid colon respectively; (ii) 19.3% and 18.9% in Dmaxof the left and right femoral heads (iii) 16.9% in D95%of PTV (iv) 12.1% in NTCP of sigmoid colon were observed with change of PSE in all directions. TCP was found to be considerably affected for PSEs larger than 4 mm in x+, y+, z+directions and 7 mm in x-, y-and z-directions, respectively.Conclusion. This study presents the effect of PSE on TCP and NTCP for the cervix carcinoma cases treated with VMAT technique and also recommends daily image guidance to mitigate the effects of PSE.

Enhanced toxicity with CDK 4/6 inhibitors and palliative radiotherapy: Non-consecutive case series and review of the literature.

Current first-line systemic treatment in most patients with metastatic hormone receptor-positive, HER-2 negative breast cancer is an aromatase inhibitor in combination with a cyclin dependant kinase (CDK) 4/6 inhibitor. Frequently, these patients require palliative radiotherapy (RT) for symptomatic disease management. There is a paucity of data on the safety of combining a CDK 4/6 inhibitor with palliative RT, with conflicting case reports in the literature. We report on 5 cases at our institution where enhanced radiotherapy toxicity was observed when palliative doses of RT was delivered during or prior to treatment with a CDK 4/6 inhibitor. After review of pre-clinical and mechanistic data, we hypothesise that the effects of CDK4/6 inhibition on normal tissue and the tumour microenvironment may impede tissue recovery and exacerbate acute radiation and radiation recall toxicities. Further studies are required to clarify the potential toxicities of this combination. Clinicians should consider the potential risks when combining CDK 4/6 inhibitors with palliative RT and individualise patient management accordingly.

Caring for Our Trainees: Lessons From Around the World.

Continuing progress in the science of oncology must be matched by an increased responsibility toward providing oncology trainees around the world with the academic guidance, emotional support, and lifelong mentoring needed to navigate an increasingly complex environment. Although the realities on the ground determine the practicalities, there are important universal lessons to be learned from heeding diverse experiences. In this paper, three faculty at different stages of their careers from countries with different resources and infrastructure share their insights into caring for trainees.

Caring for Colleagues and Loved Ones With Cancer.

Throughout the arc of a career in medicine, physicians are universally faced with the difficult decision of when to provide care for a colleague and when to refer to another physician. Gauging the magnitude of your relationship, both professionally and personally, and then weighing how to add the roles of physician and patient to your preexisting relationship is complex. We review and discuss care of family and colleagues, address ethical boundaries both firm and flexible, and explore the emotional weight of those relationships.

For Our Patients, for Ourselves: The Value of Personal Reflection in Oncology.

Caring for patients with cancer is a great privilege as well as an emotionally and intellectually challenging task. Stress and burnout are prevalent among oncology clinicians, with serious repercussions for the care of patients. Professional societies must provide guidance for trainees and practicing physicians to mitigate the negative consequences of stress on their personal lives and medical practice. Reflection, reading, and writing about personal experiences provide outlets for fortifying personal reserves and promoting resilience to allow us to recognize the joy and meaning of our work and to forge connections with our peers. Herein, we present some of our own reflections on how and why one might take time to write, and about the power of the written word in oncology and medicine.

Gallic acid induces apoptosis in human cervical epithelial cells containing human papillomavirus type 16 episomes.

The high-risk human papillomaviruses (HPV) that infect the anogenital tract are strongly associated with the development of cervical carcinoma, which is the second most common cancer in women worldwide. Therapeutic drugs specifically targeting HPV are not available. Polyphenolic compounds have gained considerable attention because of their cytotoxic effects against a variety of cancers and certain viruses. In this study, we examined the effects of several polyphenols on cellular proliferation and death of the human cervical cancer cells and human cervical epithelial cells containing stable HPV type 16 episomes (HPVep). Our results show that three polyphenols inhibited proliferation of HeLa cells dose-dependently. Furthermore, one of the examined polyphenols, gallic acid (GA), also inhibited the proliferation of HPVep cells and exhibited significant specificity towards HPV-positive cells. The anti-proliferative effect of GA on HPVep and HeLa cells was associated with apoptosis and upregulation of p53. These results suggest that GA can be a potential candidate for the development of anti-HPV agents.

Novel, potent, orally bioavailable and selective mycobacterial ATP synthase inhibitors that demonstrated activity against both replicating and non-replicating M. tuberculosis.

The mycobacterial F0F1-ATP synthase (ATPase) is a validated target for the development of tuberculosis (TB) therapeutics. Therefore, a series of eighteen novel compounds has been designed, synthesized and evaluated against Mycobacterium smegmatis ATPase. The observed ATPase inhibitory activities (IC50) of these compounds range between 0.36 and 5.45µM. The lead compound 9d [N-(7-chloro-2-methylquinolin-4-yl)-N-(3-((diethylamino)methyl)-4-hydroxyphenyl)-2,3-dichlorobenzenesulfonamide] with null cytotoxicity (CC50>300µg/mL) and excellent anti-mycobacterial activity and selectivity (mycobacterium ATPase IC50=0.51µM, mammalian ATPase IC50>100µM, and selectivity >200) exhibited a complete growth inhibition of replicating Mycobacterium tuberculosis H37Rv at 3.12µg/mL. In addition, it also exhibited bactericidal effect (approximately 2.4log10 reductions in CFU) in the hypoxic culture of non-replicating M. tuberculosis at 100µg/mL (32-fold of its MIC) as compared to positive control isoniazid [approximately 0.2log10 reduction in CFU at 5µg/mL (50-fold of its MIC)]. The pharmacokinetics of 9d after p.o. and IV administration in male Sprague-Dawley rats indicated its quick absorption, distribution and slow elimination. It exhibited a high volume of distribution (Vss, 0.41L/kg), moderate clearance (0.06L/h/kg), long half-life (4.2h) and low absolute bioavailability (1.72%). In the murine model system of chronic TB, 9d showed 2.12log10 reductions in CFU in both lung and spleen at 173µmol/kg dose as compared to the growth of untreated control group of Balb/C male mice infected with replicating M. tuberculosis H37Rv. The in vivo efficacy of 9d is at least double of the control drug ethambutol. These results suggest 9d as a promising candidate molecule for further preclinical evaluation against resistant TB strains.

Increased virulence of Mycobacterium tuberculosis H37Rv overexpressing LipY in a murine model.

We have investigated the role of Rv3097c-encoded lipase (LipY) on the virulence of Mycobacterium tuberculosis. It has been shown that the overexpression of LipY in strain H37Rv induced increase in virulence of recombinant H37Rv::LipY strain. Compared to H37Rv, infection with H37Rv::LipY caused enhanced mortality, weight loss, bacterial load in lungs, splenomegaly, worsening lung morphology and pathology. Mice immunized with recombinant LipY antigen were protected against challenge with H37Rv::LipY, which correlated with enhanced survival of challenged mice and striking decrease in pathological features observed in unimmunized mice. To probe the cause of increase in virulence of H37Rv::LipY, the immune status of the host infected with H37Rv and H37Rv::LipY was compared. It was found that overexpression of LipY compromised immune responses resulting in attenuation of Th1 and Th17 responses, significant increase in IL-10, decrease in number of macrophages and T cells, and increase in numbers of Treg, and DCs in the lungs whereas in mice immunized with LipY an increased pool of T cells and DCs was observed. This led us to conclude that the increase in the virulence of H37Rv::LipY was due to downregulation of the host's protective immunity and the Rv3097c encoded LipY lipase is a virulence factor of M. tuberculosis.

Improved laboratory diagnosis of tuberculosis--the Indian experience.

Tuberculosis (TB) is the leading cause of death worldwide attributable to a single infectious disease agent. India has more new TB cases annually than any other country. In 2008, India accounted for a fifth of the estimated 9.4 million TB cases globally. There is an overwhelming need for improving TB diagnostics in India through the use of cost effective, patient-friendly methods appropriate to different tiers of the country health system. Substantial progress has been made in India in the field of TB diagnosis and serious efforts have been made to herald the development of diagnostic tests for pulmonary TB, extra pulmonary TB and MDR-TB. Diverse approaches have been attempted towards improving smear microscopy, rapid culture and for differentiation between the Mycobacterium tuberculosis complex and non-tuberculous mycobacteria. Several laboratories have developed in-house PCR assays for diagnosing TB with high accuracy. Approaches for distinguishing M. tuberculosis and/or Mycobacterium bovis infection and disseminated Mycobacterium avium complex infection in HIV-AIDS patients have also been described. Serological tests to detect antigens or antibodies to M. tuberculosis specific components by using cocktails of Excretory/Secretory protein antigens, Ag85 complex antigens, Hsp 65 antigen, RD1 antigens and Rapid Reverse Line Blot Hybridization assays to detect MDR-TB (mutations to rifampicin, isoniazid and streptomycin) have also been developed. Other methods like measurement of adenosine deaminase activity and use of luciferase reporter phages have also been explored for TB diagnosis. These advances in the Indian context are detailed in the present chapter. The validation and application of these methods in laboratory and public health settings is likely to result in improved TB diagnosis and contribute to effective disease management in India.

A therapeutic SIV DNA vaccine elicits T-cell immune responses, but no sustained control of viremia in SIVmac239-infected rhesus macaques.

The immunologic and virologic outcome of therapeutic DNA-vaccines administered during antiretroviral therapy (ART) using electroporation with or without (interleukin) IL-2 treatment was evaluated in the SIVmac239/macaque model. Rhesus macaques inoculated with pathogenic SIVmac239 were treated with ART [(R(-9-(2-phosphonomethoxypropyl) adenine) (PMPA), FTC, Zerit] from weeks 13 to 41 postinfection (wpi). Group 1 (n = 7) received ART only, groups 2 and 3 (each n = 6) additionally received SIVmac239-derived gp140Env, GagPol, and TatRevNef plasmids by in vivo electroporation at 22, 26, 30, and 34 wpi, and group 3 also IL-2 for 14 days after each vaccination. Endpoints evaluated were viral load, Gag(181189)-specific CD8+ T-cell responses in MamuA01+ animals, lymphoproliferative responses, and CD4 T-cell counts. Viremia in all animals dropped below 200 RNA copies/ml during ART. Frequencies of Gag(181189)-specific CD8+ T cells prior to ART were detectable in all three groups (1.27-3.01%) and increased significantly (p < 0.01) postvaccination with maximum responses after the fourth immunization (0.2% versus 3.49-7.15%). Gag(181189)-specific CD8+ T-cell frequencies increased post-ART cessation in all groups and remained at significantly higher levels (p < 0.001) until the end of the study (75 wpi) in both groups of vaccinated animals. Lymphoproliferative responses were detected against Gag in a limited number of animals after vaccination and post-ART. However, plasma RNA viral loads rebounded after ART termination to similar levels in all three groups, but remained below 10(5) copies/ml until the end of the study, which could be a late effect of the triple drug therapy.

Identification of genes of Mycobacterium tuberculosis upregulated during anaerobic persistence by fluorescence and kanamycin resistance selection.

Molecular mechanisms involved in maintaining the latent infection of Mycobacterium tuberculosis are least understood. We have applied principles of in vivo expression technology (IVET) to identify upregulated genes in an in vitro simulated condition of anaerobic persistence likely to be encountered by the pathogen in lung granulomas. A promoter library of M. tuberculosis constructed in plasmid pLL192 was subjected to hypoxic condition (dissolved oxygen <1%) in a controlled fermenter. On the basis of green fluorescent protein fluorescence and kanamycin resistance the upregulated promoters were selected, identified by nucleotide sequence and the genes were confirmed by RT-PCR. The upregulated genes include Rv0050 (penicillin binding protein), Rv1511 (GDP-d-mannose dehydratase), Rv1489, Rv2257, Rv2258 (all conserved hypothetical proteins), Rv0467 (isocitrate lyase) and Rv2031c (alpha-crystalline homolog). The involvement of the last four genes in latency has been suggested before. The functional role of Rv0050 and Rv1511 may be important in determining cell wall characteristics controlling permeability of nutrients and antibiotics.