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RADIATION & CANCER BIOLOGY (Q1–20)
1. Which DNA lesion is most lethal when induced by ionizing radiation?
A. Single-strand break
B. Double-strand break
C. Base adduct
D. Heat damage
Answer: B — Double-strand breaks are the most lethal DNA lesion induced by radiation .
2. In which phase of the cell cycle are cells most radioresistant?
A. M phase
B. G1 phase
C. End of S phase
D. G2 phase
Answer: C — Cells in the end of S phase are most radioresistant .
3. What is the correct formula for EQD2 using the linear quadratic model?
A. EQD2 = Dref × [(α/β + d)/(α/β + 2Gy)]
B. EQD2 = Dref × [(2Gy)/(d + α/β)]
C. EQD2 = Dref × [(d + α/β)/(2Gy + α/β)]
D. EQD2 = Dref × [(d + α/β)/(2Gy)]
Answer: C — EQD2 = Dref × [(d + α/β)/(2Gy + α/β)] is the correct formula .
4. A typical α/β value for prostate cancer is:
A. 0.5 Gy
B. 2 Gy
C. 10–12 Gy
D. 20 Gy
Answer: C — An α/β value of 10–12 Gy for prostate cancer is commonly used for
radiobiological calculations .
5. Which drug has radiosensitizing effects that may be relevant during radiation therapy?
A. Metronidazole
B. Amoxicillin
C. Acetaminophen
D. Omeprazole
Answer: A — Metronidazole has radiosensitizing effects .
6. Hyperthermia enhances the radiation effect primarily by:
A. Increasing radioresistance of healthy tissue
B. Enhancing the oxygen effect
C. Having no effect on DNA repair
D. Decreasing tumor oxygenation
Answer: B — Hyperthermia can enhance the oxygen effect .
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7. In a single-arm phase II study of limited extrahepatic disease treated with radiation,
what dose was studied?
A. 400 mL or greater
B. 800 mL or greater
C. 1200 mL or greater
D. 1600 mL or greater
Answer: B — The study examined 800 mL or greater .
8. Regarding the CATNON trial for grade 3 non-codeleted gliomas, which treatment
improved overall survival?
A. Concurrent temozolomide only
B. Adjuvant temozolomide
C. Neither concurrent nor adjuvant
D. Both concurrent and adjuvant
Answer: B — Adjuvant temozolomide improved OS; no data yet for concurrent benefit .
9. Sublethal damage repair (SLDR) is generally complete by:
A. 5 minutes
B. 1–2 hours
C. 12 hours
D. 24 hours
Answer: B — SLDR is generally complete by 1–2 hours, not 5 minutes .
10. A D0 of 10 Gy indicates:
A. Low capacity for SLDR
B. High capacity for SLDR
C. No SLDR
D. Immediate cell death
Answer: B — A higher D0 indicates greater capacity for sublethal damage repair .
11. High temperatures >50°C:
A. Enhance SLDR
B. Enhance cell kill
C. Have no effect
D. Protect cells from radiation
Answer: B — High temperatures over 50°C would enhance cell kill .
12. When is radiation therapy delivered in high-risk neuroblastoma?
A. Prior to any chemotherapy
B. After induction chemo and surgery, before consolidation
C. After myeloablative chemotherapy with autologous stem cell transplant
D. After immunotherapy
, 3
Answer: C — RT is delivered after myeloablative chemo with autologous stem cell transplant
.
13. Which protein plays a major role in radiation-induced cellular senescence?
A. Telomerase Reverse Transcriptase (TERT)
B. Cytochrome C
C. Retinoblastoma Protein (pRB)
D. Receptor-Interacting Protein 1 (RIP1)
Answer: C — The Retinoblastoma Protein (pRB) plays a key role in radiation-induced
senescence .
14. In the phase III FORT trial comparing 4 Gy vs 24 Gy for follicular lymphoma, which was
true?
A. 4 Gy was better for time to progression
B. 4 Gy was equivalent for time to progression
C. 4 Gy was worse for time to progression
D. 4 Gy was associated with more toxicity
Answer: C — 4 Gy was worse for time to progression; 24 Gy was superior .
15. According to the Zumsteg classification, which intermediate-risk prostate patient
should receive ADT + RT?
A. cT1c, Gleason 3+4, PSA 15
B. cT1c, Gleason 3+3, PSA 15
C. cT2c, Gleason 4+3, PSA 15
D. cT2c, Gleason 3+4, PSA 5
Answer: A — Unfavorable intermediate-risk features (Gleason 3+4, PSA 15) warrant ADT +
RT .
16. In pregnant survivors of childhood cancer, what factor is associated with the highest
risk of stillbirth or neonatal death?
A. 2.5 Gy to the uterus before menarche
B. 2.5 Gy to the uterus after menarche
C. 20 Gy to the pituitary before menarche
D. 20 Gy to the pituitary after menarche
Answer: A — 2.5 Gy to the uterus before menarche is associated with highest risk .
17. For small, low-grade extremity soft tissue sarcomas following R0 resection, the
approximate 10-year local recurrence rate with surgery alone is:
A. 2%
B. 10%
C. 20%
D. 35%
Answer: B — The cumulative incidence of local recurrence at 10 years was 10.6% .
RADIATION & CANCER BIOLOGY (Q1–20)
1. Which DNA lesion is most lethal when induced by ionizing radiation?
A. Single-strand break
B. Double-strand break
C. Base adduct
D. Heat damage
Answer: B — Double-strand breaks are the most lethal DNA lesion induced by radiation .
2. In which phase of the cell cycle are cells most radioresistant?
A. M phase
B. G1 phase
C. End of S phase
D. G2 phase
Answer: C — Cells in the end of S phase are most radioresistant .
3. What is the correct formula for EQD2 using the linear quadratic model?
A. EQD2 = Dref × [(α/β + d)/(α/β + 2Gy)]
B. EQD2 = Dref × [(2Gy)/(d + α/β)]
C. EQD2 = Dref × [(d + α/β)/(2Gy + α/β)]
D. EQD2 = Dref × [(d + α/β)/(2Gy)]
Answer: C — EQD2 = Dref × [(d + α/β)/(2Gy + α/β)] is the correct formula .
4. A typical α/β value for prostate cancer is:
A. 0.5 Gy
B. 2 Gy
C. 10–12 Gy
D. 20 Gy
Answer: C — An α/β value of 10–12 Gy for prostate cancer is commonly used for
radiobiological calculations .
5. Which drug has radiosensitizing effects that may be relevant during radiation therapy?
A. Metronidazole
B. Amoxicillin
C. Acetaminophen
D. Omeprazole
Answer: A — Metronidazole has radiosensitizing effects .
6. Hyperthermia enhances the radiation effect primarily by:
A. Increasing radioresistance of healthy tissue
B. Enhancing the oxygen effect
C. Having no effect on DNA repair
D. Decreasing tumor oxygenation
Answer: B — Hyperthermia can enhance the oxygen effect .
, 2
7. In a single-arm phase II study of limited extrahepatic disease treated with radiation,
what dose was studied?
A. 400 mL or greater
B. 800 mL or greater
C. 1200 mL or greater
D. 1600 mL or greater
Answer: B — The study examined 800 mL or greater .
8. Regarding the CATNON trial for grade 3 non-codeleted gliomas, which treatment
improved overall survival?
A. Concurrent temozolomide only
B. Adjuvant temozolomide
C. Neither concurrent nor adjuvant
D. Both concurrent and adjuvant
Answer: B — Adjuvant temozolomide improved OS; no data yet for concurrent benefit .
9. Sublethal damage repair (SLDR) is generally complete by:
A. 5 minutes
B. 1–2 hours
C. 12 hours
D. 24 hours
Answer: B — SLDR is generally complete by 1–2 hours, not 5 minutes .
10. A D0 of 10 Gy indicates:
A. Low capacity for SLDR
B. High capacity for SLDR
C. No SLDR
D. Immediate cell death
Answer: B — A higher D0 indicates greater capacity for sublethal damage repair .
11. High temperatures >50°C:
A. Enhance SLDR
B. Enhance cell kill
C. Have no effect
D. Protect cells from radiation
Answer: B — High temperatures over 50°C would enhance cell kill .
12. When is radiation therapy delivered in high-risk neuroblastoma?
A. Prior to any chemotherapy
B. After induction chemo and surgery, before consolidation
C. After myeloablative chemotherapy with autologous stem cell transplant
D. After immunotherapy
, 3
Answer: C — RT is delivered after myeloablative chemo with autologous stem cell transplant
.
13. Which protein plays a major role in radiation-induced cellular senescence?
A. Telomerase Reverse Transcriptase (TERT)
B. Cytochrome C
C. Retinoblastoma Protein (pRB)
D. Receptor-Interacting Protein 1 (RIP1)
Answer: C — The Retinoblastoma Protein (pRB) plays a key role in radiation-induced
senescence .
14. In the phase III FORT trial comparing 4 Gy vs 24 Gy for follicular lymphoma, which was
true?
A. 4 Gy was better for time to progression
B. 4 Gy was equivalent for time to progression
C. 4 Gy was worse for time to progression
D. 4 Gy was associated with more toxicity
Answer: C — 4 Gy was worse for time to progression; 24 Gy was superior .
15. According to the Zumsteg classification, which intermediate-risk prostate patient
should receive ADT + RT?
A. cT1c, Gleason 3+4, PSA 15
B. cT1c, Gleason 3+3, PSA 15
C. cT2c, Gleason 4+3, PSA 15
D. cT2c, Gleason 3+4, PSA 5
Answer: A — Unfavorable intermediate-risk features (Gleason 3+4, PSA 15) warrant ADT +
RT .
16. In pregnant survivors of childhood cancer, what factor is associated with the highest
risk of stillbirth or neonatal death?
A. 2.5 Gy to the uterus before menarche
B. 2.5 Gy to the uterus after menarche
C. 20 Gy to the pituitary before menarche
D. 20 Gy to the pituitary after menarche
Answer: A — 2.5 Gy to the uterus before menarche is associated with highest risk .
17. For small, low-grade extremity soft tissue sarcomas following R0 resection, the
approximate 10-year local recurrence rate with surgery alone is:
A. 2%
B. 10%
C. 20%
D. 35%
Answer: B — The cumulative incidence of local recurrence at 10 years was 10.6% .
