Which of the following medications is a first-line antitubercular drug used routinely in children of all age groups without significant monitoring limitations?

Combination of all first-line ATT agents

All of the following are true about long-term sequelae of craniospinal radiotherapy for children with CNS tumors except:

Neuropsychological sequelae are independent of radiation dose

Prophylaxis with cotrimoxazole is recommended in all situations except for which of the following?

All symptomatic HIV infected children > 5 years of age irrespective of CD4

All HIV infected infants less than 1 year age irrespective of symptoms or CD4 counts

All HIV exposed infants till HIV infection can be ruled out

As secondary prophylaxis after initial treatment for Pneumocystis jirovecii pneumonia

A 2 year old child is seen on a routine visit in the pediatric clinic. Abdominal examination demonstrates a palpable, non-tender mass on the left side of the abdomen. The mother had no idea the mass was present and the pediatrician did not note the presence of the mass at the child's 18-month's visit for immunisation. Physical examination is otherwise unremarkable. If a CT guided biopsy of the mass were performed, which of the following histological patterns would be most suggestive of the likely diagnosis?

Triphasic pattern with tubule formation, spindle cells, and blastemal elements

Invasive papillary lesions with delicate connective tissue stalk covered with epithelium resembling that lining the bladder.

Cords of clear cells with rounded or polygonal shape and abundant clear cytoplasm

Small dark cells embedded in a finely fibrillar matrix with formation of numerous rosettes

Principles of Pediatric Chemotherapy for UPSC-CMS: High-Yield Pediatrics Lessons

Principles of Pediatric Chemotherapy - Tiny Patients, Big Differences

Pediatric physiology alters drug ADME (Absorption, Distribution, Metabolism, Excretion).
Dosing: Primarily Body Surface Area (BSA) based ($mg/m^2$).
- Carboplatin: Calvert formula (Dose = Target AUC x (GFR + 25)).
Generally higher chemo tolerance & tumor sensitivity vs. adults.
Key focus: Minimizing long-term effects (growth, neurocognitive, fertility, secondary cancers).
Aggressive supportive care vital (hydration, antiemetics, G-CSF).
Multidisciplinary team (MDT) approach is crucial.

⭐ Pediatric cancers often show higher cure rates (e.g., ALL >80-90%) and better tolerance to intensive chemotherapy than adult cancers, but have a unique malignancy spectrum and long-term sequelae.

Principles of Pediatric Chemotherapy - Little Heroes' Weapons

Pediatric cancers often highly chemosensitive. Goal: Cure with minimal long-term effects.
Targets rapidly dividing cells. Combination regimens are standard.
Key principles: cell cycle specificity, dose intensity, minimizing toxicity.
📌 Cell Cycle: M-phase (Vinca), S-phase (Antimetabolites, Etoposide), G2 (Bleomycin). Non-specific: Alkylating, Anthracyclines.

Chemotherapy drug classes and cell cycle targets

Drug Class	MoA	Examples	Uses	Toxicities
Alkylating Agents	Cross-link DNA	Cyclophosphamide	Leukemias, lymphomas, solid tumors	Myelosuppression, hemorrhagic cystitis, 2° Malign
Antimetabolites	Block DNA/RNA synthesis	Methotrexate, 6-MP	Leukemias (ALL), lymphomas	Myelosuppression, mucositis, hepatotoxicity
Anthracyclines	DNA intercalation, Topo II inh., radicals	Doxorubicin	Leukemias, lymphomas, sarcomas, Wilms	Cardiotoxicity (cumulative), myelosuppression
Vinca Alkaloids	Inhibit microtubule assembly (M-phase)	Vincristine	Leukemias, lymphomas, solid tumors	Neurotoxicity, constipation, BM sparing

Principles of Pediatric Chemotherapy - Side Effect Battles

Chemotherapy targets rapidly dividing cells, affecting cancer and healthy tissues. Managing side effects is vital.

Acute: Myelosuppression, nausea/vomiting, mucositis.
Organ-Specific: Cardiac, renal, neurotoxicity.
Long-Term: Growth issues, secondary cancers, infertility.

Key Side Effects & Management:

System/Toxicity	Key Drugs	Peds Notes	Management Highlights
Myelosuppression	Most chemo	ANC < 500/µL critical	G-CSF, transfusions
Nausea/Vomiting	Cisplatin, Doxo	High anticipatory	Ondansetron, Aprepitant
Mucositis	MTX, 5-FU	Pain, poor nutrition	Hygiene, cryotherapy
Hemorrhagic Cystitis	Cyclophos, Ifos	Acrolein toxicity	Mesna, hydration
Cardiotoxicity	Anthracyclines	Cumulative dose	Dexrazoxane, LVEF monitoring
Neurotoxicity	Vincristine, Cisplatin	Foot drop (V), Ototoxic (Cis) 📌 CisPLATin	Dose adjust
Nephrotoxicity	Cisplatin, MTX	Monitor GFR	Hydration, Leucovorin (MTX)
Tumor Lysis (TLS)	ALL, Burkitt's	Metabolic emergency	Rasburicase, hydration

Chemotherapy side effects by organ system

Management of Febrile Neutropenia:

Principles of Pediatric Chemotherapy - Dose & Future Watch

Dosing:
- Primarily Body Surface Area (BSA): $\text{BSA (m}^2\text{) = } \sqrt{(\text{Height (cm)} \times \text{Weight (kg)}) / 3600}$.
- Carboplatin: Calvert formula $\text{Dose (mg) = Target AUC} \times \text{(GFR + 25)}$.
- Age/weight bands for infants.
Pediatric Pharmacokinetics:
- ↑ GFR, ↑ metabolism (MTX, cyclophosphamide).
- Larger Vd (water-soluble drugs), ↓ protein binding.
Future Watch (Late Effects):
- Secondary malignancies (e.g., AML post-etoposide).
- Organ toxicities: cardiac (anthracyclines), pulmonary (bleomycin), renal (cisplatin), neuro (vincristine).
- Endocrine: growth issues, infertility.
- Long-term surveillance crucial.

⭐ Anthracyclines (e.g., Doxorubicin) cause dose-dependent cardiotoxicity, potentially years later, requiring long-term cardiac follow-up.

High‑Yield Points - ⚡ Biggest Takeaways

BSA-based dosing is standard for most pediatric chemotherapy.

Children exhibit higher chemosensitivity due to rapid cell proliferation.

Altered PK/PD in children significantly impacts drug efficacy and toxicity.

Long-term sequelae, including secondary malignancies and organ damage, are critical.

Sanctuary sites (CNS, testes) often require specific therapeutic approaches.

Aggressive supportive care is vital for managing treatment toxicities.

Pediatric cancers show a unique spectrum (leukemias, lymphomas, embryonal tumors).

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