What are the standard radiation oncology plans for cancer patients by stage?

Radiation Oncology Treatment Plans by Cancer Stage

Non-Small Cell Lung Cancer (NSCLC)

Early-Stage Disease (Stage I and Selected Node-Negative Stage IIA)

For medically inoperable patients or those refusing surgery, stereotactic body radiation therapy (SBRT) is the primary treatment, delivering 6-18 Gy per fraction over 2-8 sessions. 1

• SBRT with high maximum dose (BED ≥200 Gy) significantly improves outcomes: 5-year local control of 98.7% versus 92.8%, cancer-specific death reduced by 62%, and overall survival improved (61.7% vs 51.8%) compared to lower doses 2
• Standard prescription is 50-60 Gy in 5 fractions, with maximum doses reaching 62.5-100 Gy to the planning target volume 2
• This approach is increasingly used for oligometastatic disease as well 1

Locally Advanced NSCLC (Inoperable Stage II and Unresectable Stage III)

Concurrent chemoradiotherapy with 60 Gy in 30 fractions (2 Gy daily) remains the standard of care, based on RTOG 0617 which demonstrated superior outcomes compared to dose escalation. 1

• Key landmark trial: RTOG 0617 showed median overall survival of 28.7 months with 60 Gy versus 20.3 months with 74 Gy (P=0.0072), establishing 60 Gy as the evidence-based standard 1
• Concurrent chemotherapy typically consists of weekly paclitaxel 45 mg/m² and carboplatin AUC 2, followed by consolidation 1
• Doses above 60 Gy up to 70 Gy may be considered in well-selected patients with strict normal tissue constraints, but doses above 70 Gy should not be used outside clinical trials 1
• Intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) is preferred over 3D conformal techniques 1
• Critical dose constraints: Heart, lung, and esophagus doses must be carefully limited to avoid excessive morbidity 1
• Selective nodal irradiation (only proven or highly suspicious nodes) is recommended over elective nodal irradiation 1

Sequential Chemoradiotherapy Option

• For patients with large initial volumes not amenable to concurrent treatment or those unfit for intensive concurrent therapy, sequential chemoradiotherapy may be used 1
• Modified dose escalation regimens with sequential chemotherapy yield similar outcomes to concurrent treatment 3

Small Cell Lung Cancer (SCLC)

Limited Stage SCLC (Stage IIB-III)

Concurrent chemoradiotherapy with twice-daily radiation (45 Gy in 30 fractions over 3 weeks) is the treatment of choice, based on phase I dose-finding studies establishing maximum tolerated dose. 4

• Landmark dose-finding trial: Maximum tolerated dose for hyperfractionated-accelerated twice-daily RT was 45 Gy in 30 fractions (1.5 Gy twice daily) over 3 weeks 4
• Alternative daily fractionation: At least 70 Gy in 35 fractions over 7 weeks was tolerated in the same trial 4
• Concurrent chemotherapy consists of cisplatin 33 mg/m²/day on days 1-3, cyclophosphamide 500 mg/m² on day 1, and etoposide 80 mg/m²/day on days 1-3 every 3 weeks 4
• Radiation should start at the initiation of the fourth cycle of chemotherapy 4
• Prophylactic cranial irradiation should be offered after response to chemotherapy 1

Extensive Stage SCLC

• Consolidation thoracic radiation therapy after partial or complete response to systemic therapy, especially with low burden of extrathoracic disease 1
• Prophylactic cranial irradiation for patients without progression after chemotherapy 1

Cervical Cancer

Microinvasive Disease (Stage IA2, 3-5 mm Penetration)

Primary surgery with Piver II or III hysterectomy plus pelvic lymphadenectomy is standard, with radiotherapy reserved for adverse features. 1

• Lymphadenectomy must include external iliac nodes at minimum 1
• Ovarian transposition with radio-opaque markers is recommended if ovaries are conserved 1

Early-Stage Disease <4 cm (Stage IB, IIA, IIB Proximal)

Three treatment options exist with equivalent outcomes: primary surgery, primary radiotherapy, or combination radiosurgery. 1

Primary Surgery Approach:

• Stage IB: Piver II or III hysterectomy 1
• Stages IIA or IIB: Piver III or IV hysterectomy 1
• Pelvic lymphadenectomy is standard; para-aortic lymphadenectomy is optional 1
• If pelvic lymph nodes are involved: Concurrent pelvic radiochemotherapy with cisplatin is standard 1

Primary Radiotherapy Approach:

• External beam radiotherapy plus brachytherapy delivering 60 Gy to central pelvis and 45-50 Gy to lateral pelvic area 1
• Photon energy ≥10 MV using at least two fields (four fields recommended) 1
• Upper limit at L4-L5 junction; can be reset to L5-S1 for low-volume disease without nodal involvement 1
• Inferior limit: 4 cm below lowest tumor level 1
• Brachytherapy: Low-dose rate remains standard, with dosimetry per International Commission of Radiation Units recommendations 1

Poor Prognosis Disease ≥4 cm (Stage IB, IIA, IIB)

Concurrent radiochemotherapy incorporating cisplatin is the standard treatment, demonstrating significant improvement in local control (level A evidence) and overall survival (level B evidence). 1

• Landmark evidence: Cisplatin-based radiochemotherapy significantly improves outcomes compared to radiotherapy alone or radiotherapy with hydroxyurea 1
• Chemotherapy regimens:
  • Cisplatin 40 mg/m² weekly for 6 weeks during external beam radiotherapy 5
  • Alternative: Cisplatin 50-75 mg/m² every 3-4 weeks plus 5-FU 4 g/m² over 4 days 1
• Radiation doses: External beam delivers 60 Gy to central pelvis first, followed by brachytherapy 1
• For tumors ≥4 cm, external beam to whole pelvis precedes brachytherapy, with boost to 60 Gy lateral-pelvic 1
• Total treatment time must not exceed 8 weeks (external beam plus brachytherapy) 5
• Toxicity: Primarily bone marrow and gastrointestinal, greater than radiotherapy alone 1
• Salvage option: Hysterectomy after minimum 6-8 weeks for poor response to chemotherapy, especially for tumors >4 cm 1

Locally Advanced Disease (Stage III and IVA)

Concurrent radiochemotherapy with cisplatin is standard, though benefit is less clear than for earlier stages (level C evidence). 1

• Minimum 55 Gy to pelvis with possible boost to 65-70 Gy in limited areas 1
• Central pelvic dose: 60 Gy 1
• Para-aortic involvement: Para-aortic radiotherapy at 45 Gy is standard for proven metastases without distant spread 1
• Prophylactic para-aortic radiotherapy benefit not clearly established and increases bowel complications 1

Breast Cancer - Ductal Carcinoma In Situ (DCIS)

After Breast-Conserving Surgery

Whole-breast radiation therapy delivers 4,500-5,000 cGy at 180-200 cGy per fraction using opposed tangential fields, typically beginning 2-4 weeks after surgery. 1, 6

• Treatment administered daily Monday through Friday for 25 fractions 6
• Higher energy photons (≥10 MV) indicated for large-breasted women or significant dose inhomogeneity 1
• Lung constraints: Maximum 3-3.5 cm of lung in treatment field to minimize pneumonitis risk 1
• Cardiac constraints: Minimize heart exposure for left-sided lesions 1
• Boost considerations: Controversy exists regarding additional boost dose 1
  • When used, electron beam or interstitial implantation increases total dose to 6,000-6,600 cGy 1
  • May not be required for extensive resections with clearly negative margins 1
• Nodal irradiation is unnecessary for DCIS patients 6

Breast Cancer - Invasive Carcinoma

After Breast-Conserving Surgery

Whole-breast radiation therapy delivers 4,500-5,000 cGy at 180-200 cGy per fraction, with growing consensus supporting boost irradiation to the primary site. 1

• EORTC trial demonstrated favorable impact of boost on local failure rates 1
• Boost should be used for patients with focally positive or close margins 1
• Boost increases total dose to primary tumor site to approximately 6,000-6,600 cGy 1
• Electron beam boost generally preferred over interstitial implant for cost, convenience, and cosmesis when equally effective 1
• Treatment begins 2-4 weeks after uncomplicated surgery 1
• Same technical parameters as DCIS regarding energy, lung constraints, and cardiac constraints 1

High-Grade Gliomas

Anaplastic Glioma (Grade 3)

Gross tumor volume includes T2-weighted MRI sequences plus contrast enhancement in T1, with 15-20 mm isotropic expansion for clinical target volume, delivering 59.4 Gy in 33 fractions. 7

Glioblastoma Multiforme (Grade 4)

Two accepted approaches exist based on major cooperative group protocols:

RTOG Approach (Two-Phase Technique):

• Phase 1: CTV1 includes T2 hyperintensity (edema) plus 20 mm margin, treated to 46 Gy in 23 fractions 7
• Phase 2: CTV2 reduced to contrast enhancement in T1 with 25 mm margin 7
• Total dose: 60 Gy in 30 fractions 7

EORTC Approach (Single-Phase Technique):

• Unique GTV comprises T1 contrast enhancement plus 20-30 mm margin 7
• Total dose: 60 Gy in 30 fractions 7

Dose Escalation Considerations

• Doses of 70-75 Gy can be delivered in 6 weeks with relevant toxicities in <10% of patients 7
• However, randomized dose-escalation trial guided by conventional MRI showed no survival advantage 7
• More than 85% of high-grade gliomas recur in-field despite dose escalation 7
• Advanced imaging (diffusion MRI, perfusion MRI, PET, MRS) may identify high-risk regions for targeted boost, but clinical benefit remains unproven 7

Critical Common Principles Across All Sites

• Treatment planning: Three-dimensional conformal techniques or IMRT with dose homogeneity verification 1
• Normal tissue constraints must be strictly observed to balance tumor control with toxicity 1
• Total treatment time matters: Prolonged duration negatively impacts local control, particularly in cervical cancer 5
• Concurrent chemotherapy enhances radiation effectiveness but increases toxicity requiring careful monitoring 1